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Advanced Media Uploader ​

A complete media field — a Quasar-based extension, built from Quasar controls and driven by one ivue class, showing how ivue works WITH an existing UI framework: drag-and-drop or picked uploads, per-file rows with inline rename, a lightbox preview dialog, download and delete, and — missing from Quasar's stock uploader — preexisting media: hand the field bare server ids and it hydrates the rows itself. Extracted from a production application built on ivue, with the app's service layer swapped for the playground's ServerApi. In the playground the bytes land in your browser's IndexedDB with canvas-generated thumbnails; against the reference server the same component uploads to disk or S3 with sharp-generated thumbnails.

Open in StackBlitz ⚡ — boots the playground on this example's route with the class open.

The performance story ​

MediaField.ts derives 28 values through plain getters and zero computed()s — tile URLs, human-readable sizes, capacity checks, accept-list parsing, all at zero bytes per instance. The extension class adds one computed() (sortedFiles) because a whole-list sort deserves a memo. A component this rich, with a reactive footprint this small, is the argument the performance page makes in numbers.

Extension, two mechanisms at once ​

ExtendedMediaField is the showcase the base component was built for:

  • Extend the class — $ExtendedMediaField extends MediaField.$Class adds sort-by-name/newest, image dimensions (read via createImageBitmap on upload), captions persisted through the backend, copy-URL, and a total-size summary. The base SFC accepts the child class through its runner prop.
  • Inject templates — the base template exposes before--/after-- slots at the header, tiles and actions; the extended variant decorates them without duplicating a line of the base template.

Inheritance in ivue is native-JS inheritance — super, overridden getters, all of it (Inheritance & super) — so "variant of a complex component" is a subclass, not a fork.

What to notice in the playground ​

  • The preexisting-media section starts full. Its model is three bare ids; the field fetched the rows from the backend on its own — the attach-existing-documents flow every real app needs and stock QUploader cannot express.
  • Drop several images at once — each uploads through ServerApi, thumbnails appear as the backend responds.
  • Click a tile for the lightbox: prev/next, name, size, download.
  • Rename inline; the change persists through the backend.
  • The extended variant shows dimensions badges, captions and the size summary — same base template, one subclass.

The source ​

ts
// MediaField.ts — the Advanced Media Uploader engine class.
//
// Derivation budget: 28 PLAIN getters (0 bytes/instance, reactive via leaf
// tracking) and 0 computed() in this class. No derivation here is expensive
// enough to earn the ~300 bytes/instance a computed costs — each one is a
// cheap expression over already-cached state or props. The one computed
// that DOES earn it lives in ExtendedMediaField (a whole-list sort, cached
// so a render doesn't re-sort per read).

import { ref, watch } from 'vue';

import { Reactive } from '../../../ivue';
import { ServerApi } from '../server/ServerApi';
import type {
  MediaFieldEmits,
  MediaFieldModel,
  MediaFieldProps,
  MediaItem,
} from './MediaFieldProps';

export class $MediaField {
  constructor(
    public props: MediaFieldProps,
    public emit: MediaFieldEmits,
  ) {
    watch(
      () => this.props.modelValue,
      (value) => this.hydrateModel(value),
      { immediate: true },
    );
  }

  // --- state ---
  get files() {
    return ref<MediaItem[]>([]);
  }
  get isUploading() {
    return ref(false);
  }
  get uploadingCount() {
    return ref(0);
  }
  get isHydrating() {
    return ref(false);
  }
  get isDragOver() {
    return ref(false);
  }
  get errorMessage() {
    return ref<string | null>(null);
  }
  get renameId() {
    return ref<string | null>(null);
  }
  get renameDraft() {
    return ref('');
  }
  get previewOpen() {
    return ref(false);
  }
  get previewIndex() {
    return ref(0);
  }
  get fileInput() {
    return ref<HTMLInputElement | null>(null);
  }

  // --- props ---
  get multiple() {
    return this.props.multiple;
  }
  get accept() {
    return this.props.accept;
  }
  get maxFileSize() {
    return this.props.maxFileSize;
  }
  get label() {
    return this.props.label;
  }
  get hint() {
    return this.props.hint;
  }
  get readonly() {
    return this.props.readonly;
  }
  get disable() {
    return this.props.disable;
  }
  get dense() {
    return this.props.dense;
  }
  get canPreview() {
    return this.props.canPreview;
  }
  get canDownload() {
    return this.props.canDownload;
  }
  get canRename() {
    return this.props.canRename && this.isInteractive;
  }
  get canRenameCaption() {
    return this.props.canRenameCaption && this.isInteractive;
  }
  get canRemove() {
    return this.props.canRemove && this.isInteractive;
  }

  // --- derived ---
  get canSort() {
    return this.multiple && this.isInteractive && this.files.value.length > 1;
  }
  get dragIndex() {
    return ref<number | null>(null);
  }

  get isInteractive() {
    return !this.props.readonly && !this.props.disable;
  }
  get maxFiles() {
    return this.multiple ? this.props.maxFiles : 1;
  }
  get remainingSlots() {
    return Math.max(0, this.maxFiles - this.files.value.length);
  }
  get canAddMore() {
    return this.isInteractive && this.remainingSlots > 0;
  }
  get hasFiles() {
    return this.files.value.length > 0;
  }
  get fileCountLabel() {
    return `${this.files.value.length} / ${this.maxFiles}`;
  }

  /** The list the template renders — subclasses override to reorder. */
  get displayFiles(): MediaItem[] {
    return this.files.value;
  }

  get acceptedTypesText() {
    return this.acceptTokens.join(', ');
  }
  get acceptTokens() {
    return this.accept
      .split(',')
      .map((token) => token.trim().toLowerCase())
      .filter(Boolean);
  }
  get maxFileSizeLabel() {
    return this.formatBytes(this.maxFileSize, 0);
  }
  get dropHint() {
    return this.multiple
      ? 'Drop files here or click to browse'
      : 'Drop a file here or click to browse';
  }
  get uploadProgressLabel() {
    const count = this.uploadingCount.value;
    return `Uploading ${count} file${count === 1 ? '' : 's'}…`;
  }
  get thumbnailStyle() {
    return { width: this.props.thumbnailSize + 'px' };
  }
  get activeFile(): MediaItem | null {
    return this.displayFiles[this.previewIndex.value] ?? null;
  }
  get hasError() {
    return !!this.errorMessage.value;
  }

  // --- model hydration & emission ---

  /** Bare ids in the model are fetched; rows are used as-is. Echoes of our own emit are skipped by id-comparison. */
  async hydrateModel(value: MediaFieldModel | undefined) {
    const entries =
      value == null || value === ''
        ? []
        : Array.isArray(value)
          ? value
          : [value];
    const limited = this.multiple ? entries : entries.slice(0, 1);
    const ids = limited.map((entry) =>
      typeof entry === 'string' ? entry : entry.id,
    );

    if (ids.join(',') === this.files.value.map((row) => row.id).join(','))
      return;

    const missingIds = limited.filter(
      (entry): entry is string => typeof entry === 'string',
    );
    const fetchedRows = new Map<string, MediaItem>();
    if (missingIds.length) {
      this.isHydrating.value = true;
      try {
        for (const row of await ServerApi.media.get(missingIds)) {
          fetchedRows.set(row.id, row);
        }
      } catch {
        this.setError('Failed to load existing media.');
      } finally {
        this.isHydrating.value = false;
      }
    }

    const rows: MediaItem[] = [];
    for (const entry of limited) {
      if (typeof entry === 'string') {
        const fetched = fetchedRows.get(entry);
        if (fetched) rows.push(fetched);
      } else {
        rows.push(entry);
      }
    }
    this.files.value = rows;
    this.onFilesLoaded(rows);
  }

  /** Hook for subclasses — runs after hydration replaces the list. */
  onFilesLoaded(rows: MediaItem[]) {}

  moveFile(fromIndex: number, toIndex: number) {
    const list = this.files.value;
    if (
      fromIndex === toIndex ||
      fromIndex < 0 ||
      toIndex < 0 ||
      fromIndex >= list.length ||
      toIndex >= list.length
    ) {
      return;
    }
    const [moved] = list.splice(fromIndex, 1);
    list.splice(toIndex, 0, moved);
    this.files.value = [...list];
    this.emitModel();
  }

  fileMoveUp(index: number) {
    this.moveFile(index, index - 1);
  }

  fileMoveDown(index: number) {
    this.moveFile(index, index + 1);
  }

  onRowDragStart(index: number) {
    this.dragIndex.value = index;
  }

  onRowDrop(index: number) {
    if (this.dragIndex.value !== null) {
      this.moveFile(this.dragIndex.value, index);
    }
    this.dragIndex.value = null;
  }

  emitModel() {
    const rows = this.files.value;
    this.emit(
      'update:modelValue',
      this.multiple ? [...rows] : (rows[0] ?? null),
    );
  }

  // --- picking & drag-drop ---

  pickFiles() {
    if (this.canAddMore) this.fileInput.value?.click();
  }

  onFilesPicked(event: Event) {
    const input = event.target as HTMLInputElement;
    const pickedFiles = Array.from(input.files ?? []);
    input.value = '';
    void this.uploadFiles(pickedFiles);
  }

  onDragOver(event: DragEvent) {
    event.preventDefault();
    if (this.canAddMore) this.isDragOver.value = true;
  }

  onDragLeave() {
    this.isDragOver.value = false;
  }

  onDrop(event: DragEvent) {
    event.preventDefault();
    this.isDragOver.value = false;
    if (!this.canAddMore) return;
    void this.uploadFiles(Array.from(event.dataTransfer?.files ?? []));
  }

  // --- upload ---

  async uploadFiles(pickedFiles: File[]) {
    this.clearError();
    const acceptedFiles = this.validateFiles(pickedFiles);
    if (!acceptedFiles.length) return;

    this.isUploading.value = true;
    this.uploadingCount.value = acceptedFiles.length;
    try {
      const rows = await ServerApi.media.upload(acceptedFiles);
      this.onUploaded(rows);
    } catch {
      this.setError('Upload failed.');
    } finally {
      this.isUploading.value = false;
      this.uploadingCount.value = 0;
    }
  }

  /** Hook for subclasses — appends the uploaded rows and reports them. */
  onUploaded(rows: MediaItem[]) {
    this.files.value.push(...rows);
    this.emitModel();
    this.emit('uploaded', rows);
  }

  /** Filters by accept list, size limit, and remaining slots; reports every rejection. */
  validateFiles(pickedFiles: File[]): File[] {
    const problems: string[] = [];
    const acceptedFiles: File[] = [];

    for (const file of pickedFiles) {
      if (!this.isAccepted(file)) {
        problems.push(`${file.name} is not an accepted type.`);
      } else if (file.size > this.maxFileSize) {
        problems.push(
          `${file.name} exceeds the ${this.maxFileSizeLabel} limit.`,
        );
      } else {
        acceptedFiles.push(file);
      }
    }

    if (acceptedFiles.length > this.remainingSlots) {
      problems.push(`Only ${this.maxFiles} file(s) allowed.`);
      acceptedFiles.length = this.remainingSlots;
    }
    if (problems.length) this.setError(problems.join(' '));

    return acceptedFiles;
  }

  isAccepted(file: File): boolean {
    if (!this.acceptTokens.length) return true;
    const fileName = file.name.toLowerCase();
    const mimetype = file.type.toLowerCase();
    return this.acceptTokens.some((token) => {
      if (token.startsWith('.')) return fileName.endsWith(token);
      if (token.endsWith('/*')) return mimetype.startsWith(token.slice(0, -1));
      return mimetype === token;
    });
  }

  // --- remove / rename / download ---

  async removeFile(row: MediaItem) {
    if (!this.canRemove) return;
    try {
      await ServerApi.media.remove(row.id);
    } catch {
      this.setError(`Failed to remove ${row.name}.`);
      return;
    }
    const foundIndex = this.files.value.findIndex(
      (existing) => existing.id === row.id,
    );
    if (foundIndex !== -1) this.files.value.splice(foundIndex, 1);

    if (this.previewIndex.value >= this.files.value.length) {
      this.previewIndex.value = Math.max(0, this.files.value.length - 1);
    }
    if (!this.hasFiles) this.previewOpen.value = false;

    this.emitModel();
    this.emit('removed', row);
  }

  startRename(row: MediaItem) {
    if (!this.canRename) return;
    this.renameId.value = row.id;
    this.renameDraft.value = this.baseName(row.name);
  }

  async commitRename() {
    const renameId = this.renameId.value;
    const row = this.files.value.find((existing) => existing.id === renameId);
    if (!row) return this.cancelRename();

    const draft = this.renameDraft.value.trim();
    if (!draft || !this.validFilenameRegExp.test(draft)) {
      this.setError('Invalid file name.');
      return;
    }
    const extension = this.extensionOf(row.name);
    const newName = extension ? `${draft}.${extension}` : draft;
    try {
      await ServerApi.media.update({ id: row.id, name: newName });
      row.name = newName;
      this.clearError();
      this.emitModel();
    } catch {
      this.setError(`Failed to rename ${row.name}.`);
    }
    this.renameId.value = null;
  }

  cancelRename() {
    this.renameId.value = null;
  }

  downloadFile(row: MediaItem) {
    const anchor = document.createElement('a');
    anchor.href = row.url;
    anchor.download = row.name;
    document.body.appendChild(anchor);
    anchor.click();
    anchor.remove();
  }

  // --- preview navigation ---

  openPreview(index: number) {
    if (!this.canPreview) return;
    this.previewIndex.value = index;
    this.previewOpen.value = true;
  }

  closePreview() {
    this.previewOpen.value = false;
  }

  nextPreview() {
    const count = this.displayFiles.length;
    if (count) this.previewIndex.value = (this.previewIndex.value + 1) % count;
  }

  prevPreview() {
    const count = this.displayFiles.length;
    if (count) {
      this.previewIndex.value = (this.previewIndex.value - 1 + count) % count;
    }
  }

  // --- per-row helpers ---

  isImage(row: MediaItem): boolean {
    return row.mimetype.startsWith('image/');
  }

  fileExtension(row: MediaItem): string {
    return this.extensionOf(row.name).toUpperCase();
  }

  fileIcon(row: MediaItem): string {
    if (row.mimetype === 'application/pdf') return 'picture_as_pdf';
    if (row.mimetype.startsWith('video/')) return 'movie';
    if (row.mimetype.startsWith('audio/')) return 'audiotrack';
    return 'insert_drive_file';
  }

  sizeLabel(row: MediaItem): string {
    return this.formatBytes(row.size);
  }

  baseName(filename: string): string {
    const dotIndex = filename.lastIndexOf('.');
    return dotIndex > 0 ? filename.slice(0, dotIndex) : filename;
  }

  extensionOf(filename: string): string {
    const dotIndex = filename.lastIndexOf('.');
    return dotIndex > 0 ? filename.slice(dotIndex + 1) : '';
  }

  formatBytes(bytes: number, decimals = 1): string {
    if (!+bytes) return '0 B';
    const kilobyte = 1024;
    const units = ['B', 'KB', 'MB', 'GB', 'TB'];
    const unitIndex = Math.min(
      units.length - 1,
      Math.floor(Math.log(bytes) / Math.log(kilobyte)),
    );
    const amount = bytes / Math.pow(kilobyte, unitIndex);
    return `${parseFloat(amount.toFixed(decimals))} ${units[unitIndex]}`;
  }

  // --- errors ---

  setError(message: string) {
    this.errorMessage.value = message;
    this.emit('error', message);
  }

  clearError() {
    this.errorMessage.value = null;
  }

  /** Rejects Windows/macOS-forbidden characters and leading dots/spaces. */
  validFilenameRegExp = /^(?!^[ .])(?!.*[/\\:*?"<>|])(?![. ]+$)[^/\\:*?"<>|]+$/;
}

export namespace MediaField {
  export const $Class = $MediaField; // raw — children `extends` this
  export let Class = Reactive($Class); // reactive — you `new` this
  export type Instance = typeof Class.Instance;
}
vue
<script lang="ts" setup>
// MediaField.vue — the Advanced Media Uploader.
//
// Two extension mechanisms are showcased here:
//   1. The `runner` prop swaps the driving CLASS (any MediaField subclass).
//   2. Every slot has `before--`/`after--` variants (ExtendSlots) — a parent
//      injects templates at any point without duplicating this file — and the
//      `item` slot REPLACES the whole per-file row (ExtendedMediaField.vue
//      swaps the list rows for a square-tile grid through it).
// ExtendedMediaField.vue uses BOTH at once.
import {
  QBadge,
  QBtn,
  QIcon,
  QLinearProgress,
  QSpinner,
  QTooltip,
} from 'quasar';

import { MediaField } from './MediaField';
import MediaFieldPreviewDialog from './MediaFieldPreviewDialog.vue';
import {
  mediaFieldEmits,
  mediaFieldProps,
  type MediaFieldEmits,
  type MediaFieldSlots,
} from './MediaFieldProps';

const props = defineProps(mediaFieldProps);
/** Object-declared emits — ExtractEmitTypes derives the class-facing type. */
const emit = defineEmits(mediaFieldEmits) as MediaFieldEmits;
defineSlots<MediaFieldSlots>();

/** Runner implementation: swap the class that drives this component. */
const RunnerClass = (props.runner ?? MediaField.Class) as typeof MediaField.Class;
const media = new RunnerClass(props, emit);

const {
  // state refs
  isUploading,
  isHydrating,
  isDragOver,
  errorMessage,
  renameId,
  renameDraft,
  previewOpen,
  // element refs
  fileInput,
} = media;

defineExpose(media as MediaField.Instance);
</script>

<template>
  <div
    class="media-field"
    :class="{
      'media-field--dense': media.dense,
      'media-field--disabled': media.disable,
      'media-field--readonly': media.readonly,
      'media-field--error': media.hasError,
    }"
  >
    <!-- HEADER -->
    <slot name="before--header" :field="media" />
    <slot name="header" :field="media">
      <div class="media-field__header">
        <span class="media-field__label">{{ media.label }}</span>
        <q-badge
          v-if="media.hasFiles"
          rounded
          color="grey-3"
          text-color="black"
          class="media-field__count"
          :label="media.fileCountLabel"
        />
        <q-spinner v-if="isUploading || isHydrating" size="16px" :thickness="2" />
      </div>
    </slot>
    <slot name="after--header" :field="media" />

    <!-- DROP ZONE -->
    <div
      class="media-field__dropzone"
      :class="{
        'media-field__dropzone--over': isDragOver,
        'media-field__dropzone--clickable': media.canAddMore,
      }"
      @dragover="media.onDragOver"
      @dragleave="media.onDragLeave"
      @drop="media.onDrop"
    >
      <input
        ref="fileInput"
        type="file"
        class="media-field__native-input"
        :accept="media.accept"
        :multiple="media.multiple"
        @change="media.onFilesPicked"
      />

      <!-- EMPTY STATE -->
      <template v-if="!media.hasFiles">
        <slot name="before--empty" :field="media" />
        <slot name="empty" :field="media">
          <div class="media-field__empty" @click="media.pickFiles()">
            <q-icon name="cloud_upload" size="34px" color="grey-6" />
            <div class="media-field__empty-hint">{{ media.dropHint }}</div>
            <div class="media-field__empty-types">
              {{ media.acceptedTypesText }} — up to
              {{ media.maxFileSizeLabel }} each
            </div>
          </div>
        </slot>
        <slot name="after--empty" :field="media" />
      </template>

      <!-- FILE LIST — v1-style rows: [thumb] [name / caption / meta] [remove] -->
      <div v-else class="media-field__list">
        <div
          v-for="(row, index) in media.displayFiles"
          :key="row.id"
          class="media-field__item"
          :class="{ 'media-field__item--dragging': media.dragIndex.value === index }"
          :draggable="media.canSort"
          @dragstart="media.onRowDragStart(index)"
          @dragover.prevent
          @drop.prevent="media.onRowDrop(index)"
          @dragend="media.dragIndex.value = null"
        >
          <slot name="before--item" :row="row" :index="index" :field="media" />
          <slot name="item" :row="row" :index="index" :field="media">
            <!-- SORT BUTTONS — visible on hover, like the original -->
            <div v-if="media.canSort" class="media-field__sort" @click.stop>
              <q-btn
                icon="arrow_upward"
                flat
                size="xs"
                round
                :disable="index === 0"
                @click="media.fileMoveUp(index)"
              >
                <q-tooltip class="bg-grey-9">Move up</q-tooltip>
              </q-btn>
              <q-btn
                icon="arrow_downward"
                flat
                size="xs"
                round
                :disable="index === media.displayFiles.length - 1"
                @click="media.fileMoveDown(index)"
              >
                <q-tooltip class="bg-grey-9">Move down</q-tooltip>
              </q-btn>
            </div>
            <!-- THUMBNAIL BOX -->
            <div
              class="media-field__thumb"
              :class="{ 'media-field__thumb--clickable': media.canPreview }"
              @click="media.openPreview(index)"
            >
              <img
                v-if="media.isImage(row)"
                :src="row.thumbnailUrl"
                :alt="row.name"
                class="media-field__thumb-image"
              />
              <div v-else class="media-field__thumb-extension">
                {{ media.fileExtension(row) }}
              </div>

              <!-- DOWNLOAD — overlays the thumb's bottom-right corner -->
              <div class="media-field__thumb-download" @click.stop>
                <q-btn
                  v-if="media.canDownload"
                  dense
                  unelevated
                  size="10px"
                  padding="2px 4px"
                  icon="download"
                  class="media-field__download-btn"
                  @click="media.downloadFile(row)"
                >
                  <q-tooltip class="bg-grey-9">Download</q-tooltip>
                </q-btn>
              </div>
            </div>

            <!-- FILE DETAILS -->
            <div class="media-field__details">
              <!-- FILE NAME — inline rename (v1 borderless input) -->
              <input
                v-if="media.canRename"
                class="media-field__filename-input"
                placeholder="File Name"
                type="text"
                :value="renameId === row.id ? renameDraft : row.name"
                :title="row.name"
                @focus="media.startRename(row)"
                @input="renameDraft = ($event.target as HTMLInputElement).value"
                @keydown.enter.prevent="media.commitRename()"
                @keydown.esc="media.cancelRename()"
                @blur="media.commitRename()"
              />
              <div v-else class="media-field__item-name" :title="row.name">
                {{ row.name }}
              </div>

              <!-- FILE CAPTION -->
              <input
                v-if="media.canRenameCaption"
                v-model="row.caption"
                class="media-field__filename-input media-field__caption-line"
                placeholder="File Caption"
                type="text"
                @keydown.enter="(event) => event.preventDefault()"
              />
              <div v-else-if="row.caption" class="media-field__caption-line">
                {{ row.caption }}
              </div>

              <!-- EXTENSION BADGE / SIZE / STATUS -->
              <div class="media-field__meta">
                <q-badge
                  color="grey-3"
                  text-color="black"
                  class="media-field__meta-extension"
                  :label="media.fileExtension(row)"
                />
                <span class="media-field__meta-size">
                  {{ media.sizeLabel(row) }}
                </span>
                <span class="media-field__meta-status">
                  <q-icon name="check_circle" size="12px" color="positive" />
                  Uploaded
                </span>
              </div>
            </div>

            <!-- ROW ACTIONS — remove at the far right, top-aligned -->
            <div class="media-field__row-side" @click.stop>
              <slot
                name="before--item-actions"
                :row="row"
                :index="index"
                :field="media"
              />
              <slot
                name="item-actions"
                :row="row"
                :index="index"
                :field="media"
              />
              <slot
                name="after--item-actions"
                :row="row"
                :index="index"
                :field="media"
              />
              <q-btn
                v-if="media.canRemove"
                dense
                flat
                round
                size="10px"
                icon="close"
                @click="media.removeFile(row)"
              >
                <q-tooltip class="bg-grey-9">Remove</q-tooltip>
              </q-btn>
            </div>
          </slot>
          <slot name="after--item" :row="row" :index="index" :field="media" />
        </div>

        <!-- ADD-MORE AFFORDANCE -->
        <div
          v-if="media.canAddMore"
          class="media-field__add"
          @click="media.pickFiles()"
        >
          <q-icon name="attach_file" size="16px" />
          <span class="media-field__add-label">Add files</span>
        </div>
      </div>

      <q-linear-progress
        v-if="isUploading"
        indeterminate
        color="primary"
        class="media-field__progress"
      />
      <div v-if="isUploading" class="media-field__progress-label">
        {{ media.uploadProgressLabel }}
      </div>
    </div>

    <!-- ERROR / HINT LINE -->
    <div v-if="media.hasError" class="media-field__bottom media-field__bottom--error">
      {{ errorMessage }}
    </div>
    <div v-else-if="media.hint" class="media-field__bottom">
      {{ media.hint }}
    </div>

    <!-- PREVIEW LIGHTBOX -->
    <MediaFieldPreviewDialog v-model="previewOpen" :field="media" />
  </div>
</template>

<style scoped>
.media-field {
  width: 100%;
}

.media-field--disabled {
  opacity: 0.6;
  pointer-events: none;
}

.media-field__header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 6px;
}

.media-field__label {
  font-size: 14px;
  color: color-mix(in srgb, currentColor 70%, transparent);
}

.media-field--error .media-field__label {
  color: var(--q-negative, #c10015);
}

.media-field__count {
  font-size: 10px;
}

.media-field__dropzone {
  position: relative;
  border: 1px solid color-mix(in srgb, currentColor 28%, transparent);
  border-radius: 6px;
  background: color-mix(in srgb, currentColor 3%, transparent);
  transition: border-color 0.2s, background 0.2s;
}

.media-field__dropzone--over {
  border-color: var(--q-primary, #1976d2);
  background: rgba(25, 118, 210, 0.06);
}

.media-field--error .media-field__dropzone {
  border-color: var(--q-negative, #c10015);
}

.media-field__native-input {
  display: none;
}

.media-field__empty {
  padding: 26px 16px;
  text-align: center;
  cursor: pointer;
  user-select: none;
}

.media-field--dense .media-field__empty {
  padding: 14px 12px;
}

.media-field__empty-hint {
  margin-top: 6px;
  font-size: 13px;
  color: color-mix(in srgb, currentColor 70%, transparent);
}

.media-field__empty-types {
  margin-top: 2px;
  font-size: 13px;
  color: color-mix(in srgb, currentColor 45%, transparent);
}

/* --- v1 LIST-ROW LAYOUT --- */

.media-field__list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 6px;
}

.media-field--dense .media-field__list {
  gap: 2px;
  padding: 4px;
}

/* Each file is a full-width horizontal row. */
.media-field__item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  width: 100%;
  padding: 5px 6px;
  border-radius: 4px;
  transition: background 0.3s;
}

.media-field__item:hover {
  background: color-mix(in srgb, currentColor 4%, transparent);
}

/* Thumbnail box — v1: max-width 120px, height 60px, inset-shadow well. */
.media-field__thumb {
  position: relative;
  flex: 0 0 120px;
  max-width: 120px;
  height: 60px;
  border-radius: 4px;
  overflow: hidden;
  background: color-mix(in srgb, currentColor 8%, transparent);
  box-shadow: inset 2px 0 10px 5px
    color-mix(in srgb, currentColor 7%, transparent);
  display: flex;
  align-items: center;
  justify-content: center;
}

.media-field__thumb--clickable {
  cursor: pointer;
}

.media-field__thumb-image {
  width: 100%;
  height: 100%;
  aspect-ratio: 16 / 9;
  object-fit: contain;
  display: block;
}

.media-field__thumb-extension {
  font-size: 24px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: color-mix(in srgb, currentColor 45%, transparent);
}

.media-field__thumb-download {
  position: absolute;
  right: 4px;
  bottom: 4px;
}

.media-field__download-btn {
  border-radius: 3px;
  background: color-mix(in srgb, currentColor 12%, transparent);
  color: var(--q-primary, #1976d2);
}

/* Details column — name / caption / meta line. */
.media-field__details {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 12px;
  padding-top: 2px;
}

.media-field__item-name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* v1 inline-rename input — borderless; the border materializes on row hover. */
.media-field__filename-input {
  width: 100%;
  font-size: 12px;
  color: inherit;
  background: none;
  outline: none;
  border: 0;
  border-bottom: 1px solid transparent;
  line-height: 14px;
  padding: 0 0 1px;
  transition: border-color 0.3s;
}

.media-field__item:hover .media-field__filename-input {
  border-bottom-color: color-mix(in srgb, currentColor 22%, transparent);
}

.media-field__item:hover .media-field__filename-input:hover {
  border-bottom-color: color-mix(in srgb, currentColor 45%, transparent);
}

.media-field__filename-input:focus,
.media-field__item:hover .media-field__filename-input:focus {
  border-bottom-color: var(--q-primary, #1976d2);
}

.media-field__caption-line {
  color: color-mix(in srgb, currentColor 55%, transparent);
}

.media-field__caption-line::placeholder {
  color: color-mix(in srgb, currentColor 35%, transparent);
}

/* Meta line — extension badge + size + status. */
.media-field__meta {
  display: flex;
  flex-wrap: wrap;
  min-width: 0;
  align-items: center;
  gap: 4px 8px;
  font-size: 11px;
  color: color-mix(in srgb, currentColor 55%, transparent);
}

.media-field__meta-extension {
  font-size: 10px;
  text-transform: uppercase;
}

.media-field__meta-size {
  text-transform: uppercase;
}

.media-field__meta-status {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  text-transform: uppercase;
}

/* Remove button cluster — far right, top-aligned. */
.media-field__row-side {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 2px;
  align-self: flex-start;
  color: color-mix(in srgb, currentColor 60%, transparent);
}

/* Add-more affordance — a solid full-width row. */
.media-field__add {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px;
  border: 1px solid color-mix(in srgb, currentColor 25%, transparent);
  border-radius: 4px;
  cursor: pointer;
  color: color-mix(in srgb, currentColor 60%, transparent);
  transition: border-color 0.2s;
}

.media-field__add:hover {
  border-color: var(--q-primary, #1976d2);
}

.media-field__add-label {
  font-size: 13.5px;
  font-weight: 500;
}

.media-field__progress {
  border-radius: 0 0 6px 6px;
}

.media-field__progress-label {
  position: absolute;
  right: 8px;
  bottom: 6px;
  font-size: 11px;
  color: color-mix(in srgb, currentColor 55%, transparent);
}

/*
 * Hint/error line with native-Quasar spacing. The v1 field let the hint
 * crowd the control (no top padding — a long-standing bug); Quasar's own
 * .q-field__bottom reserves breathing room, so we match it here.
 */
.media-field__bottom {
  padding-top: 6px;
  font-size: 12px;
  line-height: 1;
  min-height: 18px;
  color: color-mix(in srgb, currentColor 60%, transparent);
}

.media-field__bottom--error {
  color: var(--q-negative, #c10015);
}

/* sort buttons: hidden until the row is hovered, like the original */
.media-field__sort {
  display: flex;
  flex-direction: column;
  justify-content: center;
  visibility: hidden;
  opacity: 0.7;
}
.media-field__item:hover .media-field__sort {
  visibility: visible;
}
.media-field__item--dragging {
  opacity: 0.45;
}
</style>
ts
// MediaFieldProps.ts — the params-types + params-defaults architecture.
//
// Types and defaults are declared as two separate literals so a child
// component (or app) can spread-and-extend either one, then
// `propsWithDefaults` fuses them into a defineComponent()-style props
// object. Emits are object-declared and extracted with ExtractEmitTypes;
// slots gain automatic `before--`/`after--` extension points via ExtendSlots.

import type { ExtractPropTypes, PropType } from 'vue';

import {
  propsWithDefaults,
  type ExtractEmitTypes,
  type ExtractPropDefaultTypes,
  type ExtendSlots,
} from '../../../ivue';
import type { MediaRow } from '../server/ServerApi';

/** A media row plus the client-editable caption. */
export type MediaItem = MediaRow & { caption?: string };

/**
 * The model accepts rows, bare ids, or a mix — ids are hydrated through
 * `ServerApi.media.get`. Single mode holds one entry (or null), multiple
 * mode holds an array.
 */
export type MediaFieldModel =
  | MediaItem
  | string
  | Array<MediaItem | string>
  | null;

/** Params Types */
export const mediaFieldParamsTypes = {
  multiple: { type: Boolean as PropType<boolean> },
  /** Comma-separated accept list — extensions (`.pdf`) and mime patterns (`image/*`). */
  accept: { type: String as PropType<string> },
  maxFiles: { type: Number as PropType<number> },
  /** Per-file limit in bytes. */
  maxFileSize: { type: Number as PropType<number> },
  label: { type: String as PropType<string> },
  hint: { type: String as PropType<string> },
  readonly: { type: Boolean as PropType<boolean> },
  disable: { type: Boolean as PropType<boolean> },
  dense: { type: Boolean as PropType<boolean> },
  /** Preview grid tile size in pixels. */
  thumbnailSize: { type: Number as PropType<number> },
  canPreview: { type: Boolean as PropType<boolean> },
  canDownload: { type: Boolean as PropType<boolean> },
  canRename: { type: Boolean as PropType<boolean> },
  canRenameCaption: { type: Boolean as PropType<boolean> },
  canRemove: { type: Boolean as PropType<boolean> },
  /**
   * Runner implementation — pass a subclass's `Class` to swap the logic
   * that drives the component (the class-extension showcase).
   * @see ExtendedMediaField.vue
   */
  runner: { type: Function as PropType<any> },
};

/** Params Defaults */
export const mediaFieldParamsDefaults: ExtractPropDefaultTypes<
  typeof mediaFieldParamsTypes
> = {
  multiple: false,
  accept: '.pdf, image/*',
  maxFiles: 12,
  maxFileSize: 100 * 1024 * 1024, // 100 MB
  label: 'Media',
  hint: '',
  readonly: false,
  disable: false,
  dense: false,
  thumbnailSize: 132,
  canPreview: true,
  canDownload: true,
  canRename: true,
  canRenameCaption: true,
  canRemove: true,
  runner: null,
};

/** Generated Params */
export const mediaFieldParams = propsWithDefaults(
  mediaFieldParamsDefaults,
  mediaFieldParamsTypes,
);
export type MediaFieldParams = ExtractPropTypes<typeof mediaFieldParams>;

/** Props */
export const mediaFieldProps = {
  modelValue: {
    type: [Object, Array, String] as PropType<MediaFieldModel>,
    default: null,
  },
  ...mediaFieldParams,
};
export type MediaFieldProps = ExtractPropTypes<typeof mediaFieldProps>;

/** Emits */
export const mediaFieldEmits = {
  'update:modelValue': (value: MediaFieldModel) => true,
  uploaded: (rows: MediaItem[]) => true,
  removed: (row: MediaItem) => true,
  error: (message: string) => true,
};
export type MediaFieldEmits = ExtractEmitTypes<typeof mediaFieldEmits>;

/**
 * Slot props. `field` is typed loose on purpose: the runner prop can swap
 * in ANY MediaField subclass, and injected templates call the subclass's
 * extra members (see ExtendedMediaField.vue).
 */
export interface MediaFieldSlotProps {
  field: any;
}
export interface MediaFieldItemSlotProps extends MediaFieldSlotProps {
  row: MediaItem;
  index: number;
}

/**
 * Base slots — ExtendSlots wraps every one with `before--` & `after--`
 * variants, the template-injection mechanism extended components use.
 */
export type MediaFieldSlots = ExtendSlots<{
  header(slotProps: MediaFieldSlotProps): any;
  empty(slotProps: MediaFieldSlotProps): any;
  item(slotProps: MediaFieldItemSlotProps): any;
  'item-actions'(slotProps: MediaFieldItemSlotProps): any;
}>;
vue
<script lang="ts">
// MediaFieldPreviewDialog — a QDialog lightbox over the field's media list.
//
// Derivations: 10 plain getters (0 bytes/instance) and 1 computed() —
// `isOpenModel`, a WRITABLE computed, which earns its ~300 bytes because a
// v-model target must be a stable ref handle with a setter.
import { computed, ref } from 'vue';

import { Reactive } from '../../../ivue';
import type { MediaField } from './MediaField';
import type { MediaItem } from './MediaFieldProps';

export interface MediaFieldPreviewDialogProps {
  /** The owning field instance — the dialog navigates ITS preview state. */
  field: MediaField.Instance;
  /** Dialog open state (v-model). */
  modelValue: boolean;
}

export interface MediaFieldPreviewDialogEmits {
  (event: 'update:modelValue', open: boolean): void;
}

class $MediaFieldPreviewDialog {
  constructor(
    public props: MediaFieldPreviewDialogProps,
    public emit: MediaFieldPreviewDialogEmits,
  ) {}

  // --- state ---
  get isImageLoading() {
    return ref(false);
  }
  get isMaximized() {
    return ref(false);
  }

  // --- derived ---
  get field() {
    return this.props.field;
  }
  get activeFile(): MediaItem | null {
    return this.field.activeFile;
  }
  get isActiveImage() {
    return !!this.activeFile && this.field.isImage(this.activeFile);
  }
  get hasMultiple() {
    return this.field.displayFiles.length > 1;
  }
  get positionLabel() {
    return `${this.field.previewIndex.value + 1} / ${this.field.displayFiles.length}`;
  }
  get activeSizeLabel() {
    return this.activeFile ? this.field.sizeLabel(this.activeFile) : '';
  }
  get activeExtension() {
    return this.activeFile ? this.field.fileExtension(this.activeFile) : '';
  }
  get isRenamingActive() {
    return (
      !!this.activeFile && this.field.renameId.value === this.activeFile.id
    );
  }

  beginRename() {
    if (this.activeFile) this.field.startRename(this.activeFile);
  }

  get maximizeIcon() {
    return this.isMaximized.value ? 'close_fullscreen' : 'open_in_full';
  }

  get isOpenModel() {
    return computed({
      get: () => this.isOpenValue(),
      set: (open: boolean) => this.setOpen(open),
    });
  }

  // --- methods ---

  isOpenValue() {
    return this.props.modelValue;
  }

  setOpen(open: boolean) {
    this.emit('update:modelValue', open);
  }

  close() {
    this.setOpen(false);
  }

  showPrev() {
    this.isImageLoading.value = true;
    this.field.prevPreview();
  }

  showNext() {
    this.isImageLoading.value = true;
    this.field.nextPreview();
  }

  onImageLoaded() {
    this.isImageLoading.value = false;
  }

  download() {
    if (this.activeFile) this.field.downloadFile(this.activeFile);
  }

  toggleMaximized() {
    this.isMaximized.value = !this.isMaximized.value;
  }
}

export namespace MediaFieldPreviewDialog {
  export const $Class = $MediaFieldPreviewDialog;
  export let Class = Reactive($Class);
  export type Instance = typeof Class.Instance;
}
</script>

<script lang="ts" setup>
import { QBtn, QCard, QDialog, QIcon, QSpinner, QTooltip } from 'quasar';

const props = defineProps<MediaFieldPreviewDialogProps>();
const emit = defineEmits<MediaFieldPreviewDialogEmits>();

const dialog = new MediaFieldPreviewDialog.Class(props, emit);

// the field's rename draft drives the footer's inline editor
const { renameDraft } = props.field;

const {
  // state refs
  isImageLoading,
  isMaximized,
  // computed refs
  isOpenModel,
} = dialog;

defineExpose(dialog as MediaFieldPreviewDialog.Instance);
</script>

<template>
  <q-dialog
    v-model="isOpenModel"
    class="media-preview"
    :maximized="isMaximized"
    no-shake
  >
    <q-card
      class="media-preview__card"
      :class="{ 'media-preview__card--maximized': isMaximized }"
    >
      <!-- STAGE -->
      <div class="media-preview__stage" v-if="dialog.activeFile">
        <img
          v-if="dialog.isActiveImage"
          :key="dialog.activeFile.id"
          :src="dialog.activeFile.url"
          class="media-preview__image"
          @load="dialog.onImageLoaded()"
          @error="dialog.onImageLoaded()"
        />
        <div v-else class="media-preview__placeholder">
          <q-icon
            :name="dialog.field.fileIcon(dialog.activeFile)"
            size="72px"
            color="grey-5"
          />
          <div class="media-preview__placeholder-extension">
            {{ dialog.activeExtension }}
          </div>
        </div>
        <q-spinner
          v-if="isImageLoading"
          class="media-preview__spinner"
          color="white"
          size="42px"
          :thickness="3"
        />
      </div>

      <!-- FOOTER -->
      <div class="media-preview__footer" v-if="dialog.activeFile">
        <div class="media-preview__details">
          <div
            v-if="!dialog.isRenamingActive"
            class="media-preview__name"
            :class="{ 'media-preview__name--editable': dialog.field.canRename }"
            :title="dialog.activeFile.name"
            @click="dialog.beginRename()"
          >
            {{ dialog.activeFile.name }}
            <q-icon
              v-if="dialog.field.canRename"
              name="edit"
              size="14px"
              class="media-preview__name-edit"
            />
          </div>
          <input
            v-else
            class="media-preview__name-input"
            :value="renameDraft"
            autofocus
            @input="(event: any) => (renameDraft = event.target.value)"
            @keyup.enter="dialog.field.commitRename()"
            @keyup.esc="dialog.field.cancelRename()"
            @blur="dialog.field.commitRename()"
          />
          <div class="media-preview__meta">
            {{ dialog.activeExtension }} — {{ dialog.activeSizeLabel }}
          </div>
        </div>

        <div class="media-preview__controls">
          <q-btn
            v-if="dialog.field.canDownload"
            flat
            round
            icon="download"
            color="primary"
            @click="dialog.download()"
          >
            <q-tooltip class="bg-grey-9">Download</q-tooltip>
          </q-btn>

          <span v-if="dialog.hasMultiple" class="media-preview__position">
            {{ dialog.positionLabel }}
          </span>
          <q-btn
            v-if="dialog.hasMultiple"
            flat
            round
            icon="chevron_left"
            color="primary"
            @click="dialog.showPrev()"
          >
            <q-tooltip class="bg-grey-9">Previous</q-tooltip>
          </q-btn>
          <q-btn
            v-if="dialog.hasMultiple"
            flat
            round
            icon="chevron_right"
            color="primary"
            @click="dialog.showNext()"
          >
            <q-tooltip class="bg-grey-9">Next</q-tooltip>
          </q-btn>

          <q-btn
            flat
            round
            :icon="dialog.maximizeIcon"
            color="primary"
            @click="dialog.toggleMaximized()"
          >
            <q-tooltip class="bg-grey-9">
              {{ isMaximized ? 'Minimize' : 'Maximize' }}
            </q-tooltip>
          </q-btn>
          <q-btn flat round icon="check" color="primary" @click="dialog.close()">
            <q-tooltip class="bg-grey-9">Done</q-tooltip>
          </q-btn>
        </div>
      </div>
    </q-card>
  </q-dialog>
</template>

<style scoped>
.media-preview__card {
  width: 100%;
  max-width: 960px;
  display: flex;
  flex-direction: column;
}

.media-preview__card--maximized {
  max-width: 100%;
  height: 100%;
}

.media-preview__stage {
  position: relative;
  flex: 1 1 auto;
  min-height: 320px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(229deg, #000 0%, #020d18 50%, #000 100%);
}

.media-preview__image {
  max-width: 100%;
  max-height: 70vh;
  object-fit: contain;
}

.media-preview__card--maximized .media-preview__image {
  max-height: calc(100vh - 80px);
}

.media-preview__placeholder {
  text-align: center;
  padding: 48px 0;
}

.media-preview__placeholder-extension {
  color: #9e9e9e;
  font-size: 20px;
  letter-spacing: 2px;
  margin-top: 8px;
}

.media-preview__spinner {
  position: absolute;
  top: calc(50% - 21px);
  left: calc(50% - 21px);
}

.media-preview__footer {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 8px 8px 16px;
  border-top: 1px solid #eee;
  background: #fff;
}

.body--dark .media-preview__footer {
  background: #1a2032;
  border-top-color: rgba(255, 255, 255, 0.08);
}

.media-preview__details {
  min-width: 0;
}

.media-preview__name {
  font-size: 15px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: #212121;
}

.body--dark .media-preview__name {
  color: #e8ecf8;
}

.media-preview__name--editable {
  cursor: pointer;
}
.media-preview__name-edit {
  opacity: 0.45;
  margin-left: 4px;
}
.media-preview__name-input {
  font-size: 15px;
  font-weight: 500;
  width: 100%;
  background: transparent;
  color: inherit;
  border: none;
  border-bottom: 1px solid currentColor;
  outline: none;
}

.media-preview__meta {
  font-size: 12px;
  color: #888;
}

.media-preview__controls {
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 0 0 auto;
}

.media-preview__position {
  color: #999;
  font-size: 12px;
  letter-spacing: 1px;
  min-width: 48px;
  text-align: center;
  user-select: none;
}
</style>
ts
// ExtendedMediaField.ts — the class-extension showcase.
//
// Extends MediaField.$Class (the RAW class — the namespace convention's
// whole point) and adds: sort-by-name/date toggle, image dimensions read
// via createImageBitmap and shown as a badge, a caption editor, copy-URL
// with feedback, and a total-size summary.
//
// Derivation budget: 7 plain getters (0 bytes/instance) and 1 computed() —
// `sortedFiles`. That one earns its ~300 bytes: it re-sorts the WHOLE list,
// and `displayFiles` is read many times per render (once per grid item
// binding), so the cached cell suppresses the repeated O(n log n) work.

import { computed, ref } from 'vue';

import { Reactive } from '../../../ivue';
import { ServerApi } from '../server/ServerApi';
import { MediaField } from './MediaField';
import type { MediaItem } from './MediaFieldProps';

export type MediaSortMode = 'newest' | 'name';

export class $ExtendedMediaField extends MediaField.$Class {
  // --- state ---
  get sortMode() {
    return ref<MediaSortMode>('newest');
  }
  get captionId() {
    return ref<string | null>(null);
  }
  get captionDraft() {
    return ref('');
  }
  get copiedId() {
    return ref<string | null>(null);
  }
  get imageDimensions() {
    return ref<Record<string, string>>({});
  }

  // --- derived ---
  get sortedFiles() {
    return computed(() => this.sortFiles());
  }
  override get displayFiles(): MediaItem[] {
    return this.sortedFiles.value;
  }
  get sortModeLabel() {
    return this.sortMode.value === 'newest' ? 'Newest first' : 'By name';
  }
  get sortModeIcon() {
    return this.sortMode.value === 'newest' ? 'schedule' : 'sort_by_alpha';
  }
  get totalSize() {
    return this.files.value.reduce((sum, row) => sum + row.size, 0);
  }
  get totalSizeLabel() {
    return this.formatBytes(this.totalSize);
  }

  // --- sorting ---

  sortFiles(): MediaItem[] {
    const rows = [...this.files.value];
    if (this.sortMode.value === 'name') {
      return rows.sort((left, right) => left.name.localeCompare(right.name));
    }
    return rows.sort((left, right) =>
      right.createdAt.localeCompare(left.createdAt),
    );
  }

  toggleSortMode() {
    this.sortMode.value = this.sortMode.value === 'newest' ? 'name' : 'newest';
  }

  // --- image dimensions (read on upload AND on hydration) ---

  override onUploaded(rows: MediaItem[]) {
    super.onUploaded(rows);
    rows.forEach((row) => void this.measureImage(row));
  }

  override onFilesLoaded(rows: MediaItem[]) {
    super.onFilesLoaded(rows);
    rows.forEach((row) => void this.measureImage(row));
  }

  async measureImage(row: MediaItem) {
    if (!this.isImage(row) || this.imageDimensions.value[row.id]) return;
    try {
      const blob = await (await fetch(row.url)).blob();
      const bitmap = await createImageBitmap(blob);
      this.imageDimensions.value[row.id] = `${bitmap.width}×${bitmap.height}`;
      bitmap.close();
    } catch {
      /* Non-decodable image — no badge for this row. */
    }
  }

  dimensionsOf(row: MediaItem): string {
    return this.imageDimensions.value[row.id] ?? '';
  }

  // --- copy URL ---

  async copyUrl(row: MediaItem) {
    await navigator.clipboard.writeText(row.url);
    this.copiedId.value = row.id;
    window.setTimeout(() => this.clearCopied(row.id), 1500);
  }

  clearCopied(rowId: string) {
    if (this.copiedId.value === rowId) this.copiedId.value = null;
  }

  // --- caption editor ---

  startCaption(row: MediaItem) {
    if (!this.canRenameCaption) return;
    this.captionId.value = row.id;
    this.captionDraft.value = row.caption ?? '';
  }

  async commitCaption() {
    const captionId = this.captionId.value;
    const row = this.files.value.find((existing) => existing.id === captionId);
    if (!row) return this.cancelCaption();

    const caption = this.captionDraft.value.trim();
    try {
      await ServerApi.media.update({ id: row.id, caption });
      row.caption = caption;
      this.emitModel();
    } catch {
      this.setError(`Failed to update caption for ${row.name}.`);
    }
    this.captionId.value = null;
  }

  cancelCaption() {
    this.captionId.value = null;
  }
}

export namespace ExtendedMediaField {
  export const $Class = $ExtendedMediaField;
  export let Class = Reactive($Class);
  export type Instance = typeof Class.Instance;
}
vue
<script lang="ts" setup>
// ExtendedMediaField.vue — demonstrates BOTH extension mechanisms at once:
//   1. CLASS extension: `:runner="ExtendedMediaField.Class"` makes the base
//      MediaField.vue construct the subclass — every slot receives it as
//      `field`, so injected templates call the subclass's extra members.
//   2. TEMPLATE injection: the `item` slot REPLACES the base's per-file list
//      row with a square thumbnail tile — the base renders list rows, this
//      component pulls in a completely different item template while the
//      same class hierarchy drives both. `before--`/`after--` slot variants
//      (ExtendSlots) add the sort toolbar without copying the base template.
import { QBadge, QBtn, QIcon, QTooltip } from 'quasar';

import { ExtendedMediaField } from './ExtendedMediaField';
import MediaField from './MediaField.vue';
import {
  mediaFieldEmits,
  mediaFieldProps,
  type MediaFieldEmits,
} from './MediaFieldProps';

const props = defineProps(mediaFieldProps);
/** Object-declared emits — ExtractEmitTypes derives the callable type. */
const emit = defineEmits(mediaFieldEmits) as MediaFieldEmits;

/** Square tile edge — v-bound into the grid styles below. */
const tileSize = `${props.thumbnailSize ?? 132}px`;

/** Autofocus the rename input the moment it renders (used as v-focus). */
const vFocus = {
  mounted: (element: HTMLInputElement) => element.focus(),
};
</script>

<template>
  <MediaField
    v-bind="props"
    class="extended-media"
    :runner="ExtendedMediaField.Class"
    @update:model-value="(value) => emit('update:modelValue', value)"
    @uploaded="(rows) => emit('uploaded', rows)"
    @removed="(row) => emit('removed', row)"
    @error="(message) => emit('error', message)"
  >
    <!-- SORT TOGGLE + TOTAL SIZE — injected after the base header -->
    <template #after--header="{ field }">
      <div v-if="field.hasFiles" class="extended-media__toolbar">
        <q-btn
          flat
          size="11px"
          class="extended-media__sort-btn"
          :icon="field.sortModeIcon"
          :label="field.sortModeLabel"
          @click="field.toggleSortMode()"
        >
          <q-tooltip class="bg-grey-9">Toggle sort order</q-tooltip>
        </q-btn>
        <q-badge
          color="grey-3"
          text-color="black"
          :label="'Total ' + field.totalSizeLabel"
        />
      </div>
    </template>

    <!-- SQUARE TILE — full replacement of the base's per-file list row -->
    <template #item="{ row, index, field }">
      <div class="extended-media__tile">
        <!-- SQUARE THUMBNAIL -->
        <div
          class="extended-media__thumb"
          :class="{ 'extended-media__thumb--clickable': field.canPreview }"
          @click="field.openPreview(index)"
        >
          <img
            v-if="field.isImage(row)"
            :src="row.thumbnailUrl"
            :alt="row.name"
            class="extended-media__thumb-image"
          />
          <div v-else class="extended-media__thumb-placeholder">
            <q-icon :name="field.fileIcon(row)" size="30px" color="grey-6" />
            <span class="extended-media__thumb-extension">
              {{ field.fileExtension(row) }}
            </span>
          </div>

          <!-- DIMENSIONS BADGE -->
          <q-badge
            v-if="field.dimensionsOf(row)"
            color="grey-3"
            text-color="black"
            class="extended-media__dimensions"
            :label="field.dimensionsOf(row)"
          />

          <!-- HOVER ACTIONS — incl. the subclass's copy-URL -->
          <div class="extended-media__actions" @click.stop>
            <q-btn
              v-if="field.canPreview"
              dense
              flat
              round
              size="10px"
              icon="visibility"
              color="white"
              @click="field.openPreview(index)"
            >
              <q-tooltip class="bg-grey-9">Preview</q-tooltip>
            </q-btn>
            <q-btn
              v-if="field.canDownload"
              dense
              flat
              round
              size="10px"
              icon="download"
              color="white"
              @click="field.downloadFile(row)"
            >
              <q-tooltip class="bg-grey-9">Download</q-tooltip>
            </q-btn>
            <q-btn
              v-if="field.canRename"
              dense
              flat
              round
              size="10px"
              icon="edit"
              color="white"
              @click="field.startRename(row)"
            >
              <q-tooltip class="bg-grey-9">Rename</q-tooltip>
            </q-btn>
            <q-btn
              dense
              flat
              round
              size="10px"
              :icon="field.copiedId.value === row.id ? 'check' : 'link'"
              color="white"
              @click="field.copyUrl(row)"
            >
              <q-tooltip class="bg-grey-9">
                {{ field.copiedId.value === row.id ? 'Copied!' : 'Copy URL' }}
              </q-tooltip>
            </q-btn>
            <q-btn
              v-if="field.canRemove"
              dense
              flat
              round
              size="10px"
              icon="close"
              color="white"
              @click="field.removeFile(row)"
            >
              <q-tooltip class="bg-grey-9">Remove</q-tooltip>
            </q-btn>
          </div>
        </div>

        <!-- NAME / RENAME / SIZE -->
        <div class="extended-media__tile-footer">
          <input
            v-if="field.renameId.value === row.id"
            v-model="field.renameDraft.value"
            v-focus
            class="extended-media__rename-input"
            placeholder="File name"
            @keydown.enter.prevent="field.commitRename()"
            @keydown.esc="field.cancelRename()"
            @blur="field.commitRename()"
          />
          <div v-else class="extended-media__tile-name" :title="row.name">
            {{ row.name }}
          </div>
          <div class="extended-media__tile-size">{{ field.sizeLabel(row) }}</div>
        </div>

        <!-- CAPTION EDITOR -->
        <input
          v-if="field.captionId.value === row.id"
          v-model="field.captionDraft.value"
          class="extended-media__caption-input"
          placeholder="Caption"
          @keydown.enter.prevent="field.commitCaption()"
          @keydown.esc="field.cancelCaption()"
          @blur="field.commitCaption()"
        />
        <div
          v-else-if="field.canRenameCaption"
          class="extended-media__caption"
          :class="{ 'extended-media__caption--empty': !row.caption }"
          @click="field.startCaption(row)"
        >
          {{ row.caption || 'Add caption…' }}
        </div>
        <div v-else-if="row.caption" class="extended-media__caption">
          {{ row.caption }}
        </div>
      </div>
    </template>
  </MediaField>
</template>

<style scoped>
.extended-media__toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 6px;
}

/* The base lays files out as full-width rows; the tile variant turns the
   same list container into a wrapping grid of fixed-width square tiles. */
.extended-media :deep(.media-field__list) {
  flex-direction: row;
  flex-wrap: wrap;
  gap: 8px;
  padding: 8px;
}

.extended-media :deep(.media-field__item) {
  display: block;
  width: auto;
  flex: 0 0 auto;
  padding: 0;
}

.extended-media :deep(.media-field__item:hover) {
  background: none;
}

/* The add affordance becomes a square tile alongside the thumbnails. */
.extended-media :deep(.media-field__add) {
  width: v-bind(tileSize);
  aspect-ratio: 1 / 1;
  flex-direction: column;
  gap: 2px;
  padding: 0;
}

.extended-media__tile {
  width: v-bind(tileSize);
}

.extended-media__thumb {
  position: relative;
  aspect-ratio: 1 / 1;
  border-radius: 4px;
  overflow: hidden;
  background: color-mix(in srgb, currentColor 8%, transparent);
  box-shadow: inset 0 0 10px 2px color-mix(in srgb, currentColor 6%, transparent);
  display: flex;
  align-items: center;
  justify-content: center;
}

.extended-media__thumb--clickable {
  cursor: pointer;
}

.extended-media__thumb-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.extended-media__thumb-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.extended-media__thumb-extension {
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: color-mix(in srgb, currentColor 55%, transparent);
}

.extended-media__dimensions {
  position: absolute;
  top: 4px;
  left: 4px;
  font-size: 10px;
}

.extended-media__actions {
  position: absolute;
  inset: auto 0 0 0;
  display: flex;
  justify-content: center;
  gap: 2px;
  padding: 3px 2px;
  background: linear-gradient(transparent, rgba(0, 0, 0, 0.55));
  opacity: 0;
  transition: opacity 0.2s;
}

.extended-media__tile:hover .extended-media__actions {
  opacity: 1;
}

.extended-media__tile-footer {
  padding: 4px 2px 0;
}

.extended-media__tile-name {
  font-size: 12px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.extended-media__tile-size {
  font-size: 11px;
  color: color-mix(in srgb, currentColor 50%, transparent);
}

.extended-media__rename-input {
  width: 100%;
  font-size: 12px;
  color: inherit;
  background: none;
  outline: none;
  border: 0;
  border-bottom: 1px solid var(--q-primary, #1976d2);
  padding: 0 0 1px;
}

.extended-media__caption {
  padding: 2px 2px 0;
  font-size: 11px;
  color: color-mix(in srgb, currentColor 60%, transparent);
  cursor: text;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.extended-media__caption--empty {
  color: color-mix(in srgb, currentColor 35%, transparent);
  font-style: italic;
}

.extended-media__caption-input {
  width: 100%;
  margin-top: 2px;
  font-size: 11px;
  color: inherit;
  background: none;
  outline: none;
  border: 0;
  border-bottom: 1px solid var(--q-primary, #1976d2);
  padding: 0 0 1px;
}

.extended-media__sort-btn {
  padding: 2px 12px;
}
.extended-media__sort-btn .q-icon {
  font-size: 15px;
  margin-right: 5px;
}
</style>
vue
<script setup lang="ts">
import MediaField from './MediaField.vue';
import ExtendedMediaField from './ExtendedMediaField.vue';
import { MediaFieldExample } from './MediaFieldExample';

const example = new MediaFieldExample.Class();

// the state destructure
const {
  // state refs
  preloadedMedia,
  avatarMedia,
  galleryMedia,
  documentMedia,
  extendedMedia,
  resetting,
} = example;
</script>

<template>
  <div class="pane pane-fields">
    <p class="note">
      A production-grade uploader: drag-drop, thumbnails, lightbox preview,
      rename, download, delete — every byte stored in YOUR browser
      (IndexedDB) by the mock backend. Point ServerApi at
      server-node/server.ts and the same component uploads to disk or S3
      with sharp-generated thumbnails.
    </p>

    <div class="field-grid">
      <section>
        <h3>Preexisting media — hydrated from the server</h3>
        <MediaField
          v-model="preloadedMedia"
          label="Attached earlier"
          hint="The model starts as bare IDs; the field fetches the rows itself — stock QUploader has no such path"
          accept="image/*"
          multiple
        />
      </section>

      <section>
        <h3>Single image</h3>
        <MediaField
          v-model="avatarMedia"
          label="Cover image"
          hint="One image; replace by uploading again"
          accept="image/*"
          :max-files="1"
        />
      </section>

      <section>
        <h3>Gallery — multiple images</h3>
        <MediaField
          v-model="galleryMedia"
          label="Gallery"
          hint="Drop several images at once; click a tile for the lightbox"
          accept="image/*"
          multiple
          :thumbnail-size="96"
        />
      </section>

      <section>
        <h3>Documents — any file type</h3>
        <MediaField
          v-model="documentMedia"
          label="Attachments"
          hint="Non-images render a file-type icon; rename and download from the tile"
          accept=".pdf, .txt, .md, image/*"
          multiple
          dense
          :thumbnail-size="72"
        />
      </section>

      <section>
        <h3>Extended — class extension + template injection</h3>
        <ExtendedMediaField
          v-model="extendedMedia"
          label="Extended uploader"
          hint="A child class adds sorting, image dimensions, captions, copy-URL and a size summary — the base template is reused, not copied"
          accept="image/*"
          multiple
        />
      </section>
    </div>

    <div class="row" style="margin-top: 20px">
      <button
        class="btn"
        type="button"
        :disabled="resetting"
        @click="example.resetSandbox()"
      >
        {{ resetting ? 'Resetting…' : 'Reset sandbox data' }}
      </button>
      <span class="mono">
        files live in IndexedDB — private to this browser
      </span>
    </div>
  </div>
</template>

<style scoped src="../../example-pane.css"></style>

<style scoped>
.pane-fields {
  max-width: 920px;
}
.field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(380px, 100%), 1fr));
  gap: 24px 26px;
  align-items: start;
}
.field-grid h3 {
  margin: 0 0 10px;
  padding-bottom: 6px;
  border-bottom: 1px solid rgba(148, 163, 184, 0.18);
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: #f1f5ff;
}
</style>

The backend path ​

Uploads flow through ServerApi.media.* — mock in the browser, or the TypeScript Express reference server with two storage drivers: storage-disk.ts (plain files under ./uploads, zero external services) and storage-s3.ts (private bucket, presigned GET redirects, server-side sharp thumbnails). Both implement the same contract, so the component never knows which one it's talking to.

Released under the MIT License.

ivue — Infinite Vue ∞