File drop with preview

Drop files and see them listed with a preview, kept in the browser.

A drop zone and a keyboard-friendly button to choose files, with type and size limits from your props. Images get a preview made in the browser. Nothing is uploaded, and the component says so on screen.

Try it

<file-drop-preview>

ViewPreviewCodeCSS

file-drop-preview: Drop files and see them listed with a preview, kept in the browser. A picture of the real component, drawn from its own code. The controls change the picture and the code beside it; nothing here is sent or stored.

Generated from the component's manifest and the values above.

index.html

<file-drop-preview
  locale="en"
  examples="[{&quot;name&quot;:&quot;brand-cover.png&quot;,&quot;sizeKb&quot;:842},{&quot;name&quot;:&quot;brief.pdf&quot;,&quot;sizeKb&quot;:240}]"
></file-drop-preview>

<script>
  const element = document.querySelector("file-drop-preview");
  element.addEventListener("file-drop-preview:changed", (event) => {
    console.log(event.detail);
  });
</script>

Add the site's Taggor script once; the component appears when it loads.

taggor-component.js

const element = document.createElement("file-drop-preview");
element.setAttribute("locale", "en");
element.examples = [
  {
    "name": "brand-cover.png",
    "sizeKb": 842
  },
  {
    "name": "brief.pdf",
    "sizeKb": 240
  }
];
element.addEventListener("file-drop-preview:changed", (event) => {
  console.log(event.detail);
});
document.body.append(element);

Add the site's Taggor script once; the component appears when it loads.
Lists and objects go in as a property of the element, not an attribute.

FileDropPreview.tsx

import { useEffect, useRef } from "react";

export function FileDropPreview() {
  const ref = useRef<HTMLElement>(null);

  useEffect(() => {
    const element = ref.current;
    if (!element) return;
    Object.assign(element, {
      examples: [
        {
          "name": "brand-cover.png",
          "sizeKb": 842
        },
        {
          "name": "brief.pdf",
          "sizeKb": 240
        }
      ],
    });
    const onChanged = (event: Event) => {
      console.log((event as CustomEvent).detail);
    };
    element.addEventListener("file-drop-preview:changed", onChanged);
    return () => {
      element.removeEventListener("file-drop-preview:changed", onChanged);
    };
  }, []);

  return <file-drop-preview ref={ref} locale="en" />;
}

Add the site's Taggor script once; the component appears when it loads.
React 18 sends every prop of a custom element as a text attribute.
Lists and objects go in as a property of the element, not an attribute.
The event is heard with addEventListener, inside an effect.

FileDropPreview.tsx

import { useEffect, useRef } from "react";

export function FileDropPreview() {
  const ref = useRef<HTMLElement>(null);

  useEffect(() => {
    const element = ref.current;
    if (!element) return;
    Object.assign(element, {
      examples: [
        {
          "name": "brand-cover.png",
          "sizeKb": 842
        },
        {
          "name": "brief.pdf",
          "sizeKb": 240
        }
      ],
    });
    const onChanged = (event: Event) => {
      console.log((event as CustomEvent).detail);
    };
    element.addEventListener("file-drop-preview:changed", onChanged);
    return () => {
      element.removeEventListener("file-drop-preview:changed", onChanged);
    };
  }, []);

  return <file-drop-preview ref={ref} locale="en" />;
}

Add the site's Taggor script once; the component appears when it loads.
React 19 sets a property when the element already has it, an attribute otherwise.
Lists and objects go in as a property of the element, not an attribute.
The event is heard with addEventListener, inside an effect.

src/FileDropPreview.vue

<script setup lang="ts">
function onChanged(event: Event) {
  console.log((event as CustomEvent).detail);
}
</script>

<template>
  <file-drop-preview
    locale="en"
    :examples.prop="[{&quot;name&quot;:&quot;brand-cover.png&quot;,&quot;sizeKb&quot;:842},{&quot;name&quot;:&quot;brief.pdf&quot;,&quot;sizeKb&quot;:240}]"
    @file-drop-preview:changed="onChanged"
  />
</template>

vite.config.ts

import vue from "@vitejs/plugin-vue";
import { defineConfig } from "vite";

export default defineConfig({
  plugins: [
    vue({
      template: {
        compilerOptions: {
          isCustomElement: (tag) => tag === "file-drop-preview",
        },
      },
    }),
  ],
});

Add the site's Taggor script once; the component appears when it loads.
vite.config.ts tells Vue that this tag is not a Vue component.
Lists and objects go in as a property of the element, not an attribute.

src/app/file-drop-preview.component.ts

import { afterNextRender, Component, CUSTOM_ELEMENTS_SCHEMA, DestroyRef, ElementRef, inject } from "@angular/core";

@Component({
  selector: "app-file-drop-preview",
  schemas: [CUSTOM_ELEMENTS_SCHEMA],
  template: `
    <file-drop-preview locale="en" [examples]="values.examples"></file-drop-preview>
  `,
})
export class FileDropPreviewComponent {
  readonly values = {
    examples: [
      {
        "name": "brand-cover.png",
        "sizeKb": 842
      },
      {
        "name": "brief.pdf",
        "sizeKb": 240
      }
    ],
  };

  constructor() {
    const host = inject<ElementRef<HTMLElement>>(ElementRef);
    const element = () => host.nativeElement.querySelector("file-drop-preview");
    const onChanged = (event: Event) => {
      console.log((event as CustomEvent).detail);
    };
    afterNextRender(() => element()?.addEventListener("file-drop-preview:changed", onChanged));
    inject(DestroyRef).onDestroy(() => element()?.removeEventListener("file-drop-preview:changed", onChanged));
  }
}

Add the site's Taggor script once; the component appears when it loads.
The component declares CUSTOM_ELEMENTS_SCHEMA.
Lists and objects go in as a property of the element, not an attribute.
The event is heard with addEventListener, inside an effect.

src/TaggorComponent.svelte

<script>
  function onChanged(event) {
    console.log(event.detail);
  }
</script>

<file-drop-preview
  locale="en"
  examples={[
    {
      "name": "brand-cover.png",
      "sizeKb": 842
    },
    {
      "name": "brief.pdf",
      "sizeKb": 240
    }
  ]}
  onfile-drop-preview:changed={onChanged}
></file-drop-preview>

Add the site's Taggor script once; the component appears when it loads.

How an agent gets a component like this onto a site:

taggor checktaggor publish

The CSS variables the component exposes, set the way a customer's page would.

styles.css

file-drop-preview {
  --fd-radius: 18px;
}

Props

Props of the component, read from its manifest
Prop	Type	Default	What it does
accept	list	["image/*",".pdf"]	Accepted types: MIME types (image/png), groups (image/*) or extensions (.pdf).
maxSizeKb	number 10 to 20480	2048	Largest file, in KB.
maxFiles	number 1 to 12	4	Most files in the list.
examples	list	none	Rows listed before the visitor adds a file, marked as sample content.
locale	pt-BR \| en	en	–

Prop names and descriptions are the component's own, in English, as its author wrote them.

Events

Events of the component, read from its manifest
Event	When it fires
changed	The list of files changed.

Build one with your agent

Paste this into your agent. It asks you before it signs in, pays or goes further than checking and publishing.

Build me a Taggor component like "File drop with preview" (file-drop-preview): Drop files and see them listed with a preview, kept in the browser. Fetch https://taggor.dev/agent-setup/prompt.md and follow its instructions to set me up for Taggor. Ask me before you sign in, create an account, accept terms, pay for anything or type a secret. Check it with `taggor check` and publish it with `taggor publish`, and stop there. Do not promote it to production, attach it to a site, roll back anything or use --yes, --force or --force-drop-invalid unless I ask for exactly that in this conversation.

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