PlainDownloader

ClassComponentSource

comp = PlainDownloader(
    id: str | Mapping[str, Any],
    url: str,
    loading_state: LoadingState
)

PlainDownloader is a plain and native React component.

This component is implemented by a temporarily created magic link referring to a given URL.

Since the implementation of this PlainDownloader is simply based on the HTML <a> tag, the request headers and authentication of this downloader is not customizable.

Aliases

This type can be acquired by

import dash_file_cache as dfc


dfc.PlainDownloader
dfc.components.PlainDownloader

Component Properties

Descriptions

Name	Type	Description
id	str | Mapping[str, Any]	The ID of the component. A dictionary-id is used for creating a pattern-matching callback.
url	str	The URL used to access the data to be downloaded. Each time when this value is set, a download event will be triggered. After triggering the download event, this value will be reset by a blank string.
loading_state	LoadingState	The loading state set by Dash. This value should not be used by users.

Properties

Name	Type	Interactive	Setable	Required	Default
id	str | Mapping[str, Any]				undefined
url	str				""
loading_state	LoadingState				undefined

• "Interactive" means that the property can be changed by users' interactions, thus firing a callback.
• "Setable" means that changing it by callback Output(...) will take effects.
• "Required" means that the component cannot be initialized if this value is not explicitly provided.

Examples

Minimal example

Codes

minimal_example_plain_downloader.py

from typing import Optional
import dash
import flask
from dash import html, Output, Input
from dash_file_cache.services.utilities import get_server
from dash_file_cache.components import PlainDownloader


app = dash.Dash("demo")
server = get_server(app)

app.layout = html.Div(
    (html.Button(id="btn", children="Download"), PlainDownloader(id="downloader"))
)


@server.route("/file")
def file():
    resp = flask.Response("test file content", status=200, mimetype="text/plain")
    resp.headers["Content-Disposition"] = "attachment; filename=test.txt"
    return resp


@app.callback(Output("downloader", "url"), Input("btn", "n_clicks"))
def trigger_get_file(n_clicks: Optional[int]):
    if not n_clicks:
        return dash.no_update
    return "/file"


if __name__ == "__main__":
    app.run()

Results

An application with a downloading button will be rendered.

By clicking the button, a file named text.txt will be downloaded, the file content is

test file content