137 lines
5.3 KiB
Markdown
137 lines
5.3 KiB
Markdown
If you need to save really large files bigger then the blob's size limitation or don't have
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enough RAM, then have a look at the more advanced [StreamSaver.js](https://github.com/jimmywarting/StreamSaver.js)
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that can save data directly to the hard drive asynchronously with the power of the new streams API. That will have
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support for progress, cancelation and knowing when it's done writing
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FileSaver.js
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============
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FileSaver.js implements the `saveAs()` FileSaver interface in browsers that do
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not natively support it. There is a [FileSaver.js demo][1] that demonstrates saving
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various media types.
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FileSaver.js is the solution to saving files on the client-side, and is perfect for
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webapps that need to generate files, or for saving sensitive information that shouldn't be
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sent to an external server.
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Looking for `canvas.toBlob()` for saving canvases? Check out
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[canvas-toBlob.js][2] for a cross-browser implementation.
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Supported browsers
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------------------
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| Browser | Constructs as | Filenames | Max Blob Size | Dependencies |
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| -------------- | ------------- | ------------ | ------------- | ------------ |
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| Firefox 20+ | Blob | Yes | 800 MiB | None |
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| Firefox < 20 | data: URI | No | n/a | [Blob.js](https://github.com/eligrey/Blob.js) |
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| Chrome | Blob | Yes | [500 MiB][3] | None |
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| Chrome for Android | Blob | Yes | [500 MiB][3] | None |
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| Edge | Blob | Yes | ? | None |
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| IE 10+ | Blob | Yes | 600 MiB | None |
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| Opera 15+ | Blob | Yes | 500 MiB | None |
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| Opera < 15 | data: URI | No | n/a | [Blob.js](https://github.com/eligrey/Blob.js) |
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| Safari 6.1+* | Blob | No | ? | None |
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| Safari < 6 | data: URI | No | n/a | [Blob.js](https://github.com/eligrey/Blob.js) |
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| Safari 10.1+ | Blob | Yes | n/a | None |
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Feature detection is possible:
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```js
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try {
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var isFileSaverSupported = !!new Blob;
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} catch (e) {}
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```
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### IE < 10
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It is possible to save text files in IE < 10 without Flash-based polyfills.
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See [ChenWenBrian and koffsyrup's `saveTextAs()`](https://github.com/koffsyrup/FileSaver.js#examples) for more details.
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### Safari 6.1+
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Blobs may be opened instead of saved sometimes—you may have to direct your Safari users to manually
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press <kbd>⌘</kbd>+<kbd>S</kbd> to save the file after it is opened. Using the `application/octet-stream` MIME type to force downloads [can cause issues in Safari](https://github.com/eligrey/FileSaver.js/issues/12#issuecomment-47247096).
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### iOS
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saveAs must be run within a user interaction event such as onTouchDown or onClick; setTimeout will prevent saveAs from triggering. Due to restrictions in iOS saveAs opens in a new window instead of downloading, if you want this fixed please [tell Apple](https://bugs.webkit.org/show_bug.cgi?id=102914) how this bug is affecting you.
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Syntax
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------
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```js
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FileSaver saveAs(Blob/File data, optional DOMString filename, optional Boolean disableAutoBOM)
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```
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Pass `true` for `disableAutoBOM` if you don't want FileSaver.js to automatically provide Unicode text encoding hints (see: [byte order mark](https://en.wikipedia.org/wiki/Byte_order_mark)).
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Examples
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--------
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### Saving text using require
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```js
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var FileSaver = require('file-saver');
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var blob = new Blob(["Hello, world!"], {type: "text/plain;charset=utf-8"});
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FileSaver.saveAs(blob, "hello world.txt");
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```
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### Saving text
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```js
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var blob = new Blob(["Hello, world!"], {type: "text/plain;charset=utf-8"});
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FileSaver.saveAs(blob, "hello world.txt");
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```
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The standard W3C File API [`Blob`][4] interface is not available in all browsers.
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[Blob.js][5] is a cross-browser `Blob` implementation that solves this.
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### Saving a canvas
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```js
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var canvas = document.getElementById("my-canvas"), ctx = canvas.getContext("2d");
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// draw to canvas...
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canvas.toBlob(function(blob) {
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saveAs(blob, "pretty image.png");
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});
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```
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Note: The standard HTML5 `canvas.toBlob()` method is not available in all browsers.
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[canvas-toBlob.js][6] is a cross-browser `canvas.toBlob()` that polyfills this.
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### Saving File
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You can save a File constructor without specifying a filename. The
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File itself already contains a name, There is a hand full of ways to get a file
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instance (from storage, file input, new constructor)
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But if you still want to change the name, then you can change it in the 2nd argument
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```js
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var file = new File(["Hello, world!"], "hello world.txt", {type: "text/plain;charset=utf-8"});
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FileSaver.saveAs(file);
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```
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[1]: http://eligrey.com/demos/FileSaver.js/
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[2]: https://github.com/eligrey/canvas-toBlob.js
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[3]: https://code.google.com/p/chromium/issues/detail?id=375297
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[4]: https://developer.mozilla.org/en-US/docs/DOM/Blob
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[5]: https://github.com/eligrey/Blob.js
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[6]: https://github.com/eligrey/canvas-toBlob.js
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Installation
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------------------
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```bash
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npm install file-saver --save
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bower install file-saver
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```
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Additionally, TypeScript definitions can be installed via:
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```bash
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npm install @types/file-saver --save-dev
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```
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