This Node.js module for Data URI applications is called **Dauria** (after a part of [Transbaikal](http://en.wikipedia.org/wiki/Transbaikal)).
Dauria performs conversions between Node.js [Buffers](http://nodejs.org/docs/latest/api/buffer.html) and [RFC2397-compliant](http://tools.ietf.org/html/rfc2397) Data URIs, or vice versa.
Dauria is written in JavaScript and requires [Node.js](http://nodejs.org/) to run.
* Starting from v2.0.0, Dauria requires Node.js version 5.10.0 or newer because it is rewritten in ECMAScript 2015 (ES6) and also uses the [`Buffer.from`](https://nodejs.org/docs/latest/api/buffer.html#buffer_class_method_buffer_from_string_encoding) method.
* You may run older versions of Dauria (that precede v2.0.0) with older Node.js versions (0.10.x or 0.12.x). However, those older versions of Node.js are themselves not maintained by their developers after 2016-12-31.
Dauria is tested against Node.js v5, Node.js v6, Node.js v7 and the latest stable version of Node.js.
## Installing Dauria
[](https://npmjs.org/package/dauria) [](https://npmjs.org/package/dauria)
* Latest packaged version: `npm install dauria`
* Latest githubbed version: `npm install https://github.com/Mithgol/dauria/tarball/master`
The npm package does not contain the tests, they're published on GitHub only.
You may visit https://github.com/Mithgol/dauria#readme occasionally to read the latest `README` because the package's version is not planned to grow after changes when they happen in `README` only. (And `npm publish --force` is [forbidden](http://blog.npmjs.org/post/77758351673/no-more-npm-publish-f) nowadays.)
## Using Dauria
When you `require()` the installed module, you get an object that has the following methods:
### getBase64DataURI(sourceBuffer, MIME)
Returns a string containing the `data:...` URI that represent the given source Buffer in the base64-encoded form.
An optional second parameter (`MIME`) suggests the MIME type of the given Buffer. If the parameter is not given, `'application/octet-stream'` is used.
**Example:**
### parseDataURI(dataURI)
Parses the given Data URI and returns an object with the following properties:
* `MIME` — MIME content type in the form `type/subtype` as explained in [RFC2045 Section 5.2](http://tools.ietf.org/html/rfc2045#section-5.2). If not given in the URI, `MIME` becomes `'text/plain'` by default (as recommended by [RFC2397](http://tools.ietf.org/html/rfc2397) in section 2).
* `mediaType` — MIME content type with the semicolon-separated list of parameters (if any) in the form `parameter=value` (some values may appear urlencoded, and Dauria does not decode them). If not given in the URI, `mediaType` becomes `'text/plain;charset=US-ASCII'` by default (as recommended by [RFC2397](http://tools.ietf.org/html/rfc2397) in section 2).
* `buffer` — Node.js [Buffer](http://nodejs.org/docs/latest/api/buffer.html) containing the data decoded from the given Data URI. Hexadecimal URL encoding (such as `'%20'` for a whitespace) and base64 encoding are both supported (the latter must be indicated by the string `';base64'` before the first comma in the given Data URI).
* `charset` — the value of the first `'charset=...'` parameter encountered in `mediaType`. If `mediaType` does not contain any charset parameters, `charset` becomes `'US-ASCII'`. However, if `MIME` does not start with `'text/'`, then `charset` becomes `null` regardless of any parameters.
* `text` — a JavaScript string containing the text decoded from `buffer` using `charset`. However, if `MIME` does not start with `'text/'`, then `text` becomes `null`. It also becomes `null` if the [iconv-lite](https://github.com/ashtuchkin/iconv-lite) module does not know the encountered `charset`.
If the given `dataURI` is not in fact a Data URI (does not start with `'data:'` or does not contain a comma), an error is thrown.
**Example:**
## Testing Dauria
[](https://travis-ci.org/Mithgol/dauria)
The tests are not included in the npm package of the module (to keep it small). Use the version from GitHub.
It is necessary to install [Mocha](https://mochajs.org/) and [JSHint](http://jshint.com/) for testing.
* You may install Mocha globally (`npm install mocha -g`) or locally (`npm install mocha` in the directory of Dauria).
* You may install JSHint globally (`npm install jshint -g`) or locally (`npm install jshint` in the directory of Dauria).
After that you may run `npm test` (in the directory of Dauria).
## License
MIT license (see the `LICENSE` file), with the following exceptions:
* The file `test/red-dot-5px.png` is taken from Wikipedia where it has been [released into the public domain](http://en.wikipedia.org/wiki/File%3aRed-dot-5px.png) by [Johan Elisson.](http://en.wikipedia.org/wiki/User%3aJohan_Elisson)
* The file `test/larry.gif` is decoded from [RFC2397](http://tools.ietf.org/html/rfc2397) where it was given as an example. (RFC2397's Full Copyright Statement permits publishing and distribution of derivative works that assist in its implementation.)