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author | Florian Dold <florian.dold@gmail.com> | 2017-05-03 15:35:00 +0200 |
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committer | Florian Dold <florian.dold@gmail.com> | 2017-05-03 15:35:00 +0200 |
commit | de98e0b232509d5f40c135d540a70e415272ff85 (patch) | |
tree | a79222a5b58484ab3b80d18efcaaa7ccc4769b33 /node_modules/amdefine/README.md | |
parent | e0c9d480a73fa629c1e4a47d3e721f1d2d345406 (diff) | |
download | wallet-core-de98e0b232509d5f40c135d540a70e415272ff85.tar.xz |
node_modules
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-rw-r--r-- | node_modules/amdefine/README.md | 171 |
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diff --git a/node_modules/amdefine/README.md b/node_modules/amdefine/README.md new file mode 100644 index 000000000..037a6e817 --- /dev/null +++ b/node_modules/amdefine/README.md @@ -0,0 +1,171 @@ +# amdefine + +A module that can be used to implement AMD's define() in Node. This allows you +to code to the AMD API and have the module work in node programs without +requiring those other programs to use AMD. + +## Usage + +**1)** Update your package.json to indicate amdefine as a dependency: + +```javascript + "dependencies": { + "amdefine": ">=0.1.0" + } +``` + +Then run `npm install` to get amdefine into your project. + +**2)** At the top of each module that uses define(), place this code: + +```javascript +if (typeof define !== 'function') { var define = require('amdefine')(module) } +``` + +**Only use these snippets** when loading amdefine. If you preserve the basic structure, +with the braces, it will be stripped out when using the [RequireJS optimizer](#optimizer). + +You can add spaces, line breaks and even require amdefine with a local path, but +keep the rest of the structure to get the stripping behavior. + +As you may know, because `if` statements in JavaScript don't have their own scope, the var +declaration in the above snippet is made whether the `if` expression is truthy or not. If +RequireJS is loaded then the declaration is superfluous because `define` is already already +declared in the same scope in RequireJS. Fortunately JavaScript handles multiple `var` +declarations of the same variable in the same scope gracefully. + +If you want to deliver amdefine.js with your code rather than specifying it as a dependency +with npm, then just download the latest release and refer to it using a relative path: + +[Latest Version](https://github.com/jrburke/amdefine/raw/latest/amdefine.js) + +### amdefine/intercept + +Consider this very experimental. + +Instead of pasting the piece of text for the amdefine setup of a `define` +variable in each module you create or consume, you can use `amdefine/intercept` +instead. It will automatically insert the above snippet in each .js file loaded +by Node. + +**Warning**: you should only use this if you are creating an application that +is consuming AMD style defined()'d modules that are distributed via npm and want +to run that code in Node. + +For library code where you are not sure if it will be used by others in Node or +in the browser, then explicitly depending on amdefine and placing the code +snippet above is suggested path, instead of using `amdefine/intercept`. The +intercept module affects all .js files loaded in the Node app, and it is +inconsiderate to modify global state like that unless you are also controlling +the top level app. + +#### Why distribute AMD-style modules via npm? + +npm has a lot of weaknesses for front-end use (installed layout is not great, +should have better support for the `baseUrl + moduleID + '.js' style of loading, +single file JS installs), but some people want a JS package manager and are +willing to live with those constraints. If that is you, but still want to author +in AMD style modules to get dynamic require([]), better direct source usage and +powerful loader plugin support in the browser, then this tool can help. + +#### amdefine/intercept usage + +Just require it in your top level app module (for example index.js, server.js): + +```javascript +require('amdefine/intercept'); +``` + +The module does not return a value, so no need to assign the result to a local +variable. + +Then just require() code as you normally would with Node's require(). Any .js +loaded after the intercept require will have the amdefine check injected in +the .js source as it is loaded. It does not modify the source on disk, just +prepends some content to the text of the module as it is loaded by Node. + +#### How amdefine/intercept works + +It overrides the `Module._extensions['.js']` in Node to automatically prepend +the amdefine snippet above. So, it will affect any .js file loaded by your +app. + +## define() usage + +It is best if you use the anonymous forms of define() in your module: + +```javascript +define(function (require) { + var dependency = require('dependency'); +}); +``` + +or + +```javascript +define(['dependency'], function (dependency) { + +}); +``` + +## RequireJS optimizer integration. <a name="optimizer"></name> + +Version 1.0.3 of the [RequireJS optimizer](http://requirejs.org/docs/optimization.html) +will have support for stripping the `if (typeof define !== 'function')` check +mentioned above, so you can include this snippet for code that runs in the +browser, but avoid taking the cost of the if() statement once the code is +optimized for deployment. + +## Node 0.4 Support + +If you want to support Node 0.4, then add `require` as the second parameter to amdefine: + +```javascript +//Only if you want Node 0.4. If using 0.5 or later, use the above snippet. +if (typeof define !== 'function') { var define = require('amdefine')(module, require) } +``` + +## Limitations + +### Synchronous vs Asynchronous + +amdefine creates a define() function that is callable by your code. It will +execute and trace dependencies and call the factory function *synchronously*, +to keep the behavior in line with Node's synchronous dependency tracing. + +The exception: calling AMD's callback-style require() from inside a factory +function. The require callback is called on process.nextTick(): + +```javascript +define(function (require) { + require(['a'], function(a) { + //'a' is loaded synchronously, but + //this callback is called on process.nextTick(). + }); +}); +``` + +### Loader Plugins + +Loader plugins are supported as long as they call their load() callbacks +synchronously. So ones that do network requests will not work. However plugins +like [text](http://requirejs.org/docs/api.html#text) can load text files locally. + +The plugin API's `load.fromText()` is **not supported** in amdefine, so this means +transpiler plugins like the [CoffeeScript loader plugin](https://github.com/jrburke/require-cs) +will not work. This may be fixable, but it is a bit complex, and I do not have +enough node-fu to figure it out yet. See the source for amdefine.js if you want +to get an idea of the issues involved. + +## Tests + +To run the tests, cd to **tests** and run: + +``` +node all.js +node all-intercept.js +``` + +## License + +New BSD and MIT. Check the LICENSE file for all the details. |