kopia lustrzana https://github.com/c9/core
109 wiersze
3.6 KiB
Markdown
109 wiersze
3.6 KiB
Markdown
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# Architect
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Architect is a simple but powerful structure for Node.js applications. Using Architect,
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you set up a simple configuration and tell Architect which plugins you want to load. Each
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plugin registers itself with Architect, so other plugins can use its functions. Plugins can
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be maintained as NPM packages so they can be dropped in to other Architect apps.
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## Plugin Interface
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```js
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// auth.js
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/* All plugins must export this public signature.
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* @options is the hash of options the user passes in when creating an instance
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* of the plugin.
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* @imports is a hash of all services this plugin consumes.
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* @register is the callback to be called when the plugin is done initializing.
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*/
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module.exports = function setup(options, imports, register) {
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// "database" was a service this plugin consumes
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var db = imports.database;
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register(null, {
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// "auth" is a service this plugin provides
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auth: {
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users: function (callback) {
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db.keys(callback);
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},
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authenticate: function (username, password, callback) {
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db.get(username, function (user) {
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if (!(user && user.password === password)) {
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return callback();
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}
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callback(user);
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});
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}
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}
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});
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};
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```
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Each plugin is a node module complete with a package.json file. It need not
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actually be in npm, it can be a simple folder in the code tree.
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```json
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{
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"name": "auth",
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"version": "0.0.1",
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"main": "auth.js",
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"private": true,
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"plugin": {
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"consumes": ["database"],
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"provides": ["auth"]
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}
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}
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```
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## Config Format
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The `loadConfig` function below can read an architect config file. This file can be either JSON or JS (or anything that node's require can read).
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The sample calculator app has a config like this:
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```js
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module.exports = [
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{ packagePath: "architect-http", port: 8080 },
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{ packagePath: "architect-http-static", root: "www" },
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"./plugins/calculator",
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"./plugins/db",
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"./plugins/auth"
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]
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```
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Notice that the config is a list of plugin config options. If the only option in the config is `packagePath`, then a string can be used in place of the object. If you want to pass other options to the plugin when it's being created, you can put arbitrary properties here.
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The `plugin` section in each plugin's package.json is also merged in as a prototype to the main config. This is where `provides` and `consumes` properties are usually set.
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## Architect main API
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The architect module exposes two functions as it's main API.
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### createApp(config, [callback])
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This function starts an architect config. The return value is an `Architect` instance. The optional callback will listen for both "error" and "ready" on the app object and report on which one happens first.
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### loadConfig(configPath)
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This is a sync function that loads a config file and parses all the plugins into a proper config object for use with `createApp`. While this uses sync I/O all steps along the way are memoized and I/O only occurs on the first invocation. It's safe to call this in an event loop provided a small set of configPaths are used.
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## Class: Architect
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Inherits from `EventEmitter`.
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The `createApp` function returns an instance of `Architect`.
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### Event: "service" (name, service)
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When a new service is registered, this event is emitted on the app. Name is the short name for the service, and service is the actual object with functions.
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### Event: "plugin" (plugin)
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When a plugin registers, this event is emitted.
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### Event: "ready" (app)
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When all plugins are done, the "ready" event is emitted. The value is the Architect instance itself.
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