Create api-model-remote.md

docs/api-model-remote.md

@@ -0,0 +1,136 @@
+## Remote methods and hooks
+
+You can expose a Model's instance and static methods to clients. A remote method must accept a callback with the conventional `fn(err, result, ...)` signature. 
+
+### loopback.remoteMethod(fn, [options])
+
+Expose a remote method.
+
+```js
+Product.stats = function(fn) {
+  var statsResult = {
+    totalPurchased: 123456
+  };
+  var err = null;
+  
+  // callback with an error and the result
+  fn(err, statsResult);
+}
+
+loopback.remoteMethod(
+  Product.stats,
+  {
+    returns: {arg: 'stats', type: 'object'},
+    http: {path: '/info', verb: 'get'}
+  }
+);
+```
+
+**Options**
+
+The options argument is a JSON object, described in the following table.
+
+| Option  | Required? | Description |
+| ----- | ----- |  ----- |
+| accepts   | No | Describes the remote method's arguments, as explained <a href="#argdesc">below</a>. The callback is an assumed argument; do not specify. |
+| returns    | No | Describes the remote method's callback arguments, as explained <a href="#argdesc">below</a>.. The err argument is assumed; do not specify. |
+| http | No | HTTP routing information: <ul><li> **http.path**: path (relative to the model) at which the method is exposed. May be a path fragment (for example, `/:myArg`) that will be populated by an arg of the same name in the `accepts` description. For example, the `stats` method above will be at the whole path `/products/stats`.</li><li> **http.verb**: HTTP method  (verb) from which the method is available (one of: get, post, put, del, or all).</li></ul>
+
+<a name="argdesc"></a>**Argument description**
+
+The arguments description defines either a single argument as an object or an ordered set of arguments as an array.  Each individual argument has keys for:
+ * arg: argument name
+ * type: argument datatype; must be a[loopback type](http://wiki.strongloop.com/display/DOC/LoopBack+types).  
+ * required: Boolean value indicating if argument is required.
+
+For example, a single argument, specified as an object:
+```js
+{arg: 'myArg', type: 'number'}
+```
+
+Multiple arguments, specified as an array:
+```js
+[
+  {arg: 'arg1', type: 'number', required: true},
+  {arg: 'arg2', type: 'array'}
+]
+```
+
+## Remote hooks
+
+Run a function before or after a remote method is called by a client.
+
+```js
+// *.save === prototype.save
+User.beforeRemote('*.save', function(ctx, user, next) {
+  if(ctx.user) {
+    next();
+  } else {
+    next(new Error('must be logged in to update'))
+  }
+});
+
+User.afterRemote('*.save', function(ctx, user, next) {
+  console.log('user has been saved', user);
+  next();
+});
+```
+    
+Remote hooks also support wildcards. Run a function before any remote method is called.
+
+```js
+// ** will match both prototype.* and *.*
+User.beforeRemote('**', function(ctx, user, next) {
+  console.log(ctx.methodString, 'was invoked remotely'); // users.prototype.save was invoked remotely
+  next();
+});
+```
+    
+Other wildcard examples
+
+```js
+// run before any static method eg. User.find
+User.beforeRemote('*', ...);
+
+// run before any instance method eg. User.prototype.save
+User.beforeRemote('prototype.*', ...);
+
+// prevent password hashes from being sent to clients
+User.afterRemote('**', function (ctx, user, next) {
+  if(ctx.result) {
+    if(Array.isArray(ctx.result)) {
+      ctx.result.forEach(function (result) {
+        result.password = undefined;
+      });
+    } else {
+      ctx.result.password = undefined;
+    }
+  }
+
+  next();
+});
+```
+    
+### Context
+
+Remote hooks are provided with a Context `ctx` object which contains transport specific data (eg. for http: `req` and `res`). The `ctx` object also has a set of consistent apis across transports.
+
+#### ctx.user
+
+A `Model` representing the user calling the method remotely. **Note:** this is undefined if the remote method is not invoked by a logged in user.
+
+#### ctx.result
+
+During `afterRemote` hooks, `ctx.result` will contain the data about to be sent to a client. Modify this object to transform data before it is sent. 
+
+#### Rest
+
+When [loopback.rest](#loopbackrest) is used the following `ctx` properties are available.
+
+##### ctx.req
+
+The express ServerRequest object. [See full documentation](http://expressjs.com/api.html#req).
+
+##### ctx.res
+
+The express ServerResponse object. [See full documentation](http://expressjs.com/api.html#res).