Web development/model-router - Revision history

Duff: Adding a note about method-specific routing

2013-02-20T20:36:51Z

Adding a note about method-specific routing

← Older revision		Revision as of 15:36, 20 February 2013
Line 93:		Line 93:

	<source lang="javascript">		<source lang="javascript">
	router.route('/authenticate', function(parameters, session, next) {		router.route('PUT', '/authenticate', function(parameters, session, next) {
	if (parameters.username === 'duff' && parameters.password === 'butts123') {		if (parameters.username === 'duff' && parameters.password === 'butts123') {
	session.username = 'duff'		session.username = 'duff'
Line 107:		Line 107:
	})		})
	</source>		</source>

			Wait, what's that extra parameter there at the beginning? Oh, that's just how you specify a route for a specific HTTP method! The above code will only route requests to /authenticate to that function if the HTTP request was the PUT method. If you want, you can still specify a handler for /authenticate without giving a method - in that case, the most specific routing will be used.

	We can now define routes that are only accessible to authenticated users:		We can now define routes that are only accessible to authenticated users:

Duff: All right, it's a page that tells you some stuff now.

2013-02-19T22:40:15Z

All right, it's a page that tells you some stuff now.

@@ Line 45: / Line 45: @@
 	var date = new Date()
 	if (date.getDay() === 0) {
-		next(new Error("Don't bother me on Sunday!"))
+		var err = new Error("Don't bother me on Sunday!")
 	} else {
 		next(date)
@@ Line 52: / Line 54: @@
 </source>
 Visiting that same URL on a Sunday would get you this response instead:
-<pre>{"success":false,"message":"Don't bother me on Sunday!"}</pre>
+<pre>{"success":false,"message":"Don't bother me on Sunday!","code":"RESTING"}</pre>
 In realistic scenarios, you'll probably want to only respond with errors in the case of legitimate server errors, like a query failing or a missing file or something.
@@ Line 86: / Line 88: @@
 })
 </source>

Duff: moar

2013-02-19T22:30:09Z

moar

← Older revision		Revision as of 17:30, 19 February 2013
Line 76:		Line 76:
	If you don't pass in a parameter with the request (either as part of the query string in the URL, or in the headers), you'll get back this response:		If you don't pass in a parameter with the request (either as part of the query string in the URL, or in the headers), you'll get back this response:
	<pre>{"success":false,"message":"You must provide these parameters: please","code":"MISSING_PARAMETERS"}</pre>		<pre>{"success":false,"message":"You must provide these parameters: please","code":"MISSING_PARAMETERS"}</pre>
			...but if the client does visit /counter/value?please=lol or whatever, they'll totally get the value back! And remember, that value is session-specific - visiting the same URL in a different browser could get you a completely different number.

			It's up to you to maintain whatever state you like in those session variables. Obvious candidates are user information, and state about current high-traffic jobs that the user is engaged in (if they're sending requests every second, you probably don't want to hit the database more than is necessary).

			You can (and probably want to) have session state expire after a certain amount of time. This function call will cause sessions to expire after 10 minutes of inactivity:
			<source lang="javascript">
			router.setSessionInactivityTimeout(10, function(session) {
			console.log("A user just timed out! They got their counter up to " + session.counter + " first, though.")
			})
			</source>

Duff: moar

2013-02-19T22:25:34Z

moar

← Older revision		Revision as of 17:25, 19 February 2013
Line 28:		Line 28:
	}).listen(8080)		}).listen(8080)
	</source>		</source>

			== Routing ==
			All right, your server is running. You want to add a new response to certain messages - so that requests to yourdomain.com/information/time would get the current server time back, or something dumb like that.

			<source lang="javascript">
			router.route('/information/time', function(parameters, session, next) {
			next(new Date())
			})
			</source>

			Browsing to the URL should immediately get you back this response:
			<pre>{"success":true,"output":"2013-02-19T22:00:56.507Z"}</pre>
			But let's say that something bad happens on the server - maybe it's an error if a client asks for the server time on a Sunday. You could reflect that by rewriting the function like so:
			<source lang="javascript">
			router.route('/information/time', function(parameters, session, next) {
			var date = new Date()
			if (date.getDay() === 0) {
			next(new Error("Don't bother me on Sunday!"))
			} else {
			next(date)
			}
			})
			</source>
			Visiting that same URL on a Sunday would get you this response instead:
			<pre>{"success":false,"message":"Don't bother me on Sunday!"}</pre>

			In realistic scenarios, you'll probably want to only respond with errors in the case of legitimate server errors, like a query failing or a missing file or something.

			== Session state ==
			All right, so you can easily fling data back to the client. Unbeknownst to you (before you read this sentence), it turns out that model-router also stores a session variable for each visitor (using a cookie that it sets on the client)! You can set parameters on this object whenever you like, and access them again later:
			<source lang="javascript">
			router.route('/counter/increment', function(parameters, session, next) {
			session.counter = (session.counter \|\| 0) + 1
			next()
			})
			</source>
			But now let's say that you want to see the current value of that pointless counter! But let's use a new feature that I feel like telling you about: guaranteed parameters. Like, you know, where a request is only valid if a certain value is provided? You could do a bunch of input parsing, and check to see if certain values were defined or whatnot, but model-router handles some of that for you.

			Let's only give back the current value if the user provides a parameter called "please" - we won't even bother to check what it is, as long as it's set:

			<source lang="javascript">
			router.route('/counter/value', function(parameters, session, next) {
			next(session.counter \|\| 0)
			}, ['please'])
			</source>

			If you don't pass in a parameter with the request (either as part of the query string in the URL, or in the headers), you'll get back this response:
			<pre>{"success":false,"message":"You must provide these parameters: please","code":"MISSING_PARAMETERS"}</pre>

Duff: First stuff

2013-02-19T21:58:40Z

First stuff

New page

model-router does a few things that make writing data servers easier:
* Routing
* Session handling/state
* Wrapping up authentication
* Checking for parameters existence

== Including ==
You could have multiple router-things if you wanted to - you know, in case you were running multiple sites from the same node.js server, or something - but for your purposes you'll probably just want to instantiate one.

<source lang="javascript">
var Router = require('model-router')
var router = new Router()
</source>

It doesn't launch any servers of its own, that would be rude. You'll want to create your own server in the usual way, and then tell model-router to handle it if appropriate.

model-router only sends back JSON responses, and doesn't do anything with static content out of the box, so if you want to serve HTML/JavaScript files or something, you'll have to do it yourself:

<source lang="javascript">
require('http').createServer(function(req, res) {
var pathname = require('url').parse(req.url).pathname
var match
if (match = /^\/static(\/.*)$/.exec(pathname)) {
require('send')(req, match[1]).root('./static/').pipe(res)
} else {
router.handleRequest(req, res)
}
}).listen(8080)
</source>