Express by Examples

There are 4 routing methods:

• router.get()   -get GET variables from URI
• router.post()   -get POST variable from HTML form
• router.put()   -accept put request
• router.delete()  -accept delete request

 

 router.get()

//static example - no variable is passed: /examples/static
router.get('/static', function(req, res, next) {
  res.render('examples/00static');
});

//variable vdata is passed: /examples/vars/
router.get('/vars', function(req, res, next) {
 
      //view data
      var vdata=
    {
        title: 'Work',
        name: 'John'
    }

      res.render('examples/01vars', vdata);
});


//variable is get from URI query: /examples/vars-from-url/?id=12&name=John&nick=Dixy
router.get('/vars-from-url', function(req, res, next) {
      
      var id=req.query.id;
      
      //view data
      var vdata=
    {
        id: id,
        title: 'Worker',
        name: req.query.name,
        nick: req.param('nick')
    }

//res.send(dump(vdata));

      res.render('examples/02vars_from_url', vdata);
});


//variable is get from URI parameters: /examples/vars-params/12/John
router.get('/vars-params/:id/:name', function(req, res, next) {
      
      var id=req.params.id;
      
      //view data
      var vdata=
    {
        id: id,
        title: 'Worker',
        name: req.params.name
    }

      res.render('examples/02vars_from_url', vdata);
});

 

 

 

router.post()

//variables are sent from form /examples/static via POST method
router.post('/vars-post', function(req, res, next) {
      
      var username=req.body.username;  //via body object. Must have 'body-parser' module
      var password=req.param('password', null); //via req.param() method
      
      //view data
      var vdata=
    {
        title: 'Worker',
        username: username,
        password: password
    }

      res.render('examples/03vars_from_form_post', vdata);
});

 

 

 

 

Properties and methods to get data

Main method is req.param('var' [, 'default value'])

Lookup is performed in the following order:

• req.params.name     from  /examples/John/
• req.body.username    from HTML form INPUT field 'username'
• req.query.name     from /examples/something/?name=John

 

Optionally, you can specify defaultValue to set a default value if the parameter is not found in any of the request objects.

 

 

 Response

Response can be sent with:

• res.send('string')
• res.send(404)   - sends status code
• res.render('view_file', vdata)    -sends view file to the browser

 

 

 

Regular expression in routes

 //variable as a regular expression inside URL: /examples/vars-regex/some/thing/123/
router.get('/vars-regex/(([a-z0-9\/]+))', function(req, res, next) {
    
  var reg=req.params[0];

  res.send(dump(req.params));
});

 

 To replace any character use:

router.get(/(.*)/, function(req, res, next) {
    
  var reg=req.params[0];

  res.send(dump(req.params)); //return: some/thing/123/
});

Notice: Use regex without quotation marks!