1

2

3

4

How will this lab help me?

This lab will help you generate pages in your app based on user input (and teach how to use JSON). Assignment 6 includes these tasks!

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

Links

34

Terminal

$ node app.js
Express server listening on port 3000

Troubleshoot

module.js:340
    throw err;
           ^
      Error: Cannot find module '/home/vagrant/app.js'

Are you in the lab4 directory?
If you are still having issues with express, try running the following line in the terminal:
npm install express express3-handlebars

When I try to run node app.js I get a bunch of error messages, including the line 

Error: listen EADDRINUSE

This might have happened because Node crashed or because you're running a similar or identical web server in another terminal. (When you run one application that listens on localhost:3000 and try to start another that listens at the same URL, you will get this error). Try checking to see if you have other server applications running and refreshing your browser until you get the 'No data received' message

35

Links

Troubleshoot

I get a blank page!

Make sure node is running (see previous slide).

36

37

Code

    <div class="project" id="{{id}}">
      <a href="project" class="thumbnail">
        <img src="images/{{image}}" class="img">
        <p>{{name}}</p>
      </a>
    </div>

38

Video

39

40

Code

exports.view = function(req, res){
  res.render('index', {
    'name': 'Waiting in Line',
    'image': 'lorempixel.people.1.jpeg',
    'id': 'project1'
  });
};

41

Links

Troubleshoot

My images didn't load!

Restart node, see slide 42.

Error: listen EADDRINUSE

See slide 38.

42

Code

  res.render('index', {
    'projects': [
      { 'name': 'Waiting in Line',
        'image': 'lorempixel.people.1.jpeg',
        'id': 'project1'
      },
      { 'name': 'Needfinding',
        'image': 'lorempixel.city.1.jpeg',
        'id': 'project2'
      },
      { 'name': 'Prototyping',
        'image': 'lorempixel.technics.1.jpeg',
        'id': 'project3'
      },
      { 'name': 'Heuristic Evaluation',
        'image': 'lorempixel.abstract.1.jpeg',
        'id': 'project4'
      },
      { 'name': 'Visualization',
        'image': 'lorempixel.abstract.8.jpeg',
        'id': 'project5'
      },
      { 'name': 'Social design',
        'image': 'lorempixel.people.2.jpeg',
        'id': 'project6'
      },
      { 'name': 'Gestural interaction',
        'image': 'lorempixel.technics.2.jpeg',
        'id': 'project7'
      },
      { 'name': 'Design tools',
        'image': 'lorempixel.city.2.jpeg',
        'id': 'project8'
      }
    ]  
  });

43

44

Solution

    {{#each projects}}
      <div class="project" id="{{id}}">
        <a href="project" class="thumbnail">
          <img src="images/{{image}}" ... />
          <p>{{name}}</p>
        </a>
      </div>
    {{/each}}

45

Links

Troubleshoot

My page didn't change!

Restart node, see slide 42.

46

47

Add a table of contents

    <ol>
    {{#each projects}}
      <li><a href="#{{id}}">{{name}}</a></li>
    {{/each}}
    </ol>

48

Links

Troubleshoot

The list doesn't appear on top of the page!

Scroll down to bottom of the page. Adjust the code accordingly. You know how now! :)

The list doesn't appear at all.

Restart node, see slide 42.

49

50

Add app.js route

...

var index = require('./routes/index');
var project = require('./routes/project');
// Example route
...

51

Route URL to controller

...
// Add routes here
app.get('/', index.view);
app.get('/project', project.viewProject);
// Example route
...

52

Code

exports.viewProject = function(req, res) {

  // controller code goes here

};

53

Code

  res.render('project');

54

Links

Troubleshoot

“Error: .get() requires callback functions but got a [object Undefined]”

It couldn’t find the right controller function. The route is wrong or project.js is named incorrectly.

When I click on the project, my browser responds 'Cannot GET /project.html'

Notice that we added the route '/project' not '/project.html'. Your views/index.handlebars file probably has <a href="project.html" ... >
Change it to <a href="project" ... >.
Reminder: You need to explicitly refresh localhost:3000 in order to see the change.

55

When done, submit here.