Assignment 4 Solution

Objective:




The purpose of assignment four is four-fold:

Allow for multiple pages with a mixture of static and dynamically generated content.



Begin applying good software design principles by segmenting logic into their own modules.
Get experience playing with Nodejs emitters.



Create jQuery Mobile menus.



Note: We’re going to be porting assignments 2 and lab 3 into this assignment. So if you were unable to get assignment 3 and/or assignment 2 (which was related to the aforementioned example) working properly please see an instructor or TA ASAP to get these working according to specifications.




Part 1: Create your “home page”

In Nodejs, if we set up our express server to serve up static files, then requests to the root of the server ( http://localhost:<port) will attempt to read (and respond with) a file called index.html if no handler for the endpoint / is defined.




So let’s start this assignment by creating a file called index.html that uses jQuery Mobile to set up the page as follows:




A jQuery Mobile header with the name of the assignment and menu panel (http://demos.jquerymobile.com/1.4.5/panel/)



A jQuery mobile footer with your name.



A “content” area



The menu should have three links entitled something like:

Home
Calculator



Weather






We haven’t learned about jQuery Mobile menus yet. So here’s your chance to play with them!

jQuery Mobile Menu Panel




First we need to create a div with a data-role=”panel” which will store links that make up our menu’s content:




<div data-role=”panel” id=”myPanel” <a … link1 </a

….

</div




Next within the header we need to have a link with the href attribute set to match the ID of our panel.

<div data-role=”header”

<a href=”#myPanelMenu</a




<h1Hello!</h1




</div




And there you go! A few little things…




The panel div must be right before the header div



Check out the jQuery Mobile documentation for how add icons if you like



If you add the attribute data-rel=”close” to a link in the menu the menu when you click it.






Part 2: The Content




The content area should initially give instructions on how to use the site and what it does (you’ll probably populate this after you get the remaining parts done). This should also appear when the user goes to “Home” within the menu.




Your links should be as follows




The home link should repopulate the content area with your initial instructions.



The calculator link, when clicked, will populate the content area (asynchronously) with stuff related to assignment 3 (more on this in part 3)



The weather link, when clicked, will populate the content area (asynchronously) with stuff related to assignment 2 (more on this in part 4)



Notes/Hints: If your href path is just a pound sign, #, then clicking on the link won’t redirect you to another page (it will just take you to the top of the current page).

Part 3: The Calculator




Ok. On to the tough/fun stuff! We’re now going to port your assignment 3 (the one that did computations) into this lab, but we’re going to have its rendering and computations done via its own module! The idea/flow is as follows:




When the user clicks on the Computer link, it loads the html content (scripts and body) you generated in assignment 3 into the content area (asynchronously).
Then you should be able to use the content area just like you did in assignment 3.



But we’re going to organize this to have these things done via a Calculator module:




Create a Calculator module where you export several functions, in particular: o render
o computeFactorial o computeSummation

Your main server script should then require this module and direct endpoint requests to the appropriate methods. For example:



o When the Computer navigation link is clicked, your corresponding endpoint should

call your module’s render function, populate the HTML string containing the scripts/body from HW3, and return this to the endpoint so that it can send it back in its response (if you’re creative maybe you could have this content in an external file and use the File System module to read it in….).




o When the button is clicked in this rendered view, your code (like in HW3) should call some endpoints on the server, which in turn call the corresponding functions of your module, which does the appropriate computation and returns the HTML data to be used by the AJAX call.




Notes/Hints:




To have multi-line JavaScript strings (which you may want, especially for your rendering method) the best way is to just have each line concatenate to the total string. For example:
var str = “<html” + ”<head”+

//etc..




Also remember that you might have to escape quotes within your string.



You could either do this by creating a class and binding functions to it, or by just exporting various static functions, the latter of which we described above.
Part 4: Get Weather




In Part 3 you got to play with modules and exporting functions. Now we want to play with emitters.




Let’s port your assignment 2 so that the server does a lot of the leg work! Here’s the details:




Store your weather underground key in a file on your server, one directory up from where the server is running (for security)
Create your Weather module that has the following functions/methods

Render



getZip



getWeather



Within this module, read in and store your key from your file.
When the user clicks on the Weather link in the navigation area, you should render the body (including the necessary scripts) of your HTML code using the text returned by the render method. This should basically just show a button (since you have the key on your server).



When the user clicks the button, an asynchronous request is sent to the server which:



Binds a listener to your Weather module for something to be emitted by your



getZip method

Calls the getZip method of your Weather module

This method makes an HTTP request call to weather underground



Once it has all of its data, it extracts the zip code from the response and emits a signal saying it’s done.
Once your listener gets the emitter signal from the getZip method

Grab the zip code data that was passed to your bound function.



Binds a listener for something to be emitted by your getWeather module.



Call your getWeather module
Your getWeather method should

Construct the necessary URL using the zip code and your key and makes an HTTP request call to weather underground.
Upon completion, construct an HTML response from the data it obtained and emit a signal indicating you’re done, along with this HTML data.
Once your listener gets the emitted signal from the getWeather method, send your response with the returned HTML data in it.






Notes/Hints: You can get a lot of this from the Node Part 3 slides

What to Submit




A screen cast video to detailing a thorough (both client and server side) code walk through, followed by a demo of all cases



Your source code, well internally documented



README file on how to run your code



All of the above ZIPPED together and that single compressed file uploaded to BBlearn.



Grading (50) Points




40 points: program correctness along with adherence to the stated requirements



5 points: quality of internal documentation and code style



5 points: README file