Homework #4ΒΆ

Due Mar 27th at 11:59pm. I’d suggest starting it BEFORE class on Tuesday so that you can ask questions in class or at office hours.

(See Day 11 – Tu, Feb 12th, 2013 for collaboration instructions.)

  1. Cleanup. I won’t grade your homework if this isn’t the case.

    1. Merge with my master branch:

    such that ‘git pull https://github.com/ctb/cse491-drinkz.git master’ says “up to date”, and make sure that your code includes everything through the end of HW 3. This includes fixes for anything that was graded as ‘broken’ at the end of HW 3.

    1. The default branch should be master, so,

    https://github.com/<USERNAME/cse491-drinkz/blob/master/<filename>

    should be what’s on the main page when you go to

    https://github.com/<USERNAME>/cse491-drinkz

    and when you do a ‘git clone’ of your repository, you should have your latest code in default branch.

    (See https://github.com/blog/421-pick-your-default-branch.)

  2. Refactor/fix. 10/100.

    1. Put your unit conversion code in one file, consolidated into a single function. Your tests shouldn’t need to change.
    2. Make sure all your tests pass. This doesn’t mean “delete them”, this means “fix your code.”

    Done.

  3. Integrate a Web frontend to your drinkz code. 50/100.

    Copy or merge or otherwise integrate ‘app.py’ from cse491-webz (https://github.com/ctb/cse491-webz/blob/master/app.py) into the ‘drinkz/’ directory, and then –

    1. write a ‘bin/’ script called ‘run-web’ that starts up a Web application as at the bottom of the current app.py.

    2. dynamically generate the Web pages from HW as part of ‘app.py’; for example, ‘localhost:9786/’ should show an index page that links to list of recipes, inventory, etc.

    3. provide another link on your index page that connects to a page with a form on it that takes in some amount of liquid in a text box, and, when ‘submit’ is clicked, goes to a new Web page that shows the amount converted into ml. Make sure that there are links back to the index page, too.

    4. create a new file ‘drinkz/test_app.py’ that exercises the WSGI interface by

      • initializing a clean database with some recipe data;
      • create a new SimpleApp object;
      • calls the __call_ function on the SimpleApp object with an ‘environ’ dictionary and a ‘start_response’ function of your own creation.
      • runs the code to generate the page that lists the recipes.
      • checks that the right recipe data is on that generated page.

  4. Save to/load from disk. 15/100.

    Merge really trivial file saving/loading. More specifically,

    1. merge the code in https://github.com/ctb/cse491-drinkz/tree/hw4-save-load into your repo, alter the db.load_db and db.save_db functions to save and load recipes as well, and make sure that you can “properly” save and load bottle types, inventory, and recipes.

      See bin/save-load for example usage/script creation.

    2. Create a script ‘bin/make-test-database’ that adds some data (recipes, etc.) and then saves the database into a filename provided on the command line.

    3. Modify make-html.py and app.py (from #2) to load that data in.

    Note, it would be really nice if you made sure that you could create a file with (b) that I could then load with (c), and if it were really obvious what the filename should be. Hint. HINT.

  5. Simple CSS/JavaScript. 15/100. (You’ll need to get #2 working first.)

    Integrate some really CSS and JavaScript into your HTML. Go check out the latest commit to cse491-linkz and then:

    1. Modify all your Web pages in #2 to contain the html, head, and body regions, as well as a title. Make the title different on each page, please.
    2. Modify all your Web pages in #2 to contain the <style> modification, and put an <h1> title on each page (which should now be red). The <h1> title should be different on each page.
    3. On your index page, add the button to show an alert box with JavaScript. Make sure it works!

    Note: if you have other obvious CSS and JavaScript on your pages, e.g. because you’ve put together a style thing, you can skip this part of the homework. Just make sure it’s obvious, m’kay?

  6. JSON-RPC. 15/100. (You’ll need to get #2 working first.)

    1. Change the JSON-RPC functionality in app.py to provide the following functions:

      convert_units_to_ml(amount) - given a str amount, returns ml
get_recipe_names() - returns a list of all recipe names
get_liquor_inventory() - returns a list of (mfg, liquor) tuples.

    2. Create a new file ‘drinkz/test_jsonrpc.py’ that tests these functions through the ‘app’ interface. That is, you should have at least three tests, each of which

      • initializes a clean database with some data (if needed)
      • creates a new SimpleApp object
      • calls the __call__ function on the SimpleApp object with an ‘environ’ dictionary and a ‘start_response’ function of your own creation.
      • ‘environ’ should contain the information (PATH_INFO, CONTENT_LENGTH, etc.) that makes the SimpleApp run the relevant JSON-RPC accessible function (e.g. rpc_get_recipe_names).
      • checks to make sure that the WSGI app returns the right answer.

      Under no circumstances should you directly call anything other than __call__ on the WSGI SimpleApp object, i.e. this should mimic closely a “normal” call from the WSGI server into the app object.

      Protip: use simplejson as in https://github.com/ctb/cse491-webz/blob/master/json-rpc-client.py and a StringIO object (http://docs.python.org/2/library/stringio.html) to set up environ[‘wsgi.input’] to pass in the JSON necessary to make the call. You might also want to read http://en.wikipedia.org/wiki/JSON-RPC.

  7. HTTP GET. 15/100. (You’ll need to get #2 working first.)

    Write a standalone Python script that does an HTTP GET using the ‘socket’ library in Python. More specifically, read http://effbot.org/zone/socket-intro.htm and then write a standalone script called ‘grab-page’ (not in bin, or drinkz/, and not with a .py on the end, and not with an underscore) in the root directory of your repository. This script should take two command line arguments, the hostname and the port for your running app.py server, and print out the results of submitting a GET request for ‘/’ on the app.py server.

    This might be worthwhile reading, too, if you’re confused or interested:

  8. Hand in your homework by tagging it as tag ‘hw4’:

    git tag hw4
git push origin hw4:hw4

    I strongly suggest that you make sure you can clone your repo into a new directory, check out ‘hw4’, and run all of your tests properly. You might want to double-check that everything above works, too...

    Note that it’s fairly easy to delete tags, so you should try this early on and tell me if it doesn’t work; then you can delete the first hw4 tag and update it to whatever you want to hand in.

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