Initial commit of the khanex (Khan exercise) component.

Author: ram8647

package-lock.json

@@ -8,6 +8,7 @@
 from .mchoice import MChoice, QuestionNumber
 from .blockly import Blockly
 from .quizly import Quizly
+from .khanex import Khanex
 from .codelens import Codelens
 from .clickableArea import ClickableArea
 from .datafile import DataFile

runestone/__init__.py

@@ -0,0 +1,77 @@
+README.txt
+
+The khanex directive, in this first pass looks like this:
+-----------------------------------------------
+
+.. khanex::
+   :exercise: unique-exercise-name /qs folder
+
+The quizly component uses and requires the following resources:
+----------------------------------------------
+
+runestone/khanex/khanex.py   -- creates KhanexNode from directive
+runestone/khanex/__init__.py -- imports the khanex code
+
+runestone/khanex/js   -- javascript resources
+
+
+runestone/khanex/test -- some test code
+  -- _sources         -- test files
+  -- conf.py          -- sphinx config file for runestone
+  -- pavement.py      -- needed for runestone build
+
+The files that need to be coded by the developer
+-----------------------------------------------
+
+./runestone/khanex/khanex.py 
+----------------------------
+Th script that runs during runestone build. Runestone build parses the
+source document and translates the directive and its options into a QuizlyNode.
+
+ - Copies resource files from quizly/js to the project/_static folder, from where
+   they are copied to build/quizly/_static during build, where they are used by
+   the _sources web pages.
+
+ - QuizlyNode -- defines the node. The  only option needed for this is the quizname, 
+   which is parsed from the directive. 
+
+ - visit_quizly_mode(self, node) -- appends the quizly template, instantiated, to the
+   body of the html document that will represent the quizly exercise
+
+ - Quizly(RunestoneDirective) -- its run() method instantiates and returns QuizlyNode,
+   probably called by runestone build.
+
+./runestone/khanex/__init__.py -- called by runestone build, imports khanex.py  
+------------------------------
+
+./runestone/khanex/js/khanex.js 
+-------------------------------
+
+This script runs when the html page containing the khanex iframe is loaded. It contains
+methods to render the khanex component and to handle the interface with runestone.  
+
+This script will be invoked automatically when the page is loaded, provided a khanex entry
+is made in the module.exports list in webpack.config.js.
+
+    "./runestone/khanex/js/khanex.js",
+
+khanex.js contains the following methods and functions:
+
+ -- class Khanex extends RunestoneBase -- constructs a Khanex object that holds the
+    data from the exercise.  Calls renderQuiz() method.
+
+    -- getIFrame() -- extracts the iframe from the fully instantiated html code produced
+       by khanex.py and contained in KhanexNode.
+
+    -- renderKhanex() -- renders the khanex iframe inside a container <div>.
+
+    -- submitKhanex() -- the method invoked from the callback function when the user
+       clicks "Check Me" button in the khanex exercise.
+
+$(document).bind( ,,, function() {}) -- function that sets up the callback function
+    and binds it to the html document.
+
+setupCallback(khanex)  -- defines the callback function that is invoked when the "Check Me"
+    button is clicked.  It calls khanex.submitKhanex(result), where result is the
+    khanex-graded response to the user's attempt.
+

runestone/khanex/README.txt

@@ -0,0 +1 @@
+from .khanex import *

runestone/khanex/__init__.py

@@ -0,0 +1 @@
+Header set Access-Control-Allow-Origin "*"