Add skeleton created by XBlock SDK.

.gitignore

+__pycache__/
+*.py[cod]

setup.py

+"""Setup for vectordraw XBlock."""
+
+import os
+from setuptools import setup
+
+
+def package_data(pkg, roots):
+    """Generic function to find package_data.
+
+    All of the files under each of the `roots` will be declared as package
+    data for package `pkg`.
+
+    """
+    data = []
+    for root in roots:
+        for dirname, _, files in os.walk(os.path.join(pkg, root)):
+            for fname in files:
+                data.append(os.path.relpath(os.path.join(dirname, fname), pkg))
+
+    return {pkg: data}
+
+
+setup(
+    name='vectordraw-xblock',
+    version='0.1',
+    description='vectordraw XBlock',   # TODO: write a better description.
+    packages=[
+        'vectordraw',
+    ],
+    install_requires=[
+        'XBlock',
+    ],
+    entry_points={
+        'xblock.v1': [
+            'vectordraw = vectordraw:VectorDrawXBlock',
+        ]
+    },
+    package_data=package_data("vectordraw", ["static", "public"]),
+)

vectordraw/__init__.py

+from .vectordraw import VectorDrawXBlock

vectordraw/static/README.txt

+This static directory is for files that should be included in your kit as plain
+static files.
+
+You can ask the runtime for a URL that will retrieve these files with:
+
+    url = self.runtime.local_resource_url(self, "static/js/lib.js")
+
+The default implementation is very strict though, and will not serve files from
+the static directory.  It will serve files from a directory named "public".
+Create a directory alongside this one named "public", and put files there.
+Then you can get a url with code like this:
+
+    url = self.runtime.local_resource_url(self, "public/js/lib.js")
+
+The sample code includes a function you can use to read the content of files
+in the static directory, like this:
+
+    frag.add_javascript(self.resource_string("static/js/my_block.js"))
+

vectordraw/static/css/vectordraw.css

+/* CSS for VectorDrawXBlock */
+
+.vectordraw_block .count {
+    font-weight: bold;
+}
+
+.vectordraw_block p {
+    cursor: pointer;
+}

vectordraw/static/html/vectordraw.html

+<div class="vectordraw_block">
+<p>VectorDrawXBlock: count is now
+    <span class='count'>{self.count}</span> (click me to increment).
+</p>
+</div>

vectordraw/static/js/src/vectordraw.js

+/* Javascript for VectorDrawXBlock. */
+function VectorDrawXBlock(runtime, element) {
+
+    function updateCount(result) {
+        $('.count', element).text(result.count);
+    }
+
+    var handlerUrl = runtime.handlerUrl(element, 'increment_count');
+
+    $('p', element).click(function(eventObject) {
+        $.ajax({
+            type: "POST",
+            url: handlerUrl,
+            data: JSON.stringify({"hello": "world"}),
+            success: updateCount
+        });
+    });
+
+    $(function ($) {
+        /* Here's where you'd do things on page load. */
+    });
+}

vectordraw/vectordraw.py

+"""TO-DO: Write a description of what this XBlock is."""
+
+import pkg_resources
+
+from xblock.core import XBlock
+from xblock.fields import Scope, Integer
+from xblock.fragment import Fragment
+
+
+class VectorDrawXBlock(XBlock):
+    """
+    TO-DO: document what your XBlock does.
+    """
+
+    # Fields are defined on the class.  You can access them in your code as
+    # self.<fieldname>.
+
+    # TO-DO: delete count, and define your own fields.
+    count = Integer(
+        default=0, scope=Scope.user_state,
+        help="A simple counter, to show something happening",
+    )
+
+    def resource_string(self, path):
+        """Handy helper for getting resources from our kit."""
+        data = pkg_resources.resource_string(__name__, path)
+        return data.decode("utf8")
+
+    # TO-DO: change this view to display your data your own way.
+    def student_view(self, context=None):
+        """
+        The primary view of the VectorDrawXBlock, shown to students
+        when viewing courses.
+        """
+        html = self.resource_string("static/html/vectordraw.html")
+        frag = Fragment(html.format(self=self))
+        frag.add_css(self.resource_string("static/css/vectordraw.css"))
+        frag.add_javascript(self.resource_string("static/js/src/vectordraw.js"))
+        frag.initialize_js('VectorDrawXBlock')
+        return frag
+
+    # TO-DO: change this handler to perform your own actions.  You may need more
+    # than one handler, or you may not need any handlers at all.
+    @XBlock.json_handler
+    def increment_count(self, data, suffix=''):
+        """
+        An example handler, which increments the data.
+        """
+        # Just to show data coming in...
+        assert data['hello'] == 'world'
+
+        self.count += 1
+        return {"count": self.count}
+
+    # TO-DO: change this to create the scenarios you'd like to see in the
+    # workbench while developing your XBlock.
+    @staticmethod
+    def workbench_scenarios():
+        """A canned scenario for display in the workbench."""
+        return [
+            ("VectorDrawXBlock",
+             """<vertical_demo>
+                <vectordraw/>
+                <vectordraw/>
+                <vectordraw/>
+                </vertical_demo>
+             """),
+        ]