Added the ability to save sketches

Implemented by exposing an RPC method to save the sketch and calling
from JS using `frappe.call`. Any logged-in user can create new sketches
and the owner can edit his/her own sketches.

community/lms/doctype/lms_sketch/lms_sketch.py

@@ -3,8 +3,37 @@
 # For license information, please see license.txt
 
 from __future__ import unicode_literals
-# import frappe
+import frappe
 from frappe.model.document import Document
 
 class LMSSketch(Document):
-	pass
+    def get_owner_name(self):
+        return self.owner.split("@")[0]
+
+@frappe.whitelist()
+def save_sketch(name, title, code):
+    if not name or name == "new":
+        doc = frappe.new_doc('LMS Sketch')
+        doc.title = title
+        doc.code = code
+        doc.runtime = 'python-canvas'
+        doc.insert()
+        status = "created"
+    else:
+        doc = frappe.get_doc("LMS Sketch", name)
+
+        if doc.owner != frappe.session.user:
+            return {
+                "ok": False,
+                "error": "Permission Denied"
+            }
+        doc.title = title
+        doc.code = code
+        doc.save()
+        status = "updated"
+    return {
+        "ok": True,
+        "status": status,
+        "name": doc.name,
+    }
+