Added thumbnails to the recent sketches page.

- Added an svg field to store the thumbnail
- The thumbnail is computed and cached in redis

community/lms/doctype/lms_sketch/livecode.py

@@ -0,0 +1,44 @@
+"""Utilities to work with livecode service.
+"""
+import websocket
+import json
+import drawSvg as draw
+
+def livecode_to_svg(livecode_ws_url, code, *, timeout=1):
+    """Renders the code as svg.
+    """
+    print("livecode_to_svg")
+    ws = websocket.WebSocket()
+    ws.settimeout(timeout)
+    ws.connect(livecode_ws_url)
+
+    msg = {
+        "msgtype": "exec",
+        "runtime": "python-canvas",
+        "code": code
+    }
+    ws.send(json.dumps(msg))
+
+    messages = _read_messages(ws)
+    commands = [m['cmd'] for m in messages if m['msgtype'] == 'draw']
+    img = draw_image(commands)
+    return img.asSvg()
+
+def _read_messages(ws):
+    messages = []
+    try:
+        while True:
+            msg = ws.recv()
+            if not msg:
+                break
+            messages.append(json.loads(msg))
+    except websocket.WebSocketTimeoutException:
+        pass
+    return messages
+
+def draw_image(commands):
+    img = draw.Drawing(300, 300, fill='none', stroke='black')
+    for c in commands:
+        if c['function'] == 'circle':
+            img.append(draw.Circle(cx=c['x'], cy=c['y'], r=c['d']/2))
+    return img

community/lms/doctype/lms_sketch/lms_sketch.py

@@ -3,13 +3,44 @@
 # For license information, please see license.txt
 
 from __future__ import unicode_literals
+import hashlib
+from urllib.parse import urlparse
 import frappe
 from frappe.model.document import Document
+from . import livecode
 
 class LMSSketch(Document):
     def get_owner_name(self):
         return get_userinfo(self.owner)['full_name']
 
+    def get_livecode_url(self):
+        doc = frappe.get_cached_doc("LMS Settings")
+        return doc.livecode_url
+
+    def get_livecode_ws_url(self):
+        url = urlparse(self.get_livecode_url())
+        protocol = "wss" if url.scheme == "https" else "ws"
+        return protocol + "://" + url.netloc + "/livecode"
+
+    def to_svg(self):
+        return self.svg or self.render_svg()
+
+    def render_svg(self):
+        h = hashlib.md5(self.code.encode('utf-8')).hexdigest()
+        cache = frappe.cache()
+        key = "sketch-" + h
+        value = cache.get(key)
+        if value:
+            value = value.decode('utf-8')
+        else:
+            ws_url = self.get_livecode_ws_url()
+            value = livecode.livecode_to_svg(ws_url, self.code)
+            cache.set(key, value)
+        return value
+
+    def __repr__(self):
+        return f"<LMSSketch {self.name}>"
+
 @frappe.whitelist()
 def save_sketch(name, title, code):
     if not name or name == "new":
@@ -29,6 +60,7 @@ def save_sketch(name, title, code):
             }
         doc.title = title
         doc.code = code
+        doc.svg = ''
         doc.save()
         status = "updated"
     return {
@@ -50,13 +82,13 @@ def get_recent_sketches():
     """
     sketches = frappe.get_all(
         "LMS Sketch",
-        fields=['name', 'title', 'owner', 'modified'],
+        fields='*',
         order_by='modified desc',
         page_length=100
     )
     for s in sketches:
         s['owner_name'] = get_userinfo(s['owner'])['full_name']
-    return sketches
+    return [frappe.get_doc(doctype='LMS Sketch', **doc) for doc in sketches]
 
 def get_userinfo(email):
     """Returns the username and fullname of a user.

community/www/sketches/index.html

@@ -16,13 +16,32 @@
     <a href="/sketches/sketch?sketch=new">Create a New Sketch</a>
 	</div>
 	<div class='container'>
+    <div class="row row-cols-1 row-cols-xl-5 row-cols-lg-4 row-cols-md-3 row-cols-sm-2 ">
     {% for sketch in sketches %}
-      <div class="sketch-preview mb-5">
+    <div class="col mb-4">
-        <span class="sketch-ts">{{ sketch.modified }}</span>
+      <div class="card" style="width: 200px;">
-        <a href="/sketches/sketch?sketch={{sketch.name}}">{{sketch.title}}</a>
+      <div class="card-img-top">
-        By {{sketch.owner_name}}
+        <a href="/sketches/sketch?sketch={{sketch.name}}">
+        {{ sketch.to_svg() }}
+        </a>
       </div>
+      <div class="card-footer">
+        By {{sketch.get_owner_name()}}
+      </div>
+      </div>
+    </div>
     {% endfor %}
+    </div>
 	</div>
 </section>
 {% endblock %}
+
+{% block style %}
+  {{super()}}
+  <style type="text/css">
+    svg {
+      width: 200px;
+      height: 200px;
+    }
+  </style>
+{% endblock %}

requirements.txt

@@ -1 +1,3 @@
-frappe
+frappe
+websocket_client
+drawSvg