Fix naming a tab as a number (Fix #24)

CHANGES.txt

@@ -2,6 +2,7 @@ v1.1.8
  * Add support for :linenos: to code tabs (#22)
  * Improve fallback for non-HTML builders (#19)
  * Add spelling builder to list of builders (#20)
+ * Fix naming a tab as a number (#24)
 
 v1.1.7
  * Fix css files not being removed when tabs are not used on a page

sphinx_tabs/tabs.py

@@ -90,10 +90,13 @@ def run(self):
         env = self.state.document.settings.env
 
         args = self.content[0].strip()
-        try:
-            args = json.loads(args)
-            self.content.trim_start(1)
-        except ValueError:
+        if args.startswith('{'):
+            try:
+                args = json.loads(args)
+                self.content.trim_start(1)
+            except ValueError:
+                args = {}
+        else:
             args = {}
 
         tab_name = nodes.container()

sphinx_tabs/test/basic/index.html

@@ -12,11 +12,17 @@
       <div class="docutils container">
 Oranges</div>
     </div>
+    <div class="item sphinx-data-tab-3 docutils container">
+      <div class="docutils container">
+404</div>
+    </div>
   </div>
   <div class="ui bottom attached sphinx-tab tab segment sphinx-data-tab-0 active docutils container">
 Apples are green, or sometimes red.</div>
   <div class="ui bottom attached sphinx-tab tab segment sphinx-data-tab-1 docutils container">
 Pears are green.</div>
   <div class="ui bottom attached sphinx-tab tab segment sphinx-data-tab-2 docutils container">
 Oranges are orange.</div>
+  <div class="ui bottom attached sphinx-tab tab segment sphinx-data-tab-3 docutils container">
+A number in the name.</div>
 </div>

sphinx_tabs/test/basic/index.rst

@@ -11,3 +11,7 @@
    .. tab:: Oranges
 
       Oranges are orange.
+
+   .. tab:: 404
+
+      A number in the name.