1 files changed, 92 insertions, 0 deletions
diff --git a/examples/data/plugins/on_set.py b/examples/data/plugins/on_set.py
new file mode 100644
index 0000000..130b816
--- /dev/null
+++ b/examples/data/plugins/on_set.py
@@ -0,0 +1,92 @@
+from re import compile
+from functools import partial
+
+valid_glob = compile('^[A-Za-z0-9_\*\.]+$').match
+
+def make_matcher(glob):
+    '''Make matcher function from simple glob.'''
+
+    pattern = "^%s$" % glob.replace('*', '[^\s]*')
+    return compile(pattern).match
+
+
+def exec_handlers(uzbl, handlers, key, arg):
+    '''Execute the on_set handlers that matched the key.'''
+
+    for handler in handlers:
+        if callable(handler):
+            handler(key, arg)
+
+        else:
+            uzbl.send(uzbl.cmd_expand(handler, [key, arg]))
+
+
+def check_for_handlers(uzbl, key, arg):
+    '''Check for handlers for the current key.'''
+
+    for (matcher, handlers) in uzbl.on_sets.values():
+        if matcher(key):
+            exec_handlers(uzbl, handlers, key, arg)
+
+
+def on_set(uzbl, glob, handler, prepend=True):
+    '''Add a new handler for a config key change.
+
+    Structure of the `uzbl.on_sets` dict:
+      { glob : ( glob matcher function, handlers list ), .. }
+    '''
+
+    assert valid_glob(glob)
+
+    while '**' in glob:
+        glob = glob.replace('**', '*')
+
+    if callable(handler):
+        orig_handler = handler
+        if prepend:
+            handler = partial(handler, uzbl)
+
+    else:
+        orig_handler = handler = unicode(handler)
+
+    if glob in uzbl.on_sets:
+        (matcher, handlers) = uzbl.on_sets[glob]
+        handlers.append(handler)
+
+    else:
+        matcher = make_matcher(glob)
+        uzbl.on_sets[glob] = (matcher, [handler,])
+
+    uzbl.logger.info('on set %r call %r' % (glob, orig_handler))
+
+
+def parse_on_set(uzbl, args):
+    '''Parse `ON_SET <glob> <command>` event then pass arguments to the
+    `on_set(..)` function.'''
+
+    (glob, command) = (args.split(' ', 1) + [None,])[:2]
+    assert glob and command and valid_glob(glob)
+    on_set(uzbl, glob, command)
+
+
+# plugins init hook
+def init(uzbl):
+    require('config')
+    require('cmd_expand')
+
+    export_dict(uzbl, {
+        'on_sets':  {},
+        'on_set':   on_set,
+    })
+
+    connect_dict(uzbl, {
+        'ON_SET':           parse_on_set,
+        'CONFIG_CHANGED':   check_for_handlers,
+    })
+
+# plugins cleanup hook
+def cleanup(uzbl):
+    for (matcher, handlers) in uzbl.on_sets.values():
+        del handlers[:]
+
+    uzbl.on_sets.clear()