filtered chunks table,
[redakcja.git] / apps / catalogue / templatetags / set_get_parameter.py
diff --git a/apps/catalogue/templatetags/set_get_parameter.py b/apps/catalogue/templatetags/set_get_parameter.py
new file mode 100755 (executable)
index 0000000..b3d44d7
--- /dev/null
@@ -0,0 +1,46 @@
+from re import split
+
+from django import template
+
+register = template.Library()
+
+
+"""
+In template:
+    {% set_get_paramater param1='const_value',param2=,param3=variable %}
+results with changes to query string:
+    param1 is set to `const_value' string
+    param2 is unset, if exists,
+    param3 is set to the value of variable in context
+
+Using 'django.core.context_processors.request' is required.
+
+"""
+
+
+class SetGetParameter(template.Node):
+    def __init__(self, values):
+        self.values = values
+        
+    def render(self, context):
+        request = template.Variable('request').resolve(context)
+        params = request.GET.copy()
+        for key, value in self.values.items():
+            if value == '':
+                if key in params:
+                    del(params[key])
+            else:
+                params[key] = template.Variable(value).resolve(context)
+        return '?%s' %  params.urlencode()
+
+
+@register.tag
+def set_get_parameter(parser, token):
+    parts = split(r'\s+', token.contents, 2)
+
+    values = {}
+    for pair in parts[1].split(','):
+        s = pair.split('=')
+        values[s[0]] = s[1]
+
+    return SetGetParameter(values)