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[wolnelektury.git] / src / search / templatetags / set_get_parameter.py

diff --git a/src/search/templatetags/set_get_parameter.py b/src/search/templatetags/set_get_parameter.py
new file mode 100644 (file)
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+++ b/src/search/templatetags/set_get_parameter.py
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+# This file is part of FNP-Redakcja, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+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)