#334 Create set_attributes template tag (#366)

* #334 Create set_attributes template tag

* #334 Adjust if condition in set_attributes

* #334 Add test_without_amend_tag

* #334 Edit set_attributes tag exmaple

poleno/utils/templatetags/poleno/amend.py

@@ -244,3 +244,51 @@ def action(fragment):
 
     context[u'_amend'].append(action)
     return u''
+
+@register.simple_tag(takes_context=True)
+def set_attributes(context, path, **kwargs):
+    u"""
+    Select elements specified by XPath and add, remove or edit their attributes.
+
+    Example:
+        {% amend %}
+          <ul>
+            <li aaa="foo">xxx</li>
+            <li aaa="foo">xxx</li>
+            <li aaa="foo">xxx</li>
+            <li aaa="foo">xxx</li>
+            <li aaa="foo">xxx</li>
+          </ul>
+          {% set_attributes path=".//li[1]" aaa=None bbb=None %}
+          {% set_attributes path=".//li[2]" aaa=False bbb=False %}
+          {% set_attributes path=".//li[3]" aaa=True bbb=True %}
+          {% set_attributes path=".//li[4]" aaa="bar" bbb="baz" ccc="" %}
+          {% set_attributes path=".//li[5]" aaa=1 bbb=2 ccc=0 %}
+        {% endamend %}
+
+    Result:
+        <ul>
+          <li>xxx</li>
+          <li>xxx</li>
+          <li aaa bbb>xxx</li>
+          <li aaa="bar" bbb="baz" ccc="">xxx</li>
+          <li aaa="1" bbb="2" ccc="0">xxx</li>
+        </ul>
+    """
+    if u'_amend' not in context:
+        context[u'_amend'] = []
+
+    def action(fragment):
+        elements = fragment.findall(path)
+        for element in elements:
+            for key, value in kwargs.items():
+                if value is None or value is False:
+                    element.attrib.pop(key, None)
+                elif value is True:
+                    element.set(key, None)
+                else:
+                    element.set(key, str(value))
+        return fragment
+
+    context[u'_amend'].append(action)
+    return u''

poleno/utils/tests/test_templatetags.py

@@ -423,6 +423,34 @@ def test_delete_tag(self):
                 u'</ul>'
                 u'')
 
+    def test_set_attributes_tag(self):
+        rendered = self._render(
+                u'{% load amend set_attributes from poleno.amend %}'
+                u'{% amend %}'
+                u'  <ul>'
+                u'    <li aaa="foo">xxx</li>'
+                u'    <li aaa="foo">xxx</li>'
+                u'    <li aaa="foo">xxx</li>'
+                u'    <li aaa="foo">xxx</li>'
+                u'    <li aaa="foo">xxx</li>'
+                u'  </ul>'
+                u'  {% set_attributes path=".//li[1]" aaa=None bbb=None %}'
+                u'  {% set_attributes path=".//li[2]" aaa=False bbb=False %}'
+                u'  {% set_attributes path=".//li[3]" aaa=True bbb=True %}'
+                u'  {% set_attributes path=".//li[4]" aaa="bar" bbb="baz" ccc="" %}'
+                u'  {% set_attributes path=".//li[5]" aaa=1 bbb=2 ccc=0 %}'
+                u'{% endamend %}'
+                u'')
+        self.assertHTMLEqual(rendered,
+                u'<ul>'
+                u'  <li>xxx</li>'
+                u'  <li>xxx</li>'
+                u'  <li aaa bbb>xxx</li>'
+                u'  <li aaa="bar" bbb="baz" ccc="">xxx</li>'
+                u'  <li aaa="1" bbb="2" ccc="0">xxx</li>'
+                u'</ul>'
+                u'')
+
     def test_amend_tag_on_plain_text(self):
         rendered = self._render(
                 u'{% load amend prepend append from poleno.amend %}'
@@ -485,3 +513,26 @@ def test_multiple_amend_tags(self):
                 u'  <li>xxx!</li>'
                 u'</ul>'
                 u'')
+
+    def test_without_amend_tag(self):
+        rendered = self._render(
+                u'{% load prepend append before after delete set_attributes from poleno.amend %}'
+                u'<ul>'
+                u'  <li>aaa</li>'
+                u'  <li>bbb</li>'
+                u'</ul>'
+                u'<p>foobar</p>'
+                u'{% prepend path=".//ul" %}<li>ccc</li>{% endprepend %}'
+                u'{% append path=".//ul" %}<li>ddd</li>{% endappend %}'
+                u'{% before path=".//li[2]" %}<li>eee</li>{% endbefore %}'
+                u'{% after path=".//li[2]" %}<li>fff</li>{% endafter %}'
+                u'{% delete path=".//p" %}'
+                u'{% set_attributes path=".//ul" att=True %}'
+                u'')
+        self.assertHTMLEqual(rendered,
+                u'<ul>'
+                u'  <li>aaa</li>'
+                u'  <li>bbb</li>'
+                u'</ul>'
+                u'<p>foobar</p>'
+                u'')