Ticket #3523: unpacking-for.diff

django/template/defaulttags.py

@@ -5 +5 @@
-from django.template import get_library, Library, InvalidTemplateLibrary
-from django.conf import settings
-import sys
+import re
-
-register = Library()
-
@@ -61 +62 @@
-        return ''
-
-class ForNode(Node):
-
-, self.sequence = loopvar
+s
+s, self.sequence = loopvars
-        self.reversed = reversed
-        self.nodelist_loop = nodelist_loop
-
@@ -72 +73 @@
-        else:
-            reversed = ''
-        return "<For Node: for %s in %s, tail_len: %d%s>" % \
-self.loopvar
+', '.join( self.loopvars )
-
-    def __iter__(self):
-        for node in self.nodelist_loop:
@@ -107 +108 @@
-                for index in range(len(data)-1, -1, -1):
-                    yield data[index]
-            values = reverse(values)
+        unpack = len(self.loopvars) > 1
-        for i, item in enumerate(values):
-            context['forloop'] = {
-                # shortcuts for current loop iteration number
@@ -120 +122 @@
-                'last': (i == len_values - 1),
-                'parentloop': parentloop,
-            }
-
+
+
+
+
+
-            for node in self.nodelist_loop:
-                nodelist.append(node.render(context))
+            if unpack:
+                # The loop variables were pushed on to the context so pop them
+                # off again. This is necessary because the tag lets the length
+                # of loopvars differ to the length of each set of items and we
+                # don't want to leave any vars from the previous loop on the
+                # context.
+                context.pop()
-        context.pop()
-        return nodelist.render(context)
-
@@ -486 +499 @@
-    nodelist = parser.parse(('endfilter',))
-    parser.delete_first_token()
-    return FilterNode(filter_expr, nodelist)
-
+do_
-
-#@register.tag
-def firstof(parser, token):
@@ -530 +543 @@
-        {% endfor %}
-        </ul>
-
-also 
+
-    ``{% for obj in list reversed %}``.
+    
+    You can also unpack multiple values from a two-dimensional array::
+    
+        {% for key,value in dict.items %}
+            {{ key }}: {{ value }}
+        {% endfor %}
-
-    The for loop sets a number of variables available within the loop:
-
@@ -552 +571 @@
-
-    """
-    bits = token.contents.split()
-
-
-
-
-
-
-
-
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-    nodelist_loop = parser.parse(('endfor',))
-    parser.delete_first_token()
-
+s
-do_for = register.tag("for", do_for)
-
-def do_ifequal(parser, token, negate):

tests/regressiontests/templates/tests.py

@@ -289 +289 @@
-            'for-tag-vars02': ("{% for val in values %}{{ forloop.counter0 }}{% endfor %}", {"values": [6, 6, 6]}, "012"),
-            'for-tag-vars03': ("{% for val in values %}{{ forloop.revcounter }}{% endfor %}", {"values": [6, 6, 6]}, "321"),
-            'for-tag-vars04': ("{% for val in values %}{{ forloop.revcounter0 }}{% endfor %}", {"values": [6, 6, 6]}, "210"),
+            'for-tag-unpack01': ("{% for key,value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
+            'for-tag-unpack03': ("{% for key, value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
+            'for-tag-unpack04': ("{% for key , value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
+            'for-tag-unpack05': ("{% for key ,value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
+            'for-tag-unpack06': ("{% for key value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, template.TemplateSyntaxError),
+            'for-tag-unpack07': ("{% for key,,value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, template.TemplateSyntaxError),
+            'for-tag-unpack08': ("{% for key,value, in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, template.TemplateSyntaxError),
+            # Ensure that a single loopvar doesn't truncate the list in val.
+            'for-tag-unpack09': ("{% for val in items %}{{ val.0 }}:{{ val.1 }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
+            # Otherwise, silently truncate if the length of loopvars differs to the length of each set of items.
+            'for-tag-unpack10': ("{% for x,y in items %}{{ x }}:{{ y }}/{% endfor %}", {"items": (('one', 1, 'carrot'), ('two', 2, 'orange'))}, "one:1/two:2/"),
+            'for-tag-unpack11': ("{% for x,y,z in items %}{{ x }}:{{ y }},{{ z }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, ("one:1,/two:2,/", "one:1,INVALID/two:2,INVALID/")),
+            'for-tag-unpack12': ("{% for x,y,z in items %}{{ x }}:{{ y }},{{ z }}/{% endfor %}", {"items": (('one', 1, 'carrot'), ('two', 2))}, ("one:1,carrot/two:2,/", "one:1,carrot/two:2,INVALID/")),
+            'for-tag-unpack13': ("{% for x,y,z in items %}{{ x }}:{{ y }},{{ z }}/{% endfor %}", {"items": (('one', 1, 'carrot'), ('two', 2, 'cheese'))}, ("one:1,carrot/two:2,cheese/", "one:1,carrot/two:2,cheese/")),
-
-            ### IF TAG ################################################################
-            'if-tag01': ("{% if foo %}yes{% else %}no{% endif %}", {"foo": True}, "yes"),

docs/templates.txt

@@ -444 +444 @@
-~~~
-
-Loop over each item in an array.  For example, to display a list of athletes
-give
+provided i
-
-    <ul>
-    {% for athlete in athlete_list %}
@@ -452 +452 @@
-    {% endfor %}
-    </ul>
-
-also 
+
-
+If you need to loop over a list of lists, you can unpack the values
+in each sub-list into a set of known names. For example, if your context contains
+a list of (x,y) coordinates called ``points``, you could use the following
+to output the list of points:: 
+
+    {% for x, y in points %}
+        There is a point at {{ x }},{{ y }}
+    {% endfor %}
+    
+This can also be useful if you need to access the values in a dictionary. 
+For example, if your context contained a dictionary ``dict``, the following
+would display the keys and values of the dictionary::
+
+    {% for key, value in dict.items %}
+        {{ key }}: {{ value }}
+    {% endfor %}
+
-The for loop sets a number of variables available within the loop:
-
-    ==========================  ================================================