Ticket #20709: widthratio-as.patch

AUTHORS

@@ -570 +570 @@
     Travis Swicegood <travis@domain51.com>
     Pascal Varet
     SuperJared
+    Jonathan Slenders
     Radek Švarz <http://www.svarz.cz/translate/>
     Swaroop C H <http://www.swaroopch.info>
     Aaron Swartz <http://www.aaronsw.com/>

django/template/defaulttags.py

@@ -458 +458 @@
         return self.content
 
 class WidthRatioNode(Node):
-    def __init__(self, val_expr, max_expr, max_width):
+    def __init__(self, val_expr, max_expr, max_width, asvar=None):
         self.val_expr = val_expr
         self.max_expr = max_expr
         self.max_width = max_width
+        self.asvar = asvar
 
     def render(self, context):
         try:
@@ -480 +481 @@
             return '0'
         except (ValueError, TypeError):
             return ''
-        return str(int(round(ratio)))
+        result = str(int(round(ratio)))
+
+        if self.asvar:
+            context[self.asvar] = result
+            return ''
+        else:
+            return result
 
 class WithNode(Node):
     def __init__(self, var, name, nodelist, extra_context=None):
@@ -1353 +1360 @@
 
     For example::
 
-        <img src='bar.gif' height='10' width='{% widthratio this_value max_value max_width %}' />
+        <img src="bar.png" alt="Bar"
+             height="10" width="{% widthratio this_value max_value max_width %}" />
 
     If ``this_value`` is 175, ``max_value`` is 200, and ``max_width`` is 100,
     the image in the above example will be 88 pixels wide
     (because 175/200 = .875; .875 * 100 = 87.5 which is rounded up to 88).
+
+    In some cases you might want to capture the result of widthratio in a
+    variable. It can be useful for instance in a blocktrans like this::
+
+        {% widthratio this_value max_value max_width as width %}
+        {% blocktrans %}The width is: {{ width }}{% endblocktrans %}
     """
     bits = token.split_contents()
-    if len(bits) != 4:
-        raise TemplateSyntaxError("widthratio takes three arguments")
-    tag, this_value_expr, max_value_expr, max_width = bits
+    if len(bits) == 4:
+        tag, this_value_expr, max_value_expr, max_width = bits
+        asvar = None
+    elif len(bits) == 6:
+        tag, this_value_expr, max_value_expr, max_width, as_, asvar = bits
+        if as_ != 'as':
+            raise TemplateSyntaxError("Invalid syntax in widthratio tag. Expecting 'as' keyword")
+    else:
+        raise TemplateSyntaxError("widthratio takes at least three arguments")
 
     return WidthRatioNode(parser.compile_filter(this_value_expr),
                           parser.compile_filter(max_value_expr),
-                          parser.compile_filter(max_width))
+                          parser.compile_filter(max_width),
+                          asvar=asvar)
 
 @register.tag('with')
 def do_with(parser, token):

docs/ref/templates/builtins.txt

@@ -1108 +1108 @@
 image in the above example will be 88 pixels wide
 (because 175/200 = .875; .875 * 100 = 87.5 which is rounded up to 88).
 
+.. versionchanged:: 1.7
+
+In some cases you might want to capture the result of widthratio in a variable.
+It can be useful for instance in a blocktrans like this::
+
+    {% widthratio this_value max_value max_width as width %}
+    {% blocktrans %}The width is: {{ width }}{% endblocktrans %}
+
 .. templatetag:: with
 
 with

docs/releases/1.7.txt

@@ -156 +156 @@
   :meth:`~django.contrib.auth.models.User.email_user()` are passed to the
   underlying :meth:`~django.core.mail.send_mail()` call.
 
+* The widthratio template tag now accepts an "as" parameter, to capture the
+  result in a variable.
+
 Backwards incompatible changes in 1.7
 =====================================
 

tests/template_tests/tests.py

@@ -1575 +1575 @@
             # Test whitespace in filter argument
             'widthratio15': ('{% load custom %}{% widthratio a|noop:"x y" b 0 %}', {'a':50,'b':100}, '0'),
 
+            # Widthratio with variable assignment
+            'widthratio16': ('{% widthratio a b 100 as variable %}-{{ variable }}-', {'a':50,'b':100}, '-50-'),
+            'widthratio17': ('{% widthratio a b 100 as variable %}-{{ variable }}-', {'a':100,'b':100}, '-100-'),
+
+            'widthratio18': ('{% widthratio a b 100 as %}', { }, template.TemplateSyntaxError),
+            'widthratio19': ('{% widthratio a b 100 not_as variable %}', { }, template.TemplateSyntaxError),
+
             ### WITH TAG ########################################################
             'with01': ('{% with key=dict.key %}{{ key }}{% endwith %}', {'dict': {'key': 50}}, '50'),
             'legacywith01': ('{% with dict.key as key %}{{ key }}{% endwith %}', {'dict': {'key': 50}}, '50'),