Ticket #3826: with_tag.patch

File with_tag.patch, 3.4 KB (added by Chris Beaven, 18 years ago)

with tests and docs

  • django/template/defaulttags.py

     
    354354            return ''
    355355        return str(int(round(ratio)))
    356356
     357class WithNode(Node):
     358    def __init__(self, var, name, nodelist):
     359        self.var = var
     360        self.name = name
     361        self.nodelist = nodelist
     362
     363    def __repr__(self):
     364        return "<WithNode>"
     365
     366    def render(self, context):
     367        val = self.var.resolve(context)
     368        context.push()
     369        context[self.name] = val
     370        output = self.nodelist.render(context)
     371        context.pop()
     372        return output
     373
    357374#@register.tag
    358375def comment(parser, token):
    359376    """
     
    967984    return WidthRatioNode(parser.compile_filter(this_value_expr),
    968985                          parser.compile_filter(max_value_expr), max_width)
    969986widthratio = register.tag(widthratio)
     987
     988#@register.tag
     989def do_with(parser, token):
     990    """
     991    Add a value to the context (inside of this block) for caching and easy
     992    access. For example::
     993
     994        {% with person.some_sql_method as total %}
     995            {{ total }} object{{ total|pluralize }}
     996        {% endwith %}
     997    """
     998    bits = list(token.split_contents())
     999    if len(bits) != 4 or bits[2] != "as":
     1000        raise TemplateSyntaxError, "%r expected format is 'value as name'" % tagname
     1001    var = parser.compile_filter(bits[1])
     1002    name = bits[3]
     1003    nodelist = parser.parse(('endwith',))
     1004    parser.delete_first_token()
     1005    return WithNode(var, name, nodelist)
     1006do_with = register.tag('with', do_with)
  • docs/templates.txt

     
    878878above example will be 88 pixels wide (because 175/200 = .875; .875 * 100 = 87.5
    879879which is rounded up to 88).
    880880
     881with
     882~~~~
     883
     884**New in Django development version**
     885
     886Useful for caching a method which will be used more than once.
     887
     888For example::
     889
     890    {% with person.some_sql_method as total %}
     891        {{ total }} person object{{ total|pluralize }}
     892    {% endwith %}
     893
     894The populated variable (in the example above, ``total``) is only available
     895inside of ``{% with %}`` block.
     896
    881897Built-in filter reference
    882898-------------------------
    883899
  • tests/regressiontests/templates/tests.py

     
    650650            'widthratio09': ('{% widthratio a b %}', {'a':50,'b':100}, template.TemplateSyntaxError),
    651651            'widthratio10': ('{% widthratio a b 100.0 %}', {'a':50,'b':100}, template.TemplateSyntaxError),
    652652
     653            ### WITH TAG ########################################################
     654            'with01': ('{% with dict.key as key %}{{ key }}{% endwith %}', {'dict': {'key':50}}, '50'),
     655            'with02': ('{{ key }}{% with dict.key as key %}{{ key }}-{{ dict.key }}-{{ key }}{% endwith %}{{ key }}', {'dict': {'key':50}}, ('50-50-50', 'INVALID50-50-50INVALID')),
     656
    653657            ### NOW TAG ########################################################
    654658            # Simple case
    655659            'now01' : ('{% now "j n Y"%}', {}, str(datetime.now().day) + ' ' + str(datetime.now().month) + ' ' + str(datetime.now().year)),
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