Ticket #3523: for_tag.4.patch

File for_tag.4.patch, 7.9 KB (added by SmileyChris, 8 years ago)

small bug fix and tighter format checking

  • django/template/defaulttags.py

     
    6161        return ''
    6262
    6363class ForNode(Node):
    64     def __init__(self, loopvar, sequence, reversed, nodelist_loop):
    65         self.loopvar, self.sequence = loopvar, sequence
     64    def __init__(self, loopvars, sequence, reversed, nodelist_loop):
     65        self.loopvars, self.sequence = loopvars, sequence
    6666        self.reversed = reversed
    6767        self.nodelist_loop = nodelist_loop
    6868
     
    7272        else:
    7373            reversed = ''
    7474        return "<For Node: for %s in %s, tail_len: %d%s>" % \
    75             (self.loopvar, self.sequence, len(self.nodelist_loop), reversed)
     75            (', '.join( self.loopvars ), self.sequence, len(self.nodelist_loop), reversed)
    7676
    7777    def __iter__(self):
    7878        for node in self.nodelist_loop:
     
    107107                for index in range(len(data)-1, -1, -1):
    108108                    yield data[index]
    109109            values = reverse(values)
     110        unpack = len(loopvars) > 1
    110111        for i, item in enumerate(values):
    111112            context['forloop'] = {
    112113                # shortcuts for current loop iteration number
     
    120121                'last': (i == len_values - 1),
    121122                'parentloop': parentloop,
    122123            }
    123             context[self.loopvar] = item
     124            if unpack:
     125                # If multiple loop variables, unpack the item to them.
     126                context.update(dict(zip(self.loopvars, item)))
     127            else:
     128                context[self.loopvars[0]] = item
    124129            for node in self.nodelist_loop:
    125130                nodelist.append(node.render(context))
     131            if unpack:
     132                # The loop variables were pushed on to the context so pop them
     133                # off again. This is necessary because the tag lets the length
     134                # of loopvars differ to the length of each set of items and we
     135                # don't want to leave any vars from this previous loop on the
     136                # context.
     137                context.pop()
    126138        context.pop()
    127139        return nodelist.render(context)
    128140
     
    486498    nodelist = parser.parse(('endfilter',))
    487499    parser.delete_first_token()
    488500    return FilterNode(filter_expr, nodelist)
    489 filter = register.tag("filter", do_filter)
     501do_filter = register.tag("filter", do_filter)
    490502
    491503#@register.tag
    492504def firstof(parser, token):
     
    530542        {% endfor %}
    531543        </ul>
    532544
    533     You can also loop over a list in reverse by using
     545    You can loop over a list in reverse by using
    534546    ``{% for obj in list reversed %}``.
     547   
     548    You can also unpack multiple values from a two-dimensional array::
     549   
     550        {% for key,value in dict.items %}
     551            {{ key }}: {{ value }}
     552        {% endfor %}
    535553
    536554    The for loop sets a number of variables available within the loop:
    537555
     
    552570
    553571    """
    554572    bits = token.contents.split()
    555     if len(bits) == 5 and bits[4] != 'reversed':
    556         raise TemplateSyntaxError, "'for' statements with five words should end in 'reversed': %s" % token.contents
    557     if len(bits) not in (4, 5):
    558         raise TemplateSyntaxError, "'for' statements should have either four or five words: %s" % token.contents
    559     if bits[2] != 'in':
    560         raise TemplateSyntaxError, "'for' statement must contain 'in' as the second word: %s" % token.contents
    561     loopvar = bits[1]
    562     sequence = parser.compile_filter(bits[3])
    563     reversed = (len(bits) == 5)
     573    if len(bits) < 4:
     574        raise TemplateSyntaxError, "'for' statements should have at least four words: %s" % token.contents
     575
     576    reversed = bits[-1] == 'reversed'
     577    in_index = reversed and -3 or -2
     578    if bits[in_index] != 'in':
     579        raise TemplateSyntaxError, "'for' statements should use the format 'for x in y': %s" % token.contents
     580
     581    loopvars = ' '.join(bits[1:in_index]).replace(', ', ',').split(',')
     582    for var in loopvars:
     583        if not var or ' ' in var:
     584            raise TemplateSyntaxError, "'for' tag received an invalid argument: %s" % token.contents
     585
     586    sequence = parser.compile_filter(bits[in_index+1])
    564587    nodelist_loop = parser.parse(('endfor',))
    565588    parser.delete_first_token()
    566     return ForNode(loopvar, sequence, reversed, nodelist_loop)
     589    return ForNode(loopvars, sequence, reversed, nodelist_loop)
    567590do_for = register.tag("for", do_for)
    568591
    569592def do_ifequal(parser, token, negate):
  • docs/templates.txt

     
    444444~~~
    445445
    446446Loop over each item in an array.  For example, to display a list of athletes
    447 given ``athlete_list``::
     447provided in ``athlete_list``::
    448448
    449449    <ul>
    450450    {% for athlete in athlete_list %}
     
    452452    {% endfor %}
    453453    </ul>
    454454
    455 You can also loop over a list in reverse by using ``{% for obj in list reversed %}``.
     455You can loop over a list in reverse by using ``{% for obj in list reversed %}``.
    456456
     457For advanced use, you can unpack multiple values from a list of fixed length
     458lists. For example, to display the keys and values of a Python dictionary::
     459
     460    {% for key, value in dict.iteritems %}
     461        {{ key }}: {{ value }}
     462    {% endfor %}
     463
    457464The for loop sets a number of variables available within the loop:
    458465
    459466    ==========================  ================================================
  • tests/regressiontests/templates/tests.py

     
    289289            'for-tag-vars02': ("{% for val in values %}{{ forloop.counter0 }}{% endfor %}", {"values": [6, 6, 6]}, "012"),
    290290            'for-tag-vars03': ("{% for val in values %}{{ forloop.revcounter }}{% endfor %}", {"values": [6, 6, 6]}, "321"),
    291291            'for-tag-vars04': ("{% for val in values %}{{ forloop.revcounter0 }}{% endfor %}", {"values": [6, 6, 6]}, "210"),
     292            'for-tag-unpack01': ("{% for key,value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
     293            'for-tag-unpack02': ("{% for key, value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
     294            'for-tag-unpack03': ("{% for key value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, template.TemplateSyntaxError),
     295            'for-tag-unpack04': ("{% for key,,value in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, template.TemplateSyntaxError),
     296            'for-tag-unpack05': ("{% for key,value, in items %}{{ key }}:{{ value }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, template.TemplateSyntaxError),
     297            # Ensure that a single loopvar doesn't truncate the list in val.
     298            'for-tag-unpack06': ("{% for val in items %}{{ val.0 }}:{{ val.1 }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, "one:1/two:2/"),
     299            # Otherwise, silently truncate if the length of loopvars differs to the length of each set of items.
     300            'for-tag-unpack07': ("{% for x,y in items %}{{ x }}:{{ y }}/{% endfor %}", {"items": (('one', 1, 'carrot'), ('two', 2, 'orange'))}, "one:1/two:2/"),
     301            'for-tag-unpack08': ("{% 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/")),
     302            'for-tag-unpack09': ("{% 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/")),
    292303
    293304            ### IF TAG ################################################################
    294305            'if-tag01': ("{% if foo %}yes{% else %}no{% endif %}", {"foo": True}, "yes"),
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