django-tag-parser 3.2

参数和关键字参数

要解析类似

{% my_tag "arg1" keyword1="bar" keyword2="foo" %}

的语法

from django.template import Library
from tag_parser.basetags import BaseNode

register = Library()


@register.tag('my_tag')
class MyTagNode(BaseNode):
    max_args = 1
    allowed_kwargs = ('keyword1', 'keyword2',)

    def render_tag(self, context, *tag_args, **tag_kwargs):
        return "Tag Output"

包含标签

要创建具有可覆盖的template_name的包含标签

{% my_include_tag "foo" template="custom/example.html" %}

的语法

from django.template import Library
from tag_parser.basetags import BaseInclusionNode

register = Library()

@register.tag("my_include_tag")
class MyIncludeTag(BaseInclusionNode):
    template_name = "mytags/default.html"
    max_args = 1

    def get_context_data(self, parent_context, *tag_args, **tag_kwargs):
        (foo,) = *tag_args
        return {
            'foo': foo
        }

可以覆盖get_template_name()方法以支持动态解析模板名称。默认情况下，它检查template标签关键字参数和template_name属性。请注意，模板节点之后将被缓存，每次调用时不能返回随机的模板。

赋值标签

要创建可以自我渲染或返回上下文数据的赋值标签

{% get_tags template="custom/example.html" %}
{% get_tags as popular_tags %}

的语法

from django.template import Library
from tag_parser.basetags import BaseAssignmentOrInclusionNode

register = Library()


@register.tag('get_tags')
class GetPopularTagsNode(BaseAssignmentOrInclusionNode):
    template_name = "myblog/templatetags/popular_tags.html"
    context_value_name = 'tags'
    allowed_kwargs = (
        'order', 'orderby', 'limit',
    )

    def get_value(self, context, *tag_args, **tag_kwargs):
        return query_tags(**tag_kwargs)   # Something that reads the tags.

块标签

要有一个“开始..结束”块，在类中定义end_tag_name

{% my_tag keyword1=foo %}
    Tag contents, possibly other tags.
{% end_my_tag %}

的语法

from django.template import Library
from tag_parser.basetags import BaseAssignmentOrInclusionNode

register = Library()


@register.tag('my_tag')
class MyTagNode(BaseNode):
    max_args = 1
    allowed_kwargs = ('keyword1', 'keyword2',)
    end_tag_name = 'end_my_tag'

    def render_tag(self, context, *tag_args, **tag_kwargs):
        # Render contents inside
        return self.nodelist.render(context)

自定义解析

使用Django的标准Node类，可以更容易地实现自定义语法。例如，要解析

{% getfirstof val1 val2 as val3 %}

的语法

from django.template import Library, Node, TemplateSyntaxError
from tag_parser import parse_token_kwargs, parse_as_var

register = Library()


@register.tag('getfirstof')
class GetFirstOfNode(Node):
    def __init__(self, options, as_var):
        self.options = options    # list of FilterExpression nodes.
        self.as_var = as_var

    @classmethod
    def parse(cls, parser, token):
        bits, as_var = parse_as_var(parser, token)
        tag_name, options, _ = parse_token_kwargs(parser, bits, allowed_kwargs=())

        if as_var is None or not choices:
            raise TemplateSyntaxError("Expected syntax: {{% {0} val1 val2 as val %}}".format(tag_name))

        return cls(options, as_var)

    def render(self, context):
        value = None
        for filterexpr in self.options:
            # The ignore_failures argument prevents that the value becomes TEMPLATE_STRING_IF_INVALID.
            value = filterexpr.resolve(context, ignore_failures=True)
            if value is not None:
                break

        context[self.as_var] = value
        return ''

贡献

本模块旨在通用。如果对它有任何不满，或者认为它不够灵活，请告诉我们。我们很高兴改进它！

如果您有任何其他有价值的贡献、建议或想法，也请告诉我们，因为我们将会考虑。我们也欢迎pull requests。:-)