IfChangedNode

Fields

Attribute	Type	Defined in
`__dict__`	`getset_descriptor`	django.template.base.Node
`__weakref__`	`getset_descriptor`	django.template.base.Node

Attributes

Attribute	Value	Defined in
`child_nodelists`	`('nodelist_true', 'nodelist_false')`	django.template.defaulttags.IfChangedNode
`child_nodelists`	`('nodelist',)`	django.template.base.Node
`must_be_first`	`False`	django.template.base.Node
`token`	`None`	django.template.base.Node

Methods

def __init__(self, nodelist_true, nodelist_false, *varlist)

django.template.defaulttags.IfChangedNode

Initialize self.  See help(type(self)) for accurate signature.

    def __init__(self, nodelist_true, nodelist_false, *varlist):
        self.nodelist_true = nodelist_true
        self.nodelist_false = nodelist_false
        self._varlist = varlist

def get_nodes_by_type(self, nodetype)

django.template.base.Node

Return a list of all nodes (within this node and its nodelist)
of the given type

    def get_nodes_by_type(self, nodetype):
        """
        Return a list of all nodes (within this node and its nodelist)
        of the given type
        """
        nodes = []
        if isinstance(self, nodetype):
            nodes.append(self)
        for attr in self.child_nodelists:
            nodelist = getattr(self, attr, None)
            if nodelist:
                nodes.extend(nodelist.get_nodes_by_type(nodetype))
        return nodes

def render(self, context)

django.template.defaulttags.IfChangedNode

Return the node rendered as a string.

    def render(self, context):
        # Init state storage
        state_frame = self._get_context_stack_frame(context)
        state_frame.setdefault(self)

        nodelist_true_output = None
        if self._varlist:
            # Consider multiple parameters. This behaves like an OR evaluation
            # of the multiple variables.
            compare_to = [
                var.resolve(context, ignore_failures=True) for var in self._varlist
            ]
        else:
            # The "{% ifchanged %}" syntax (without any variables) compares
            # the rendered output.
            compare_to = nodelist_true_output = self.nodelist_true.render(context)

        if compare_to != state_frame[self]:
            state_frame[self] = compare_to
            # render true block if not already rendered
            return nodelist_true_output or self.nodelist_true.render(context)
        elif self.nodelist_false:
            return self.nodelist_false.render(context)
        return ""

django.template.base.Node

Return the node rendered as a string.

    def render(self, context):
        """
        Return the node rendered as a string.
        """
        pass

def render_annotated(self, context)

django.template.base.Node

Render the node. If debug is True and an exception occurs during
rendering, the exception is annotated with contextual line information
where it occurred in the template. For internal usage this method is
preferred over using the render method directly.

    def render_annotated(self, context):
        """
        Render the node. If debug is True and an exception occurs during
        rendering, the exception is annotated with contextual line information
        where it occurred in the template. For internal usage this method is
        preferred over using the render method directly.
        """
        try:
            return self.render(context)
        except Exception as e:
            if context.template.engine.debug:
                # Store the actual node that caused the exception.
                if not hasattr(e, "_culprit_node"):
                    e._culprit_node = self
                if (
                    not hasattr(e, "template_debug")
                    and context.render_context.template.origin == e._culprit_node.origin
                ):
                    e.template_debug = (
                        context.render_context.template.get_exception_info(
                            e,
                            e._culprit_node.token,
                        )
                    )
            raise

class IfChangedNode

Ancestors (MRO)

Fields

Attributes

Methods