Jinja supports extensions that can add extra filters, tests, globals or even extend the parser. The main motivation of extensions is to move often used code into a reusable class like adding support for internationalization.
Extensions are added to the Jinja environment at creation time. Once the environment is created additional extensions cannot be added. To add an extension pass a list of extension classes or import paths to the extensions
parameter of the Environment
constructor. The following example creates a Jinja environment with the i18n extension loaded:
jinja_env = Environment(extensions=['jinja2.ext.i18n'])
Import name: jinja2.ext.i18n
The i18n extension can be used in combination with gettext or Babel. When it’s enabled, Jinja provides a trans
statement that marks a block as translatable and calls gettext
.
After enabling, an application has to provide gettext
and ngettext
functions, either globally or when rendering. A _()
function is added as an alias to the gettext
function.
After enabling the extension, the environment provides the following additional methods:
jinja2.Environment.install_gettext_translations(translations, newstyle=False)
Installs a translation globally for the environment. The translations
object must implement gettext
and ngettext
(or ugettext
and ungettext
for Python 2). gettext.NullTranslations
, gettext.GNUTranslations
, and Babels Translations
are supported.
Changed in version 2.5: Added new-style gettext support.
jinja2.Environment.install_null_translations(newstyle=False)
Install no-op gettext functions. This is useful if you want to prepare the application for internationalization but don’t want to implement the full system yet.
Changed in version 2.5: Added new-style gettext support.
jinja2.Environment.install_gettext_callables(gettext, ngettext, newstyle=False)
Install the given gettext
and ngettext
callables into the environment. They should behave exactly like gettext.gettext()
and gettext.ngettext()
(or ugettext
and ungettext
for Python 2).
If newstyle
is activated, the callables are wrapped to work like newstyle callables. See New Style Gettext for more information.
New in version 2.5: Added new-style gettext support.
jinja2.Environment.uninstall_gettext_translations()
Uninstall the environment’s globally installed translation.
jinja2.Environment.extract_translations(source)
Extract localizable strings from the given template node or source.
For every string found this function yields a (lineno, function,
message)
tuple, where:
lineno
is the number of the line on which the string was found.function
is the name of the gettext
function used (if the string was extracted from embedded Python code).message
is the string itself (unicode
on Python 2), or a tuple of strings for functions with multiple arguments.If Babel is installed, see Babel Integration to extract the strings.
For a web application that is available in multiple languages but gives all the users the same language (for example, multilingual forum software installed for a French community), the translation may be installed when the environment is created.
translations = get_gettext_translations() env = Environment(extensions=["jinja2.ext.i18n"]) env.install_gettext_translations(translations)
The get_gettext_translations
function would return the translator for the current configuration, for example by using gettext.find
.
The usage of the i18n
extension for template designers is covered in the template documentation.
New in version 2.10.
Within {% trans %}
blocks, it can be useful to trim line breaks and whitespace so that the block of text looks like a simple string with single spaces in the translation file.
Linebreaks and surrounding whitespace can be automatically trimmed by enabling the ext.i18n.trimmed
policy.
New in version 2.5.
New style gettext calls are less to type, less error prone, and support autoescaping better.
You can use “new style” gettext calls by setting env.newstyle_gettext = True
or passing newstyle=True
to env.install_translations
. They are fully supported by the Babel extraction tool, but might not work as expected with other extraction tools.
With standard gettext
calls, string formatting is a separate step done with the |format
filter. This requires duplicating work for ngettext
calls.
{{ gettext("Hello, World!") }} {{ gettext("Hello, %(name)s!")|format(name=name) }} {{ ngettext( "%(num)d apple", "%(num)d apples", apples|count )|format(num=apples|count) }}
New style gettext
make formatting part of the call, and behind the scenes enforce more consistency.
{{ gettext("Hello, World!") }} {{ gettext("Hello, %(name)s!", name=name) }} {{ ngettext("%(num)d apple", "%(num)d apples", apples|count) }}
The advantages of newstyle gettext are:
|format
filter.%%
, such as 100%%
.|safe
if it has already been escaped.Import name: jinja2.ext.do
The “do” aka expression-statement extension adds a simple do
tag to the template engine that works like a variable expression but ignores the return value.
Import name: jinja2.ext.loopcontrols
This extension adds support for break
and continue
in loops. After enabling, Jinja provides those two keywords which work exactly like in Python.
Import name: jinja2.ext.with_
Changed in version 2.9: This extension is now built-in and no longer does anything.
Import name: jinja2.ext.autoescape
Changed in version 2.9: This extension was removed and is now built-in. Enabling the extension no longer does anything.
Import name: jinja2.ext.debug
Adds a {% debug %}
tag to dump the current context as well as the available filters and tests. This is useful to see what’s available to use in the template without setting up a debugger.
By writing extensions you can add custom tags to Jinja. This is a non-trivial task and usually not needed as the default tags and expressions cover all common use cases. The i18n extension is a good example of why extensions are useful. Another one would be fragment caching.
When writing extensions you have to keep in mind that you are working with the Jinja template compiler which does not validate the node tree you are passing to it. If the AST is malformed you will get all kinds of compiler or runtime errors that are horrible to debug. Always make sure you are using the nodes you create correctly. The API documentation below shows which nodes exist and how to use them.
The following example implements a cache
tag for Jinja by using the cachelib library:
from jinja2 import nodes from jinja2.ext import Extension class FragmentCacheExtension(Extension): # a set of names that trigger the extension. tags = {"cache"} def __init__(self, environment): super(FragmentCacheExtension, self).__init__(environment) # add the defaults to the environment environment.extend(fragment_cache_prefix="", fragment_cache=None) def parse(self, parser): # the first token is the token that started the tag. In our case # we only listen to ``'cache'`` so this will be a name token with # `cache` as value. We get the line number so that we can give # that line number to the nodes we create by hand. lineno = next(parser.stream).lineno # now we parse a single expression that is used as cache key. args = [parser.parse_expression()] # if there is a comma, the user provided a timeout. If not use # None as second parameter. if parser.stream.skip_if("comma"): args.append(parser.parse_expression()) else: args.append(nodes.Const(None)) # now we parse the body of the cache block up to `endcache` and # drop the needle (which would always be `endcache` in that case) body = parser.parse_statements(["name:endcache"], drop_needle=True) # now return a `CallBlock` node that calls our _cache_support # helper method on this extension. return nodes.CallBlock( self.call_method("_cache_support", args), [], [], body ).set_lineno(lineno) def _cache_support(self, name, timeout, caller): """Helper callback.""" key = self.environment.fragment_cache_prefix + name # try to load the block from the cache # if there is no fragment in the cache, render it and store # it in the cache. rv = self.environment.fragment_cache.get(key) if rv is not None: return rv rv = caller() self.environment.fragment_cache.add(key, rv, timeout) return rv
And here is how you use it in an environment:
from jinja2 import Environment from cachelib import SimpleCache env = Environment(extensions=[FragmentCacheExtension]) env.fragment_cache = SimpleCache()
Inside the template it’s then possible to mark blocks as cacheable. The following example caches a sidebar for 300 seconds:
{% cache 'sidebar', 300 %} <div class="sidebar"> ... </div> {% endcache %}
gettext
The following example demonstrates using Extension.filter_stream()
to parse calls to the _()
gettext function inline with static data without needing Jinja blocks.
<h1>_(Welcome)</h1> <p>_(This is a paragraph)</p>
It requires the i18n extension to be loaded and configured.
# -*- coding: utf-8 -*- import re from jinja2.exceptions import TemplateSyntaxError from jinja2.ext import Extension from jinja2.lexer import count_newlines from jinja2.lexer import Token _outside_re = re.compile(r"\\?(gettext|_)\(") _inside_re = re.compile(r"\\?[()]") class InlineGettext(Extension): """This extension implements support for inline gettext blocks:: <h1>_(Welcome)</h1> <p>_(This is a paragraph)</p> Requires the i18n extension to be loaded and configured. """ def filter_stream(self, stream): paren_stack = 0 for token in stream: if token.type != "data": yield token continue pos = 0 lineno = token.lineno while 1: if not paren_stack: match = _outside_re.search(token.value, pos) else: match = _inside_re.search(token.value, pos) if match is None: break new_pos = match.start() if new_pos > pos: preval = token.value[pos:new_pos] yield Token(lineno, "data", preval) lineno += count_newlines(preval) gtok = match.group() if gtok[0] == "\\": yield Token(lineno, "data", gtok[1:]) elif not paren_stack: yield Token(lineno, "block_begin", None) yield Token(lineno, "name", "trans") yield Token(lineno, "block_end", None) paren_stack = 1 else: if gtok == "(" or paren_stack > 1: yield Token(lineno, "data", gtok) paren_stack += gtok == ")" and -1 or 1 if not paren_stack: yield Token(lineno, "block_begin", None) yield Token(lineno, "name", "endtrans") yield Token(lineno, "block_end", None) pos = match.end() if pos < len(token.value): yield Token(lineno, "data", token.value[pos:]) if paren_stack: raise TemplateSyntaxError( "unclosed gettext expression", token.lineno, stream.name, stream.filename, )
Extensions always have to extend the jinja2.ext.Extension
class:
class jinja2.ext.Extension(environment)
Extensions can be used to add extra functionality to the Jinja template system at the parser level. Custom extensions are bound to an environment but may not store environment specific data on self
. The reason for this is that an extension can be bound to another environment (for overlays) by creating a copy and reassigning the environment
attribute.
As extensions are created by the environment they cannot accept any arguments for configuration. One may want to work around that by using a factory function, but that is not possible as extensions are identified by their import name. The correct way to configure the extension is storing the configuration values on the environment. Because this way the environment ends up acting as central configuration storage the attributes may clash which is why extensions have to ensure that the names they choose for configuration are not too generic. prefix
for example is a terrible name, fragment_cache_prefix
on the other hand is a good name as includes the name of the extension (fragment cache).
identifier
The identifier of the extension. This is always the true import name of the extension class and must not be changed.
If the extension implements custom tags this is a set of tag names the extension is listening for.
attr(name, lineno=None)
Return an attribute node for the current extension. This is useful to pass constants on extensions to generated template code.
self.attr('_my_attribute', lineno=lineno)
call_method(name, args=None, kwargs=None, dyn_args=None, dyn_kwargs=None, lineno=None)
Call a method of the extension. This is a shortcut for attr()
+ jinja2.nodes.Call
.
filter_stream(stream)
It’s passed a TokenStream
that can be used to filter tokens returned. This method has to return an iterable of Token
s, but it doesn’t have to return a TokenStream
.
parse(parser)
If any of the tags
matched this method is called with the parser as first argument. The token the parser stream is pointing at is the name token that matched. This method has to return one or a list of multiple nodes.
preprocess(source, name, filename=None)
This method is called before the actual lexing and can be used to preprocess the source. The filename
is optional. The return value must be the preprocessed source.
The parser passed to Extension.parse()
provides ways to parse expressions of different types. The following methods may be used by extensions:
class jinja2.parser.Parser(environment, source, name=None, filename=None, state=None)
This is the central parsing class Jinja uses. It’s passed to extensions and can be used to parse expressions or statements.
filename
The filename of the template the parser processes. This is not the load name of the template. For the load name see name
. For templates that were not loaded form the file system this is None
.
name
The load name of the template.
stream
The current TokenStream
fail(msg, lineno=None, exc=<class 'jinja2.exceptions.TemplateSyntaxError'>)
Convenience method that raises exc
with the message, passed line number or last line number as well as the current name and filename.
free_identifier(lineno=None)
Return a new free identifier as InternalName
.
parse_assign_target(with_tuple=True, name_only=False, extra_end_rules=None, with_namespace=False)
Parse an assignment target. As Jinja allows assignments to tuples, this function can parse all allowed assignment targets. Per default assignments to tuples are parsed, that can be disable however by setting with_tuple
to False
. If only assignments to names are wanted name_only
can be set to True
. The extra_end_rules
parameter is forwarded to the tuple parsing function. If with_namespace
is enabled, a namespace assignment may be parsed.
parse_expression(with_condexpr=True)
Parse an expression. Per default all expressions are parsed, if the optional with_condexpr
parameter is set to False
conditional expressions are not parsed.
parse_statements(end_tokens, drop_needle=False)
Parse multiple statements into a list until one of the end tokens is reached. This is used to parse the body of statements as it also parses template data if appropriate. The parser checks first if the current token is a colon and skips it if there is one. Then it checks for the block end and parses until if one of the end_tokens
is reached. Per default the active token in the stream at the end of the call is the matched end token. If this is not wanted drop_needle
can be set to True
and the end token is removed.
parse_tuple(simplified=False, with_condexpr=True, extra_end_rules=None, explicit_parentheses=False)
Works like parse_expression
but if multiple expressions are delimited by a comma a Tuple
node is created. This method could also return a regular expression instead of a tuple if no commas where found.
The default parsing mode is a full tuple. If simplified
is True
only names and literals are parsed. The no_condexpr
parameter is forwarded to parse_expression()
.
Because tuples do not require delimiters and may end in a bogus comma an extra hint is needed that marks the end of a tuple. For example for loops support tuples between for
and in
. In that case the extra_end_rules
is set to ['name:in']
.
explicit_parentheses
is true if the parsing was triggered by an expression in parentheses. This is used to figure out if an empty tuple is a valid expression or not.
class jinja2.lexer.TokenStream(generator, name, filename)
A token stream is an iterable that yields Token
s. The parser however does not iterate over it but calls next()
to go one token ahead. The current active token is stored as current
.
current
The current Token
.
__next__()
Go one token ahead and return the old one.
Use the built-in next()
instead of calling this directly.
property eos
Are we at the end of the stream?
expect(expr)
Expect a given token type and return it. This accepts the same argument as jinja2.lexer.Token.test()
.
look()
Look at the next token.
next_if(expr)
Perform the token test and return the token if it matched. Otherwise the return value is None
.
push(token)
Push a token back to the stream.
skip(n=1)
Got n tokens ahead.
skip_if(expr)
Like next_if()
but only returns True
or False
.
class jinja2.lexer.Token
Token class.
lineno
The line number of the token
type
The type of the token. This string is interned so you may compare it with arbitrary strings using the is
operator.
value
The value of the token.
test(expr)
Test a token against a token expression. This can either be a token type or 'token_type:token_value'
. This can only test against string values and types.
test_any(*iterable)
Test against multiple token expressions.
There is also a utility function in the lexer module that can count newline characters in strings:
jinja2.lexer.count_newlines(value)
Count the number of newline characters in the string. This is useful for extensions that filter a stream.
The AST (Abstract Syntax Tree) is used to represent a template after parsing. It’s build of nodes that the compiler then converts into executable Python code objects. Extensions that provide custom statements can return nodes to execute custom Python code.
The list below describes all nodes that are currently available. The AST may change between Jinja versions but will stay backwards compatible.
For more information have a look at the repr of jinja2.Environment.parse()
.
class jinja2.nodes.Node
Baseclass for all Jinja nodes. There are a number of nodes available of different types. There are four major types:
All nodes have fields and attributes. Fields may be other nodes, lists, or arbitrary values. Fields are passed to the constructor as regular positional arguments, attributes as keyword arguments. Each node has two attributes: lineno
(the line number of the node) and environment
. The environment
attribute is set at the end of the parsing process for all nodes automatically.
find(node_type)
Find the first node of a given type. If no such node exists the return value is None
.
find_all(node_type)
Find all the nodes of a given type. If the type is a tuple, the check is performed for any of the tuple items.
iter_child_nodes(exclude=None, only=None)
Iterates over all direct child nodes of the node. This iterates over all fields and yields the values of they are nodes. If the value of a field is a list all the nodes in that list are returned.
iter_fields(exclude=None, only=None)
This method iterates over all fields that are defined and yields (key, value)
tuples. Per default all fields are returned, but it’s possible to limit that to some fields by providing the only
parameter or to exclude some using the exclude
parameter. Both should be sets or tuples of field names.
set_ctx(ctx)
Reset the context of a node and all child nodes. Per default the parser will all generate nodes that have a ‘load’ context as it’s the most common one. This method is used in the parser to set assignment targets and other nodes to a store context.
set_environment(environment)
Set the environment for all nodes.
set_lineno(lineno, override=False)
Set the line numbers of the node and children.
class jinja2.nodes.Expr
Baseclass for all expressions.
as_const(eval_ctx=None)
Return the value of the expression as constant or raise Impossible
if this was not possible.
An EvalContext
can be provided, if none is given a default context is created which requires the nodes to have an attached environment.
Changed in version 2.4: the eval_ctx
parameter was added.
can_assign()
Check if it’s possible to assign something to this node.
class jinja2.nodes.BinExpr(left, right)
Baseclass for all binary expressions.
class jinja2.nodes.Add(left, right)
Add the left to the right node.
class jinja2.nodes.And(left, right)
Short circuited AND.
class jinja2.nodes.Div(left, right)
Divides the left by the right node.
class jinja2.nodes.FloorDiv(left, right)
Divides the left by the right node and truncates conver the result into an integer by truncating.
class jinja2.nodes.Mod(left, right)
Left modulo right.
class jinja2.nodes.Mul(left, right)
Multiplies the left with the right node.
class jinja2.nodes.Or(left, right)
Short circuited OR.
class jinja2.nodes.Pow(left, right)
Left to the power of right.
class jinja2.nodes.Sub(left, right)
Subtract the right from the left node.
class jinja2.nodes.Call(node, args, kwargs, dyn_args, dyn_kwargs)
Calls an expression. args
is a list of arguments, kwargs
a list of keyword arguments (list of Keyword
nodes), and dyn_args
and dyn_kwargs
has to be either None
or a node that is used as node for dynamic positional (*args
) or keyword (**kwargs
) arguments.
class jinja2.nodes.Compare(expr, ops)
Compares an expression with some other expressions. ops
must be a list of Operand
s.
class jinja2.nodes.Concat(nodes)
Concatenates the list of expressions provided after converting them to unicode.
class jinja2.nodes.CondExpr(test, expr1, expr2)
A conditional expression (inline if expression). ({{
foo if bar else baz }}
)
class jinja2.nodes.ContextReference
Returns the current template context. It can be used like a Name
node, with a 'load'
ctx and will return the current Context
object.
Here an example that assigns the current template name to a variable named foo
:
Assign(Name('foo', ctx='store'), Getattr(ContextReference(), 'name'))
This is basically equivalent to using the contextfunction()
decorator when using the high-level API, which causes a reference to the context to be passed as the first argument to a function.
class jinja2.nodes.DerivedContextReference
Return the current template context including locals. Behaves exactly like ContextReference
, but includes local variables, such as from a for
loop.
New in version 2.11.
class jinja2.nodes.EnvironmentAttribute(name)
Loads an attribute from the environment object. This is useful for extensions that want to call a callback stored on the environment.
class jinja2.nodes.ExtensionAttribute(identifier, name)
Returns the attribute of an extension bound to the environment. The identifier is the identifier of the Extension
.
This node is usually constructed by calling the attr()
method on an extension.
class jinja2.nodes.Filter(node, name, args, kwargs, dyn_args, dyn_kwargs)
This node applies a filter on an expression. name
is the name of the filter, the rest of the fields are the same as for Call
.
If the node
of a filter is None
the contents of the last buffer are filtered. Buffers are created by macros and filter blocks.
class jinja2.nodes.Getattr(node, attr, ctx)
Get an attribute or item from an expression that is a ascii-only bytestring and prefer the attribute.
class jinja2.nodes.Getitem(node, arg, ctx)
Get an attribute or item from an expression and prefer the item.
class jinja2.nodes.ImportedName(importname)
If created with an import name the import name is returned on node access. For example ImportedName('cgi.escape')
returns the escape
function from the cgi module on evaluation. Imports are optimized by the compiler so there is no need to assign them to local variables.
class jinja2.nodes.InternalName(name)
An internal name in the compiler. You cannot create these nodes yourself but the parser provides a free_identifier()
method that creates a new identifier for you. This identifier is not available from the template and is not threated specially by the compiler.
class jinja2.nodes.Literal
Baseclass for literals.
class jinja2.nodes.Const(value)
All constant values. The parser will return this node for simple constants such as 42
or "foo"
but it can be used to store more complex values such as lists too. Only constants with a safe representation (objects where eval(repr(x)) == x
is true).
class jinja2.nodes.Dict(items)
Any dict literal such as {1: 2, 3: 4}
. The items must be a list of Pair
nodes.
class jinja2.nodes.List(items)
Any list literal such as [1, 2, 3]
class jinja2.nodes.TemplateData(data)
A constant template string.
class jinja2.nodes.Tuple(items, ctx)
For loop unpacking and some other things like multiple arguments for subscripts. Like for Name
ctx
specifies if the tuple is used for loading the names or storing.
class jinja2.nodes.MarkSafe(expr)
Mark the wrapped expression as safe (wrap it as Markup
).
class jinja2.nodes.MarkSafeIfAutoescape(expr)
Mark the wrapped expression as safe (wrap it as Markup
) but only if autoescaping is active.
New in version 2.5.
class jinja2.nodes.Name(name, ctx)
Looks up a name or stores a value in a name. The ctx
of the node can be one of the following values:
store
: store a value in the nameload
: load that nameparam
: like store
but if the name was defined as function parameter.class jinja2.nodes.NSRef(name, attr)
Reference to a namespace value assignment
class jinja2.nodes.Slice(start, stop, step)
Represents a slice object. This must only be used as argument for Subscript
.
class jinja2.nodes.Test(node, name, args, kwargs, dyn_args, dyn_kwargs)
Applies a test on an expression. name
is the name of the test, the rest of the fields are the same as for Call
.
class jinja2.nodes.UnaryExpr(node)
Baseclass for all unary expressions.
class jinja2.nodes.Neg(node)
Make the expression negative.
class jinja2.nodes.Not(node)
Negate the expression.
class jinja2.nodes.Pos(node)
Make the expression positive (noop for most expressions)
class jinja2.nodes.Helper
Nodes that exist in a specific context only.
class jinja2.nodes.Keyword(key, value)
A key, value pair for keyword arguments where key is a string.
class jinja2.nodes.Operand(op, expr)
Holds an operator and an expression. The following operators are available: %
, **
, *
, +
, -
, //
, /
, eq
, gt
, gteq
, in
, lt
, lteq
, ne
, not
, notin
class jinja2.nodes.Pair(key, value)
A key, value pair for dicts.
class jinja2.nodes.Stmt
Base node for all statements.
class jinja2.nodes.Assign(target, node)
Assigns an expression to a target.
class jinja2.nodes.AssignBlock(target, filter, body)
Assigns a block to a target.
class jinja2.nodes.Block(name, body, scoped)
A node that represents a block.
class jinja2.nodes.Break
Break a loop.
class jinja2.nodes.CallBlock(call, args, defaults, body)
Like a macro without a name but a call instead. call
is called with the unnamed macro as caller
argument this node holds.
class jinja2.nodes.Continue
Continue a loop.
class jinja2.nodes.EvalContextModifier(options)
Modifies the eval context. For each option that should be modified, a Keyword
has to be added to the options
list.
Example to change the autoescape
setting:
EvalContextModifier(options=[Keyword('autoescape', Const(True))])
class jinja2.nodes.ScopedEvalContextModifier(options, body)
Modifies the eval context and reverts it later. Works exactly like EvalContextModifier
but will only modify the EvalContext
for nodes in the body
.
class jinja2.nodes.ExprStmt(node)
A statement that evaluates an expression and discards the result.
class jinja2.nodes.Extends(template)
Represents an extends statement.
class jinja2.nodes.FilterBlock(body, filter)
Node for filter sections.
class jinja2.nodes.For(target, iter, body, else_, test, recursive)
The for loop. target
is the target for the iteration (usually a Name
or Tuple
), iter
the iterable. body
is a list of nodes that are used as loop-body, and else_
a list of nodes for the else
block. If no else node exists it has to be an empty list.
For filtered nodes an expression can be stored as test
, otherwise None
.
class jinja2.nodes.FromImport(template, names, with_context)
A node that represents the from import tag. It’s important to not pass unsafe names to the name attribute. The compiler translates the attribute lookups directly into getattr calls and does not use the subscript callback of the interface. As exported variables may not start with double underscores (which the parser asserts) this is not a problem for regular Jinja code, but if this node is used in an extension extra care must be taken.
The list of names may contain tuples if aliases are wanted.
class jinja2.nodes.If(test, body, elif_, else_)
If test
is true, body
is rendered, else else_
.
class jinja2.nodes.Import(template, target, with_context)
A node that represents the import tag.
class jinja2.nodes.Include(template, with_context, ignore_missing)
A node that represents the include tag.
class jinja2.nodes.Macro(name, args, defaults, body)
A macro definition. name
is the name of the macro, args
a list of arguments and defaults
a list of defaults if there are any. body
is a list of nodes for the macro body.
class jinja2.nodes.Output(nodes)
A node that holds multiple expressions which are then printed out. This is used both for the print
statement and the regular template data.
class jinja2.nodes.OverlayScope(context, body)
An overlay scope for extensions. This is a largely unoptimized scope that however can be used to introduce completely arbitrary variables into a sub scope from a dictionary or dictionary like object. The context
field has to evaluate to a dictionary object.
Example usage:
OverlayScope(context=self.call_method('get_context'), body=[...])
New in version 2.10.
class jinja2.nodes.Scope(body)
An artificial scope.
class jinja2.nodes.With(targets, values, body)
Specific node for with statements. In older versions of Jinja the with statement was implemented on the base of the Scope
node instead.
New in version 2.9.3.
class jinja2.nodes.Template(body)
Node that represents a template. This must be the outermost node that is passed to the compiler.
exception jinja2.nodes.Impossible
Raised if the node could not perform a requested action.
© 2007–2020 Pallets
Licensed under the BSD 3-clause License.
https://jinja.palletsprojects.com/en/2.11.x/extensions/