mirror of
https://github.com/django/django.git
synced 2024-12-29 12:36:08 +00:00
0be14b0b96
git-svn-id: http://code.djangoproject.com/svn/django/trunk@14722 bcc190cf-cafb-0310-a4f2-bffc1f526a37
81 lines
3.2 KiB
Python
81 lines
3.2 KiB
Python
"""
|
|
This is the Django template system.
|
|
|
|
How it works:
|
|
|
|
The Lexer.tokenize() function converts a template string (i.e., a string containing
|
|
markup with custom template tags) to tokens, which can be either plain text
|
|
(TOKEN_TEXT), variables (TOKEN_VAR) or block statements (TOKEN_BLOCK).
|
|
|
|
The Parser() class takes a list of tokens in its constructor, and its parse()
|
|
method returns a compiled template -- which is, under the hood, a list of
|
|
Node objects.
|
|
|
|
Each Node is responsible for creating some sort of output -- e.g. simple text
|
|
(TextNode), variable values in a given context (VariableNode), results of basic
|
|
logic (IfNode), results of looping (ForNode), or anything else. The core Node
|
|
types are TextNode, VariableNode, IfNode and ForNode, but plugin modules can
|
|
define their own custom node types.
|
|
|
|
Each Node has a render() method, which takes a Context and returns a string of
|
|
the rendered node. For example, the render() method of a Variable Node returns
|
|
the variable's value as a string. The render() method of an IfNode returns the
|
|
rendered output of whatever was inside the loop, recursively.
|
|
|
|
The Template class is a convenient wrapper that takes care of template
|
|
compilation and rendering.
|
|
|
|
Usage:
|
|
|
|
The only thing you should ever use directly in this file is the Template class.
|
|
Create a compiled template object with a template_string, then call render()
|
|
with a context. In the compilation stage, the TemplateSyntaxError exception
|
|
will be raised if the template doesn't have proper syntax.
|
|
|
|
Sample code:
|
|
|
|
>>> from django import template
|
|
>>> s = u'<html>{% if test %}<h1>{{ varvalue }}</h1>{% endif %}</html>'
|
|
>>> t = template.Template(s)
|
|
|
|
(t is now a compiled template, and its render() method can be called multiple
|
|
times with multiple contexts)
|
|
|
|
>>> c = template.Context({'test':True, 'varvalue': 'Hello'})
|
|
>>> t.render(c)
|
|
u'<html><h1>Hello</h1></html>'
|
|
>>> c = template.Context({'test':False, 'varvalue': 'Hello'})
|
|
>>> t.render(c)
|
|
u'<html></html>'
|
|
"""
|
|
|
|
# Template lexing symbols
|
|
from django.template.base import (ALLOWED_VARIABLE_CHARS, BLOCK_TAG_END,
|
|
BLOCK_TAG_START, COMMENT_TAG_END, COMMENT_TAG_START,
|
|
FILTER_ARGUMENT_SEPARATOR, FILTER_SEPARATOR, SINGLE_BRACE_END,
|
|
SINGLE_BRACE_START, TOKEN_BLOCK, TOKEN_COMMENT, TOKEN_TEXT, TOKEN_VAR,
|
|
TRANSLATOR_COMMENT_MARK, UNKNOWN_SOURCE, VARIABLE_ATTRIBUTE_SEPARATOR,
|
|
VARIABLE_TAG_END, VARIABLE_TAG_START, filter_re, tag_re)
|
|
|
|
# Exceptions
|
|
from django.template.base import (ContextPopException, InvalidTemplateLibrary,
|
|
TemplateDoesNotExist, TemplateEncodingError, TemplateSyntaxError,
|
|
VariableDoesNotExist)
|
|
|
|
# Template parts
|
|
from django.template.base import (Context, FilterExpression, Lexer, Node,
|
|
NodeList, Parser, RequestContext, Origin, StringOrigin, Template,
|
|
TextNode, Token, TokenParser, Variable, VariableNode, constant_string,
|
|
filter_raw_string)
|
|
|
|
# Compiling templates
|
|
from django.template.base import (compile_string, resolve_variable,
|
|
unescape_string_literal, generic_tag_compiler)
|
|
|
|
# Library management
|
|
from django.template.base import (Library, add_to_builtins, builtins,
|
|
get_library, get_templatetags_modules, get_text_list, import_library,
|
|
libraries)
|
|
|
|
__all__ = ('Template', 'Context', 'RequestContext', 'compile_string')
|