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