Mercurial > genshi > genshi-test
comparison doc/text-templates.txt @ 429:6911f3c5a7e8
Updated docs for code blocks and changed error handling.
| author | cmlenz |
|---|---|
| date | Thu, 22 Mar 2007 17:00:09 +0000 |
| parents | ebc7c1a3bc4d |
| children | ff7c72b52fb2 |
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| 428:540dd825d072 | 429:6911f3c5a7e8 |
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| 90 >>> from genshi.template import TextTemplate | 90 >>> from genshi.template import TextTemplate |
| 91 >>> tmpl = TextTemplate('${dict.foo}') | 91 >>> tmpl = TextTemplate('${dict.foo}') |
| 92 >>> print tmpl.generate(dict={'foo': 'bar'}) | 92 >>> print tmpl.generate(dict={'foo': 'bar'}) |
| 93 bar | 93 bar |
| 94 | 94 |
| 95 Another difference is that you can access variables that are not defined, and | 95 Because there are two ways to access either attributes or items, expressions |
| 96 won't get a ``NameError`` exception:: | 96 do not raise the standard ``AttributeError`` or ``IndexError`` exceptions, but |
| 97 | 97 rather an exception of the type ``UndefinedError``. The same kind of error is |
| 98 >>> from genshi.template import TextTemplate | 98 raised when you try to access a top-level variable that is not in the context |
| 99 >>> tmpl = TextTemplate('${doh}') | 99 data. |
| 100 >>> print tmpl.generate() | 100 |
| 101 <BLANKLINE> | 101 Built-in Functions & Types |
| 102 | 102 ========================== |
| 103 You **will** however get a ``NameError`` if you try to call an undefined | 103 |
| 104 variable, or do anything else with it, such as accessing its attributes. If you | 104 The following functions and types are available by default in template code, in |
| 105 need to know whether a variable is defined, you can check its type against the | 105 addition to the standard built-ins that are available to all Python code. |
| 106 ``Undefined`` class, for example in an `#if`_ directive:: | 106 |
| 107 | 107 ``defined(name)`` |
| 108 >>> from genshi.template import TextTemplate | 108 ----------------- |
| 109 >>> tmpl = TextTemplate('${type(doh) is Undefined}') | 109 |
| 110 >>> print tmpl.generate() | 110 This function determines whether a variable of the specified name exists in |
| 111 True | 111 the context data, and returns ``True`` if it does. |
| 112 | |
| 113 ``value_of(name, default=None)`` | |
| 114 -------------------------------- | |
| 115 | |
| 116 This function returns the value of the variable with the specified name if | |
| 117 such a variable is defined, and returns the value of the ``default`` | |
| 118 parameter if no such variable is defined. | |
| 119 | |
| 120 ``Markup(text)`` | |
| 121 ---------------- | |
| 122 | |
| 123 The ``Markup`` type marks a given string as being safe for inclusion in markup, | |
| 124 meaning it will *not* be escaped in the serialization stage. Use this with care, | |
| 125 as not escaping a user-provided string may allow malicious users to open your | |
| 126 web site to cross-site scripting attacks. | |
| 112 | 127 |
| 113 | 128 |
| 114 .. _`directives`: | 129 .. _`directives`: |
| 115 | 130 |
| 116 ------------------- | 131 ------------------- |