Chameleon 2.0-rc14

Fast HTML/XML Template Compiler.

Overview

Chameleon is an HTML/XML template engine for Python. It uses the page templates language.

You can use it in any Python web application with just about any version of Python (2.5 and up, including 3.x and pypy).

Visit the website for more information or the documentation.

License and Copyright

This software is made available as-is under a BSD-like license [1] (see included copyright notice).

Notes

[1]

This software is licensed under the Repoze license.

Changes

2.0-rc14 (2011-07-13)

Bugfixes:

• The tab character (\t) is now parsed correctly when used inside tags.

Features:

• The RepeatDict class now works as a proxy behind a seperate dictionary instance.

• Added template constructor option keep_body which is a flag (also available as a class attribute) that controls whether to save the template body input in the body attribute.

  This is disabled by default, unless debug-mode is enabled.

• The page template loader class now accepts an optional formats argument which can be used to select an alternative template class.

2.0-rc13 (2011-07-07)

Bugfixes:

• The backslash character (followed by optional whitespace and a line break) was not correctly interpreted as a continuation for Python expressions.

Features:

• The Python expression implementation is now more flexible for external subclassing via a new parse method.

2.0-rc12 (2011-07-04)

Bugfixes:

• Initial keyword arguments passed to a template now no longer “leak” into the template variable space after a macro call.

• An unexpected end tag is now an unrecoverable error.

Features:

• Improve exception output.

2.0-rc11 (2011-05-26)

Bugfixes:

• Fixed issue where variable names that begin with an underscore were seemingly allowed, but their use resulted in a compiler error.

Features:

• Template variable names are now allowed to be prefixed with a single underscore, but not two or more (reserved for internal use).

  Examples of valid names:

  item
  ITEM
  _item
  camelCase
  underscore_delimited
  help

• Added support for Genshi’s comment “drop” syntax:

  <!--! This comment will be dropped -->

  Note the additional exclamation (!) character.

  This fixes addresses issue #10.

2.0-rc10 (2011-05-24)

Bugfixes:

• The tal:attributes statement now correctly operates case-insensitive. The attribute name given in the statement will replace an existing attribute with the same name, without respect to case.

Features:

• Added meta:interpolation statement to control expression interpolation setting.

  Strings that disable the setting: "off" and "false". Strings that enable the setting: "on" and "true".

• Expression interpolation now works inside XML comments.

2.0-rc9 (2011-05-05)

Features:

• Better debugging support for string decode and conversion. If a naive join fails, each element in the output will now be attempted coerced to unicode to try and trigger the failure near to the bad string.

2.0-rc8 (2011-04-11)

Bugfixes:

• If a macro defines two slots with the same name, a caller will now fill both with a single usage.

• If a valid of None is provided as the translation function argument, we now fall back to the class default.

2.0-rc7 (2011-03-29)

Bugfixes:

• Fixed issue with Python 2.5 compatibility AST. This affected at least PyPy 1.4.

Features:

• The auto_reload setting now defaults to the class value; the base template class gives a default value of chameleon.config.AUTO_RELOAD. This change allows a subclass to provide a custom default value (such as an application-specific debug mode setting).

2.0-rc6 (2011-03-19)

Features:

• Added support for target_language keyword argument to render method. If provided, the argument will be curried onto the translation function.

Bugfixes:

• The HTML entities ‘lt’, ‘gt’ and ‘quot’ appearing inside content subtition expressions are now translated into their native character values. This fixes an issue where you could not dynamically create elements using the structure (which is possible in ZPT). The need to create such structure stems from the lack of an expression interpolation operator in ZPT.

• Fixed duplicate file pointer issue with test suite (affected Windows platforms only). This fixes issue #9. [oliora]

• Use already open file using os.fdopen when trying to write out the module source. This fixes LP #731803.

2.0-rc5 (2011-03-07)

Bugfixes:

• Fixed a number of issues concerning the escaping of attribute values:

  1. Static attribute values are now included as they appear in the source.

     This means that invalid attribute values such as "true && false" are now left alone. It’s not the job of the template engine to correct such markup, at least not in the default mode of operation.

  2. The string expression compiler no longer unescapes values. Instead, this is left to each expression compiler. Currently only the Python expression compiler unescapes its input.

  3. The dynamic escape code sequence now correctly only replaces ampersands that are part of an HTML escape format.

Imports:

• The page template classes and the loader class can now be imported directly from the chameleon module.

Features:

• If a custom template loader is not provided, relative paths are now resolved using os.abspath (i.e. to the current working directory).

• Absolute paths are normalized using os.path.normpath and os.path.expanduser. This ensures that all paths are kept in their “canonical” form.

2.0-rc4 (2011-03-03)

Bugfixes:

• Fixed an issue where the output of an end-to-end string expression would raise an exception if the expression evaluated to None (it should simply output nothing).

• The convert function (which is configurable on the template class level) now defaults to the translate function (at run-time).

  This fixes an issue where message objects were not translated (and thus converted to a string) using the a provided translate function.

• Fixed string interpolation issue where an expression immediately succeeded by a right curly bracket would not parse.

  This fixes issue #5.

• Fixed error where tal:condition would be evaluated after tal:repeat.

Features:

• Python expression is now a TALES expression. That means that the pipe operator can be used to chain two or more expressions in a try-except sequence.

  This behavior was ported from the 1.x series. Note that while it’s still possible to use the pipe character (“|”) in an expression, it must now be escaped.

• The template cache can now be shared by multiple processes.

2.0-rc3 (2011-03-02)

Bugfixes:

• Fixed atexit handler.

  This fixes issue #3.

• If a cache directory is specified, it will now be used even when not in debug mode.

• Allow “comment” attribute in the TAL namespace.

  This fixes an issue in the sense that the reference engine allows any attribute within the TAL namespace. However, only “comment” is in common use.

• The template constructor now accepts a flag debug which puts the template instance into debug-mode regardless of the global setting.

  This fixes issue #1.

Features:

• Added exception handler for exceptions raised while evaluating an expression.

  This handler raises (or attempts to) a new exception of the type RenderError, with an additional base class of the original exception class. The string value of the exception is a formatted error message which includes the expression that caused the exception.

  If we are unable to create the exception class, the original exception is re-raised.

2.0-rc2 (2011-02-28)

• Fixed upload issue.

2.0-rc1 (2011-02-28)

• Initial public release. See documentation for what’s new in this series.