Usage

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There are two usage scenarios:

Filter modules enabled for mod_xml2enc

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Modules such as mod_proxy_html version 3.1 and up use the xml2enc_charset optional function to retrieve the charset argument to pass to the libxml2 parser, and may use the xml2enc_filter optional function to postprocess to another encoding. Using mod_xml2enc with an enabled module, no configuration is necessary: the other module will configure mod_xml2enc for you (though you may still want to customise it using the configuration directives below).

Non-enabled modules

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To use it with a libxml2-based module that isn't explicitly enabled for mod_xml2enc, you will have to configure the filter chain yourself. For example, to use it with mod_publisher to improve the latter's i18n support with HTML and XML, you could use

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FilterProvider iconv    xml2enc Content-Type $text/html

FilterProvider iconv    xml2enc Content-Type $xml

FilterProvider markup   markup-publisher Content-Type $text/html

FilterProvider markup   markup-publisher Content-Type $xml

FilterChain iconv markup

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mod_publisher will now support any character set supported by either (or both) of libxml2 or apr_xlate/iconv.

Programming API

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Programmers writing libxml2-based filter modules are encouraged to enable them for mod_xml2enc, to provide strong i18n support for your users without reinventing the wheel. The programming API is exposed in mod_xml2enc.h, and a usage example is mod_proxy_html.

Configuration

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The following configuration directives are available:

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xml2EncDefault

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    Syntax xml2EncDefault name

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    This defines the default encoding to assume when absolutely no charset information is available from the backend server. The default value for this is ISO-8859-1, as specified in HTTP/1.0 and assumed in earlier modules.

xml2EncAlias

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    Syntax xml2EncAlias charset alias [alias ...]

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    This server-wide directive aliases one or more charset to another charset. This enables encodings not recognised by libxml2 to be handled internally by libxml2's charset support using the translation table for a recognised charset. This serves two purposes: to support character sets (or names) not recognised either by libxml2 or iconv, and to skip conversion for a charset where it is known to be unnecessary.

xml2StartParse

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    Syntax xml2StartParse element [elt*]

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    Specify that the markup parser should start at the first instance of any of the elements specified. This can be used where a broken backend inserts leading junk that messes up the parser (example here). It should never be used for XML, nor well-formed HTML.

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Post-Processing

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There is currently no direct way to configure post-processing. Another module can invoke post-processing to output a desired character set, but a system administrator cannot do so directly.

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