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package xml-light
Xml Light DTD
This module provide several functions to create, check, and use DTD to prove Xml documents :
- using the DTD types, you can directly create your own DTD structure
- the
Dtd.checkfunction can then be used to check that all DTD states have been declared, that no attributes are declared twice, and so on. - the
Dtd.provefunction can be used to check anXmldata structure with a checked DTD. The function will return the expanded Xml document or raise an exception if the DTD proving fails.
Note about ENTITIES:
While parsing Xml, PCDATA is always parsed and the Xml entities & > < ' " are replaced by their corresponding ASCII characters. For Xml attributes, theses can be put between either double or simple quotes, and the backslash character can be used to escape inner quotes. There is no support for CDATA Xml nodes or PCDATA attributes declarations in DTD, and no support for user-defined entities using the ENTITY DTD element.
type dtd_child = Xml_light_types.dtd_child = The DTD Types
type dtd_element_type = Xml_light_types.dtd_element_type = | DTDEmpty| DTDAny| DTDChild of dtd_child
type dtd_attr_default = Xml_light_types.dtd_attr_default = type dtd_attr_type = Xml_light_types.dtd_attr_type = type dtd_item = Xml_light_types.dtd_item = | DTDAttribute of string * string * dtd_attr_type * dtd_attr_default| DTDElement of string * dtd_element_type
type dtd = dtd_item listtype checked = Xml_light_dtd_check.checkedThe DTD Functions
val parse_file : string -> dtdParse the named file into a Dtd data structure. Raise Xml.File_not_found if an error occured while opening the file. Raise Dtd.Parse_error if parsing failed.
val parse_in : Stdlib.in_channel -> dtdRead the content of the in_channel and parse it into a Dtd data structure. Raise Dtd.Parse_error if parsing failed.
val parse_string : string -> dtdParse the string containing a Dtd document into a Dtd data structure. Raise Dtd.Parse_error if parsing failed.
Check the Dtd data structure declaration and return a checked DTD. Raise Dtd.Check_error if the DTD checking failed.
val prove : checked -> string -> Xml_light_types.xml -> Xml_light_types.xmlProve an Xml document using a checked DTD and an entry point. The entry point is the first excepted tag of the Xml document, the returned Xml document has the same structure has the original one, excepted that non declared optional attributes have been set to their default value specified in the DTD. Raise Dtd.Check_error ElementNotDeclared if the entry point is not found, raise Dtd.Prove_error if the Xml document failed to be proved with the DTD.
val to_string : dtd_item -> stringPrint a DTD element into a string. You can easily get a DTD document from a DTD data structure using for example String.concat "\n" (List.map Dtd.to_string) my_dtd
The DTD Exceptions
There is three types of DTD excecptions :
Dtd.Parse_erroris raised when an error occured while parsing a DTD document into a DTD data structure.Dtd.Check_erroris raised when an error occured while checking a DTD data structure for completeness, or when the prove entry point is not found when callingDtd.prove.Dtd.Prove_erroris raised when an error occured while proving an Xml document.
Several string conversion functions are provided to enable you to report errors to the user.
type parse_error_msg = Xml_light_errors.dtd_parse_error_msg = type check_error = Xml_light_errors.dtd_check_error = type prove_error = Xml_light_errors.dtd_prove_error = type parse_error = parse_error_msg * Xml_light_errors.error_posexception Parse_error of parse_errorexception Check_error of check_errorexception Prove_error of prove_errorval parse_error : parse_error -> stringval check_error : check_error -> stringval prove_error : prove_error -> stringOn This Page