hxt-8.0.0: doc/hdoc/src/Text-XML-HXT-Validator-ValidationFilter.html
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<pre><a name="line-1"></a><span class='comment'>-- |</span>
<a name="line-2"></a><span class='comment'>-- This module provides functions for validating XML documents represented as</span>
<a name="line-3"></a><span class='comment'>-- XmlTree.</span>
<a name="line-4"></a>
<a name="line-5"></a><span class='comment'>-- Unlike other popular XML validation tools the validation functions return</span>
<a name="line-6"></a><span class='comment'>-- a list of errors instead of aborting after the first error was found.</span>
<a name="line-7"></a><span class='comment'>-- </span>
<a name="line-8"></a><span class='comment'>-- Note: The validation process has been split into validation and transformation!</span>
<a name="line-9"></a><span class='comment'>-- If @validate@ did not report any errors, @transform@</span>
<a name="line-10"></a><span class='comment'>-- should be called, to change the document the way a validating parser</span>
<a name="line-11"></a><span class='comment'>-- is expected to do.</span>
<a name="line-12"></a>
<a name="line-13"></a><span class='comment'>--</span>
<a name="line-14"></a><span class='comment'>-- Author : .\\artin Schmidt</span>
<a name="line-15"></a><span class='comment'>-- Version : $Id: ValidationFilter.hs,v 1.1 2004/11/23 15:50:23 hxml Exp $</span>
<a name="line-16"></a>
<a name="line-17"></a><span class='keyword'>module</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Validator</span><span class='varop'>.</span><span class='conid'>ValidationFilter</span>
<a name="line-18"></a> <span class='layout'>(</span> <span class='varid'>getDTDSubset</span>
<a name="line-19"></a> <span class='layout'>,</span> <span class='varid'>validate</span>
<a name="line-20"></a> <span class='layout'>,</span> <span class='varid'>validateDTD</span>
<a name="line-21"></a> <span class='layout'>,</span> <span class='varid'>validateDoc</span>
<a name="line-22"></a> <span class='layout'>,</span> <span class='varid'>removeDoublicateDefs</span>
<a name="line-23"></a> <span class='layout'>,</span> <span class='varid'>transform</span>
<a name="line-24"></a> <span class='layout'>)</span>
<a name="line-25"></a>
<a name="line-26"></a><span class='keyword'>where</span>
<a name="line-27"></a>
<a name="line-28"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>DOM</span><span class='varop'>.</span><span class='conid'>XmlTree</span>
<a name="line-29"></a>
<a name="line-30"></a><span class='keyword'>import</span> <span class='keyword'>qualified</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Validator</span><span class='varop'>.</span><span class='conid'>DTDValidation</span> <span class='keyword'>as</span> <span class='conid'>DTDValidation</span>
<a name="line-31"></a><span class='keyword'>import</span> <span class='keyword'>qualified</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Validator</span><span class='varop'>.</span><span class='conid'>DocValidation</span> <span class='keyword'>as</span> <span class='conid'>DocValidation</span>
<a name="line-32"></a><span class='keyword'>import</span> <span class='keyword'>qualified</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Validator</span><span class='varop'>.</span><span class='conid'>IdValidation</span> <span class='keyword'>as</span> <span class='conid'>IdValidation</span>
<a name="line-33"></a><span class='keyword'>import</span> <span class='keyword'>qualified</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Validator</span><span class='varop'>.</span><span class='conid'>DocTransformation</span> <span class='keyword'>as</span> <span class='conid'>DocTransformation</span>
<a name="line-34"></a>
<a name="line-35"></a><span class='comment'>-- |</span>
<a name="line-36"></a><span class='comment'>-- Main validation filter. Check if the DTD and the document are valid.</span>
<a name="line-37"></a><span class='comment'>--</span>
<a name="line-38"></a><span class='comment'>--</span>
<a name="line-39"></a><span class='comment'>-- - returns : a function which expects a complete document as XmlTree input</span>
<a name="line-40"></a><span class='comment'>-- and returns a list of all errors found.</span>
<a name="line-41"></a>
<a name="line-42"></a><a name="validate"></a><span class='definition'>validate</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span>
<a name="line-43"></a><span class='definition'>validate</span> <span class='keyglyph'>=</span> <span class='varid'>validateDTD</span> <span class='varop'>+++</span> <span class='varid'>validateDoc</span>
<a name="line-44"></a>
<a name="line-45"></a><span class='comment'>-- |</span>
<a name="line-46"></a><span class='comment'>-- Check if the DTD is valid.</span>
<a name="line-47"></a><span class='comment'>--</span>
<a name="line-48"></a><span class='comment'>--</span>
<a name="line-49"></a><span class='comment'>-- - returns : a function which expects an XmlTree from the parser as input</span>
<a name="line-50"></a><span class='comment'>-- and returns a list of all errors found in the DTD.</span>
<a name="line-51"></a>
<a name="line-52"></a><a name="validateDTD"></a><span class='definition'>validateDTD</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span>
<a name="line-53"></a><span class='definition'>validateDTD</span>
<a name="line-54"></a> <span class='keyglyph'>=</span> <span class='varid'>choice</span> <span class='keyglyph'>[</span> <span class='varid'>getDTDSubset</span>
<a name="line-55"></a> <span class='conop'>:-></span> <span class='conid'>DTDValidation</span><span class='varop'>.</span><span class='varid'>validateDTD</span>
<a name="line-56"></a> <span class='layout'>,</span> <span class='varid'>this</span>
<a name="line-57"></a> <span class='conop'>:-></span> <span class='varid'>err</span> <span class='str'>"Can't validate DTD: There is no DOCTYPE declaration in the document."</span>
<a name="line-58"></a> <span class='keyglyph'>]</span>
<a name="line-59"></a><span class='comment'>-- |</span>
<a name="line-60"></a><span class='comment'>-- Check if the document corresponds to the given DTD.</span>
<a name="line-61"></a><span class='comment'>--</span>
<a name="line-62"></a><span class='comment'>--</span>
<a name="line-63"></a><span class='comment'>-- - returns : a function which expects a complete document as XmlTree input</span>
<a name="line-64"></a><span class='comment'>-- and returns a list of all errors found in the content part.</span>
<a name="line-65"></a>
<a name="line-66"></a><a name="validateDoc"></a><span class='definition'>validateDoc</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span>
<a name="line-67"></a><span class='definition'>validateDoc</span> <span class='varid'>t</span>
<a name="line-68"></a> <span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>if</span> <span class='varid'>null</span> <span class='varid'>dtds</span>
<a name="line-69"></a> <span class='keyword'>then</span> <span class='varid'>err</span> <span class='str'>"Can't validate document: There is no DOCTYPE declaration in the document."</span>
<a name="line-70"></a> <span class='keyword'>else</span> <span class='layout'>(</span> <span class='conid'>DocValidation</span><span class='varop'>.</span><span class='varid'>validateDoc</span> <span class='varid'>dtdPart</span>
<a name="line-71"></a> <span class='varop'>+++</span>
<a name="line-72"></a> <span class='conid'>IdValidation</span><span class='varop'>.</span><span class='varid'>validateIds</span> <span class='varid'>dtdPart</span>
<a name="line-73"></a> <span class='layout'>)</span>
<a name="line-74"></a> <span class='layout'>)</span> <span class='varop'>$</span> <span class='varid'>t</span>
<a name="line-75"></a> <span class='keyword'>where</span>
<a name="line-76"></a> <span class='varid'>dtds</span> <span class='keyglyph'>=</span> <span class='varid'>getDTDSubset</span> <span class='varop'>.></span> <span class='varid'>processBottomUp</span> <span class='varid'>removeDoublicateDefs</span> <span class='varop'>$</span> <span class='varid'>t</span>
<a name="line-77"></a> <span class='varid'>dtdPart</span> <span class='keyglyph'>=</span> <span class='varid'>head</span> <span class='varid'>dtds</span>
<a name="line-78"></a>
<a name="line-79"></a><span class='comment'>-- |</span>
<a name="line-80"></a><span class='comment'>-- filter for transforming a document with respect to the given DTD.</span>
<a name="line-81"></a><span class='comment'>--</span>
<a name="line-82"></a><span class='comment'>-- Validating parsers</span>
<a name="line-83"></a><span class='comment'>-- are expected to normalize attribute values and add default values.</span>
<a name="line-84"></a><span class='comment'>-- This function should be called after a successful validation.</span>
<a name="line-85"></a><span class='comment'>--</span>
<a name="line-86"></a><span class='comment'>--</span>
<a name="line-87"></a><span class='comment'>-- - returns : a function which expects a complete XML document tree</span>
<a name="line-88"></a><span class='comment'>-- and returns the transformed XmlTree</span>
<a name="line-89"></a>
<a name="line-90"></a><a name="transform"></a><span class='definition'>transform</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span>
<a name="line-91"></a><span class='definition'>transform</span>
<a name="line-92"></a> <span class='keyglyph'>=</span> <span class='varid'>choice</span> <span class='keyglyph'>[</span> <span class='varid'>isRoot</span>
<a name="line-93"></a> <span class='conop'>:-></span> <span class='varid'>transformDoc</span>
<a name="line-94"></a> <span class='layout'>,</span> <span class='varid'>this</span>
<a name="line-95"></a> <span class='conop'>:-></span> <span class='varid'>fatal</span> <span class='str'>"Can't transform document: No document root given"</span>
<a name="line-96"></a> <span class='keyglyph'>]</span>
<a name="line-97"></a> <span class='keyword'>where</span>
<a name="line-98"></a> <span class='varid'>transformDoc</span> <span class='varid'>t</span>
<a name="line-99"></a> <span class='keyglyph'>|</span> <span class='varid'>null</span> <span class='varid'>dtds</span>
<a name="line-100"></a> <span class='keyglyph'>=</span> <span class='varid'>this</span> <span class='varid'>t</span>
<a name="line-101"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span>
<a name="line-102"></a> <span class='keyglyph'>=</span> <span class='conid'>DocTransformation</span><span class='varop'>.</span><span class='varid'>transform</span> <span class='layout'>(</span><span class='varid'>head</span> <span class='varid'>dtds</span><span class='layout'>)</span> <span class='varid'>t</span>
<a name="line-103"></a> <span class='keyword'>where</span>
<a name="line-104"></a> <span class='varid'>dtds</span> <span class='keyglyph'>=</span> <span class='varid'>getDTDSubset</span> <span class='varop'>.></span> <span class='varid'>processBottomUp</span> <span class='varid'>removeDoublicateDefs</span> <span class='varop'>$</span> <span class='varid'>t</span>
<a name="line-105"></a>
<a name="line-106"></a><span class='comment'>-- |</span>
<a name="line-107"></a><span class='comment'>-- Removes doublicate declarations from the DTD which first declaration is</span>
<a name="line-108"></a><span class='comment'>-- binding. This is the case for ATTLIST and ENTITY declarations.</span>
<a name="line-109"></a><span class='comment'>--</span>
<a name="line-110"></a><span class='comment'>--</span>
<a name="line-111"></a><span class='comment'>-- - returns : A function that replaces the children of DOCTYPE nodes by a list</span>
<a name="line-112"></a><span class='comment'>-- where all multiple declarations are removed.</span>
<a name="line-113"></a>
<a name="line-114"></a><a name="removeDoublicateDefs"></a><span class='definition'>removeDoublicateDefs</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span>
<a name="line-115"></a><span class='definition'>removeDoublicateDefs</span>
<a name="line-116"></a> <span class='keyglyph'>=</span> <span class='conid'>DTDValidation</span><span class='varop'>.</span><span class='varid'>removeDoublicateDefs</span>
<a name="line-117"></a>
<a name="line-118"></a><span class='comment'>--</span>
<a name="line-119"></a><span class='comment'>-- selects the DTD part of a document</span>
<a name="line-120"></a><span class='comment'>-- but only, if there is more than the internal part for the 4 predefined XML entities</span>
<a name="line-121"></a>
<a name="line-122"></a><a name="getDTDSubset"></a><span class='definition'>getDTDSubset</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span>
<a name="line-123"></a><span class='definition'>getDTDSubset</span>
<a name="line-124"></a> <span class='keyglyph'>=</span> <span class='varid'>getChildren</span> <span class='varop'>.></span> <span class='varid'>isDoctype</span> <span class='varop'>.></span> <span class='varid'>hasRootName</span>
<a name="line-125"></a> <span class='keyword'>where</span>
<a name="line-126"></a> <span class='varid'>hasRootName</span> <span class='keyglyph'>=</span> <span class='varid'>isOf</span> <span class='layout'>(</span><span class='varid'>hasEntry</span> <span class='varid'>a_name</span> <span class='varop'>.</span> <span class='varid'>attrlOfDTD</span><span class='layout'>)</span>
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