/usr/share/doc/libsaxon-java/conformance.html is in libsaxon-java-doc 1:6.5.5-12.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 | <html>
<head>
<title>Standards Conformance</title>
<body leftmargin="150" bgcolor="#ddeeff"><font face="Arial, Helvetica, sans-serif">
<div align=right><a href="index.html">SAXON home page</a></div>
<p><b><font FACE="Arial, Helvetica, sans-serif" color="#FF0080" size="7">
Standards Conformance</font></b></p>
<h2>XSLT and XPath conformance</h2>
<p><i>SAXON XSLT implements the
XSLT 1.0 and XPath 1.0 Recommendations from the World Wide Web Consortium, found at
<a href="http://www.w3.org/TR/1999/REC-xslt-19991116">
http://www.w3.org/TR/1999/REC-xslt-19991116</a> and
<a href="http://www.w3.org/TR/1999/REC-xpath-19991116">
http://www.w3.org/TR/1999/REC-xpath-19991116</a>, which are
referred to here collectively as "XSLT"</i></p>
<p>SAXON is 100% conformant to the mandatory requirements of these standards, subject to the
<a href="#limitations">limitations</a> noted below.</p>
<p>SAXON also
implements certain facilities defined in the draft XSLT 1.1 specification, but these
are only available when the stylesheet specifies <code>version="1.1"</code>, or when the relevant
construct is within a literal result element that specifies <code>xsl:version="1.1"</code>.
Note that the W3C XSL Working Group has announced that XSLT 1.1 will not be taken beyond
working draft status. Most of these facilities (with the exception of the Java and Javascript
language bindings) have been carried forward into XSLT 2.0, but in some cases with different syntax.</p>
<p>The XSLT 1.1 features supported are as follows:</p>
<ul>
<li><p>SAXON will automatically convert a result tree fragment to a node-set when required,
as defined in the draft XSLT 1.1 specification. (This feature is retained in XSLT 2.0, though in
a more generalized form).</p></li>
<li><p>SAXON supports the <xsl:document> element defined in the draft XSLT 1.1 specification.
The implementation is incomplete: in particular (a) the href attribute is interpreted
as a filename relative to the current directory (not the base URI), and (b) the provisions
relating to use of <xsl:document> while the current output destination is a temporary tree
are not yet implemented. (In XSLT 2.0, this feature is provided by the <xsl:result-document>
element. XSLT 2.0 has a new, unrelated, instruction named <xsl:document>).</p></li>
<li><p>SAXON supports the use of <b>xsl:script</b> to define external Java functions. The archive
attribute is available only with a JDK1.2 or later JVM. The rules for identifying a Java
class and a method within the class are as defined in the working draft XSLT 1.1 specification.
The Context object implements the XSLTContext interface defined in XSLT 1.1.</p></li>
<li><p>SAXON supports the use of <b>xml:base</b> to define the Base URI of a node, as defined in
the XSLT 1.1 specifications, except in the case of the base URI of a processing instruction contained
in an external entity. (This feature is supported regardless of the setting of
<code>[xsl:]version</code>)</p></li>
<p>SAXON also supports synonyms <code>saxon:script</code> for <code>xsl:script</code>, and
<code>saxon:output</code> for <code>xsl:document</code>; the synonyms can be used in a version 1.0
stylesheet, following the normal rules for extension elements. Conversion of a result tree fragment
to a node-set can be achieved using the <code>saxon:node-set()</code> or <code>exslt:node-set()</code>
extension functions, regardless of the version setting.</p>
</ul>
<p>SAXON is dependant on the user-selected XML parser to ensure conformance with the XML 1.0
Recommendation and the XML Namespaces Recommendation.</p>
<p>SAXON implements the <?xml-stylesheet?> processing instruction as described in the
W3C Recommendation <i>Associating StyleSheets with XML Documents</i>.
The <b>href</b> pseudo-attribute must be a URI identifying an XML document containing a stylesheet,
or a URI with a fragment identifier identifying an embedded stylesheet. The fragment must be the value
of an ID attribute declared as such in the DTD.</p>
<hr>
<h3><a name="limitations">Limitations</a></h3>
<p>For a more up-to-date list of limitations in this release see
<a href="http://saxon.sf.net/saxon6.5.4/limitations.html">limitations.html</a>.</p>
<ul>
<li><p>SAXON supports language-dependent sorting and numbering only for English, but offers
APIs that allow support of other languages via user-written additions.</p></li>
<li><p>The XSLT 1.0 specification defines the semantics of the <code>format-number</code>
function in terms of the <code>DecimalFormat</code> class in Java JDK 1.1. In Saxon,
the behavior follows whichever version of the JDK is actually being used. This means that
extensions defined in later JDK releases will be available in Saxon even though they are
errors according to the specification. In addition, Saxon's <code>format-number</code> requires
all characters used in the decimal format string to be 16-bit characters; Unicode surrogate
pairs are not supported.</p>
<p><i>The JDK 1.1 implementation of <code>DecimalFormat</code> included a "feature" that was
not described in the JDK 1.1 documentation, but was subsequently made part of the specification:
if a subpicture is included for negative numbers, the only part of the subpicture that is taken into
account is the prefix and suffix. Because Saxon relies on the Java implementation, it incorporates
this "feature", which has not been retained in the XSLT 2.0 specification of <code>format-number</code>.</i></p>
<p><i>Another limitation imposed by the Java <code>DecimalFormat</code> class is that the characters
used for digits, for the decimal point and grouping separator, and for other roles such as percent signs,
must all be 2-byte characters, that is, Unicode characters with codepoints less than 65536.</i></p></li>
<li><p>An erratum to the XSLT 1.0 specification states that <code>xsl:copy</code> and <code>xsl:copy-of</code>
may be used to add a namespace node to a newly constructed element. This works correctly in Saxon, provided
that the name of the namespace node does not clash with the namespace prefix that Saxon has allocated to the
element for serialization purposes. (In principle, this namespace prefix should not be present in the result
tree, and should therefore be incapable of causing a conflict.) More details: see bug
<a href="http://sourceforge.net/tracker/index.php?func=detail&aid=637117&group_id=29872&atid=397617">637117</a>.</p></li>
<li><p>Saxon's checking of the characters used in a QName is an approximation to the rules in the XML specification.
Some rarely-used characters are permitted when they should be rejected, and there may also be a few cases where
valid characters are rejected.</p></li>
<li><p>As permitted by the XSLT specification, Saxon imposes limits on the processing resources that can
be used by a transformation. Most of these limits are implicit in the design of the NamePool:</p>
<ul>
<li>65535 different namespace URIs</li>
<li>65535 different namespace prefixes</li>
<li>255 different prefixes for any one namespace URI</li>
<li>1024 different expanded-names in any one hash bucket, where the number of hash buckets
is fixed as 1024</li>
</ul>
<p>These limits apply to all the documents sharing a single NamePool. The limits can be extended by
using multiple NamePool instances.</p></li>
</ul>
<h3>Documentation</h3>
<p>The XSLT specification says that the documentation for an implementation should specify
which URI schemes
are supported. SAXON supports the URI scheme implemented by the Java <code>java.net.URL</code> class, with
the optional addition of a fragment identifier, as described below.
Additionally,
SAXON allows the user to nominate a URIResolver class which can be used to implement any URI scheme
the user wants.</p>
<p>The XSLT specification says that the documentation for an implementation should specify for which
media types fragment identifiers are supported. The standard URI resolver supports access to
XML documents
only. A simple fragment identifier is allowed, consisting of the value of an ID attribute in the
document. The effect is to return the subdocument rooted at the element with this identifier if there
is one, or an empty document otherwise. For example, the URI mydoc.xml#aaa locates the XML document
mydoc.xml, and if it contains an element <eeee id="aaa">, where id is an attribute of type ID, then
the document retrieved is an XML document with this <eeee> element as its outermost (document)
element.</p>
<p>The values of the vendor-specific system properties are:</p>
<table>
<tr><td width="120">xsl:version</td><td>1.0</td></tr>
<tr><td>xsl:vendor</td><td>SAXON n.n.n from Michael Kay</td></tr>
<tr><td>xsl:vendor-url</td><td>http://saxon.sf.net/</td></tr>
</table>
<p>All three values are subject to change in future releases. Users wishing to test whether the
processor is SAXON are advised to test whether the xsl:vendor system property starts with the string
"SAXON".</p>
<h3>Extensions</h3>
<p>SAXON implements a number of extensions to standard XSLT, following the rules for extension
functions and extension elements where appropriate. The extensions are documented in
<a href="extensions.html">extensions.html</a>. They are all implemented in accordance with
the provisions in the standard for extensibility.</p>
<h2>Character encodings supported</h2>
<p>The following is the list of encodings recognized by the built-in AElfred
parser (case-insensitive):</p>
<pre>
ISO-8859-1, 8859_1, ISO8859_1
US-ASCII, ASCII
UTF-8, UTF8
ISO-10646-UCS-2, UTF-16, UTF-16BE, UTF-16LE
</pre>
<p>The encodings available on output are the intersection of:</p>
<pre>
ascii, us-ascii, utf-8, utf8, utf-16, utf16, iso-8859-1, iso-8859-2
ko18-r, cp852, cp1250, windows-1250, cp1251, windows-1251
(again case-insensitive)
</pre>
<p>with whatever your Java VM supports.</p>
<p>If you select an encoding that the Java VM recognizes, but which is not in the
above list, then the output will be written in the requested encoding, but all non-ASCII
characters will be written as character references.</p>
<h2>XML 1.0 Conformance</h2>
<p>Saxon can be used with any SAX-conformant XML parser. The extent of XML conformance
depends entirely on the chosen parser.</p>
<p>The default parser is a version of Ælfred. There is one known non-conformance in
the version of the AElfred parser provided with the Saxon product: it does not enforce the
constraint that the contents of a general entity must be well-formed. Note, however, that this
parser does not perform XML validation.</p>
<h2>DOM Conformance</h2>
<p>SAXON accepts input (both source document and stylesheet) from any standards-compliant DOM
implementation.</p>
<p>SAXON allows the result tree to be attached to any Document or Element node of an existing
DOM. Any DOM implementation can be used, provided it is mutable.</p>
<p>SAXON's internal tree structure (which is visible through the Java API, including the case
where Java extensions functions are called from XPath expressions) conforms with the minimal
requirements of the DOM level 2 core Java language binding. This DOM interface is read-only,
so all attempts to call updating methods throw an appropriate DOM exception. No optional
features are implemented. The DOM interfaces to Saxon's tree structure do not reveal namespace
nodes as attributes. This means it is not possible to get information about namespace
declarations except by calls such as getPrefix() and getNamespaceURI() on Element and Attr nodes).</p>
<p>If an extension function returns a DOM Node or NodeList, this must consist only of Nodes
in a tree constructed using Saxon. Since Saxon's trees cannot be updated using DOM methods, this
means that the nodes returned must either be nodes from the original source tree, or nodes from
a tree constructed using Saxon's proprietary API. It is <b>not</b> possible to construct
the tree using DOM methods such as createElement() and createAttribute().</p>
<h2>JAXP 1.1 Conformance</h2>
<p>Saxon implements the JAXP 1.1 API (including TrAX), as defined in
<a href="http://java.sun.com/aboutJava/communityprocess/review/jsr063/index.html">JSR-63</a>.
Saxon implements the interfaces in the javax.xml.transform package in full, including support for
SAX, DOM, and Stream input, and SAX, DOM, and Stream output.</p>
<p>There are restrictions in using transform() on a DOMSource when the node to be transformed
is a node other than the root (i.e. the DOM Document node). These apply only if the
supplied DOM is a third-party DOM, not if it is a Saxon-constructed tree.
Specifically, if the start node
is not the root then it must be an element; and it must not have an ancestor or preceding-sibling
node, or an ancestor with a preceding-sibling node, that is an entity reference node or CDATA
section node. In addition, the element must be part of a tree that is rooted at a Document node.</p>
<p>When an identity transform is carried out (that is, a transform that uses no Templates object),
with the source being a DOMSource, then the entire DOM Document is copied, regardless of the start node
wrapped by the DOMSource object. The specification in this area is not clear, but Saxon's behavior
differs from other implementations.</p>
<p>Saxon also implements the <code>javax.xml.parsers</code> API. The SAX interfaces are implemented in full.
The DOM interfaces are limited by the capabilities of the Saxon DOM, specifically the fact that
it is read-only. Nevertheless, the DocumentBuilder may be used to construct a Saxon tree, or to
obtain an empty Document node which can be supplied in a DOMResult to hold the result of a
transformation.</p>
<a name="errorrecovery"><h2>Error recovery policy</h2></a>
<p>Where the XSLT specification requires that an error be signaled, Saxon produces an error
message and terminates stylesheet execution. In the case of errors detected at compile
time, it attempts to report as many errors as possible before terminating; in the case
of run-time errors, it terminates after the first error.</p>
<p>Where the XSLT specification states that the processor may recover from an error, Saxon takes
one of three actions as described in the table below. Either it signals the error and terminates
execution, or it recovers silently from the error in the manner permitted by the specification,
or it places the action under user control. In the latter case there are three options: report the
error and terminate, recover silently, or (the default) recover after writing a warning
to the system error output stream. These actions can be modified by supplying a user-defined
ErrorListener.</p>
<p>Handling of individual recoverable errors is described in the table below.</p>
<table>
<tr><td><b>Error</b></td><td><b>Action</b></td></tr>
<tr>
<td valign="top">There is more than one template rule that matches a node, with the
same import precedence and priority</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">There is more that one xsl:namespace-alias statement for a given prefix,
with the same import precedence</td>
<td valign="top">Recover silently</td>
</tr>
<tr>
<td valign="top">An element name defined using xsl:element is invalid</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">An attribute name defined using xsl:attribute is invalid</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">There are several attribute sets with the same import precedence that
define the same named attribute</td>
<td valign="top">Recover silently</td>
</tr>
<tr>
<td valign="top">A processing-instruction name defined using xsl:processing-instruction is invalid</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">A node other than a text node is written to the result tree while instantiating
xsl:attribute, xsl:comment, or xsl:processing-instruction</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">Invalid characters are written to the content of a comment or processing instruction</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">An attribute node or namespace node is written directly to the root of a result
tree fragment, or to any other node that is not an element node.</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">The document() function identifies a resource that cannot be retrieved</td>
<td valign="top">User option</td>
</tr>
<tr>
<td valign="top">There are several xsl:output elements specifying the same attribute with the same
import precedence</td>
<td valign="top">Recover silently</td>
</tr>
<tr>
<td valign="top">disable-output-escaping is used for a text node while instantiating
xsl:attribute, xsl:comment, or xsl:processing-instruction</td>
<td valign="top">Recover silently</td>
</tr>
<tr>
<td valign="top">disable-output-escaping is used for a text node within a result tree fragment
that is subsequently converted to a string or number</td>
<td valign="top">Recover silently</td>
</tr>
<tr>
<td valign="top">disable-output-escaping is used for a text node containing a character that cannot
be output using the target encoding</td>
<td valign="top">Recover silently</td>
</tr>
</table>
<hr>
<p align="center">Michael H. Kay<br>
<a href="http://www.saxonica.com/">Saxonica Limited</a><br>
22 June 2005</p>
</body>
</html>
|