1tnc(n) tnc(n)
2______________________________________________________________________________
6
8 tnc - tnc is an expat parser object extension, that validates the XML
9 stream against the document DTD while parsing.
10
12 package require tdom
13 package require tnc
14 set parser [expat]
16 tnc $parser enable
18_________________________________________________________________
19
21 tnc adds the C handler set "tnc" to a tcl expat parser obj. This han‐
22 dler set is a simple DTD validator. If the validator detects a valida‐
23 tion error, it sets the interp result, signals error and stops parsing.
24 There isn't any validation error recovering. As a consequence, only
25 valid documents are completely parsed.
26 This handler set has only three methods:
28 tnc parserObj enable
30 Adds the tnc C handler set to a Tcl expat parser object.
33 tnc parserObj remove
35 Removes the tnc validatore from the parser parserObj and frees
38 all information, stored by it.
39 tnc parserObj getValidateCmd ?validateCmdName?
41 Returns a new created validation command, if one is avaliable
44 from the parser command, otherwise it signals error. The name of
45 the validation command is the validateCmdName, if this optional
46 argument was given, or a random choosen name. A validation com‐
47 mand is avaliable in a parser command, if the parser with tnc
48 enabled was previously used, to parse an XML document with a
49 valid doctype declaration, a valid external subset, if one was
50 given by the doctype declaration, and a valid internal subset.
51 The further document doesn't need to be valid, to make the vali‐
52 dation command avaliable. The validation command can only get
53 received one time from the parser command. The created valida‐
54 tion command has this syntax:
55 validationCmd method ?args?
59 The valid methods are:
61 validateDocument domDocument ?varName?
63 Checks, if the given domDocument is valid against the DTD
64 information represented by the validation command.
65 Returns 1, if the document ist valid, 0 otherwise. If the
66 varName argument is given, then the variable it names is
67 set to the detected reason for the validation error or to
68 the empty string in case of a valid document.
69 validateTree elementNode ?varName?
71 Checks, if the given subtree with domNode as root element
72 is a posible valid subtree of a document conforming to
73 the DTD information represented by teh validation com‐
74 mand. IDREF could not checked, while validating only a
75 subtree, but it is checked, that every known ID attribute
76 in the subtree is unique. Returns 1, if the subtree is
77 OK, 0 otherwise. If the varName argument is given, then
78 the variable it names is set to the detected reason for
79 the validation error or to the empty string in case of a
80 valid subtree.
81 validateAttributes elementNode ?varName?
83 Checks, if there is an element declaration for the name
84 of the elementNode in the DTD represented by the valida‐
85 tion command and, if yes, if the attributes of the ele‐
86 mentNode are conform to the ATTLIST declarations for that
87 element in the DTD. Returns 1, if the attributes and
88 there value types are OK, 0 otherwise. If the varName
89 argument is given, then the variable it names is set to
90 the detected reason for the validation error or to the
91 empty string in case the element has all its required
92 attributes, only declared attributes and the values of
93 the attributes matches there type.
94 delete Deletes the validation command and frees the memory used
96 by it. Returns the empty string.
97
99 The validation error reports could be much more informative and user-
100 friendly.
101 The validator doesn't detect ambiguous content models (see XML recomen‐
103 dation Section 3.2.1 and Appendix E). Most Java validators also
104 doesn't, but handle such content models right anyhow. Tnc does not; if
105 your DTD has such ambiguous content models, tnc can not used to vali‐
106 date documents against such (not completely XML spec compliant) DTDs.
107 It isn't possible to validate XML documents with standalone="yes" in
109 the XML Declaration
110 Violations of the validity constraints Proper Group/PE Nesting and
112 Proper Conditional Section/PE Nesting are not detected. They could only
113 happen inside a invalid DTD, not in the content of a document.
114
116 Validation, DTD
117Tcl tnc(n)