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comparison Implab/Xml/XmlNameContext.cs @ 227:8d5de4eb9c2c v2

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Reimplemented JsonXmlReader, added support for null values: JSON null values are mapped to empty nodes with 'xsi:nil' attribute set to 'true'
author cin
date Sat, 09 Sep 2017 03:53:13 +0300
parents
children 5f7a3e1d32b9
comparison
equal deleted inserted replaced
226:9428ea36838e 227:8d5de4eb9c2c
1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Text;
5 using System.Threading.Tasks;
6 using System.Xml;
7
8 namespace Implab.Xml {
9 public class XmlNameContext {
10 public const string XmlnsNamespace = "http://www.w3.org/2000/xmlns/";
11 public const string XmlnsPrefix = "xmlns";
12 public const string XmlNamespace = "http://www.w3.org/XML/1998/namespace";
13 public const string XmlPrefix = "xml";
14 public const string XsiNamespace = "http://www.w3.org/2001/XMLSchema-instance";
15 public const string XsiPrefix = "xsi";
16
17 readonly static char[] _qNameDelim = new[] { ':' };
18
19 Dictionary<string, string> m_ns2prefix;
20 Dictionary<string, string> m_prefix2ns;
21 int m_nextPrefix = 1;
22
23 public XmlNameContext ParentContext { get; private set; }
24
25 public XmlNameContext(XmlNameContext parent) {
26 ParentContext = parent;
27 if (parent == null) {
28 DefinePrefixNoCheck(XmlnsNamespace, XmlnsPrefix);
29 DefinePrefixNoCheck(XmlNamespace, XmlPrefix);
30 } else {
31 m_nextPrefix = parent.m_nextPrefix;
32 }
33 }
34
35 public bool LookupNamespacePrefix(string ns, out string prefix) {
36 if (ns == null)
37 ns = string.Empty;
38
39 prefix = null;
40 for (var ctx = this; ctx != null; ctx = ctx.ParentContext) {
41 if (ctx.m_ns2prefix?.TryGetValue(ns, out prefix) == true) {
42 if (ctx != this) // cache for the future use
43 DefinePrefixNoCheck(ns, prefix);
44 return true;
45 }
46 }
47 return false;
48 }
49
50 public string CreateNamespacePrefix(string ns) {
51 var prefix = $"p{m_nextPrefix++}";
52 DefinePrefixNoCheck(ns, prefix);
53 return prefix;
54 }
55
56 void DefinePrefixNoCheck(string ns, string prefix) {
57 if (ns == null)
58 ns = string.Empty;
59 if (prefix == null)
60 prefix = string.Empty;
61
62 if (m_ns2prefix == null)
63 m_ns2prefix = new Dictionary<string, string>();
64 m_ns2prefix[ns] = prefix;
65
66 if (m_prefix2ns == null)
67 m_prefix2ns = new Dictionary<string, string>();
68 m_prefix2ns[prefix] = ns;
69 }
70
71 public void DefinePrefix(string ns, string prefix) {
72 // according to https://www.w3.org/TR/xml-names/#ns-decl
73
74 // It MUST NOT be declared . Other prefixes MUST NOT be bound to this namespace name, and it MUST NOT be declared as the default namespace
75 if (ns == XmlnsNamespace)
76 throw new Exception($"Attempt to define xmlns:{prefix}='{ns}'");
77
78 // It MAY, but need not, be declared, and MUST NOT be bound to any other namespace name
79 if (ns == XmlNamespace && prefix != XmlPrefix)
80 throw new Exception($"Attempt to define xmlns:{prefix}='{ns}'");
81
82 // add mapping
83 DefinePrefixNoCheck(ns, prefix);
84 }
85
86 public string ResolvePrefix(string prefix) {
87 if (prefix == null)
88 prefix = string.Empty;
89 string ns = null;
90 for(var ctx = this; ctx != null; ctx = ctx.ParentContext) {
91 if (ctx.m_prefix2ns?.TryGetValue(prefix, out ns) == true) {
92 if (ctx != this) // cache for the future use
93 DefinePrefixNoCheck(ns, prefix);
94 return ns;
95 }
96 }
97 return null;
98 }
99
100 public XmlQualifiedName Resolve(string name) {
101 Safe.ArgumentNotEmpty(name, nameof(name));
102 var parts = name.Split(_qNameDelim, 2, StringSplitOptions.RemoveEmptyEntries);
103
104 if (parts.Length == 2) {
105 return new XmlQualifiedName(parts[1], ResolvePrefix(parts[0]));
106 } else {
107 return new XmlQualifiedName(parts[0], ResolvePrefix(string.Empty));
108 }
109 }
110 }
111 }