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
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
|
//
// XamlParser.cs
//
// Author:
// Stephane Delcroix <stephane@mi8.be>
//
// Copyright (c) 2013 Mobile Inception
// Copyright (c) 2013-2014 Xamarin, Inc
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Xml;
namespace Xamarin.Forms.Xaml
{
static class XamlParser
{
public static void ParseXaml(RootNode rootNode, XmlReader reader)
{
IList<KeyValuePair<string, string>> xmlns;
var attributes = ParseXamlAttributes(reader, out xmlns);
var prefixes = PrefixesToIgnore(xmlns);
(rootNode.IgnorablePrefixes ?? (rootNode.IgnorablePrefixes=new List<string>())).AddRange(prefixes);
rootNode.Properties.AddRange(attributes);
ParseXamlElementFor(rootNode, reader);
}
static void ParseXamlElementFor(IElementNode node, XmlReader reader)
{
Debug.Assert(reader.NodeType == XmlNodeType.Element);
var elementName = reader.Name;
var isEmpty = reader.IsEmptyElement;
if (isEmpty)
return;
while (reader.Read())
{
switch (reader.NodeType)
{
case XmlNodeType.EndElement:
Debug.Assert(reader.Name == elementName); //make sure we close the right element
return;
case XmlNodeType.Element:
// 1. Property Element.
if (reader.Name.Contains("."))
{
XmlName name;
if (reader.Name.StartsWith(elementName + ".", StringComparison.Ordinal))
name = new XmlName(reader.NamespaceURI, reader.Name.Substring(elementName.Length + 1));
else //Attached DP
name = new XmlName(reader.NamespaceURI, reader.LocalName);
var prop = ReadNode(reader);
if (prop != null)
node.Properties.Add(name, prop);
}
// 2. Xaml2009 primitives, x:Arguments, ...
else if (reader.NamespaceURI == "http://schemas.microsoft.com/winfx/2009/xaml" && reader.LocalName == "Arguments")
{
var prop = ReadNode(reader);
if (prop != null)
node.Properties.Add(XmlName.xArguments, prop);
}
// 3. DataTemplate (should be handled by 4.)
else if (node.XmlType.NamespaceUri == "http://xamarin.com/schemas/2014/forms" &&
(node.XmlType.Name == "DataTemplate" || node.XmlType.Name == "ControlTemplate"))
{
var prop = ReadNode(reader, true);
if (prop != null)
node.Properties.Add(XmlName._CreateContent, prop);
}
// 4. Implicit content, implicit collection, or collection syntax. Add to CollectionItems, resolve case later.
else
{
var item = ReadNode(reader, true);
if (item != null)
node.CollectionItems.Add(item);
}
break;
case XmlNodeType.Whitespace:
break;
case XmlNodeType.Text:
node.CollectionItems.Add(new ValueNode(reader.Value.Trim(), (IXmlNamespaceResolver)reader));
break;
default:
Debug.WriteLine("Unhandled node {0} {1} {2}", reader.NodeType, reader.Name, reader.Value);
break;
}
}
}
static INode ReadNode(XmlReader reader, bool nested = false)
{
var skipFirstRead = nested;
Debug.Assert(reader.NodeType == XmlNodeType.Element);
var name = reader.Name;
List<INode> nodes = new List<INode>();
INode node = null;
while (skipFirstRead || reader.Read())
{
skipFirstRead = false;
switch (reader.NodeType)
{
case XmlNodeType.EndElement:
Debug.Assert(reader.Name == name);
if (nodes.Count == 0) //Empty element
return null;
if (nodes.Count == 1)
return nodes[0];
return new ListNode(nodes, (IXmlNamespaceResolver)reader, ((IXmlLineInfo)reader).LineNumber,
((IXmlLineInfo)reader).LinePosition);
case XmlNodeType.Element:
var isEmpty = reader.IsEmptyElement && reader.Name == name;
var elementName = reader.Name;
var elementNsUri = reader.NamespaceURI;
var elementXmlInfo = (IXmlLineInfo)reader;
IList<KeyValuePair<string, string>> xmlns;
var attributes = ParseXamlAttributes(reader, out xmlns);
var prefixes = PrefixesToIgnore(xmlns);
IList<XmlType> typeArguments = null;
if (attributes.Any(kvp => kvp.Key == XmlName.xTypeArguments))
{
typeArguments =
((ValueNode)attributes.First(kvp => kvp.Key == XmlName.xTypeArguments).Value).Value as IList<XmlType>;
}
node = new ElementNode(new XmlType(elementNsUri, elementName, typeArguments), elementNsUri,
reader as IXmlNamespaceResolver, elementXmlInfo.LineNumber, elementXmlInfo.LinePosition);
((IElementNode)node).Properties.AddRange(attributes);
(node.IgnorablePrefixes ?? (node.IgnorablePrefixes = new List<string>())).AddRange(prefixes);
ParseXamlElementFor((IElementNode)node, reader);
nodes.Add(node);
if (isEmpty || nested)
return node;
break;
case XmlNodeType.Text:
node = new ValueNode(reader.Value.Trim(), (IXmlNamespaceResolver)reader, ((IXmlLineInfo)reader).LineNumber,
((IXmlLineInfo)reader).LinePosition);
nodes.Add(node);
break;
case XmlNodeType.Whitespace:
break;
default:
Debug.WriteLine("Unhandled node {0} {1} {2}", reader.NodeType, reader.Name, reader.Value);
break;
}
}
throw new XamlParseException("Closing PropertyElement expected", (IXmlLineInfo)reader);
}
static IList<KeyValuePair<XmlName, INode>> ParseXamlAttributes(XmlReader reader, out IList<KeyValuePair<string,string>> xmlns)
{
Debug.Assert(reader.NodeType == XmlNodeType.Element);
var attributes = new List<KeyValuePair<XmlName, INode>>();
xmlns = new List<KeyValuePair<string, string>>();
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
//skip xmlns
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/") {
xmlns.Add(new KeyValuePair<string, string>(reader.LocalName, reader.Value));
continue;
}
var namespaceUri = reader.NamespaceURI;
if (reader.LocalName.Contains(".") && namespaceUri == "")
namespaceUri = ((IXmlNamespaceResolver)reader).LookupNamespace("");
var propertyName = new XmlName(namespaceUri, reader.LocalName);
object value = reader.Value;
if (reader.NamespaceURI == "http://schemas.microsoft.com/winfx/2006/xaml")
{
switch (reader.Name) {
case "x:Key":
propertyName = XmlName.xKey;
break;
case "x:Name":
propertyName = XmlName.xName;
break;
case "x:Class":
continue;
default:
Debug.WriteLine("Unhandled attribute {0}", reader.Name);
continue;
}
}
if (reader.NamespaceURI == "http://schemas.microsoft.com/winfx/2009/xaml")
{
switch (reader.Name) {
case "x:Key":
propertyName = XmlName.xKey;
break;
case "x:Name":
propertyName = XmlName.xName;
break;
case "x:TypeArguments":
propertyName = XmlName.xTypeArguments;
value = TypeArgumentsParser.ParseExpression((string)value, (IXmlNamespaceResolver)reader, (IXmlLineInfo)reader);
break;
case "x:DataType":
propertyName = XmlName.xDataType;
break;
case "x:Class":
continue;
case "x:FactoryMethod":
propertyName = XmlName.xFactoryMethod;
break;
case "x:Arguments":
propertyName = XmlName.xArguments;
break;
default:
Debug.WriteLine("Unhandled attribute {0}", reader.Name);
continue;
}
}
var propertyNode = GetValueNode(value, reader);
attributes.Add(new KeyValuePair<XmlName, INode>(propertyName, propertyNode));
}
reader.MoveToElement();
return attributes;
}
static IList<string> PrefixesToIgnore(IList<KeyValuePair<string, string>> xmlns)
{
var prefixes = new List<string>();
foreach (var kvp in xmlns) {
var prefix = kvp.Key;
string typeName = null, ns = null, asm = null, targetPlatform = null;
XmlnsHelper.ParseXmlns(kvp.Value, out typeName, out ns, out asm, out targetPlatform);
if (targetPlatform == null)
continue;
TargetPlatform os;
if (Enum.TryParse<TargetPlatform>(targetPlatform, out os) && os != Device.OS)
prefixes.Add(prefix);
}
return prefixes;
}
static IValueNode GetValueNode(object value, XmlReader reader)
{
var valueString = value as string;
if (valueString != null && valueString.Trim().StartsWith("{}", StringComparison.Ordinal))
{
return new ValueNode(valueString.Substring(2), (IXmlNamespaceResolver)reader, ((IXmlLineInfo)reader).LineNumber,
((IXmlLineInfo)reader).LinePosition);
}
if (valueString != null && valueString.Trim().StartsWith("{", StringComparison.Ordinal))
{
return new MarkupNode(valueString.Trim(), reader as IXmlNamespaceResolver, ((IXmlLineInfo)reader).LineNumber,
((IXmlLineInfo)reader).LinePosition);
}
return new ValueNode(value, (IXmlNamespaceResolver)reader, ((IXmlLineInfo)reader).LineNumber,
((IXmlLineInfo)reader).LinePosition);
}
static IList<XmlnsDefinitionAttribute> s_xmlnsDefinitions;
static void GatherXmlnsDefinitionAttributes()
{
//this could be extended to look for [XmlnsDefinition] in all assemblies
var assemblies = new [] {
typeof(View).GetTypeInfo().Assembly,
typeof(XamlLoader).GetTypeInfo().Assembly,
};
s_xmlnsDefinitions = new List<XmlnsDefinitionAttribute>();
foreach (var assembly in assemblies)
foreach (XmlnsDefinitionAttribute attribute in assembly.GetCustomAttributes(typeof(XmlnsDefinitionAttribute))) {
s_xmlnsDefinitions.Add(attribute);
attribute.AssemblyName = attribute.AssemblyName ?? assembly.FullName;
}
}
public static Type GetElementType(XmlType xmlType, IXmlLineInfo xmlInfo, Assembly currentAssembly,
out XamlParseException exception)
{
if (s_xmlnsDefinitions == null)
GatherXmlnsDefinitionAttributes();
var namespaceURI = xmlType.NamespaceUri;
var elementName = xmlType.Name;
var typeArguments = xmlType.TypeArguments;
exception = null;
var lookupAssemblies = new List<XmlnsDefinitionAttribute>();
var lookupNames = new List<string>();
foreach (var xmlnsDef in s_xmlnsDefinitions) {
if (xmlnsDef.XmlNamespace != namespaceURI)
continue;
lookupAssemblies.Add(xmlnsDef);
}
if (lookupAssemblies.Count == 0) {
string ns, asmstring, _;
XmlnsHelper.ParseXmlns(namespaceURI, out _, out ns, out asmstring, out _);
lookupAssemblies.Add(new XmlnsDefinitionAttribute(namespaceURI, ns) {
AssemblyName = asmstring ?? currentAssembly.FullName
});
}
lookupNames.Add(elementName);
lookupNames.Add(elementName + "Extension");
for (var i = 0; i < lookupNames.Count; i++)
{
var name = lookupNames[i];
if (name.Contains(":"))
name = name.Substring(name.LastIndexOf(':') + 1);
if (typeArguments != null)
name += "`" + typeArguments.Count; //this will return an open generic Type
lookupNames[i] = name;
}
Type type = null;
foreach (var asm in lookupAssemblies) {
foreach (var name in lookupNames)
if ((type = Type.GetType($"{asm.ClrNamespace}.{name}, {asm.AssemblyName}")) != null)
break;
if (type != null)
break;
}
if (type != null && typeArguments != null)
{
XamlParseException innerexception = null;
var args = typeArguments.Select(delegate(XmlType xmltype)
{
XamlParseException xpe;
var t = GetElementType(xmltype, xmlInfo, currentAssembly, out xpe);
if (xpe != null)
{
innerexception = xpe;
return null;
}
return t;
}).ToArray();
if (innerexception != null)
{
exception = innerexception;
return null;
}
type = type.MakeGenericType(args);
}
if (type == null)
exception = new XamlParseException($"Type {elementName} not found in xmlns {namespaceURI}", xmlInfo);
return type;
}
}
}
|