public static MarkupExtensionInfo Parse(string input)
{
if (!MarkupExtensionPattern.IsMatch(input))
{
throw new InvalidOperationException($"{input} is not a MarkupExtension.");
}
var resultInfo = new MarkupExtensionInfo();
using (var reader = new StringReader(input))
{
var parsingMode = MarkupExtensionParsingModeEnum.Start;
try
{
//Debug.Print("Parsing '{0}'", input);
//Debug.Indent();
while ((MarkupExtensionParsingModeEnum.End != parsingMode)
&& (MarkupExtensionParsingModeEnum.Unexpected != parsingMode))
{
//Debug.Print(context.ToString());
//Debug.Indent();
switch (parsingMode)
{
case MarkupExtensionParsingModeEnum.Start:
parsingMode = reader.ReadMarkupExtensionStart();
break;
case MarkupExtensionParsingModeEnum.MarkupName:
parsingMode = reader.ReadMarkupName(resultInfo);
break;
case MarkupExtensionParsingModeEnum.NameValuePair:
parsingMode = reader.ReadNameValuePair(resultInfo);
break;
}
//Debug.Unindent();
}
}
catch (Exception e)
{
throw new InvalidDataException($"Cannot parse markup extension string:\r\n \"{input}\"", e);
}
}
return resultInfo;
}
private static MarkupExtensionParsingModeEnum ReadMarkupName(this StringReader reader, MarkupExtensionInfo info)
{
char[] stopChars = {' ', '}'};
var resultParsingMode = MarkupExtensionParsingModeEnum.Unexpected;
var buffer = new StringBuilder();
while (!reader.IsEnd())
{
char c = reader.ReadChar();
if (stopChars.Contains(c))
{
switch (c)
{
case ' ':
resultParsingMode = MarkupExtensionParsingModeEnum.NameValuePair;
break;
case '}':
resultParsingMode = MarkupExtensionParsingModeEnum.End;
break;
default:
throw new InvalidDataException($"[{nameof(ReadMarkupName)}] Should not encounter '{c}'.");
}
info.Name = buffer.ToString().Trim();
buffer.Clear();
break;
}
buffer.Append(c);
}
if (MarkupExtensionParsingModeEnum.Unexpected == resultParsingMode)
{
throw new InvalidDataException($"[{nameof(ReadMarkupName)}] Invalid result context: {resultParsingMode}");
}
return resultParsingMode;
}
private static MarkupExtensionParsingModeEnum ReadNameValuePair(
this StringReader reader,
MarkupExtensionInfo info)
{
char[] stopChars = {',', '=', '}'};
MarkupExtensionParsingModeEnum resultParsingMode;
string key = null;
object value = null;
reader.SeekTill(_ => !Char.IsWhiteSpace(_));
// When '{' is the starting char, the following must be a value instead of a key.
//
// E.g.,
// <Setter x:Uid="Setter_75"
// Property="Foreground"
// Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" />
//
// In other words, "key" shall not start with '{', as it won't be a valid property name.
if (reader.PeekChar() != '{')
{
string temp = reader.ReadTill(stopChars.Contains).Trim();
char keyValueIndicatorChar = reader.PeekChar();
switch (keyValueIndicatorChar)
{
case ',':
case '}':
value = temp;
break;
case '=':
key = temp;
// Consume the '='
reader.Read();
break;
default:
throw new InvalidDataException($"[{nameof(ReadNameValuePair)}] Should not encounter '{keyValueIndicatorChar}'.");
}
}
if (value == null)
{
reader.SeekTill(_ => !(Char.IsWhiteSpace(_)));
string input = reader.ReadValueString();
if (MarkupExtensionPattern.IsMatch(input))
{
value = Parse(input);
}
else
{
value = input;
}
}
if (String.IsNullOrEmpty(key))
{
info.ValueOnlyProperties.Add(value);
}
else
{
info.KeyValueProperties.Add(new KeyValuePair<string, object>(key, value));
}
reader.SeekTill(_ => !Char.IsWhiteSpace(_));
char stopChar = reader.ReadChar();
switch (stopChar)
{
case ',':
resultParsingMode = MarkupExtensionParsingModeEnum.NameValuePair;
break;
case '}':
resultParsingMode = MarkupExtensionParsingModeEnum.End;
break;
default:
throw new InvalidDataException($"[{nameof(ReadNameValuePair)}] Should not encounter '{stopChar}'.");
}
if (MarkupExtensionParsingModeEnum.Unexpected == resultParsingMode)
{
throw new InvalidDataException($"[{nameof(ReadNameValuePair)}] Invalid result context: {resultParsingMode}");
}
return resultParsingMode;
}
