/// <summary>
/// Parses the specified condition string and turns it into
/// <see cref="ConditionExpression" /> tree.
/// </summary>
/// <param name="expressionText">The expression to be parsed.</param>
/// <param name="configurationItemFactories">
/// Instance of <see cref="ConfigurationItemFactory" /> used to resolve references to condition methods and layout renderers.
/// </param>
/// <returns>The root of the expression syntax tree which can be used to get the value of the condition in a specified context.</returns>
public static ConditionExpression ParseExpression(string expressionText, ConfigurationItemFactory configurationItemFactories)
{
if (expressionText == null)
{
return null;
}
var parser = new ConditionParser(new SimpleStringReader(expressionText), configurationItemFactories);
var expression = parser.ParseExpression();
if (!parser.tokenizer.IsEOF())
{
throw new ConditionParseException("Unexpected token: " + parser.tokenizer.TokenValue);
}
return expression;
}
/// <summary>
/// Parses the specified condition string and turns it into
/// <see cref="ConditionExpression" /> tree.
/// </summary>
/// <param name="stringReader">The string reader.</param>
/// <param name="configurationItemFactories">
/// Instance of <see cref="ConfigurationItemFactory" /> used to resolve references to condition methods and layout renderers.
/// </param>
/// <returns>
/// The root of the expression syntax tree which can be used to get the value of the condition in a specified context.
/// </returns>
internal static ConditionExpression ParseExpression(SimpleStringReader stringReader, ConfigurationItemFactory configurationItemFactories)
{
var parser = new ConditionParser(stringReader, configurationItemFactories);
var expression = parser.ParseExpression();
return expression;
}