Parser Schemas– Easy and Powerful parsing of XML-based languages

/***********************************************************************\
 * Comnicate.CodeDom.Xml.ParserSchemas                                 *
 * Parses xml-based languages according to a user defined schema.      *
 * Copyright � 2005 Tomas Deml (as Comnicate!)                         *
 *                  tomasdeml@msn.com                                  *
 *                                                                     *
 * This library is free software; you can redistribute it and/or       *
 * modify it under the terms of the GNU Lesser General Public          *
 * License as published by the Free Software Foundation; either        *
 * version 2.1 of the License, or (at your option) any later version.  *
 *                                                                     *
 * This library is distributed in the hope that it will be useful,     *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of      *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU   *
 * Lesser General Public License for more details.                     *
\***********************************************************************/

using System;
using System.Collections.Generic;
using System.Text;
using Comnicate.CodeDom.Xml.ParserSchemas.Rules.Evaluated;
using Comnicate.CodeDom.Xml.ParserSchemas.Rules.Evaluation;
using System.Xml.XPath;

namespace Comnicate.CodeDom.Xml.ParserSchemas.Rules
{
    /// <summary>
    /// Represents a rule that matches an attribute. It is also able to validate the value of the attribute.
    /// </summary>
    /// <remarks>This rule supports value validation.</remarks>
    public class AttributeRule : ValidatingNonParentalRule
    {
        #region .ctors

        /// <summary>
        /// Initializes a new instance of the <see cref="AttributeRule"/> class.
        /// </summary>
        /// <param name="attributeName">Name of the attribute that can be parsed by the rule.</param>
        public AttributeRule(string attributeName) : base(attributeName) { }
        
        /// <summary>
        /// Initializes a new instance of the <see cref="AttributeRule"/> class.
        /// </summary>
        /// <param name="attributeName">Name of the attribute that can be parsed by the rule.</param>
        /// <param name="valueValidator">An instance of a class implementing the <see cref="IValueValidator"/> interface that will validate the value of the attribute.</param>
        public AttributeRule(string attributeName, IValueValidator valueValidator) : base(attributeName, valueValidator) { }
        
        /// <summary>
        /// Initializes a new instance of the <see cref="AttributeRule"/> class.
        /// </summary>
        /// <param name="attributeName">Name of the attribute that can be parsed by the rule.</param>
        /// <param name="namespaceUri">The namespace uri of the attribute.</param>
        public AttributeRule(string attributeName, Uri namespaceUri) : base(attributeName, namespaceUri) { }

        /// <summary>
        /// Initializes a new instance of the <see cref="AttributeRule"/> class.
        /// </summary>
        /// <param name="attributeName">Name of the attribute that can be parsed by the rule.</param>
        /// <param name="namespaceUri">The namespace uri of the attribute.</param>
        /// <param name="valueValidator">An instance of a class implementing the <see cref="IValueValidator"/> interface that will validate the value of the attribute.</param>
        public AttributeRule(string attributeName, Uri namespaceUri, IValueValidator valueValidator) : base(attributeName, namespaceUri, valueValidator) { }

        /// <summary>
        /// Initializes a new instance of the <see cref="AttributeRule"/> class.
        /// </summary>
        /// <param name="attributeName">Name of the attribute that can be parsed by the rule.</param>
        /// <param name="namespaceUri">The namespace uri of the attribute.</param>
        /// <param name="options">Options indicating how to resolve the node value.</param>
        public AttributeRule(string attributeName, Uri namespaceUri, NodeValueOptions options) : base(attributeName, namespaceUri, options) { }

        /// <summary>
        /// Initializes a new instance of the <see cref="AttributeRule"/> class.
        /// </summary>
        /// <param name="attributeName">Name of the attribute that can be parsed by the rule.</param>
        /// <param name="namespaceUri">The namespace uri of the attribute.</param>
        /// <param name="options">Options indicating how to resolve the node value.</param>
        /// <param name="valueValidator">An instance of a class implementing the <see cref="IValueValidator"/> interface that will validate the value of the attribute.</param>
        public AttributeRule(string attributeName, Uri namespaceUri, NodeValueOptions options, IValueValidator valueValidator) : base(attributeName, namespaceUri, options, valueValidator) { }

        #endregion

        #region Properties

        /// <summary>
        /// Gets the information about the type of node navigator that can be matched by this rule.
        /// </summary>
        public override XPathNodeType MatchingNodeType
        {
            get { return XPathNodeType.Attribute; }
        }

        #endregion

        #region Methods

        /// <summary>
        /// Parses node navigator the XPathNavigator instance points to, according to the rule.
        /// </summary>
        /// <param name="nodeNavigator">XPathNavigator instance pointing to the node to parse.</param>
        /// <returns>Evaluated rule.</returns>
        public override EvaluatedNonParentalRule Evaluate(XPathNavigator nodeNavigator)
        {
            // Null?
            if (nodeNavigator == null) throw new ArgumentNullException("nodeNavigator");

            // Evaluated rule
            EvaluatedNonParentalRule result = new EvaluatedNonParentalRule(this);

            // Resolve value
            this.ResolveValueOptions(nodeNavigator, result);

            // Validate value
            this.ValidateValue(nodeNavigator.Value);

            // Return eventData
            return result;
        }

        #endregion
    }
}