#region License
/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#endregion
#region Imports
using System.Configuration;
using System.Globalization;
using System.Xml;
using Spring.Core.TypeResolution;
using Spring.Util;
#endregion
namespace Spring.Context.Support{
/// <summary>
/// Configuration section handler for the Spring.NET <c>typeAliases</c>
/// config section.
/// </summary>
/// <remarks>
/// <p>
/// Type aliases can be used instead of fully qualified type names anywhere
/// a type name is expected in a Spring.NET configuration file.
/// </p>
/// <p>
/// This includes type names specified within an object definition, as well
/// as values of the properties or constructor arguments that expect
/// <see cref="System.Type"/> instances.
/// </p>
/// </remarks>
/// <example>
/// <p>
/// The following example shows how to configure both this section handler and
/// how to define type aliases within a Spring.NET config section:
/// </p>
/// <code escaped="true">
/// <configuration>
/// <configSections>
/// <sectionGroup name="spring">
/// <section name="typeAliases" type="Spring.Context.Support.TypeAliasesSectionHandler, Spring.Core"/>
/// </sectionGroup>
/// </configSections>
/// <spring>
/// <typeAliases>
/// <alias name="WebServiceExporter" type="Spring.Web.Services.WebServiceExporter, Spring.Web"/>
/// <alias name="MyType" type="MyCompany.MyProject.MyNamespace.MyType, MyAssembly"/>
/// ...
/// </typeAliases>
/// ...
/// </spring>
/// </configuration>
/// </code>
/// </example>
/// <author>Aleksandar Seovic</author>
/// <seealso cref="Spring.Core.TypeResolution.TypeRegistry"/>
public class TypeAliasesSectionHandler : IConfigurationSectionHandler
{
private const string AliasElementName = "alias";
private const string NameAttributeName = "name";
private const string TypeAttributeName = "type";
/// <summary>
/// Populates <see cref="TypeRegistry"/> using values specified in
/// the <c>typeAliases</c> config section.
/// </summary>
/// <param name="parent">
/// The configuration settings in a corresponding parent
/// configuration section.
/// </param>
/// <param name="configContext">
/// The configuration context when called from the ASP.NET
/// configuration system. Otherwise, this parameter is reserved and
/// is <see langword="null"/>.
/// </param>
/// <param name="section">
/// The <see cref="System.Xml.XmlNode"/> for the section.
/// </param>
/// <returns>
/// This method always returns <see langword="null"/>, because the
/// <see cref="TypeRegistry"/> is populated as a side-effect of this
/// object's execution and thus there is no need to return anything.
/// </returns>
public object Create(object parent, object configContext, XmlNode section)
{
if (section != null)
{
XmlNodeList aliases = ((XmlElement) section).GetElementsByTagName(AliasElementName);
foreach (XmlElement aliasElement in aliases)
{
string alias = GetRequiredAttributeValue(aliasElement, NameAttributeName, section);
string typeName = GetRequiredAttributeValue(aliasElement, TypeAttributeName, section);
TypeRegistry.RegisterType(alias, typeName);
}
}
return null;
}
private static string GetRequiredAttributeValue(
XmlElement aliasElement, string requiredAttributeName, XmlNode section)
{
XmlAttribute attribute = aliasElement.GetAttributeNode(requiredAttributeName);
if (attribute == null)
{
string errorMessage = string.Format(CultureInfo.InvariantCulture,
"The '{0}' attribute is required for the (type) <alias/> element.", requiredAttributeName);
throw ConfigurationUtils.CreateConfigurationException(errorMessage, section);
}
return attribute.Value;
}
}
}
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