#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;
using System.Collections.Specialized;
using System.Globalization;
using Common.Logging;
#endregion
namespace Spring.Objects.Factory.Config{
/// <summary>
/// Overrides default values in one or more object definitions.
/// </summary>
/// <remarks>
/// <p>
/// Instances of this class <b>override</b> already existing values, and is
/// thus best suited to replacing defaults. If you need to <i>replace</i>
/// placeholder values, consider using the
/// <seea cref="Spring.Objects.Factory.Config.PropertyPlaceholderConfigurer"/>
/// class instead.
/// </p>
/// <p>
/// In contrast to the
/// <see cref="Spring.Objects.Factory.Config.PropertyPlaceholderConfigurer"/>
/// class, the original object definition can have default
/// values or no values at all for such object properties. If an overriding
/// configuration file does not have an entry for a certain object property,
/// the default object value is left as is. Also note that it is not
/// immediately obvious to discern which object definitions will be mutated by
/// one or more
/// <see cref="Spring.Objects.Factory.Config.PropertyOverrideConfigurer"/>s
/// simply by looking at the object configuration.
/// </p>
/// <p>
/// Each line in a referenced configuration file is expected to take the
/// following form...
/// </p>
/// <code escaped="true">
/// <add key="name.property" value="the override"/>
/// </code>
/// <p>
/// The <c>name.property</c> key refers to the object name and the
/// property that is to be overridden; and the value is the overridding
/// value that will be inserted into the appropriate object definition's
/// named property.
/// </p>
/// <p>
/// Please note that in the case of multiple
/// <see cref="Spring.Objects.Factory.Config.PropertyOverrideConfigurer"/>s
/// that define different values for the same object definition value, the
/// <b>last</b> overridden value will win (due to the fact that the values
/// supplied by previous
/// <see cref="Spring.Objects.Factory.Config.PropertyOverrideConfigurer"/>s
/// will be overridden).
/// </p>
/// </remarks>
/// <example>
/// <p>
/// The following XML context definition defines an object that has a number
/// of properties, all of which have <b>default</b> values...
/// </p>
/// <code escaped="true">
/// <object id="connStringProvider"
/// type="MyNamespace.OracleConnectionStringProvider, MyAssembly">
/// <property name="dataSource" value="MyOracleDB"/>
/// <property name="userId" value="sa"/>
/// <property name="password" value="g0ly4dk1n"/>
/// <property name="integratedSecurity" value="true"/>
/// </object>
/// </code>
/// <p>
/// What follows is a .NET config file snippet for the above example (assuming
/// the need to override one of the default values)...
/// </p>
/// <code escaped="true">
/// <name-values>
/// <add key="database.userid" value="test"/>
/// <add key="database.password" value="0bl0m0v"/>
/// </name-values>
/// </code>
/// </example>
/// <author>Juergen Hoeller</author>
/// <author>Simon White (.NET)</author>
/// <seealso cref="Spring.Objects.Factory.Config.PropertyResourceConfigurer"/>
/// <seealso cref="Spring.Objects.Factory.Config.PropertyPlaceholderConfigurer"/>
/// <seealso cref="Spring.Objects.Factory.Config.IObjectDefinition"/>
[Serializable]
public class PropertyOverrideConfigurer : PropertyResourceConfigurer
{
private ILog _logger = LogManager.GetLogger(typeof (PropertyOverrideConfigurer));
/// <summary>
/// Apply the given properties to the supplied
/// <see cref="Spring.Objects.Factory.Config.IConfigurableListableObjectFactory"/>.
/// </summary>
/// <param name="factory">
/// The <see cref="Spring.Objects.Factory.Config.IConfigurableListableObjectFactory"/>
/// used by the application context.
/// </param>
/// <param name="props">The properties to apply.</param>
/// <exception cref="Spring.Objects.ObjectsException">
/// If an error occured.
/// </exception>
protected override void ProcessProperties(
IConfigurableListableObjectFactory factory, NameValueCollection props)
{
foreach (string key in props.AllKeys)
{
ProcessKey(factory, key, props[key]);
}
}
/// <summary>
/// Process the given key as 'name.property' entry.
/// </summary>
/// <param name="factory">
/// The object factory containing the object definitions that are to be
/// processed.
/// </param>
/// <param name="key">The key.</param>
/// <param name="value">The value.</param>
/// <exception cref="Spring.Objects.ObjectsException">
/// If an error occurs.
/// </exception>
/// <exception cref="Spring.Objects.FatalObjectException">
/// If the property was not well formed (i.e. not in the format "name.property").
/// </exception>
protected virtual void ProcessKey(
IConfigurableListableObjectFactory factory, string key, string value)
{
int dotIndex = key.IndexOf('.');
if (dotIndex == -1)
{
throw new FatalObjectException(
string.Format(CultureInfo.InvariantCulture,
"Invalid key '{0}': expected 'objectName.property' form.", key));
}
string name = key.Substring(0, dotIndex);
string objectProperty = key.Substring(dotIndex + 1);
IObjectDefinition definition = factory.GetObjectDefinition(name);
if(definition != null)
{
PropertyValue pv = definition.PropertyValues.GetPropertyValue(objectProperty);
if (pv != null && pv.Value is RuntimeObjectReference)
{
definition.PropertyValues.Add(objectProperty, new RuntimeObjectReference(value));
}
else if (pv != null && pv.Value is ExpressionHolder)
{
definition.PropertyValues.Add(objectProperty, new ExpressionHolder(value));
}
else
{
definition.PropertyValues.Add(objectProperty, value);
}
}
else
{
#region Instrumentation
if (_logger.IsWarnEnabled)
{
_logger.Warn(string.Format(CultureInfo.InvariantCulture,
"Cannot find object '{0}' when overriding properties; check configuration.", name));
}
#endregion
}
#region Instrumentation
if (_logger.IsDebugEnabled)
{
_logger.Debug(string.Format(CultureInfo.InvariantCulture,
"Property '{0}' set to '{1}'.", key, value));
}
#endregion
}
}
}
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