Optional Resources in Spring.Net - ioc-container

Question

How to include Spring configuration files optionally? I think about something simular to this:
<spring>
<context>
<resource uri="file:///Objects/RequiredObjects.xml" />
<resource uri="file:///Objects/OptionalObjects.xml" required="false" />
</context>
This way I could provide developers the possibility to override some configuration parts (e.g. for a local speed improvement or automatism during app startup) without affecting the app.config and the problem that a developer could checkin his modified file when it is not really his intent to change the config for all.

Answer 1

Not as simple as in AutoFac (because there is already a builtin way) but possible to achieve something similar with a little coding:
using System.IO;
using System.Xml;
using Spring.Core.IO;
public class OptionalFileSystemResource : FileSystemResource
{
public OptionalFileSystemResource(string uri)
: base(uri)
{
}
public override Stream InputStream
{
get
{
if (System.IO.File.Exists(this.Uri.LocalPath))
{
return base.InputStream;
}
return CreateEmptyStream();
}
}
private static Stream CreateEmptyStream()
{
var xml = new XmlDocument();
xml.LoadXml("<objects />");
var stream = new MemoryStream();
xml.Save(stream);
stream.Position = 0;
return stream;
}
}
Register a section handler:
<sectionGroup name="spring">
...
<section name="resourceHandlers" type="Spring.Context.Support.ResourceHandlersSectionHandler, Spring.Core"/>
...
</sectionGroup>
...
<spring>
<resourceHandlers>
<handler protocol="optionalfile" type="MyCoolStuff.OptionalFileSystemResource, MyCoolStuff" />
</resourceHandlers>
...
<context>
<resource uri="file://Config/MyMandatoryFile.xml" />
<resource uri="optionalfile://Config/MyOptionalFile.xml" />
...
You'll find more information about resources and resource handlers in the Spring.Net documentation.