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c#configurationexpressionspring.netspring-el

Spring.NET Expression that References an Object Definition


I'm trying to reference another object I've defined in a Spring config file from within an expression. Specifically, I'm trying to populate a property with the value of an expression where I call a method and then a property on the object returned from that method.
I've tried the following (names have been changed):

<property name="NullableIntProperty"
          expression="#{Some.Object.Id}.Get().NullableIntValue"/>

where Some.Object.Id is a reference to another object I have defined in a config file such as:

<object id="Some.Object.Id" ... >

but my app fails to start with the parsing exception expecting "COLON", found '}'. I think it's expecting a namespace, but I'm not finding the documentation for this.

I've tried several things, but everywhere I hit a dead end. I originally tried a combination of the MethodInvokingFactoryObject and PropertyRetrievingFactoryObject which we use in other places for non-nullable types, but this fails for nullables that are actually null since Spring sees an object factory returning null as a failure (which it usually is).


Solution

  • You can use the @(object-id-here) expression syntax to retrieve an object from the Spring context using an expression:

    <property name="NullableIntProperty"
              expression="@(Some.Object.Id).PropertyOnSomeObject"/>