Properly modeling and implementing the modify method

Implementing the modify method can be a bit tricky. A standardized modify method has to deal with optimistic locking and business level validation.

Here is the general pattern

Model

In your model you should have the three standard layers: Facade, Service Layer and Entity. The following are the class diagrams for each layer:

Entity:

Service Layer:

One note, if the sl.SampleDetails should not modify every field of Sample, then model the following association instead:

Facade:

Code

In the sl.MaintainSample there is a modifySample method that looks like this:

public ValidationResult modifySample(SampleDetails sampleDetails) {

  SampleKey key = new SampleKey();

  key.sampleID = sampleDetails.dtls.sampleID;

  Sample sampleObj = SampleFactory.newInstance();

  // Read for update

  SampleDtls dtls = sampleObj.read(key, true);

  // Perform validation here

  // For now everything passes.

  ValidationResult validationResult = new ValidationResult();

  validationResult.validInd = true;

  dtls.assign(sampleDetails.dtls);

  // If you are not aggregating the entity directy then use

  // dtls.assign(sampleDetails);

  sampleObj.modify(key, dtls);

  return validationResult;

}

In the facade, there is a modifySample method as well which looks like this:

public ModifySampleResult modifySample(ModifySampleDetails details) {

  SecurityImplementationFactory.register();

  ModifySampleResult result = new ModifySampleResult();

  result.validationResults = 

    MaintainSampleFactory.newInstance().modifySample(details.details);

  return result;

}

In the UIM you need to make sure to pass in the versionNo field as well if you are using Optimistic Locking.

<CONNECT>

  <SOURCE NAME="DISPLAY" PROPERTY="versionNo" />

  <TARGET NAME="ACTION" PROPERTY="versionNo" />

</CONNECT>