Adding Features for Crosscutting Concerns

Features are additions to the expandersExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. which aim to add pieces of code to multiple expandersExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact.. A feature can then be enabled with some option or another condition to add logic to multiple artifactsArtifactA build or deployment result, such as a Docker container image or Java archive, produced by a software project. at once.

That way, crosscutting concerns can be extracted from the expandersExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. to provide further decoupling.

Here is an example to paint a clearer image. Let's say we want to expose a new method of the dataElement-bean:

public <F> SearchResult<CityDetails> findAllDetails(ParameterContext<F> parameter) {
  ...
}

This method also needs to be added to the Remote interface:

<F> SearchResult<CityDetails> findAllDetails(ParameterContext<F> parameter);

And some more to the Local, Proxy and Agent.

Creating a Feature

Create a new feature through the idea:

And give it a decent name:

This will generate:

• a {Feature}.xml file containing a condition, which is similar to the isApplicable of the ExpanderExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. and a type, which can be custom (each insertion is different for each artifactArtifactA build or deployment result, such as a Docker container image or Java archive, produced by a software project.) or uniform (each artifactArtifactA build or deployment result, such as a Docker container image or Java archive, produced by a software project. has the same insertion)
• a {Feature}.md file which contains a description of the feature
• a {Feature}Test.java file which contains the units tests

Implementing a Feature with type custom

For each ExpanderExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. that will be modified by the Feature, an ExpanderFeature should be created. The ExpanderFeature provides the mapping and templates for the inserted code.

Select the Feature you wish to extend and select new > ExpanderExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. Feature:

Then select the target ExpanderExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. (with the ... button):

This will add the ExpanderFeature to {Feature}.xml and generate:

• a {Feature}.{Expander}Mapping.xml file to provide additional mappings for the insertion
• a {Feature}.{Expander}.stg file to provide a template
• a {Feature}{Expander}Test.java file for the units tests
• a {Feature}{Expander}Test.stg file to provide the test templates

The content of the {Feature}.{Expander}.stg file should contain hooks with the insertions:

base() ::= <<
@hook:methods:start
public \<F\> SearchResult\<<dataelement>Details\> findAllDetails(ParameterContext\<F\> parameter) {
  ...
}
@hook:methods:end
>>

The @hook:methods refers to an @anchor:methods feature anchorAnchorA marker within generated source code reserved for adding custom logic during re-expansion. in the original expanderExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. template. You can add these feature anchorsAnchorA marker within generated source code reserved for adding custom logic during re-expansion. to your own ExpandersExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. to allow for them to be extended.

When expanding, the insertion will be injected into the artifactArtifactA build or deployment result, such as a Docker container image or Java archive, produced by a software project. at the place of the feature anchorAnchorA marker within generated source code reserved for adding custom logic during re-expansion. as follows:

// @anchor:methods:start
public <F> SearchResult<CityDetails> findAllDetails(ParameterContext<F> parameter) {
  ...
}
// @anchor:methods:end