Shrinkwrap Descriptor: Factory based API Proposal

[rbattenfeld]

Hi

I was looking for factory based API and I played a little bit around. The result is simple hand made implementation proving the idea I had in mind. I think, the result is in the nature very similar to Aslak's proposal. I am just not so happy with the class type approach.

What does the proposal show? It shows:

• No up() method. All the generic typos are gone.
• A factory class that creates all the standard nodes. A user type just the . (dot) and the IDE will show all possible options. Most of the time, there will be only one.
• A particular node can be instantiated decoupled from the descriptor instance.
• To provide conventient behavour is very simple to implement. I implementet a simple test case for this.

I didn't looked so far how the factory will be created and available for the user. I guess there will be one for a particular descriptor. So, this is left out at the moment.

First Example: Simple Demonstation

    @Test

    public void testFactory() throws Exception {

        final ConnectorDescriptor jca10Generated = create();

        final Factory factory = jca10Generated.getFactory();

        jca10Generated

            .description("It is a sample resource adapter")

            .setResourceadapter(factory.Resourceadapter()

                .addConfigProperty(factory.ConfigProperty()

                    .configPropertyName("Input")

                    .configPropertyType("java.lang.String")

                    .configPropertyValue("test messages")));

    }

Second Example: Detached Demonstation (technically the same but show that you can create a node instance separate)

    @Test

    public void testDetachedMode() throws Exception {

        final ConnectorDescriptor jca10Generated = create();

        final Factory factory = jca10Generated.getFactory();

        final Resourceadapter resourceAdapter = factory.Resourceadapter();       

        final ConfigProperty property = factory.ConfigProperty()

                .configPropertyName("Input")

                .configPropertyType("java.lang.String")

                .configPropertyValue("test messages");

        jca10Generated

            .description("It is a sample resource adapter")

            .setResourceadapter(resourceAdapter.addConfigProperty(property));

    }

Third Example: Convenient Behavour

    @Test

    public void testConvenientResourceAdapter() throws Exception {

        final ConnectorDescriptor jca10Generated = create();

        final Factory factory = jca10Generated.getFactory();

        // this class just adds additional information. Can also be provided within a factory class

        final ConvenientResourceAdapter resourceAdapter = new ConvenientResourceAdapter();

        final ConfigProperty property = factory.ConfigProperty()

                .configPropertyName("Input")

                .configPropertyType("java.lang.String")

                .configPropertyValue("test messages");

        jca10Generated

            .description("It is a sample resource adapter")

            .setResourceadapter(resourceAdapter.addConfigProperty(property));

        String generatedRaXml = jca10Generated.exportAsString();

        System.out.println(generatedRaXml);

    }

The output is then:

  <?xml version="1.0" encoding="UTF-8" standalone="yes"?>

  <connector attr="val">

    <description>It is a sample resource adapter</description>

    <my-node my-attribute="great">my-text</my-node>

    <resourceadapter>

      <config-property>

        <config-property-name>Input</config-property-name>

        <config-property-type>java.lang.String</config-property-type>

        <config-property-value>test messages</config-property-value>

      </config-property>

    </resourceadapter>

  </connector>

For single node assigment I propose: set<NodeName> e.g. setResourceadapter(..)

For adding an instance to a list I propose: add<NodeName>  e.g. addConfigProperty(property)

You can find the implementation here: https://github.com/rbattenfeld/descriptors/tree/prototype

I am sending a pull request as Andrew mentioned in the reboot thread but I am not sure if that is correct:-)

Would be great to push this project further.

Regards,

Ralf