Component Task
Description
The component task automates the creation of component deployment meta data.
Attributes
| type | Set the component type classname (required). |
| key | Required only when declaring a nested component within a type. The key corresponds to the internal key that uniquely identifies the child component within the scope of the enclosing component type. |
| name | Optional overriding of the component profile name. If not supplied the component profile name will default to the name of the underlying component type. |
| activation | Set the auto-activation policy (optional). The default value is SYSTEM. Possible values include STARTUP (triggers activation on startup), DEMAND (activation trigger on demand) and SYSTEM (activation decesions are delagated to the container). |
| collection | Overrides the component garbage collection policy (optional). Allowable values include WEAK, SOFT and HARD. A component declaring a WEAK collection policy will be garbage collected at the discretion of the JVM. A component declaring a SOFT collection policy will be garbage collected in the event of memory contention. A component declaring the HARD collection policy will remain in memory for the lifetime of the JVM unless explicitly removed via a management system or controlling application. |
Special Test Attributes
| test | The test attribute internally switches the implementation to generate a local file reference for the project jar file when constructing the component classloader defintion. This enables the deployment of the component type in a unit test prior to the publication of the project jar file. Used only in conjunction with top-level component declarations. Typically used in conjunction with the dest attribute. |
| dest | Normally the component will construct an artifact under the project target/deliverables/parts directory. When generating deployment descriptors for local testing the dest enables the nomination of a local destination filename. Setting dest to any value will disable production of a deliverable artifact. Normally used in conjuction with the test attribute. |
Nested Elements
| categories | The categories element may contain 0..n logging <category> directives. A category directive allows manipulation of logging channel priorities and targets. |
| configuration | Declaration of a default configuration instance. |
| parameters | Declaration of a default parameters instance. |
| context | Declaration of the component initial context state. |
| parts | Declaration of the nested componets. |
Examples
Simple Example
Example of the creation of a test component directive using the test attribute in conjunction with the dest attribute. The example includes the declaration of lazy activation and HARD collection policy. The nested context definition asserts an initial value for the color context entry to the Color RED.
<component xmlns="dpml:metro" dest="target/test/composite.part" test="true" activation="false"
type="net.dpml.test.composite.CompositeComponent" name="composite" collection="hard">
<context>
<entry key="color" method="RED"/>
</context>
</component>