Basic Anatomy of a Component

Typically, a component has five classes that extend/implement the specified classes/interfaces defined by the Isight framework:

Executor: Used when the component is run.
Editor: The GUI to allow configuration of the component.
Post-processor: Used to provide a summary of the output.
Handler: Used for validation at design time.
Preference Editor: Used to specify preferences for all instances of the given component.

You can have other supporting classes as needed. The following table summarizes the Isight framework defined interfaces/classes for the above mentioned entities.

Isight Framework for Component Development

Component Type	Interface	Super-class
Executor	`com.engineous.sdk.runtime.Component`	`com.engineous.sdk.runtime.` `AbstractComponent`
Editor	`com.engineous.desktop.sdk.` `DesktopEditor`	`com.engineous.desktop.sdk.` `AbstractDesktopEditor`
Post-processor	`com.engineous.sdk.runtime.` `PostProcessor`	`com.engineous.sdk.component.` `DefaultComponentPostProcessor`
Handler	`com.engineous.sdk.component.` `ComponentHandler`	`com.engineous.sdk.component.` `DefaultComponentHandler`
Preference Editor	`com.engineous.sdk.preferences.` `PreferencePanel`	`com.engineous.sdk.preferences.` `AbstractPreferencePanel`

In addition to these classes you must have an xml file called component descriptor and a manifest file. Both files must contain vital information about the component. You must provide the component descriptor file. Typically, the manifest file is created by the project build file.

A typical component descriptor file with numbered placeholders for various values follows:

<?xml version="1.0" encoding="UTF-8"?>
<MetaModel name=" 1 "
supername="com.engineous.system.component.Activity"
superversion="*.*.*" version=" 2 ">

<Requires>
   <SystemRelease>2.0.0</SystemRelease>
</Requires>

<DisplayName> 3 </DisplayName>
<Description> 4 </Description>

<Icon> 5 </Icon>

<Editor type=
"com.engineous.desktop.sdk.DesktopEditor"> 6 </Editor>
<Runtime type="com.engineous.sdk.runtime.Component"> 6 
</Runtime>
<Handler type=
"com.engineous.sdk.component.ComponentHandler">
6 </Handler>
<PostProcessor type=
"com.engineous.sdk.runtime.PostProcessor">
6 </PostProcessor>
<PreferencesPanel type=
"com.engineous.sdk.preferences.PreferencePanel"> 6 
</PreferencesPanel>

<Variables>
   <Variable description=" 4 " model="Local" name=" 7 " 
   tag=" 7 " role="Property" structure="Scalar"
   type="com.engineous.datatype.String 8">
   </Variable>
</Variables>

<Preferences>
   <Preference name=" 7 " tag=" 7 "
   type="com.engineous.datatype.String">
      <Value>" 9 " </Value
   </Preference>
</Preferences>

</MetaModel>

The significance of placeholders in the component descriptor above is:

Placeholder	Value
`1`	The metamodel name of the component (e.g., `com.engineous.component.adams`).
`2`	The version number (e.g., 1.0.0).
`3`	The name of the component.
`4`	A brief description.
`5`	The path to the icon of the component (e.g., `com/engineous/component/adams/adamsicon.gif`).
`6`	Full name of the appropriate class (e.g., `com.engineous.component.adams.AdamsEditor`).
`7`	The name/tag of the variable/preference.
`8`	The data type (see Datatype Development).
`9`	The initial value of the preference.