ambari-views/examples/favorite-view/docs/index.md

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Favorite View Example
======

Description
-----
The Favoriate View is a very simple view example. It demonstrates the very basics of how
to write and expose a REST service which works with instance parameters and instance data.

Package
-----
All views are packaged as a view archive. The view archive contains the configuration
file and various optional components of the view.

#####view.xml

The view.xml file is the only required file for a view archive.  The view.xml is the configuration that describes the view and view instances for Ambari.
The view.xml for this example defines two required parameters for configuring a view instance: what.is.the.question and i.do.not.know. The view also
defines a single resource that exposes a REST service at the /favorite end point.

    <view>
      <name>FAVORITE</name>
      <label>Favorite</label>
      <version>1.0.0</version>
      <parameter>
        <name>what.is.the.question</name>
        <description>Ask a question</description>
        <required>true</required>
      </parameter>
      <parameter>
        <name>i.do.not.know</name>
        <description>If you do not know</description>
        <required>true</required>
      </parameter>
      <resource>
        <name>favorite</name>
        <service-class>org.apache.ambari.view.favorite.FavoriteService</service-class>
      </resource>
    </view>

Build
-----

The view can be built as a maven project.

    cd ambari-views/examples/favorite-view
    mvn clean package

The build will produce the view archive.

    ambari-views/examples/favorite-view/target/favorite-view-1.0.0.jar

Place the view archive on the Ambari Server and restart to deploy.    

    cp favorite-view-1.0.0.jar /var/lib/ambari-server/resources/views/
    ambari-server restart
    
Create View Instance
-----

With the view deployed, create an instance of the view to be used by Ambari users.

    POST
    /api/v1/views/FAVORITE/versions/1.0.0/instances/FAVCOLOR
    
    [ {
      "ViewInstanceInfo" : {
        "label" : "Colors",
        "description" : "Choose your favorite color",
        "properties" : {
          "what.is.the.question" : "What is your favorite color?",
          "i.do.not.know" : "green"
        }
      }
    } ]

Access the view service end point:

    /api/v1/views/FAVORITE/versions/1.0.0/instances/FAVCOLOR/resources/favorite

To get the favorite color:

    GET
    /api/v1/views/FAVORITE/versions/1.0.0/instances/FAVCOLOR/resources/favorite/item

To set the favorite color:

    POST
    /api/v1/views/FAVORITE/versions/1.0.0/instances/FAVCOLOR/resources/favorite/item/blue