First, we create a resource integration project for our bundle fragment. Elastic Path provides a Maven Archetype to simplify the task to create a new resource integration. Archetypes are project templates that contain some of the standard components you'll need for your project.

1. Open a command prompt and navigate to your Extensions Directory.
2. Run the following command to create a Cortex resource integration project:

   mvn archetype:generate -DarchetypeArtifactId=ep-cortex-resource-integration-archetype -DarchetypeGroupId=com.elasticpath.cortex.dce -DarchetypeVersion=<your-artifact-version>

   Tip: Stack Trace Tip

   You may see a stack trace preceded by a warning similar to the following:

   [WARNING] Error reading archetype catalog http://repo1.maven.org/maven2
   org.apache.maven.wagon.TransferFailedException: Error transferring file: Connection timed out: connect
               

   This can occur if you are operating Maven in online mode. It can be safely ignored.

   Tip: Troubleshooting Tip

   Build fails when generating the archetype? See: Knowledge Base.

3. Enter the following information when prompted:

   Table 1. Archetype Variable Values

   Variable	Value
   groupId	com.elasticpath.tutorials
   artifactId	resource-integration-fragment-override
   version	1.0-SNAPSHOT
   package	com.elasticpath.tutorials

4. Change to the newly created project directory and execute the following command to build the resource integration JAR file:

   mvn install

Once the base project is set up, add the appropriate rest resource dependency to it. Because we are building an itemdefinitions resource integration, we'll add the itemdefinitions rest resource dependency.

Our project is now an itemdefinitions resource integration bundle fragment. Now we need to implement our custom logic in the fragment project.

In our use case, we only care about changing the itemdefinition's display-name and details. Therefore, we only need to implement the ItemDefinitionLookupStrategy in our fragment project. The other functionality in OOTB itemdefinitions resource integration will be unaffected by this change.

We need to declare our new strategy implementation, so it's called instead of the out-of-the-box implementation's strategy. To do this, we create an application context XML file and declare our new bean in it.

1. In the resource-integration-fragment-override project, navigate to resources/OSGI-INF/blueprint/ and create a new XML file called applicationContext-itemdefinitions-integration.xml. This is the same name of the application context file in the OOTB itemdefinition resource integration.
2. In applicationContext-itemdefinitions-integration.xml, declare a new spring bean with id itemDefinitionLookupStrategy. This is the ID of the bean we want to override in the OOTB itemdefinition resource integration. Set the bean's class to the new ItemDefinitionStrategyImpl class. The contents of the xml file look similar to the following:

   <xml version="1.0" encoding="UTF-8"?>
   <beans
   		xmlns="http://www.springframework.org/schema/beans"
   		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   		xmlns:context="http://www.springframework.org/schema/context"
   		xsi:schemaLocation="http://www.springframework.org/schema/beans
   			http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   			http://www.springframework.org/schema/context
   			http://www.springframework.org/schema/context/spring-context-3.0.xsd">
   
       <bean id="itemDefinitionLookupStrategy" class="com.example.resource.integration.ItemDefinitionLookupStrategyImpl" />
   
   </beans>
   

3. In command line, navigate to the fragment project root, and build the project by running:

   mvn install

Now we need to add the bundle fragment to our application, so it attaches to our itemdefinitions resource integration during Cortex web application startup.

To make this change, you will need to shut down Cortex web application, modify the web application's POM file, and then restart the web application.

1. With a text editor, open the Cortex web application's POM file.
2. Add the new bundle fragment as a <dependency> and as an <artifactItem> to the web app's pom as shown below:

   ...
   
     <dependencies>
   		<!-- Add Extension resources or Integration modules as maven dependencies here. -->
   		
   	<dependency>
   		<groupId>com.elasticpath.tutorials</groupId>
   		<artifactId>resource-integration-fragment-override</artifactId>
   		<version>1.0-SNAPSHOT</version>
   		<scope>provided</scope>
   	</dependency>
   
   ...
   
   	<plugins>
   		<plugin>
   			<groupId>org.apache.maven.plugins</groupId>
   			<artifactId>maven-dependency-plugin</artifactId>
   				<executions>
   					<execution>
   						<id>copy-extra-cortex-resources</id>
   						<phase>prepare-package</phase>
   						<goals>
   							<goal>copy</goal>
   						</goals>
   						<configuration>
   							<artifactItems>
   								<!-- Add Extension resources or Integration modules as maven artifacts here. -->
   									
   								<artifactItem>
   									<groupId>com.elasticpath.tutorials</groupId>
   									<artifactId>resource-integration-fragment-override</artifactId>
   								</artifactItem>
   												
   								</artifactItems>
   						</configuration>
   					</execution>
   				</executions>
   		</plugin>
   
   ...

3. In a command line, navigate to your Cortex web application folder and execute:

   mvn clean install -DskipAllTests

With the new fragment in place, queries for itemdefinitions return the same display-name and details as we have configured them to do in this sample fragment bundle.

To test this capability:

1. Start up your Cortex web application.
2. Using a REST client, log into the demo store using these credentials:
   • Username: oliver.harris@elasticpath.com
   • Password: password
3. Using your REST client, create a search by sending the following request:

   Table 2.

   HTTP Request Method	URL	Header	Body
   POST	https://localhost:8443/cortex/searches/mobee/keywords/items	Content-type: Application/json	{"keywords":"twilight"}

4. Now in the links returned, follow the link with the rel "element" to retrieve the item. Then follow the rel "itemdefinitions" to retrieve item definitions for Twilight. The Response should be similar to the following:

   {
     "self": {
       "type": "elasticpath.itemdefinitions.item-definition",
       "uri": "/commerce-legacy/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2",
       "href": "http://localhost/cortex/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2"
     },
     "details": [
       {
         "display-name": "Item Ext Display Name",
         "display-value": "Item Ext Display Value",
         "name": "itemextname",
         "value": "itemextvalue"
       }
     ],
     "display-name": "Item Display",
     "links": [
       {
         "type": "elasticpath.items.item",
         "rel": "item",
         "rev": "definition",
         "href": "http://localhost/cortex/items/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2",
         "uri": "/commerce-legacy/items/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2"
       },
       {
         "type": "elasticpath.collections.links",
         "rel": "options",
         "rev": "definition",
         "href": "http://localhost/cortex/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2/options",
         "uri": "/commerce-legacy/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2/options"
       },
       {
         "type": "elasticpath.collections.links",
         "rel": "assets",
         "rev": "definition",
         "href": "http://localhost/cortex/assets/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2",
         "uri": "/commerce-legacy/assets/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2"
       },
       {
         "type": "elasticpath.prices.item-price-range",
         "rel": "fromprice",
         "rev": "definition",
         "href": "http://localhost/cortex/prices/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2",
         "uri": "/commerce-legacy/prices/itemdefinitions/mobee/m5yxissunrjgovjqnrefsrluizlweq2ejfkgcy2onnghkz2ujfsvgrkpljdhoqlyoazu44tekvhhmwshk5ywiscrgrhuizzqjzkfumdeo46t2"
       }
     ]
     
   }