How to create a callout that extends from another callout

Introduction

This howto discusses how to implement a callout that extends from another callout. This howto only explain the main important elements needed for the new feature. More details about callouts can be found in the How to create a Callout howto.

This feature is available from version 3.0PR16Q4

Example Module

This howto is supported by an example module which shows examples of the code shown and discussed.

The code of the example module can be downloaded from this public mercurial repository: org.openbravo.client.application.examples.

Defining callouts

It are going to show two callouts. One of them is the parent callout and the other one is the child callout.In this example, these two callouts are working in 'Assets' window.

Defining Parent Callout

The following example follows this guide to implement the callout. The example shows a callout that edits value of the 'Name' field.

<source lang="java"> package org.openbravo.client.application.examples.callouts;

import javax.servlet.ServletException;

import org.openbravo.erpCommon.ad_callouts.SimpleCallout;

public class OBEXAPP_Assets_Name extends SimpleCallout {

 protected static final String MODIFIED_FIELD = "_UPDATED";

 @Override
 protected void execute(CalloutInfo info) throws ServletException {

   // get value of field name and update value
   final String name = info.getStringParameter("inpname");
   info.addResult("inpname", name + MODIFIED_FIELD);

   // Combo example. Added three currencies to currency combo.
   info.addSelect("inpcCurrencyId");
   // USD currency is selected.
   info.addSelectResult("100", "USD", true);
   info.addSelectResult("102", "EUR", false);
   info.addSelectResult("103", "DEM", false);
   info.endSelect();
 }

} </source>

As you can see the callout gets the value of 'Name' field and concatenates the following string: '_UPDATED'. Besides you can see a code that defines a combo. This code it will explain in following section.

Defining Child Callout

This example callout extends from the parent callout that is defined above. Combo example is explained in next section.

<source lang="java"> package org.openbravo.client.application.examples.callouts;

import javax.servlet.ServletException;

public class OBEXAPP_Assets_Desc extends OBEXAPP_Assets_Name {

 @Override
 protected void execute(CalloutInfo info) throws ServletException {

   // OBEXAPP_Assets_Name callout is executed
   super.execute(info);

   // Combo example. Removed USD currency from combo and select DEM currency.
   info.addSelect("inpcCurrencyId");
   info.removeSelectResult("100");
   info.addSelectResult("103", "DEM", true);
   info.endSelect();

   // Checks if name field has been updated by parent callout.
   String name = info.getStringParameter("inpname");
   String message = "Feature 'Extends a Callout' works as expected.";
   if (name.endsWith(MODIFIED_FIELD)) {
     info.addResult("inpdescription", message);
     info.addResult("MESSAGE", message);
   } else {
     message = "Feature 'Extends a Callout' not works as expected.";
     info.addResult("inpdescription", message);
     info.addResult("ERROR", message);
   }

   // Now it is possible to update the 'name' field again and the value will be overwritten
   info.addResult("inpname", "UPDATED...");
 }

} </source>

First of all, OBEXAPP_Assets_Desc callout extends from OBEXAPP_Assets_Name. In this situation, you should take into account the following sections in this callout:

• Run parent callout.

<source lang="java">

   // OBEXAPP_Assets_Name callout is executed
   super.execute(info);

</source>

• Operations for combo field are executed. This code is explained in next section.

<source lang="java">

   // Combo example. Removed USD currency from combo and select DEM currency.
   info.addSelect("inpcCurrencyId");
   info.removeSelectResult("100");
   info.addSelectResult("103", "DEM", true);
   info.endSelect();

</source>

• Operations after parent callout is executed. In this case, child callout checks if name is been modified by parent callout. Then child callout takes two actions. Update the description field with a message and shows an information or failure message. Finally name field is updated again.

<source lang="java">

  // Checks if name field has been updated by parent callout.
   String name = info.getStringParameter("inpname");
   String message = "Feature 'Extends a Callout' works as expected.";
   if (name.endsWith(MODIFIED_FIELD)) {
     info.addResult("inpdescription", message);
     info.addResult("MESSAGE", message);
   } else {
     message = "Feature 'Extends a Callout' not works as expected.";
     info.addResult("inpdescription", message);
     info.addResult("ERROR", message);
   }

   // Now it is possible to update the 'name' field again and the value will be overwritten
   info.addResult("inpname", "UPDATED...");

</source>

In the following screenshot you can see how failure message is displayed.

900px

Working with combos

As you can see in above sections, the OBEXAPP_Assets_Name callout builds a currency combo. This combo is populated with 3 currencies and one of them is selected. <source lang="java"> ............

   // Combo example. Added three currencies to currency combo.
   info.addSelect("inpcCurrencyId");
   // USD currency is selected.
   info.addSelectResult("100", "USD", true);
   info.addSelectResult("102", "EUR", false);
   info.addSelectResult("103", "DEM", false);
   info.endSelect();

   ............

</source>

You can see the currency combo with 3 currencies and 'USD' as selected currency.

900px

Then, child callout (OBEXAPP_Assets_Desc) removes a currency and select another one. This child callout extends OBEXAPP_Assets_Name and change the currency combo.

<source lang="java"> ............

   // Combo example. Removed USD currency from combo and select DEM currency.
   info.addSelect("inpcCurrencyId");
   info.removeSelectResult("100");
   info.addSelectResult("103", "DEM", true);
   info.endSelect();

   ............

</source>

In this screenshot you can see how currency combo is displayed when child callout is executed.

The DEM currency is selected and USD currency has been removed.

900px

Using getStringParameter method

This method is used in callouts to get values of any field of the window.(e.g. value of name field in Assets window).

Now, with the inclusion of this project this method takes into account if a parent callout modified a value. If a value was modified, "getStringParameter()" method returns value modified by parent callout. If not, "getStringParameter()" method returns the initial value of the parameter.