Java Class Template

Use this class as a template for a class that accesses record data and uses it to perform some operation. (The class is intentionally overly-complete, because it's a lot easier to remove something you don't need than it is to look up the syntax, or even know it is there in the first place.)

<syntaxhighlight lang="java" enclose="div">

package com.platform.yourCompany.yourApplication;

// Basic imports import com.platform.api.*; import java.util.*;

// Reference static functions without having to specify the Functions class. // So Functions.throwError() can be written as throwError(). // (Code is shorter that way, but it's less obvious where things are defined.) import static com.platform.api.Functions.*;

// These are needed for advanced operations. //import com.platform.beans.*; //import static com.platform.api.CONSTANTS.*;

public class YourClass {

  // Convenience methods to display a message to the user or add it the debug log.
  // Note:
  //   When showMessage() is called multiple times, the strings are concatenated. 
  //   One long string is then displayed when the code returns to the platform.
  //   We add an HTML linebreak (
) to separate them.
  public void show(String msg) throws Exception { Functions.showMessage(msg+"
"); }
  public void log(String msg) throws Exception { Logger.info(msg, "YourClass"); }
  public void debug(String msg) throws Exception { show(msg); log(msg); }

  /**
   * CALLED FROM THE PLATFORM (hence the Parameters argument)
   */
  public void doSomething(Parameters p) throws Exception
  {
     try {
        //Record incoming parameters in the log
        //log( "Method params:\n"+ p.toString().replace(" ","\n") );

        String objectID = p.get("object_id");
        String recordID = p.get("id");  

        // Define the parameters for some operation
        Parameters params = Functions.getParametersInstance();
        params.add("key", "value");
        //...

        // Do it.
        // Result.getCode() >= 0 on success, -1 on failure
        Result r = Functions.doSomething(params);
        if (r.getCode() < 0) {
           // Display message to user, add an entry to debug log, and
           // roll back the current transaction (no changes are committed).
           String msg = "Error <doing something>:\n"+ r.getMessage();
           Functions.throwError(msg);      
        }  
        debug("Success");
     } catch (Exception e) {
        String msg = e.getMessage() + "\n methodName(): "+e.getClass().getName(); 
        log(msg);  
        Functions.throwError(msg);
     }
  }

  /**
   * CALLED INTERNALLY(a utility function of some sort)
   */
  public String getSomeValue(String x) throws Exception
  {
     try {
        ...
     } catch (Exception e) {
        String msg = e.getMessage() + "\n methodName(): "+e.getClass().getName(); 
        Functions.throwError(msg);
     }
  }

  /**
   * UNIT TEST. (Note the @TestMethod pragma)
   */
  @TestMethod
  public void test1_DescribeTheTestHere() throws Exception
  {
     String expect = "some result";        
     String actual = methodThatReturnsSomeResult();
     RunTest.assertEquals(expect, actual);
  }

} // end class </syntaxhighlight>

Best Practice: Wrap code in a try..catch block, to guard against unexpected exceptions. (If not caught, they are simply ignored, and the method fails silently.) When you detect an error, put a detailed message into the Debug Log. Then call Functions.throwError to generate an exception, display a message for the user, and roll back the current transaction.

Additional Notes:

• Incoming Parameters

A Java method is always invoked in the context of some record. The method signature is therefore required to have take a Parameters argument, which contains the record fields, along with additional parameters.

Learn more:

• Standard Object Fields
• Standard Parameters

• Object names and IDs

• Most APIs take either object name or object ID. (Only a few require object ID.)
• For most operations you'll know which object you're operating on, so you'll specify the object name in a string.
• But the object ID is also available in the incoming Parameters, when you need it.

Learn more:

• Standard Fields
• Objects
  • System Objects
  • Custom Objects
  • Composite Objects