> For the complete documentation index, see [llms.txt](https://ism-docs.xnarum.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ism-docs.xnarum.com/implementing-a-task.md). # Implementing a Task A task can be added on the fly during runtime. You implement a task class and put that class under Swordfish\_installed\_directory/custom directory. Then it will be automatically loaded when you open flow designer. To implement a task, a task class must implement TaskHandler and define an TaskDefinition java annotation. ## TaskHandler interface 
package com.ism.was.flow.entity;

import java.util.Map;
import java.util.Properties;

public interface TaskHandler {
public boolean initializeTask(Properties props);
public boolean execute(String flowId, String taskId, String transactionId, FlowTask \[] tasks, Map requestData);
public TaskResult getResult();
public String getName();
public boolean finalizeTask();
}
Signature
public boolean initializeTask(Properties props);
DescriptionUsed when extra additional initialization is required for a task
Parametersprops - input attributes defined in flow.
Return

boolean value.

  • True - initialization succeeded
  • False - initialization failed
Signature
public boolean execute(String flowId, String taskId, String transactionId, FlowTask [] tasks, Map requestData);
DescriptionMain method of a task
Parameters
  • flowId - flow id
  • taskId - task id
  • transactionId - transaction id
  • tasks - tasks executed previously
  • requestData - collection of output data from previous tasks
Return

boolean value.

  • True - succeeded
  • False - failed
Signature
public TaskResult getResult();
DescriptionReturns the result of task execution. This result contains the input and output data of the task execution
Parameters
ReturnTaskResult may contain error information, if it failed.
Signature
public boolean finalizeTask();
DescriptionUsed when an additional finalization is required of a task
Parameters
Return

boolean value.

  • True - succeeded
  • False - failed
## TaskDefinition annotation 
package com.ism.was.flow.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface TaskDefinition {
public String name();
public String description();
public int arguments();
public String html() default "";
public String type() default "java";
public String icon() default "";
public FieldDefinition \[] fields() default {};
public FieldDefinition \[] outs() default {};
public boolean test() default false;
public String testLink() default "";
public boolean custom() default false;
public String customPage() default "";
}
Attributes
NameDescription
nameTask name displayed in flow designer
descriptionTask description
argumentsNumber of input attribute. For display purpose only.
htmlcustom html page for input/output attributes
typetask type. For display purpose only
iconpath of task icon. ex) images/task.png
fieldsinput attribute list
outsoutput attribute list
testwhether test page is provided
testLinkcustom html page for testing
customTrue if custom html page is provided for input attibutes
customPage

The class path of the html page

ex) com/ism/was/flow/handler/html/ftptransfer-task.html

## FieldDefinition 
package com.ism.was.flow.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface FieldDefinition {

```
public String name();
public String label() default "";
public String help() default "";
public int width() default 0;
public String type() default "text";
public int height() default 0;
public int rows() default 3;
public int cols() default 80;
public String selectFrom() default "";
public String [] options() default {};
public String [] labels() default {};
```

}
Attributes
NameDescription
nameAttribute name displayed in property editor
labelLabel of attribute
helpHelp message
widthNot used. For display purpose only. HTML text box
heightNot used. For display purpose only. HTML text box
rowsFor display purpose only. HTML textarea
colsFor display purpose only. HTML textarea
selectFromUsed only when option list of HTML select is from a class invocation
optionsAvailable values of the attribute. HTML select
labelsFor display purpose only. HTML select
## Example implementation - Wait Task 
package com.ism.was.flow.handler;

import java.sql.Connection;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Vector;

import com.ism.common.Common;
import com.ism.common.logger.DefaultLogger;
import com.ism.was.flow\.annotation.FieldDefinition;
import com.ism.was.flow\.annotation.TaskDefinition;
import com.ism.was.flow\.config.FlowConstants;
import com.ism.was.flow\.entity.FlowTask;
import com.ism.was.flow\.entity.SubFlowExecution;
import com.ism.was.flow\.entity.TaskHandler;
import com.ism.was.flow\.entity.TaskResult;
import com.ism.was.flow\.log.SubFlowExecutionLog;
import com.ism.was.flow\.log.SubflowLogManager;
import com.ism.was.flow\.util.FlowUtil;

@TaskDefinition(
name="Wait", description="Wait sub flow completion", arguments=-1,
custom=false,type="function",
icon="images/wait.png",
fields = {
@FieldDefinition(name="SubFlowId", width=100, height=30, rows=10, cols=80, type="select", selectFrom="com.ism.projects.jpa.web.flow\.FlowProcessor" ),
@FieldDefinition(name="ExecutionCount", width=100, height=30, rows=10, cols=80, type="text" ),
@FieldDefinition(name="Timeout", width=100, height=30, rows=10, cols=80, type="text" ),
},
outs = {

```
	}
)
```

public class WaitSubTask implements TaskHandler {

```
protected Properties props;
protected TaskResult result;

protected Properties outprops;

private String resultValueName = null;

public boolean initializeTask(Properties props) {
	// TODO Auto-generated method stub
	this.props = props;
	return true;
}

public boolean execute(String flowId, String taskId, String gidSeq, FlowTask[] tasks, Map imap) {
	// TODO Auto-generated method stub
	
	result = new TaskResult(gidSeq);
	result.setStartTime();
	
	Vector imaps = new Vector();
	HashMap omap = new HashMap();
	omap.putAll(imap);
	
	result.setSuccess(true);
	
String gid = (String)imap.get("GID");
	
String subFlowId = (String)props.get("SubFlowId");
String executionCount = (String)props.get("ExecutionCount");
String timeout = (String)props.get("Timeout");
	
resultValueName = (String)props.get("out-ResultValue");
if ( resultValueName == null || resultValueName.trim().length() < 1 ) {
	resultValueName = "ResultValue";
}
	
Object rtn = null;

int completedCount = 0;
	try {
		executionCount = (String)FlowUtil.getValue(imap, props, executionCount);
		if ( executionCount == null ) {
			throw new Exception("ExecutionCount cannot be null or empty");
		}
		int executionCountInt = -1;
		try {
			executionCountInt = Integer.parseInt(executionCount.trim());	
		}catch( Exception e ) {
			throw new Exception("ExecutionCount value is invalid[" + executionCount + "]");
		}
		long start = System.currentTimeMillis();
		long timeoutLong = Long.parseLong(timeout) * 1000; //30 sec
		boolean succeeded = false;
		int interval = 0;
		while ( true ) {
		String fkey = String.format("%s-%s-%s", flowId, subFlowId, gid);
    			int count = SubflowLogManager.countComplete(fkey);
    		if ( ++interval % 10 == 0 ) {
    				DefaultLogger.logN("Expected count = {}, logged count = {}, {}, {}, {} ", executionCountInt, count, flowId, subFlowId, gid);
			}else {
    				DefaultLogger.logV("Expected count = {}, logged count = {}, {}, {}, {} ", executionCountInt, count, flowId, subFlowId, gid);
			}
        		if ( count != executionCountInt ) {
    				Thread.sleep(2000);
    			}else {
        			succeeded = true;
        			SubflowLogManager.removeSubflows(fkey);
    				break;
        		}
    			if ( Common.shutdown ) {
    				break;
        		}
    			long now = System.currentTimeMillis();
        		if ( now > (start + timeoutLong) ) {
    				break;
    			}
		}
	omap.put(resultValueName, rtn);
		result.setSuccess(succeeded);
	}catch( Exception e ) {
		DefaultLogger.logE(e, "Failed to executing function");
    		result.setErrorMessage(e.getMessage());
    		result.setException(e);
		result.setSuccess(false);
	}
result.setData(omap);
	result.setEndTime();
	
	return result.isSuccess();
}

public TaskResult getResult() {
	// TODO Auto-generated method stub
	return result;
}

public String getName() {
	// TODO Auto-generated method stub
	return null;
}

public boolean finalizeTask() {
	// TODO Auto-generated method stub
	return false;
}
```

}