java - Set onlyIf dependency on Gradle plugin task -

i've implemented gradle plugin in java. followed this tutorial.

my plugin class looks follows:

public class demoplugin implements plugin<project> {     @override     public void apply(project project) {         project.getextensions().create("demosetting", demopluginextension.class);          project.gettasks().create("demo", demotask.class);     } } 

currently intended implement onlyif feature unfortunately did not succeed yet.

my try following:

public class demoplugin implements plugin<project> {     @override     public void apply(project project) {         demopluginextension ext = project.getextensions().create("demosetting", demopluginextension.class);          closure closure = new closure(this) {             public object docall() {                 return ext.isexecutetask();             }         };          project.gettasks().create("demoproperties", demotask.class).onlyif(closure);     } } 

the error observing following:

what went wrong: execution failed task ':demo'. cannot call task.setonlyif(closure) on task ':demo' after task has started execution.

i appreciate if give me hint solving issue.

finally solved using following code:

public class demoplugin implements plugin<project> {     @override     public void apply(project project) {         demopluginextension ext = project.getextensions().create("demosetting", demopluginextension.class);          project.gettasks().create("demoproperties", demotask.class).onlyif(new closure(this) {             public object call(object arguments) {                 return true;             }         });     } } 

please note implementation of method

public object call(object arguments)

instead of

public object docall()