When are gradle task inputs evaluated?

See Project.files(…) where you can use a Task as the source for a FileCollection

A Task . Converted to the task’s output files. The task is executed if the file collection is used as an input to another task

So a FileCollection has two pieces of information that Gradle uses

• Task dependencies
• The actual files

Gradle first uses task dependencies to determine the DAG which defines the task order. It only iterates the actual files under the hood during each task’s “UP-TO-DATE” check prior to task execution.

Many of Gradle’s file based configuration methods accept Object which you can pass a task instance.

So you can do the following and Gradle will create the task dependencies based on TaskInputs

task task1 {
   outputs.dir "path/to/output" 
   doLast {
      // create files in output dir 
   } 
}
task task2(type:Copy) {
   from task1
   into "another/path" 
} 
task task3 {
   inputs.files task2
   doLast {
      task2.files.each { println it } 
   } 
}