api / org.gradle.api.tasks.incremental / IncrementalTaskInputs

IncrementalTaskInputs

@Incubating @NonExtensible interface IncrementalTaskInputs

Provides access to any input files that need to be processed by an incremental task.

An incremental task action is one that accepts a single IncrementalTaskInputs parameter. The task can then provide an action to execute for all input files that are out of date with respect to the previous execution of the task, and a separate action for all input files that have been removed since the previous execution.

 class IncrementalReverseTask extends DefaultTask { @InputDirectory def File inputDir @OutputDirectory def File outputDir @TaskAction void execute(IncrementalTaskInputs inputs) { if (!inputs.incremental) project.delete(outputDir.listFiles()) inputs.outOfDate { change -> def targetFile = project.file("$outputDir/${change.file.name}") targetFile.text = change.file.text.reverse() } inputs.removed { change -> def targetFile = project.file("$outputDir/${change.file.name}") if (targetFile.exists()) { targetFile.delete() } } } } 

In the case where Gradle is unable to determine which input files need to be reprocessed, then all of the input files will be reported as #outOfDate. Cases where this occurs include:

Note that this is a stateful API:

Functions

isIncremental

abstract fun isIncremental(): Boolean

Indicates if it was possible for Gradle to determine which exactly input files were out of date compared to a previous execution. This is not possible in the case of no previous execution, changed input properties, output files, etc.

When true:

  • Any input file that has been added or modified since previous execution will be considered 'out-of-date' and reported to #outOfDate.
  • Any input files that has been removed since previous execution will be reported to #removed.

When false:

  • Every input file will be considered to be 'out-of-date' and will be reported to #outOfDate.
  • No input files will be reported to #removed.

outOfDate

abstract fun outOfDate(outOfDateAction: Action<in InputFileDetails>): Unit

Executes the action for all of the input files that are out-of-date since the previous task execution. The action may also be supplied as a groovy.lang.Closure.

  • When #isIncremental() == true, the action will be executed for any added or modified input file.
  • When #isIncremental() == false, the action will be executed for every input file for the task.

This method may only be called a single time for a single IncrementalTaskInputs instance.

removed

abstract fun removed(removedAction: Action<in InputFileDetails>): Unit

Executes the action for all of the input files that were removed since the previous task execution. The action may also be supplied as a groovy.lang.Closure.

This method may only be called a single time for a single IncrementalTaskInputs instance.

This method may only be called after #outOfDate has been called.