PresentSelector (Apache Ant API)
Date: 2016-04-09

org.apache.tools.ant.types.selectors

## Class PresentSelector

- java.lang.Object
- - org.apache.tools.ant.ProjectComponent
  - - org.apache.tools.ant.types.DataType
    - - org.apache.tools.ant.types.selectors.BaseSelector
      - - org.apache.tools.ant.types.selectors.PresentSelector

- All Implemented Interfaces:
    java.lang.Cloneable, FileSelector

      public class PresentSelector
      extends BaseSelector

  Selector that filters files based on whether they appear in another directory tree. It can contain a mapper element, so isn't available as an ExtendSelector (since those parameters can't hold other elements).
  Since:
    1.5

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class and Description
    --- | ---
    `static class` | `PresentSelector.FilePresence` Enumerated attribute with the values for indicating where a file's presence is allowed and required.

  - ### Field Summary

    - ### Fields inherited from class org.apache.tools.ant.types.DataType

      `checked, ref`

    - ### Fields inherited from class org.apache.tools.ant.ProjectComponent

      `description, location, project`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `PresentSelector()` Creates a new `PresentSelector` instance.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `addConfigured(FileNameMapper fileNameMapper)` Add a configured FileNameMapper instance.
    `Mapper` | `createMapper()` Defines the FileNameMapper to use (nested mapper element).
    `boolean` | `isSelected(java.io.File basedir, java.lang.String filename, java.io.File file)` The heart of the matter.
    `void` | `setPresent(PresentSelector.FilePresence fp)` This sets whether to select a file if its dest file is present.
    `void` | `setTargetdir(java.io.File targetdir)` The name of the file or directory which is checked for matching files.
    `java.lang.String` | `toString()` Basic DataType toString().
    `void` | `verifySettings()` Checks to make sure all settings are kosher.

    - ### Methods inherited from class org.apache.tools.ant.types.selectors.BaseSelector

      `getError, setError, validate`

    - ### Methods inherited from class org.apache.tools.ant.types.DataType

      `checkAttributesAllowed, checkChildrenAllowed, circularReference, clone, dieOnCircularReference, dieOnCircularReference, dieOnCircularReference, getCheckedRef, getCheckedRef, getCheckedRef, getCheckedRef, getDataTypeName, getRefid, invokeCircularReferenceCheck, isChecked, isReference, noChildrenAllowed, pushAndInvokeCircularReferenceCheck, setChecked, setRefid, tooManyAttributes`

    - ### Methods inherited from class org.apache.tools.ant.ProjectComponent

      `getDescription, getLocation, getProject, log, log, setDescription, setLocation, setProject`

    - ### Methods inherited from class java.lang.Object

      `equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### PresentSelector

          public PresentSelector()

      Creates a new `PresentSelector` instance.

  - ### Method Detail

    - #### toString

          public java.lang.String toString()

      Description copied from class: `DataType`
      Basic DataType toString().
      Overrides:
        `toString` in class `DataType`
      Returns:
        a string describing this object

    - #### setTargetdir

          public void setTargetdir(java.io.File targetdir)

      The name of the file or directory which is checked for matching files.
      Parameters:
        `targetdir` - the directory to scan looking for matching files.

    - #### createMapper

          public Mapper createMapper()
                              throws BuildException

      Defines the FileNameMapper to use (nested mapper element).
      Returns:
        a mapper to be configured
      Throws:
        `BuildException` - if more than one mapper defined

    - #### addConfigured

          public void addConfigured(FileNameMapper fileNameMapper)

      Add a configured FileNameMapper instance.
      Parameters:
        `fileNameMapper` - the FileNameMapper to add
      Throws:
        `BuildException` - if more than one mapper defined
      Since:
        Ant 1.8.0

    - #### setPresent

          public void setPresent(PresentSelector.FilePresence fp)

      This sets whether to select a file if its dest file is present. It could be a `negate` boolean, but by doing things this way, we get some documentation on how the system works. A user looking at the documentation should clearly understand that the ONLY files whose presence is being tested are those that already exist in the source directory, hence the lack of a `destonly` option.
      Parameters:
        `fp` - An attribute set to either `srconly`both.

    - #### verifySettings

          public void verifySettings()

      Checks to make sure all settings are kosher. In this case, it means that the targetdir attribute has been set and we have a mapper.
      Overrides:
        `verifySettings` in class `BaseSelector`

    - #### isSelected

          public boolean isSelected(java.io.File basedir,
                           java.lang.String filename,
                           java.io.File file)

      The heart of the matter. This is where the selector gets to decide on the inclusion of a file in a particular fileset.
      Specified by:
        `isSelected` in interface `FileSelector`
      Specified by:
        `isSelected` in class `BaseSelector`
      Parameters:
        `basedir` - the base directory the scan is being done from
        `filename` - is the name of the file to check
        `file` - is a java.io.File object the selector can use
      Returns:
        whether the file should be selected or not