com.paypal.butterfly.extensions.api

Class TransformationOperation<T extends TransformationOperation>

java.lang.Object

com.paypal.butterfly.extensions.api.TransformationUtility<T>

com.paypal.butterfly.extensions.api.TransformationOperation<T>

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

AddElementTO, ChangeOrRemoveElementTO

public abstract class TransformationOperation<T extends TransformationOperation>
extends TransformationUtility<T>

Special type of TransformationUtility that applies a modification to the project.
Transformation operations are also known by TO.
Differences between a regular transformation utility (TU) and transformation operations (TO):

• TU never modifies application. TO always does.
• TU usually returns a value, but not necessarily. TO never does.
• TU usually saves its result, but not necessarily. TO always does.
• TO allows multiple operations.

The default value for TransformationUtility.relative(String) is null, which means it must be set explicitly, unless an absolute path is set via TransformationUtility.absolute(String) or TransformationUtility.absolute(String, String)

Field Summary

Fields inherited from class com.paypal.butterfly.extensions.api.TransformationUtility

UTILITY_NAME_SYNTAX

Constructor Summary

Constructors

Constructor and Description
TransformationOperation()

Method Summary

Modifier and Type	Method and Description
protected java.io.File	getOrCreateReadFile(java.io.File transformedAppFolder, TransformationContext transformationContext) Creates and returns a temporary read-only copy of the file to be modified.
PerformResult	perform(java.io.File transformedAppFolder, TransformationContext transformationContext) Performs the transformation utility against the application to be transformed.
protected T	setSaveResult(boolean saveResult) Sets whether or not the value produced by the transformation utility execution, and also its result object as a whole, should both be saved in the transformation context object.

Methods inherited from class com.paypal.butterfly.extensions.api.TransformationUtility

abortOnFailure, abortOnFailure, absolute, absolute, applyPropertiesFromContext, checkDependencies, checkForBlankString, checkForEmptyString, checkForNull, clone, copy, dependsOn, equals, executeIf, executeIf, executeUnless, execution, getAbortionMessage, getAbsoluteFile, getContextAttributeName, getDependencies, getDescription, getIfConditionAttributeName, getName, getOrder, getParent, getRelativePath, getRelativePath, getSimpleClassName, getTransformationTemplate, getUnlessConditionAttributeName, hasBeenPerformed, hashCode, hashCode, isAbortOnFailure, isFileSet, isSaveResult, normalizeRelativePathSeparator, relative, set, setContextAttributeName, setName, setParent, toString, wasFileExplicitlySet

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

TransformationOperation

public TransformationOperation()

Method Detail

setSaveResult

protected final T setSaveResult(boolean saveResult)

Description copied from class: TransformationUtility

Sets whether or not the value produced by the transformation utility execution, and also its result object as a whole, should both be saved in the transformation context object. See also TransformationUtility.isSaveResult().

Overrides:

setSaveResult in class TransformationUtility<T extends TransformationOperation>

Parameters:

saveResult - if the value produced by the transformation utility execution, and also its result object as a whole, should both be saved in the transformation context object

Returns:

this transformation utility instance

getOrCreateReadFile

protected final java.io.File getOrCreateReadFile(java.io.File transformedAppFolder,
                                                 TransformationContext transformationContext)
                                          throws java.io.IOException

Creates and returns a temporary read-only copy of the file to be modified.
The file to be modified by any transformation operation is set via TransformationUtility.relative(String), TransformationUtility.absolute(String) or TransformationUtility.absolute(String, String)). Some transformation operations though might need to read the file to be modified as a stream, and modify it by writing to an output stream as that same file is read. Since it is impossible to modify a file at the same time it is being read, this utility method offers a convenient way to create a temporary read-only copy of the file to be modified. This copy should be used to be read, while the original file can be modified.
Important notes:

1. At the first time this method is called, the temporary file will be created and returned. If called again, the same temporary file created at the first time will be returned.
2. The read-only file will not reflect the changes performed in the original file at any moment, always keeping its original state.
3. There is no need to delete the temporary file after using it. Butterfly automatically deletes it when the JVM terminates.

Parameters:

transformedAppFolder - the folder where the transformed application code is

transformationContext - the transformation context object

Returns:

a temporary read-only copy of the file to be modified

Throws:

java.io.IOException - if the temporary file could not be created, if the specified file is actually a directory, or if it does not exist

perform

public final PerformResult perform(java.io.File transformedAppFolder,
                                   TransformationContext transformationContext)
                            throws TransformationUtilityException

Description copied from class: TransformationUtility

Performs the transformation utility against the application to be transformed. After this method is called, regardless of the result, even in case of skipped execution, TransformationUtility.hasBeenPerformed() has to return true.
This is the one called by the transformation engine, and regardless of any customization it could have, it must always:

1. 1- Call TransformationUtility.applyPropertiesFromContext(TransformationContext)
2. 2- Call TransformationUtility.execution(File, TransformationContext)

This method is NOT supposed to be overwritten, unless you really know what you are doing.

Overrides:

perform in class TransformationUtility<T extends TransformationOperation>

Parameters:

transformedAppFolder - the folder where the transformed application code is

transformationContext - the transformation context object

Returns:

the result

Throws:

TransformationUtilityException