Rewrite plugin: when using own source key in chain the initial value is used

Problem/Motivation

When using the Rewrite plugin after an other plugin, the source value on the item remains unchanged. That's because Feeds Tamper currently writes the tampered value back to the item after all tampers have been applied.

Say for example you have the following value on a source field called "WORK_PHONE":

123/456-7890

And you want that to transform to:

(123)456-7890

If you apply a plugin first that replaces a slash with a close bracket and then apply the Rewrite plugin after that, in the end result what the first applied tamper had done is lost. You'll get "(123/456-7890" instead of "(123)456-7890".

Steps to reproduce

1. Have a source item with the following values:
   • WORK_PHONE: 123/456-7890
2. Configure the following tampers for the source "WORK_PHONE":
   • Find replace:
     • Text to find: /
     • Text to replace: )
   • Rewrite:
     • Replacement pattern: ([WORK_PHONE]
3. Run the Feeds import

Expected result: (123)456-7890

Actual result: (123/456-7890

Proposed resolution

In FeedsSubscriber, write back the value to the item after each applied Tamper plugin (instead of doing this after the whole chain of Tamper plugins are applied).

Remaining tasks

• Work out the source of the problem.
• Fix the problem.
• Review/Merge

User interface changes

None

API changes

None

Data model changes

None