Refactored Pipeline processor handling

[McFistyBuns]

Refactored processor handling to more closely resemble what Elasticsearch ingest pipeline endpoint expects.

Fixes #1810

All three ways of setting the processors should now work as expected:

$pipeline = new Pipeline($client);
$pipeline->setId('pageattachment')->setDescription('Extract attachment information');

//Create attachment processor
$attachproc = new AttachmentProcessor('pageDescBinary');
$attachproc->setIndexedChars(-1);
$attachproc->setTargetField('desc_attachment');

//Create remove processor 
$removeproc = new RemoveProcessor('pageDescBinary');

//Create second attachment processor 
$attachproc2 = new AttachmentProcessor('pageSpreadsheetBinary');
$attachproc2->setIndexedChars(-1);
$attachproc2->setTargetField('spreadsheet_attachment');

//Create second remove processor 
$removeproc2 = new RemoveProcessor('pageSpreadsheetBinary');

//Add processors to the pipeline
$pipeline->addProcessor($attachproc);
$pipeline->addProcessor($removeproc);
$pipeline->addProcessor($attachproc2);
$pipeline->addProcessor($removeproc2);

$response = $pipeline->create();

$processors = [
    [
        'attachment' => [
            'field' => 'pageDescBinary',
            'indexed_chars' => -1,
            'target_field' => 'desc_attachment',
        ],
    ],
    [
        'remove' => [
            'field' => 'pageDescBinary',
        ],
    ],
    [
        'attachment' => [
            'field' => 'pageSpreadsheetBinary',
            'indexed_chars' => -1,
            'target_field' => 'spreadsheet_attachment',
        ],
    ],
    [
        'remove' => [
            'field' => 'pageSpreadsheetBinary',
        ],
    ],
];
$pipeline->setRawProcessors($processors);
$pipeline->create();

$pipeline->setProcessors([$attachproc, $removeproc, $attachproc2, $removeproc2]);
$pipeline->create();

Should now produce the expected pipeline in elasticsearch:

curl -X GET http://localhost:9200/_ingest/pipeline/pageattachment?pretty=true
{
  "pageattachment" : {
    "processors" : [
      {
        "attachment" : {
          "field" : "pageDescBinary",
          "indexed_chars" : -1,
          "target_field" : "desc_attachment"
        }
      },
      {
        "remove" : {
          "field" : "pageDescBinary"
        }
      },
      {
        "attachment" : {
          "field" : "pageSpreadsheetBinary",
          "indexed_chars" : -1,
          "target_field" : "spreadsheet_attachment"
        }
      },
      {
        "remove" : {
          "field" : "pageSpreadsheetBinary"
        }
      }
    ],
    "description" : "Extract attachment information"
  }
}

[ruflin]

Thanks for the addition. I'm a big fan of PR's that remove code instead of adding new one :-) Feeding all to params simplifies also the handling.

It seems the linting rule has a tiny complaint, could you take a look? Could you also add an entry to the changelog file?

[McFistyBuns]

Sorry about that. I thought I had run PHP-CS-Fixer. Must have made that test change after I ran it.

[ruflin]

Thanks for the contribution @McFistyBuns !