Porter 3.0 – Transformers

.travis.yml

@@ -31,11 +31,6 @@ install:
 script:
   - composer test -- --coverage-clover=build/logs/clover.xml
 
-  # Remove mapper and run all non-Mapper tests again.
-  - composer --dev --no-update-with-dependencies remove scriptfusion/mapper
-  - '! composer info | grep ^scriptfusion/mapper\\b'
-  - composer test -- --exclude-group Mapper
-
 after_success:
   - composer require satooshi/php-coveralls
   - vendor/bin/coveralls -v

composer.json

@@ -18,13 +18,12 @@
     "zendframework/zend-uri": "^2"
   },
   "require-dev": {
-    "scriptfusion/mapper": "^1",
     "phpunit/phpunit": "^4.8",
     "mockery/mockery": "^0.9.4",
     "symfony/process": "^3"
   },
   "suggest" : {
-    "scriptfusion/mapper": "Transforms imported data."
+    "transformers/mapping": "Transforms array collections using Mappings."
   },
   "autoload": {
     "psr-4": {

src/Porter.php

@@ -1,26 +1,21 @@
 <?php
 namespace ScriptFUSION\Porter;
 
-use ScriptFUSION\Mapper\CollectionMapper;
-use ScriptFUSION\Mapper\Mapping;
 use ScriptFUSION\Porter\Cache\CacheAdvice;
 use ScriptFUSION\Porter\Cache\CacheToggle;
 use ScriptFUSION\Porter\Cache\CacheUnavailableException;
-use ScriptFUSION\Porter\Collection\CountableMappedRecords;
 use ScriptFUSION\Porter\Collection\CountablePorterRecords;
 use ScriptFUSION\Porter\Collection\CountableProviderRecords;
-use ScriptFUSION\Porter\Collection\FilteredRecords;
-use ScriptFUSION\Porter\Collection\MappedRecords;
 use ScriptFUSION\Porter\Collection\PorterRecords;
 use ScriptFUSION\Porter\Collection\ProviderRecords;
 use ScriptFUSION\Porter\Collection\RecordCollection;
 use ScriptFUSION\Porter\Connector\RecoverableConnectorException;
-use ScriptFUSION\Porter\Mapper\PorterMapper;
 use ScriptFUSION\Porter\Provider\ObjectNotCreatedException;
 use ScriptFUSION\Porter\Provider\Provider;
 use ScriptFUSION\Porter\Provider\ProviderFactory;
 use ScriptFUSION\Porter\Provider\Resource\ProviderResource;
 use ScriptFUSION\Porter\Specification\ImportSpecification;
+use ScriptFUSION\Porter\Transform\Transformer;
 use ScriptFUSION\Retry\ExceptionHandler\ExponentialBackoffExceptionHandler;
 
 /**
@@ -40,11 +35,6 @@ class Porter
      */
     private $providerFactory;
 
-    /**
-     * @var CollectionMapper
-     */
-    private $mapper;
-
     /**
      * @var CacheAdvice
      */
@@ -63,7 +53,6 @@ class Porter
     public function __construct()
     {
         $this->defaultCacheAdvice = CacheAdvice::SHOULD_NOT_CACHE();
-        $this->fetchExceptionHandler = new ExponentialBackoffExceptionHandler;
     }
 
     /**
@@ -84,13 +73,7 @@ public function import(ImportSpecification $specification)
             $records = $this->createProviderRecords($records, $specification->getResource());
         }
 
-        if ($specification->getFilter()) {
-            $records = $this->filter($records, $specification->getFilter(), $specification->getContext());
-        }
-
-        if ($specification->getMapping()) {
-            $records = $this->map($records, $specification->getMapping(), $specification->getContext());
-        }
+        $records = $this->transformRecords($records, $specification->getTransformers(), $specification->getContext());
 
         return $this->createPorterRecords($records, $specification);
     }
@@ -121,27 +104,10 @@ public function importOne(ImportSpecification $specification)
         return $one;
     }
 
-    private function createProviderRecords(\Iterator $records, ProviderResource $resource)
-    {
-        if ($records instanceof \Countable) {
-            return new CountableProviderRecords($records, count($records), $resource);
-        }
-
-        return new ProviderRecords($records, $resource);
-    }
-
-    private function createPorterRecords(RecordCollection $records, ImportSpecification $specification)
-    {
-        if ($records instanceof \Countable) {
-            return new CountablePorterRecords($records, count($records), $specification);
-        }
-
-        return new PorterRecords($records, $specification);
-    }
-
     private function fetch(ProviderResource $resource, CacheAdvice $cacheAdvice = null)
     {
         $provider = $this->getProvider($resource->getProviderClassName(), $resource->getProviderTag());
+
         $this->applyCacheAdvice($provider, $cacheAdvice ?: $this->defaultCacheAdvice);
 
         if (($records = \ScriptFUSION\Retry\retry(
@@ -164,35 +130,42 @@ function (\Exception $exception) {
         throw new ImportException(get_class($provider) . '::fetch() did not return an Iterator.');
     }
 
-    private function filter(ProviderRecords $records, callable $predicate, $context)
+    /**
+     * @param RecordCollection $records
+     * @param Transformer[] $transformers
+     * @param mixed $context
+     *
+     * @return RecordCollection
+     */
+    private function transformRecords(RecordCollection $records, array $transformers, $context)
     {
-        $filter = function () use ($records, $predicate, $context) {
-            foreach ($records as $record) {
-                if ($predicate($record, $context)) {
-                    yield $record;
-                }
+        foreach ($transformers as $transformer) {
+            if ($transformer instanceof PorterAware) {
+                $transformer->setPorter($this);
             }
-        };
 
-        return new FilteredRecords($filter(), $records, $filter);
+            $records = $transformer->transform($records, $context);
+        }
+
+        return $records;
     }
 
-    private function map(RecordCollection $records, Mapping $mapping, $context)
+    private function createProviderRecords(\Iterator $records, ProviderResource $resource)
     {
-        return $this->createMappedRecords(
-            $this->getOrCreateMapper()->mapCollection($records, $mapping, $context),
-            $records,
-            $mapping
-        );
+        if ($records instanceof \Countable) {
+            return new CountableProviderRecords($records, count($records), $resource);
+        }
+
+        return new ProviderRecords($records, $resource);
     }
 
-    private function createMappedRecords(\Iterator $records, RecordCollection $previous, Mapping $mapping)
+    private function createPorterRecords(RecordCollection $records, ImportSpecification $specification)
     {
-        if ($previous instanceof \Countable) {
-            return new CountableMappedRecords($records, count($previous), $previous, $mapping);
+        if ($records instanceof \Countable) {
+            return new CountablePorterRecords($records, count($records), $specification);
         }
 
-        return new MappedRecords($records, $previous, $mapping);
+        return new PorterRecords($records, $specification);
     }
 
     private function applyCacheAdvice(Provider $provider, CacheAdvice $cacheAdvice)
@@ -266,7 +239,7 @@ public function getProvider($name, $tag = null)
                 return $provider;
             }
         } catch (ObjectNotCreatedException $exception) {
-            // Intentionally empty.
+            // We will throw our own exception.
         }
 
         throw new ProviderNotFoundException(
@@ -304,26 +277,6 @@ private function getOrCreateProviderFactory()
         return $this->providerFactory ?: $this->providerFactory = new ProviderFactory;
     }
 
-    /**
-     * @return CollectionMapper
-     */
-    private function getOrCreateMapper()
-    {
-        return $this->mapper ?: $this->mapper = new PorterMapper($this);
-    }
-
-    /**
-     * @param CollectionMapper $mapper
-     *
-     * @return $this
-     */
-    public function setMapper(CollectionMapper $mapper)
-    {
-        $this->mapper = $mapper;
-
-        return $this;
-    }
-
     /**
      * Gets the maximum number of fetch attempts per import.
      *
@@ -353,7 +306,7 @@ public function setMaxFetchAttempts($attempts)
      */
     private function getFetchExceptionHandler()
     {
-        return $this->fetchExceptionHandler;
+        return $this->fetchExceptionHandler ?: $this->fetchExceptionHandler = new ExponentialBackoffExceptionHandler;
     }
 
     /**

src/Specification/DuplicateTransformerException.php

@@ -0,0 +1,10 @@
+<?php
+namespace ScriptFUSION\Porter\Specification;
+
+/**
+ * The exception that is thrown when a transformer already exists at the target site.
+ */
+class DuplicateTransformerException extends \RuntimeException
+{
+    // Intentionally empty.
+}