Improve Base collection, model and repository

- Add collection pipeline methods
- Add save collection method

src/BaseModel.php

@@ -69,6 +69,18 @@ abstract class BaseModel
 		return $model;
 	}
 
+	/**
+	 * Magic isset method. Returns true if the field exists, either in the data prperty array or in any of the local properties.
+	 * Used by array_column() on an array of objects.
+	 *
+	 * @param $name
+	 * @return bool
+	 */
+	public function __isset($name)
+	{
+		return in_array($name, array_merge(array_keys($this->data), array_keys(get_object_vars($this))));
+	}
+
 	/**
 	 * Magic getter. This allows to retrieve model fields with the following syntax:
 	 * - $model->field (outside of class)
@@ -80,9 +92,7 @@ abstract class BaseModel
 	 */
 	public function __get($name)
 	{
-		if (empty($this->data['id'])) {
-			throw new HTTPException\InternalServerErrorException(static::class . ' record uninitialized');
-		}
+		$this->checkValid();
 
 		if (!array_key_exists($name, $this->data)) {
 			throw new HTTPException\InternalServerErrorException('Field ' . $name . ' not found in ' . static::class);
@@ -104,4 +114,11 @@ abstract class BaseModel
 	{
 		return $this->data;
 	}
+
+	protected function checkValid()
+	{
+		if (empty($this->data['id'])) {
+			throw new HTTPException\InternalServerErrorException(static::class . ' record uninitialized');
+		}
+	}
 }