Improved documentation and added example CSV file

docs/assets/usage/import_export/part_import_example.csv

@@ -0,0 +1,4 @@
+name;description;category;notes;footprint;tags;quantity;storage_location;mass;ipn;mpn;manufacturing_status;manufacturer;supplier;spn;price;favorite;needs_review;minamount;partUnit;manufacturing_status
+BC547;NPN transistor;Transistors -> NPN;very important notes;TO -> TO-92;NPN,Transistor;5;Room 1 -> Shelf 1 -> Box 2;10;;;Manufacturer;;You need to fill this line, to use spn and price;BC547C;2,3;0;;;;
+BC557;PNP transistor;<b>HTML</b>;;TO -> TO-92;PNP,Transistor;10;Room 2-> Box 3;;Internal1234;;;;;;;;1;;;active
+Copper Wire;;Wire;;;;;;;;;;;;;;;;;Meter;

docs/usage/import_export.md

@@ -11,6 +11,11 @@ Part-DB offers the possibility to import existing data (parts, datastructures, e
 
 ## Import
 
+{: .note }
+> As data import is a very powerful feature and can easily fill up your database with lots of data, import is by default only available for
+> administrators. If you want to allow other users to import data, or can not import data, check the permissions of the user. You can enable import for each data structure
+> individually in the permissions settings.
+
 ### Import parts
 
 Part-DB supports the import of parts from CSV files and other formats. This can be used to import existing parts from other databases or datasources into Part-DB. The import can be done via the "Tools -> Import parts" page, which you can find in the "Tools" sidebar panel.
@@ -65,6 +70,8 @@ The following fields can be used to specify the supplier/distributor, supplier p
 #### Example data
 Here you can find some example data for the import of parts, you can use it as a template for your own import (especially the CSV file).
 
+* [Part import CSV example]({% link assets/usage/import_export/part_import_example.csv %}) with all possible fields
+
 ## Export
 
 By default every user, who can read the datastructure, can also export the data of this datastructure, as this does not give the user any additional information.

src/Controller/PartImportExportController.php

@@ -33,6 +33,7 @@ use Symfony\Component\HttpFoundation\File\UploadedFile;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
+use Symfony\Component\Serializer\Exception\NotNormalizableValueException;
 use UnexpectedValueException;
 
 class PartImportExportController extends AbstractController
@@ -93,6 +94,9 @@ class PartImportExportController extends AbstractController
                 $errors = $this->entityImporter->importFileAndPersistToDB($file, $options, $entities);
             } catch (UnexpectedValueException $e) {
                 $this->addFlash('error', 'parts.import.flash.error.invalid_file');
+                if ($e instanceof NotNormalizableValueException) {
+                    $this->addFlash('error', $e->getMessage());
+                }
                 goto ret;
             }
 

src/Serializer/PartNormalizer.php

@@ -103,13 +103,24 @@ class PartNormalizer implements NormalizerInterface, DenormalizerInterface, Cach
             $data['ipn'] = null;
         }
 
+        //Fill empty needs_review and needs_review_comment fields with false
+        if (empty($data['needs_review'])) {
+            $data['needs_review'] = false;
+        }
+        if (empty($data['favorite'])) {
+            $data['favorite'] = false;
+        }
+        if (empty($data['minamount'])) {
+            $data['minamount'] = 0.0;
+        }
+
         $object = $this->normalizer->denormalize($data, $type, $format, $context);
 
         if (!$object instanceof Part) {
             throw new \InvalidArgumentException('This normalizer only supports Part objects!');
         }
 
-        if (isset($data['instock']) || isset($data['storelocation'])) {
+        if ((isset($data['instock']) && trim($data['instock']) !== "") || (isset($data['storelocation']) && trim($data['storelocation']) !== "")) {
             $partLot = new PartLot();
 
             if (isset($data['instock']) && $data['instock'] !== "") {