From 35e1f9217f8cfcc70cc006e27530b2d78b5ab899 Mon Sep 17 00:00:00 2001
From: Georgi Hristov <ghristov@gmx.de>
Date: Wed, 5 Aug 2020 16:02:22 +0200
Subject: [PATCH] [update] accept Closure for Model:getFields filter and
 provide 'persisting' filter preset

---
 src/Model.php                 | 93 +++++++++++++++++------------------
 src/Persistence/Sql/Query.php | 40 ++-------------
 2 files changed, 50 insertions(+), 83 deletions(-)

diff --git a/src/Model.php b/src/Model.php
index 340acf4b24..2aa8108e2b 100644
--- a/src/Model.php
+++ b/src/Model.php
@@ -613,26 +613,49 @@ public function getFields($filter = null): array
     {
         if ($filter === null) {
             return $this->fields;
-        } elseif (is_string($filter)) {
+        } elseif (!is_array($filter)) {
             $filter = [$filter];
         }
 
-        return array_filter($this->fields, function (Field $field, $name) use ($filter) {
-            // do not return fields outside of "only_fields" scope
-            if ($this->only_fields && !in_array($name, $this->only_fields, true)) {
-                return false;
-            }
-            foreach ($filter as $f) {
-                if (
-                    ($f === 'system' && $field->system)
-                    || ($f === 'not system' && !$field->system)
-                    || ($f === 'editable' && $field->isEditable())
-                    || ($f === 'visible' && $field->isVisible())
-                ) {
+        $filterPresets = [
+            'system' => function (Field $field) {
+                return $this->isOnlyField($field->short_name) && $field->system;
+            },
+            'not system' => function (Field $field) {
+                return $this->isOnlyField($field->short_name) && !$field->system;
+            },
+            'editable' => function (Field $field) {
+                return $this->isOnlyField($field->short_name) && $field->isEditable();
+            },
+            'visible' => function (Field $field) {
+                return $this->isOnlyField($field->short_name) && $field->isVisible();
+            },
+            'persisting' => function (Field $field) {
+                if ($field->never_persist) {
+                    return false;
+                }
+
+                if (!$field->system) {
+                    return $this->isOnlyField($field->short_name);
+                }
+
+                return true;
+            },
+        ];
+
+        return array_filter($this->fields, function (Field $field, $name) use ($filter, $filterPresets) {
+            foreach ($filter as $fx) {
+                if (!$fx instanceof \Closure) {
+                    if (!isset($filterPresets[$fx])) {
+                        throw (new Exception('Filter is not supported'))
+                            ->addMoreInfo('filter', $fx);
+                    }
+
+                    $fx = $filterPresets[$fx];
+                }
+
+                if ($fx($field, $name)) {
                     return true;
-                } elseif (!in_array($f, ['system', 'not system', 'editable', 'visible'], true)) {
-                    throw (new Exception('Filter is not supported'))
-                        ->addMoreInfo('filter', $f);
                 }
             }
 
@@ -640,6 +663,11 @@ public function getFields($filter = null): array
         }, ARRAY_FILTER_USE_BOTH);
     }
 
+    public function isOnlyField($fieldName)
+    {
+        return !$this->only_fields || in_array($fieldName, $this->only_fields, true);
+    }
+
     /**
      * Set field value.
      *
@@ -1675,38 +1703,7 @@ public function export(array $fields = null, $key_field = null, $typecast_data =
 
         // prepare array with field names
         if ($fields === null) {
-            $fields = [];
-
-            if ($this->only_fields) {
-                // Add requested fields first
-                foreach ($this->only_fields as $field) {
-                    $f_object = $this->getField($field);
-                    if ($f_object->never_persist) {
-                        continue;
-                    }
-                    $fields[$field] = true;
-                }
-
-                // now add system fields, if they were not added
-                foreach ($this->getFields() as $field => $f_object) {
-                    if ($f_object->never_persist) {
-                        continue;
-                    }
-                    if ($f_object->system && !isset($fields[$field])) {
-                        $fields[$field] = true;
-                    }
-                }
-
-                $fields = array_keys($fields);
-            } else {
-                // Add all model fields
-                foreach ($this->getFields() as $field => $f_object) {
-                    if ($f_object->never_persist) {
-                        continue;
-                    }
-                    $fields[] = $field;
-                }
-            }
+            $fields = array_keys($this->getFields('persisting'));
         }
 
         // add key_field to array if it's not there
diff --git a/src/Persistence/Sql/Query.php b/src/Persistence/Sql/Query.php
index 90105cb31a..25590e7992 100644
--- a/src/Persistence/Sql/Query.php
+++ b/src/Persistence/Sql/Query.php
@@ -75,42 +75,12 @@ protected function initSelect($fields = null): void
             return;
         }
 
-        // add fields
-        if (is_array($fields)) {
-            // Set of fields is strictly defined for purposes of export,
-            // so we will ignore even system fields.
-            foreach ($fields as $fieldName) {
-                $this->addField($this->model->getField($fieldName));
-            }
-        } elseif ($this->model->only_fields) {
-            $addedFields = [];
-
-            // Add requested fields first
-            foreach ($this->model->only_fields as $fieldName) {
-                $field = $this->model->getField($fieldName);
-                if ($field->never_persist) {
-                    continue;
-                }
-                $this->addField($field);
-                $addedFields[$fieldName] = true;
-            }
+        if (!is_array($fields)) {
+            $fields = array_keys($this->model->getFields('persisting'));
+        }
 
-            // now add system fields, if they were not added
-            foreach ($this->model->getFields() as $fieldName => $field) {
-                if ($field->never_persist) {
-                    continue;
-                }
-                if ($field->system && !isset($addedFields[$fieldName])) {
-                    $this->addField($field);
-                }
-            }
-        } else {
-            foreach ($this->model->getFields() as $fieldName => $field) {
-                if ($field->never_persist) {
-                    continue;
-                }
-                $this->addField($field);
-            }
+        foreach ($fields as $fieldName) {
+            $this->addField($this->model->getField($fieldName));
         }
     }