Added Sortable livewire trait helper

Author: nahime0

Diff for: src/Contracts/Livewire/Sortable.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace Illegal\LaravelUtils\Contracts\Livewire;
+
+/**
+ * A sortable trait for livewire list components.
+ * Import the trait in your livewire component than:
+ * 1. Use the contructor to populate $this->sortDefaultField with the field that should be sorted by default.
+ * 2. Use the contructor to populate $this->sortFields with the fields that can be sorted (key = query string field, value = table field).
+ *
+ * If you want to persist the sort field and direction in the url, use the following code in your livewire component:
+ * 1. Declare a protected $queryString array.
+ * 2. Use the contructor to populate the $queryString array with the sortField and sortDirection.
+ *
+ * For example:
+ * ```php
+ * $this->queryString = [
+ *     'sortField'     => ['except' => $this->sortDefaultField],
+ *     'sortDirection' => ['except' => $this->sortDirection]
+ * ];
+ * ```
+ */
+trait Sortable
+{
+    /**
+     * @var string $sortDefaultField The default sort field.
+     */
+    public string $sortDefaultField = "";
+
+    /**
+     * @var string $sortField The current sort field.
+     */
+    public string $sortField = "";
+
+    /**
+     * @var string $sortDirection The current sort direction.
+     */
+    public string $sortDirection = 'desc';
+
+    /**
+     * @var array $sortFields The fields that can be sorted.
+     */
+    public array $sortFields = [];
+
+    /**
+     * Sort the table by the given field.
+     *
+     * @param string $field The field to sort by.
+     * @return void
+     */
+    public function sortBy(string $field): void
+    {
+        if ($this->sortField === $field) {
+            $this->sortDirection = $this->sortDirection == 'asc' ? 'desc' : 'asc';
+        } else {
+            $this->sortField     = $field;
+            $this->sortDirection = 'asc';
+        }
+    }
+
+    /**
+     * Get the sort array.
+     *
+     * @return array The sort array, first value is the field and the second value is the direction.
+     */
+    protected function getSort(): array
+    {
+        /**
+         * Allow only fields that are in the $sortFields array and direction can only be asc or desc
+         */
+        $this->sortField     = in_array($this->sortField, $this->sortFields) ? $this->sortField : $this->sortDefaultField;
+        $this->sortDirection = in_array($this->sortDirection, ['asc', 'desc']) ? $this->sortDirection : 'desc';
+
+        return [$this->sortField, $this->sortDirection];
+    }
+}