Add option to define column alias/aliases to prevent column ambiguous when using SELECT JOIN

Fix for issue #2

Author: ngekoding

README.md

@@ -1,12 +1,12 @@
 # CodeIgniter DataTables
 
-DataTables server-side for CodeIgniter, supported both for CodeIgniter 3 and CodeIgniter 4.
+DataTables server-side for CodeIgniter, supported for both CodeIgniter 3 and CodeIgniter 4.
 
-**Note:** This library only handle the server-side part, you still needs to configure the client side like jQuery, DataTables library and including the styles.
+**Note:** This library only handle the server-side part, you still needs to configure the client side like jQuery, DataTables library and including the styles. Don't worry, we already give the examples below.
 
 ## Requirements
 
-If you are using CodeIgniter, you can use this library with no extra requirement.
+If you are using CodeIgniter, let's go! You don't needs any extra requirements.
 
 ## Installation
 
@@ -160,6 +160,17 @@ $datatables->addColumn('action', function($row) {
   return '<a href="url/to/delete/post/'.$row->id.'">Delete</a>';
 });
 
+// Add column alias
+// It is very useful when we use SELECT JOIN to prevent column ambiguous
+$datatables->addColumnAlias('p.id', 'id');
+
+// Add column aliases
+// Same as the addColumnAlias, but for multiple alias at once
+$datatables->addColumnAliases([
+  'p.id' => 'id',
+  'c.name' => 'category'
+]);
+
 // Add squence number
 // The default key is `sequenceNumber`
 // You can change it with give the param
@@ -180,5 +191,6 @@ Please look at these files:
 - application/models/M_post.php
 - application/views/template.php
 - application/views/posts/index-datatables.php
+- application/views/posts/index-datatables-array.php
 - application/helpers/api_helper.php
 - assets/js/custom.js

src/DataTables.php

@@ -81,6 +81,39 @@ public function addColumn($key, $callback)
         return $this;
     }
 
+    /**
+     * Add column alias
+     * Very useful when using SELECT JOIN to prevent column ambiguous
+     * @param string $key The key of the column name (e.g. including the table name: posts.id or p.id)
+     * @param string $alias The column alias
+     * 
+     * @return $this
+     */
+    public function addColumnAlias($key, $alias)
+    {
+        $this->columnAliases[$alias] = $key;
+        return $this;
+    }
+
+    /**
+     * Add multiple column alias
+     * @param array $aliases The column aliases with key => value format
+     * 
+     * @return $this
+     */
+    public function addColumnAliases($aliases)
+    {
+        if ( ! is_array($aliases)) {
+            throw new \Exception('The $aliases parameter must be an array.');
+        }
+
+        foreach ($aliases as $key => $alias) {
+            $this->addColumnAlias($key, $alias);
+        }
+
+        return $this;
+    }
+
     /**
      * Only return the column as defined
      * @param string|array $columns The columns to only will be returned