Allow to specify formatter by name.

CsvTable.php

@@ -162,10 +162,11 @@ public static function fromFile($filepath, $separator = ',', $enclosure = '"', $
   /**
    * Format the CSV data.
    *
-   * @param callable|string|null $formatter
-   *   A callable to formatter the output. Can be a function name, a class name,
-   *   a closure, or an array containing a class name and a method name. If NULL
-   *   is provided, the default formatter will be used.
+   * @param string|array<int, string>|callable|null $formatter
+   *   Formatter to use. Can be a function name, a class name, a closure, an
+   *   array containing a class name and a method name, or a predefined
+   *   formatter available as format<Name> method. If NULL is provided, the
+   *   'CSV" formatter will be used.
    * @param array<mixed> $options
    *   An array of options to pass to the formatter. Defaults to an empty array.
    *
@@ -175,9 +176,18 @@ public static function fromFile($filepath, $separator = ',', $enclosure = '"', $
    * @throws \Exception
    *   When the formatter is not callable.
    */
-  public function format(callable|string|null $formatter = NULL, array $options = []): string {
-    $formatter = $formatter ?? [static::class, 'formatCsv'];
-    $formatter = is_string($formatter) && class_exists($formatter) ? [$formatter, 'format'] : $formatter;
+  public function format(string|array|callable|null $formatter = NULL, array $options = []): string {
+    $formatter = $formatter ?? 'csv';
+
+    if (is_string($formatter) && !function_exists($formatter)) {
+      if (class_exists($formatter)) {
+        $formatter = [$formatter, 'format'];
+      }
+      else {
+        $method = 'format' . str_replace(' ', '', ucwords(str_replace(['-', '_'], ' ', strtolower($formatter))));
+        $formatter = method_exists($this, $method) ? [$this, $method] : NULL;
+      }
+    }
 
     if (!is_callable($formatter)) {
       throw new \Exception('Formatter must be callable.');

README.md

@@ -66,10 +66,10 @@ col21,col22,col23
 col31,col32,col33
 ```
 
-### Using `CsvTable::formatTextTable()` formatter
+### Using `text_table` formatter
 
 ```php
-print (CsvTable::fromFile($file))->format([CsvTable::class, 'formatTextTable']);
+print (CsvTable::fromFile($file))->format('text_table');
 ```
 will produce table content:
 ```csv
@@ -79,10 +79,10 @@ col21|col22|col23
 col31|col32|col33     
 ```
 
-### Using `CsvTable::formatTextTable()` formatter without a header
+### Using `text_table` formatter without a header
 
 ```php
-print (CsvTable::fromFile($file))->withoutHeader()->format([CsvTable::class, 'formatTextTable']);
+print (CsvTable::fromFile($file))->withoutHeader()->format('text_table');
 ```
 will produce table content:
 ```csv
@@ -91,10 +91,10 @@ col21|col22|col23
 col31|col32|col33     
 ```
 
-### Using `CsvTable::formatMarkdownTable()` formatter
+### Using `markdown_table` formatter
 
 ```php
-print (CsvTable::fromFile($file))->withoutHeader()->format([CsvTable::class, 'formatMarkdownTable']);
+print (CsvTable::fromFile($file))->withoutHeader()->format('markdown_table');
 ```
 will produce Markdown table:
 ```markdown
@@ -104,7 +104,7 @@ will produce Markdown table:
 | col31 | col32 | col33 |     
 ```
 
-### Custom formatter as a callback
+### Custom formatter as an anonymous callback
 
 ```php
 print (CsvTable::fromFile($file))->format(function ($header, $rows, $options) {
@@ -128,6 +128,19 @@ col21|col22|col23
 col31|col32|col33     
 ```
 
+### Custom formatter as a class with default `format` method
+
+```php
+print (CsvTable::fromFile($file))->withoutHeader()->format(CustomFormatter::class);
+```
+
+### Custom formatter as a class with a custom method and options
+
+```php
+$formatter_options = ['option1' => 'value1', 'option2' => 'value2'];
+print (CsvTable::fromFile($file))->withoutHeader()->format([CustomFormatter::class, 'customFormat'], $formatter_options);
+```
+
 ## Maintenance
 
 ```bash

composer.json

@@ -31,6 +31,11 @@
             "AlexSkrypnyk\\CsvTable\\": ""
         }
     },
+    "autoload-dev": {
+        "psr-4": {
+            "AlexSkrypnyk\\CsvTable\\Tests\\": "tests"
+        }
+    },
     "config": {
         "allow-plugins": {
             "dealerdirect/phpcodesniffer-composer-installer": true,