Added Smarty::setExtensions(), fixed unit test for the null coalescing operator. Updated docs about registering a custom extension.

CHANGELOG.md

@@ -8,7 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 - Added support for PHP8.2
-- Added a new way to extend Smarty functionality using `Smarty::addExtension()`. Please see the docs for more information.
+- Added a new way to extend Smarty functionality using `Smarty::addExtension()` or `Smarty::setExtensions()`. Please see the docs for more information.
 - Custom tags can accept positional parameters, so you can write a block compiler that support this: `{trans "Jack" "dull boy"}All work and no play makes %s a %s.{/trans}` [#164](https://github.com/smarty-php/smarty/issues/164)
 - Full support for ternary operator: `{$test ? $a : $b}` and `{$var ?: $value_if_falsy}` [#881](https://github.com/smarty-php/smarty/issues/881)
 - Full support for null coalescing operator: `{$var ?? $value_if_null}` [#882](https://github.com/smarty-php/smarty/issues/882)

docs/api/extending/extensions.md

@@ -1,5 +1,7 @@
 # Creating an extension
 
+## Default extensions
+
 In order to organize your custom tags and modifiers, you can create an Extension.
 In fact, most of Smarty itself is organized into two extensions:
 
@@ -12,6 +14,8 @@ In fact, most of Smarty itself is organized into two extensions:
 > There is also the 'BCPluginsAdapter' extension, which does not add any new functionality, but
 > wraps calls to deprecated methods such as `Smarty\Smarty::addPluginsDir()` and `Smarty\Smarty::loadFilter()`.
 
+## Writing your own extension
+
 In order to write your own custom extension, you must write a class that implements `Smarty\Extension\ExtensionInterface`.
 However, it is usually easier to extend `Smarty\Extension\Base` which provides empty implementation for each of the methods
 required by `Smarty\Extension\ExtensionInterface`. This allows you to only override the method(s) you need.
@@ -61,3 +65,37 @@ Writing an extension allows you to add a group of tags, block tags and modifiers
 It also allows you to register pre-, post- and output-filters in a structured way. 
 The files in `src/Extension/` in the `smarty/smarty` dir should give you all the information you need to start
 writing your own extension.
+
+## Registering an extension
+
+When you have written your extension, add it to a Smarty instance as follows:
+
+```php
+<?php
+
+use Smarty\Smarty;
+
+$smarty = new Smarty();
+
+$smarty->addExtension(new MyCustomExtension());
+```
+
+This will add `MyCustomExtension` to the end of the extension list, meaning that you cannot override tags or modifiers
+from one of Smarty's default extensions.
+
+Should you wish to insert your extension at the top of the extension list, or create a very limited Smarty version that
+only contains the core extension, you can use `Smarty\Smarty::setExtensions()` to override the list of extensions.
+
+```php
+<?php
+
+use Smarty\Smarty;
+
+$smarty = new Smarty();
+
+$smarty->setExtensions([
+    new Smarty\Extension\CoreExtension(),
+    new MyCustomExtension(),
+    new Smarty\Extension\DefaultExtension(),
+]);
+```

src/Smarty.php

@@ -557,6 +557,17 @@ class Smarty extends \Smarty\TemplateBase {
 		return $this->extensions;
 	}
 
+	/**
+	 * Replace the entire list extensions, allowing you to determine the exact order of the extensions.
+	 *
+	 * @param ExtensionInterface[] $extensions
+	 *
+	 * @return void
+	 */
+	public function setExtensions(array $extensions): void {
+		$this->extensions = $extensions;
+	}
+
 	/**
 	 * Check if a template resource exists
 	 *

tests/UnitTests/SmartyMethodsTests/RegisterModifier/RegisterModifierTest.php

@@ -120,6 +120,20 @@ class RegisterModifierTest extends PHPUnit_Smarty
 		$this->assertEquals($expectedValue, $this->smarty->fetch('string:' . $template));
 	}
 
+	/**
+	 * test register wildcard modifier using setExtensions
+	 * @dataProvider dataUnknownModifiers
+	 */
+	public function testSetExtensions($template, $expectedValue)
+	{
+		$this->cleanDirs();
+		$this->smarty->setExtensions([
+			new \Smarty\Extension\CoreExtension(),
+			new WildcardExtension()
+		]);
+		$this->assertEquals($expectedValue, $this->smarty->fetch('string:' . $template));
+	}
+
 }
 
 class WildcardExtension extends \Smarty\Extension\Base {

tests/UnitTests/TemplateSource/NullCoalescingTest.php

@@ -25,7 +25,7 @@ class NullCoalescingTest extends PHPUnit_Smarty {
 	public function dataForOther() {
 		return [
 			[null, 'undefined'],
-			['blah', ''],
+			['blah', 'blah'],
 			['', ''],
 			[false, false],
 		];