Merge pull request tempestphp#323 from tempestphp/elseif-attribute

Elseif attribute

src/Tempest/View/Attributes/AttributeFactory.php

@@ -13,6 +13,7 @@ public function make(View $view, string $name, ?string $value): Attribute
     {
         return match(true) {
             $name === ':if' => new IfAttribute(),
+            $name === ':elseif' => new ElseIfAttribute(),
             $name === ':else' => new ElseAttribute(),
             $name === ':foreach' => new ForeachAttribute($view, $value),
             $name === ':forelse' => new ForelseAttribute(),

src/Tempest/View/Attributes/ElseAttribute.php

@@ -15,17 +15,25 @@
     public function apply(Element $element): Element
     {
         $previous = $element->getPrevious();
+        $previousCondition = false;
 
-        if (
-            ! $previous instanceof GenericElement
-            || ! $previous->hasAttribute('if')
-        ) {
-            throw new Exception('No valid if condition found in preceding element');
+        if (! $previous instanceof GenericElement) {
+            throw new Exception("Invalid preceding element before :else");
         }
 
-        $condition = $previous->getAttribute('if');
+        // Check all :elseif and :if conditions for previous elements
+        // If one of the previous element's conditions is true, we'll stop.
+        // We won't have to render this :else element
+        while (
+            $previousCondition === false
+            && $previous instanceof GenericElement
+            && ($previous->hasAttribute('if') || $previous->hasAttribute('elseif'))
+        ) {
+            $previousCondition = (bool) ($previous->getAttribute('if') ?? $previous->getAttribute('elseif'));
+            $previous = $previous->getPrevious();
+        }
 
-        if ($condition) {
+        if ($previousCondition) {
             return new EmptyElement();
         }
 

src/Tempest/View/Attributes/ElseIfAttribute.php

@@ -0,0 +1,52 @@
+<?php
+
+// draft
+
+declare(strict_types=1);
+
+namespace Tempest\View\Attributes;
+
+use Exception;
+use Tempest\View\Attribute;
+use Tempest\View\Element;
+use Tempest\View\Elements\EmptyElement;
+use Tempest\View\Elements\GenericElement;
+
+final readonly class ElseIfAttribute implements Attribute
+{
+    public function apply(Element $element): Element
+    {
+        if (! $element instanceof GenericElement) {
+            throw new Exception("Invalid element with :elseif");
+        }
+
+        $previous = $element->getPrevious();
+        $previousCondition = false;
+
+        if (! $previous instanceof GenericElement) {
+            throw new Exception("Invalid preceding element before :elseif");
+        }
+
+        // Check all :elseif and :if conditions for previous elements
+        // If one of the previous element's conditions is true, we'll stop.
+        // We won't have to render this :elseif element
+        while (
+            $previousCondition === false
+            && $previous instanceof GenericElement
+            && ($previous->hasAttribute('if') || $previous->hasAttribute('elseif'))
+        ) {
+            $previousCondition = (bool) ($previous->getAttribute('if') ?? $previous->getAttribute('elseif'));
+            $previous = $previous->getPrevious();
+        }
+
+        $currentCondition = (bool) $element->getAttribute('elseif');
+
+        // For this element to render, the previous conditions need to be false,
+        // and the current condition must be true
+        if ($previousCondition === false && $currentCondition === true) {
+            return $element;
+        }
+
+        return new EmptyElement();
+    }
+}

tests/Integration/View/TempestViewRendererTest.php

@@ -49,6 +49,44 @@ public function test_if_attribute(): void
         );
     }
 
+    public function test_elseif_attribute(): void
+    {
+        $this->assertSame(
+            '<div :if="$this->a">A</div>',
+            $this->render(view('<div :if="$this->a">A</div><div :elseif="$this->b">B</div><div :else>None</div>')->data(a: true, b: true)),
+        );
+
+        $this->assertSame(
+            '<div :if="$this->a">A</div>',
+            $this->render(view('<div :if="$this->a">A</div><div :elseif="$this->b">B</div><div :else>None</div>')->data(a: true, b: false)),
+        );
+
+        $this->assertSame(
+            '<div :elseif="$this->b">B</div>',
+            $this->render(view('<div :if="$this->a">A</div><div :elseif="$this->b">B</div><div :else>None</div>')->data(a: false, b: true)),
+        );
+
+        $this->assertSame(
+            '<div :else>None</div>',
+            $this->render(view('<div :if="$this->a">A</div><div :elseif="$this->b">B</div><div :else>None</div>')->data(a: false, b: false)),
+        );
+
+        $this->assertSame(
+            '<div :elseif="$this->c">C</div>',
+            $this->render(view('<div :if="$this->a">A</div><div :elseif="$this->b">B</div><div :elseif="$this->c">C</div><div :else>None</div>')->data(a: false, b: false, c: true)),
+        );
+
+        $this->assertSame(
+            '<div :elseif="$this->b">B</div>',
+            $this->render(view('<div :if="$this->a">A</div><div :elseif="$this->b">B</div><div :elseif="$this->c">C</div><div :else>None</div>')->data(a: false, b: true, c: true)),
+        );
+
+        $this->assertSame(
+            '<div :else>None</div>',
+            $this->render(view('<div :if="$this->a">A</div><div :elseif="$this->b">B</div><div :elseif="$this->c">C</div><div :else>None</div>')->data(a: false, b: false, c: false)),
+        );
+    }
+
     public function test_else_attribute(): void
     {
         $this->assertSame(