Added support {{#if condition}} {{else if condition}} {{else if condition}} {{/if}}

README.md

@@ -270,16 +270,19 @@ You can use the if helper to conditionally render a block. If its argument retur
 ```html
 {{#if isActive}}
     This part will be shown if it is active
+{{#else if isValid}}
+    This part will be shown if it is valid
 {{else}}
-    This part will not show if isActive is true
+    This part will be shown if isActive and isValid are both "falsy" values
 {{/if}}
 ```
 
 ```php
 <?php
 
 $model = [
-    "isActive" => true
+    "isActive" => true,
+    "isValid" => false
 ];
 
 echo $handlebars->render($template, $model);
@@ -449,8 +452,10 @@ $model = [
 ```html
 {{#if isActive}}
     This part will be shown if it is active
+{{#else if isValid}}
+    This part will be shown if it is valid
 {{else}}
-    This part will not show if isActive is true
+    This part will be shown if isActive and isValid are both "falsy" values
 {{/if}}
 ```
 

src/Handlebars/Helpers.php

@@ -204,6 +204,10 @@ public function isEmpty()
      *
      * {{#if condition}}
      *      Something here
+     * {{else if condition}}
+     *      something else if here
+     * {{else if condition}}
+     *      something else if here
      * {{else}}
      *      something else here
      * {{/if}}
@@ -218,14 +222,53 @@ public function isEmpty()
      */
     public function helperIf($template, $context, $args, $source)
     {
+        $tpl = $template->getEngine()->loadString('{{#if ' . $args . '}}' . $source . '{{/if}}');
+        $tree = $tpl->getTree();
         $tmp = $context->get($args);
         if ($tmp) {
-            $template->setStopToken('else');
+            $token = 'else';
+            foreach ($tree[0]['nodes'] as $node) {
+                $name = trim($node['name'] ?? '');
+                if ($name && substr($name, 0, 7) == 'else if') {
+                    $token = $node['name'];
+                    break;
+                }
+            }
+            $template->setStopToken($token);
             $buffer = $template->render($context);
             $template->setStopToken(false);
             $template->discard();
             return $buffer;
         } else {
+            foreach ($tree[0]['nodes'] as $key => $node) {
+                $name = trim(isset($node['name']) ? $node['name'] : '');
+                if ($name && substr($name, 0, 7) == 'else if') {
+                    $template->setStopToken($node['name']);
+                    $template->discard();
+                    $template->setStopToken(false);
+                    $args = $this->parseArgs($context, substr($name, 7));
+                    $token = 'else';
+                    $remains = array_slice($tree[0]['nodes'], $key + 1);
+                    foreach ($remains as $remain) {
+                        $name = trim($remain['name'] ?? '');
+                        if ($name && substr($name, 0, 7) == 'else if') {
+                            $token = $remain['name'];
+                            break;
+                        }
+                    }
+                    if (isset($args[0]) && $args[0]) {
+                        $template->setStopToken($token);
+                        $buffer = $template->render($context);
+                        $template->setStopToken(false);
+                        $template->discard();
+                        return $buffer;
+                    } else if ($token != 'else') {
+                        continue;
+                    } else {
+                        return $this->renderElse($template, $context);
+                    }
+                }
+            }
             return $this->renderElse($template, $context);
         }
     }
@@ -730,4 +773,28 @@ private function extractSlice($string)
         }
         return [$m[1], $slice_start, $slice_end];
     }
+
+    /**
+     * Parse avariable from current args
+     *
+     * @param \Handlebars\Context  $context  context object
+     * @param array                $args     passed arguments to helper
+     * @return array
+     */
+    private function parseArgs($context, $args)
+    {
+        $args = preg_replace('/\s+/', ' ', trim($args));
+        $eles = explode(' ', $args);
+        foreach ($eles as $key => $ele) {
+            if (in_array(substr($ele, 0, 1), ['\'', '"'])) {
+                $val = trim($ele, '\'"');
+            } else if (is_numeric($ele)) {
+                $val = $ele;
+            } else {
+                $val = $context->get($ele);
+            }
+            $eles[$key] = $val;
+        }
+        return $eles;
+    }
 }