Make generated example IDs page specific (#210)

* Make example id attribute counter reset on each page (fixes #205)

Author: AllenJB

phpdotnet/phd/PIHandler.php

@@ -2,6 +2,9 @@
 namespace phpdotnet\phd;
 
 abstract class PIHandler {
+    /**
+     * @var \phpdotnet\phd\Format
+     */
     protected $format;
 
     public function __construct($format) {

phpdotnet/phd/Package/Generic/XHTML.php

@@ -548,6 +548,12 @@ abstract class Package_Generic_XHTML extends Format_Abstract_XHTML {
 
     protected int $exampleCounter = 0;
 
+    protected int $perPageExampleCounter = 0;
+
+    protected bool $exampleCounterIsPerPage = false;
+
+    protected array $perPageExampleIds = [];
+
     public function __construct(
         Config $config,
         OutputHandler $outputHandler
@@ -631,7 +637,11 @@ public function createLink($for, &$desc = null, $type = Format::SDESC) {
             $rsl = $this->indexes[$for];
             $retval = $rsl["filename"] . $this->ext;
             if ($rsl["filename"] != $rsl["docbook_id"]) {
-                $retval .= '#' . $rsl["docbook_id"];
+                if (isset($this->perPageExampleIds[$for])) {
+                    $retval .= '#' . $this->perPageExampleIds[$for];
+                } else {
+                    $retval .= '#' . $rsl["docbook_id"];
+                }
             }
             $desc = $rsl["sdesc"] ?: $rsl["ldesc"];
         }
@@ -2538,4 +2548,23 @@ public function format_whitespace($whitespace, $elementStack, $currentDepth) {
     public function format_caption($open, $name, $attrs, $props) {
         return $open ? '<div class="caption">' : '</div>';
     }
+
+    public function getGeneratedExampleID($index)
+    {
+        $originalId = parent::getGeneratedExampleID($index);
+        if (! $this->exampleCounterIsPerPage) {
+            return $originalId;
+        }
+        if (preg_match('/^example\-[0-9]+$/', $originalId)) {
+            $this->perPageExampleCounter++;
+            $this->perPageExampleIds[$originalId] = 'example-' . $this->perPageExampleCounter;
+            return $this->perPageExampleIds[$originalId];
+        }
+        return $originalId;
+    }
+
+    public function onNewPage(): void
+    {
+        $this->perPageExampleCounter = 0;
+    }
 }

phpdotnet/phd/Package/PHP/CHM.php

@@ -208,6 +208,7 @@ public function __construct(
     ) {
         parent::__construct($config, $outputHandler);
         $this->registerFormatName("PHP-CHM");
+        $this->exampleCounterIsPerPage = false;
     }
 
     public function __destruct() {

phpdotnet/phd/Package/PHP/EnhancedCHM.php

@@ -15,6 +15,7 @@ public function __construct(
     ) {
         parent::__construct($config, $outputHandler);
         $this->registerFormatName("PHP-EnhancedCHM");
+        $this->exampleCounterIsPerPage = false;
     }
 
     public function update($event, $value = null) {

phpdotnet/phd/Package/PHP/Epub.php

@@ -30,6 +30,7 @@ public function __construct(
         parent::__construct($config, $outputHandler);
         $this->setExt('.xhtml');
         $this->registerFormatName("PHP-Epub");
+        $this->exampleCounterIsPerPage = false;
     }
 
     public function update($event, $value = null) {

phpdotnet/phd/Package/PHP/Web.php

@@ -17,6 +17,7 @@ public function __construct(
         $this->setTitle("PHP Manual");
         $this->setChunked(true);
         $this->setExt($this->config->ext === null ? ".php" : $this->config->ext);
+        $this->exampleCounterIsPerPage = true;
     }
 
     public function close() {
@@ -54,6 +55,7 @@ public function appendData($data) {
     }
 
     public function writeChunk($id, $fp) {
+        $this->onNewPage();
         $filename = $this->getOutputDir() . $id . $this->getExt();
 
         rewind($fp);

phpdotnet/phd/TestPHPChunkedXHTML.php

@@ -25,6 +25,7 @@ public function update($event, $value = null) {
     }
 
     public function writeChunk($id, $fp) {
+        $this->onNewPage();
         $filename = $this->getOutputDir() . $id . $this->getExt();
 
         rewind($fp);