Partial implementation of DOMParser

lib/DOMParser.php

@@ -0,0 +1,58 @@
+<?php
+/** @license MIT
+ * Copyright 2017 , Dustin Wilson, J. King et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace MensBeam\HTML;
+
+use MensBeam\Mime\MimeType;
+use MensBeam\Intl\Encoding;
+
+/** The DOMParser interface allows authors to create new DOMDocument objects by parsing strings, as either HTML or XML. */
+class DOMParser {
+    protected const TYPES = [
+        "text/html",
+        "text/xml",
+        "application/xml",
+        "application/xhtml+xml",
+        "image/svg+xml"
+    ];
+
+    /** Parses `$string` using either the HTML or XML parser, according to `$type`, and returns the resulting `DOMDocument`. 
+     * 
+     * `$type` can be `"text/html"` (which will invoke the HTML parser), or any of `"text/xml"`, `"application/xml"`, 
+     * `"application/xhtml+xml"`, or `"image/svg+xml"` (which will invoke the XML parser).
+     * 
+     * For the XML parser, if `$string` cannot be parsed, then the returned `DOMDocument` will contain elements describing the resulting error.
+     * 
+     * Note that script elements are not evaluated during parsing, and the resulting document's encoding will always be UTF-8.
+     * 
+     * Values other than the above for `$type` will cause an `InvalidArgumentException` exception to be thrown.
+     * 
+     * Since PHP strings are bytes, `$type` may include a `charset` parameter. If no parameter is is supplied UTF-8 is assumed.
+     */
+    public function parseFromString(string $string, string $type): \DOMDocument {
+        // start by parsing the type
+        $t = MimeType::parseBytes($type);
+        if (!in_array($t->essence, self::TYPES)) {
+            throw new \InvalidArgumentException("\$type must be one of ".implode(", ", self::TYPES));
+        }
+        $charset = $t->params['charset'] ?? "UTF-8";
+        $encoding = Encoding::matchLabel($charset);
+        if (!$encoding) {
+            throw new \InvalidArgumentException("Specified charset is not supported");
+        }
+        $charset = $encoding['name'];
+        // parse the string as either HTML or XML
+        if ($t->essence === "text/html") {
+            // for HTML we invoke our parser
+            $config = new Parser\Config;
+            $config->encodingFallback = "UTF-8";
+            $config->encodingPrescanBytes = 0;
+            return Parser::parse($string, $charset, $config);
+        } else {
+            // for XML we have to jump through a few hoops to make sure the DOMDocument doesn't make a hash of things, or try to detect encoding
+        }
+    }
+}