Move low-level xml outputting code to a class

Made a class for outputting XML code

1 files changed, 223 insertions, 0 deletions

diff --git a/lib/xmloutputter.php b/lib/xmloutputter.php
new file mode 100644
index 000000000..9a7d12e4c
--- /dev/null
+++ b/lib/xmloutputter.php
@@ -0,0 +1,223 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * Low-level generator for XML
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Output
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @author    Sarven Capadisli <csarven@controlyourself.ca>
+ * @copyright 2008 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Low-level generator for XML
+ *
+ * This is a thin wrapper around PHP's XMLWriter. The main
+ * advantage is the element() method, which simplifies outputting
+ * an element.
+ *
+ * @category Output
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @author   Sarven Capadisli <csarven@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://laconi.ca/
+ * @see      Action
+ * @see      HTMLOutputter
+ */
+
+class XMLOutputter
+{
+    /**
+     * Wrapped XMLWriter object, which does most of the heavy lifting
+     * for output.
+     */
+
+    var $xw = null;
+
+    /**
+     * Constructor
+     *
+     * Initializes the wrapped XMLWriter.
+     *
+     * @param $output URL for outputting, defaults to stdout
+     * @param $indent Whether to indent output, default true
+     */
+
+    function __construct($output='php://output', $indent=true)
+    {
+        $this->xw = new XMLWriter();
+        $this->xw->openURI($output);
+        $this->xw->setIndent($indent);
+        $this->xw->startDocument('1.0', 'UTF-8');
+    }
+
+    /**
+     * Start a new XML document
+     *
+     * @param string $doc    document element
+     * @param string $public public identifier
+     * @param string $system system identifier
+     *
+     * @return void
+     */
+
+    function startXML($doc=null, $public=null, $system=null)
+    {
+        if ($doc) {
+            $this->xw->writeDTD($doc, $public, $system);
+        }
+    }
+
+    /**
+     * finish an XML document
+     *
+     * It's probably a bad idea to continue to use this object
+     * after calling endXML().
+     *
+     * @return void
+     */
+
+    function endXML()
+    {
+        $this->xw->endDocument();
+        $this->xw->flush();
+    }
+
+    /**
+     * output an XML element
+     *
+     * Utility for outputting an XML element. A convenient wrapper
+     * for a bunch of longer XMLWriter calls. This is best for
+     * when an element doesn't have any sub-elements; if that's the
+     * case, use elementStart() and elementEnd() instead.
+     *
+     * The $content element will be escaped for XML. If you need
+     * raw output, use elementStart() and elementEnd() with a call
+     * to raw() in the middle.
+     *
+     * @param string $tag     Element type or tagname
+     * @param array  $attrs   Array of element attributes, as
+     *                        key-value pairs
+     * @param string $content string content of the element
+     *
+     * @return void
+     */
+
+    function element($tag, $attrs=null, $content=null)
+    {
+        $this->elementStart($tag, $attrs);
+        if (!is_null($content)) {
+            $this->xw->text($content);
+        }
+        $this->elementEnd($tag);
+    }
+
+    /**
+     * output a start tag for an element
+     *
+     * Mostly used for when an element has content that's
+     * not a simple string.
+     *
+     * @param string $tag   Element type or tagname
+     * @param array  $attrs Array of element attributes
+     *
+     * @return void
+     */
+
+    function elementStart($tag, $attrs=null)
+    {
+        $this->xw->startElement($tag);
+        if (is_array($attrs)) {
+            foreach ($attrs as $name => $value) {
+                $this->xw->writeAttribute($name, $value);
+            }
+        } else if (is_string($attrs)) {
+            $this->xw->writeAttribute('class', $attrs);
+        }
+    }
+
+    /**
+     * output an end tag for an element
+     *
+     * Used in conjunction with elementStart(). $tag param
+     * should match the elementStart() param.
+     *
+     * For HTML 4 compatibility, this method will force
+     * a full end element (</tag>) even if the element is
+     * empty, except for a handful of exception tagnames.
+     * This is a hack.
+     *
+     * @param string $tag Element type or tagname.
+     *
+     * @return void
+     */
+
+    function elementEnd($tag)
+    {
+        static $empty_tag = array('base', 'meta', 'link', 'hr',
+                                  'br', 'param', 'img', 'area',
+                                  'input', 'col');
+        // XXX: check namespace
+        if (in_array($tag, $empty_tag)) {
+            $this->xw->endElement();
+        } else {
+            $this->xw->fullEndElement();
+        }
+    }
+
+    /**
+     * output plain text
+     *
+     * Text will be escaped. If you need it not to be,
+     * use raw() instead.
+     *
+     * @param string $txt Text to output.
+     *
+     * @return void
+     */
+
+    function text($txt)
+    {
+        $this->xw->text($txt);
+    }
+
+    /**
+     * output raw xml
+     *
+     * This will spit out its argument verbatim -- no escaping is
+     * done.
+     *
+     * @param string $xml XML to output.
+     *
+     * @return void
+     */
+
+    function raw($xml)
+    {
+        $this->xw->writeRaw($xml);
+    }
+}