xpath 用 [img] 替换 [en-media] 元素

Question

我需要在 Evernote xml 文件中查找和替换。它包含多个这样的条目：

<en-media alt="Evernote Logo" hash="4914ced8925f9adcc1c58ab87813c81f" type="image/png"></en-media>
<en-media alt="Evernote Logo" hash="4914dsd8925f9adcc1c58ab87813c81f" type="image/png"></en-media>

与

<img src="https://sandbox.evernote.com/shard/s1/res/143c8ad0-da92-4271-8410-651b88e8a2f1" height="something" width="something"/>
<img src="https://sandbox.evernote.com/shard/s1/res/143c8233-da92-4271-8410-651b88e8a2f1" height="something" width="something"/>

我这样做是因为 Evernote 的 SDK 诚然缺乏一种简单的方法来在单个（或多个简单的）命令中显示文本和 mime 数据（图像、pdf 等）。 p>

这是我的“查找”尝试，但现在我需要“替换”：

$content=html_entity_decode($content); //content contains   and — causing simplexml to complain
$content=str_replace('&',htmlentities('&'),$content); //encode & -- Lewis & Clark

$x = new SimpleXMLElement($content);
$x = xpath('//en-media'); //find
[?????] MYCODE_getLink(); //replace
$content=$x->asXML(); //output
$content=htmlentities($content); //put entities back

Answer 1

以下是我的解决方案，它只是附加，因为我无法弄清楚替换。对于最终的 HTML 演示文稿，我仍然需要删除某些 XML 标记。无论如何，它有效，所以我把它贴在这里以防它帮助你：

$f = new NoteFilter();
$f->notebookGuid="e0a42e90-0297-442f-8157-44a596e5b8b5"; //default
//$f->notebookGuid="b733f6ab-e3b7-443a-8f5a-2bbe77ea1c1e"; //MyStuff

$n = $noteStore->findNotes($authToken, $f, 0, 100); // Fetch up to 100 notes
$total=$n->totalNotes;
if (!empty($n->notes)) {
foreach ($n->notes as $note) {
    $fullNote = $noteStore->getNote($authToken, $note->guid, true, false, false, false);
    $content  = $fullNote->content;


    $dom = new DOMDocument;
    $dom->loadXml($content);

    //list all <en-media>
    $medias = $dom->getElementsByTagName('en-media');
    foreach ($medias as $media) {
        $hash = $media->getAttribute('hash');
        $hash = hashXmlToBin($hash); //xml to bin for ByHash method below
        $resource=$noteStore->getResourceByHash($authToken, $note->guid,$hash,0,0,0,0);

        //get url 
        $url=resourceUrl($authToken,$resource);

        //if image, show inline 
        $inline=array('image/png','image/jpeg','image/jpg','image/gif');
        if (in_array($resource->mime,$inline)) {
            $img=$dom->createElement('img');
            $img->setAttribute('src', $url);
            $img->setAttribute('width', $resource->width);
            $img->setAttribute('height', $resource->height);
        }else { //show link
            $rewrite=array('application/pdf'=>'PDF');
            $mime=str_replace('application/','',$resource->mime);
            $filename=$resource->attributes->fileName;
            $img=$dom->createElement('a',"Download {$filename} ({$mime})");
            $img->setAttribute('href', $url);
            $img->setAttribute('class', "download-attachement");
        }
        // append to DOM
        $media->appendChild($img);
    }//foreach medias
    $content=$dom->saveXML();
    $out[]=$content;
    }//foreach notes 
    foreach ($out as $val)
        print "<hr/>".$val; //each note
}//notes exist

/*
 * http://discussion.evernote.com/topic/4521-en-media-hash/
 */
function hashXmlToBin($hash) {

    $chunks = explode("\n", chunk_split($hash,2,"\n"));
    $calc_hash = "";
    foreach ($chunks as $chunk) {
        $newdata="";
        if (!empty($chunk)) {
            $len = strlen($chunk);
            for($i=0;$i<$len;$i+=2) {
                $newdata .= pack("C",hexdec(substr($chunk,$i,2)));
            }
            $bin_chunk = $newdata;
            $calc_hash .= $bin_chunk;
        }
    }
    return $calc_hash;
}

/*
 * return a resource url
 */
function resourceUrl($authToken, $resource, $resize = FALSE, $thumbnailSize = 150) {
    //build URL
    if (!$resize)
        $url=EVERNOTE_SERVER."/shard/".$_SESSION['shard']."/res/".$resource->guid; //originals
    else
        $url=EVERNOTE_SERVER."/shard/".$_SESSION['shard']."/thm/res/".$resource->guid."?size={$thumbnailSize}"; //thumbnail

    return $url;
}