当我需要UTF-8时PHP以ASCII输出XML [重复]

Ok, I have one more question then I think the PHP part of my program will be ready to rock and roll. Thank you everyone for the help you've given me so far!

I have the following PHP file uploaded to a website to act as a web service for my app to retrieve data from a MySQL Database and return the things that I need in my app in the form of XML. I think it is formatted correctly and is how I would like it (though any and all input is of course welcome). I'll get to the problem I'm having after the snippet.

To see the output, simply cURL this URL (it's the same URL I'm calling in NSURL): http://jeffstockdale.com/API/get_blog_posts.php

The PHP file looks like this

<?php
mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
mysql_select_db(DB_NAME);

$sql = "SELECT post_date_gmt, post_content, post_title FROM schema.wp_posts WHERE post_status = \"publish\" && post_type = \"post\" ORDER BY post_date_gmt DESC;";
$res = mysql_query($sql);

$xml = new XMLWriter();

$xml->openURI("php://output");
$xml->startDocument();
$xml->setIndent(true);

$xml->startElement('BlogPosts');

while ($row = mysql_fetch_assoc($res)) {

    $xml->startElement("Post");

    $xml->startElement("PostTitle");
    $xml->text($row['post_title']);
    $xml->endElement();

    $xml->startElement("PostDate");
    $xml->text($row['post_date_gmt']);
    $xml->endElement();

    $xml->startElement("PostContent");
    $xml->writeCData($row['post_content']);
    $xml->endElement();

    $xml->endElement();

}

$xml->endElement();

header('Content-type: text/html; charset=utf-8');
$xml->flush();

?>

And now to the problem. I go into my Xcode Project, create a NSURL (the file downloads correctly) and hand it over to my NSXMLParser, which then gives me the following error from parseErrorOccurred:

2014-10-09 15:03:41.114 AppName[8667:521529] NSXMLParser encountered an error: Error Domain=NSXMLParserErrorDomain Code=9 "The operation couldn’t be completed. (NSXMLParserErrorDomain error 9.)" UserInfo=0x7fbddd0b1a10 {NSXMLParserErrorColumn=44, NSXMLParserErrorLineNumber=1352, NSXMLParserErrorMessage=Input is not proper UTF-8, indicate encoding ! Bytes: 0x85 0x3C 0x2F 0x50 }

I'm taking that as my PHP file is returning it's data in ASCII when it needs to be in UTF-8. So my question is, how do I either get it to output to UTF-8 so NSXMLParser can parse it?

</div>

It seems that your MySQL database does not contain UTF-8 encoded data. As a result it's output is not in UTF-8 but rather some other encoding (maybe iso-latin1? but definitely not ASCII). You may either re-encode from whatever encoding it is to UTF-8 for display (see the PHP doc, e.g. mb_convert_encoding), or re-encode your database.

For the first solution, simply wrap the data obtained from the SQL query like so:

...
$xml->text(mb_convert_encoding($row['post_title'], "UTF-8", "ISO-8859-1"));
// replace ISO-8859-1 (aka latin1) with the encoding actually used
...

Update: XMLWriter requires UTF-8 strings as input. So it cannot accept other encoding even if declaring the encoding with startDocument. See this other question for more information. So there's always the two solutions above.

What it looks like is you need to declare your encoding type in the XMLwriter.

Like so $xml->startDocument('1.0','utf-8'); That way your XML encoding is declared when NSXML parses it.

If it was your data input then XMLwriter would throw an error cause it only accepts UTF-8.

The XML that is generated by this PHP script is valid. The problem does not seem to reside in this part of my program. Thank you to everyone for the very useful information.