XML error at ampersand (&)

Question

I have a php file which prints an xml based on a MySql db.

I get an error every time at exactly the point where there is an & sign.

Here is some php:

$query = mysql_query($sql);

$_xmlrows = '';

while ($row = mysql_fetch_array($query)) {
    $_xmlrows .= xmlrowtemplate($row);
}

function xmlrowtemplate($dbrow){
    return "<AD>
              <CATEGORY>".$dbrow['category']."</CATEGORY>
            </AD>
}

The output is what I want, i.e. the file outputs the correct category, but still gives an error.

The error says: xmlParseEntityRef: no name

And then it points to the exact character which is a & sign.

This complains only if the $dbrow['category'] is something with an & sign in it, for example: "cars & trucks", or "computers & telephones".

Anybody know what the problem is?

BTW: I have the encoding set to UTF-8 in all documents, as well as the xml output.

Please share more details. Also, please explain how this is related to [tag:html], [tag:mysql], or [tag:database] — Nico Haase, Oct 06 '21 at 08:56

score 55 · Accepted Answer · edited May 23 '17 at 11:54

55

& in XML starts an entity. As you haven't defined an entity &WhateverIsAfterThat an error is thrown. You should escape it with &.

$string = str_replace('&', '&amp;', $string);

How do I escape ampersands in XML

To escape the other reserved characters:

function xmlEscape($string) {
    return str_replace(array('&', '<', '>', '\'', '"'), array('&amp;', '&lt;', '&gt;', '&apos;', '&quot;'), $string);
}

edited May 23 '17 at 11:54

Community

1
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answered Oct 26 '10 at 18:02

NikiC

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(Addition, but for poster) So use & to properly escape it -- although instead of (dumb) string interpolation you should use something that *understands* XML (e.g. what happens when the input contains "<"? – Oct 26 '10 at 18:03
15

Or, more compact, `htmlspecialchars($string, ENT_QUOTES);` – Wrikken Oct 26 '10 at 22:37
2

wrapping in <![CDATA tags is the more logical solution – matthy Dec 27 '13 at 17:52
3

To be sure the string is actually safe, I think it should be done in two stages. For example: $string = 'Foo & Bar'; $string = str_replace('&', '&', $string); // Foo & Bar $string = str_replace('&', '&', $string); // Foo & Bar If there is only one stage, result can be 'Foo & Bar' – sznowicki Oct 22 '14 at 20:43
4

I would suggest you want to use the `ENT_XML1` option: `htmlspecialchars($string, ENT_XML1);` to ensure that the string is escaped appropriately for XML. – joshweir Nov 07 '15 at 11:17

pevik · Answer 2 · 2021-10-06T08:51:50.780

6

$string =htmlspecialchars($string,ENT_XML1);

is the most universal way to solve all encoding errors (IMHO better that write custom functions + there is no point to solve just &).

Credit: Put Wrikken's and joshweir's comment as answer to be more visible.

edited Oct 06 '21 at 08:51

answered Aug 29 '20 at 16:04

pevik

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score 2 · Answer 3 · edited May 23 '17 at 12:03

2

You need to either turn & into its entity &, or wrap the contents in CDATA tags.

If you choose the entity route, there are additional characters you need to turn into entities:

>  &gt;
<  &lt;
'  &apos;
"  &quot;

Background: Beware of the ampersand when using XML

Wikipedia: List of XML character entity references

edited May 23 '17 at 12:03

Community

1
1

answered Oct 26 '10 at 18:03

Pekka

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score 0 · Answer 4 · answered Feb 13 '19 at 10:42

Switch and regex with using xml escape function.

 function XmlEscape(str) {
    if (!str || str.constructor !== String) {
        return "";
    }

    return str.replace(/[\"&><]/g, function (match) {
        switch (match) {
        case "\"":
            return "&quot;";
        case "&":
            return "&amp;";
        case "<":
            return "&lt;";
        case ">":
            return "&gt;";
        }
    });
};

Denise Ignatova · Answer 5 · 2018-03-24T10:28:56.630

-1

public function sanitize(string $data) {
    return str_replace('&', '&amp;', $data);
}

You are right: here is more context - the example is in relation to the ' how to deal with data containing '&' when we pass this data to SimpleXml. Of course there is also other solution to use <![CDATA[some stuff]]>

edited Mar 24 '18 at 10:28

answered Mar 20 '18 at 12:14

Denise Ignatova

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What about some more context? – Nico Haase Mar 20 '18 at 12:33

XML error at ampersand (&)

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