Send special character in Request body via Httprequest in Delphi XE2?

Question

I am consuming an API (POST), via Delphi for sending NF-e XML. I am using Httprequest.

In the body of the request (body) I must pass the xml as follows: xml=

But the issuer’s social reason (xName) contains the special character "&". By sending the information to the API it returns an error:

Note XML with broken or invalid syntax: Premature end of data in tag xNome line 1

From what I understand, the API is understanding that this & refers to a new parameter, breaking the XML string.

How do I send information with this special character "&" so that the API does not understand as parameter but as text/string of Xml?

My code is like this:

Request.Uri := BASE_URL + '?token='+ FToken;
Request.Method := 'POST';
Request.Headers.SetValue('Accept', 'application/xml');
Request.Headers.SetValue('Content-Type', 'application/x-www-form-urlencoded');
Request.Headers.SetValue('Authorization', 'Basic '+EncodeString(Format('%s:%s', [FUsuario, FSenha])));
Request.SetContent(TEncoding.UTF8.GetBytes(Concat('xml=', FXML.Text)));

Answer 1

You only need to use the escape characters.

Escape character is a way for you to say that character & is a character really and not just a parameter.

If you put a character like < inside an element XML element, it will generate an error because the parser interprets it as the start of a new element.

To avoid this, you must replace the character < by an entity reference, thus:

That:

<mensagem>se saldo < 1000 então não tenho dinheiro</mensagem>

Turn that around:

<mensagem>se saldo &lt; 1000 então não tenho dinheiro</mensagem>

There are 5 predefined entity references in XML:

"   "
'   '
<   &lt;
>   &gt;
&   &amp;

Then when informing the issuer’s corporate name, simply change the & for &

You can see a little more about that in this link, in this here and in this other also.