Question

I just don’t get it.

My case is, that my application is sending all the needed GUI text by JSON at page startup from my PHP server. On my PHP server I have all text special characters written in UTF-8. Example: Für

So on the client side I have exactly the same value, and it gets displayed nicely everywhere except on input fields. When I do this with JavaScript:

document.getElementById('myInputField').value = "FÖr";

Then it is written exactly like that without any transformation into the special character.

Did I understand something wrong in UTF-8 concepts?

Thanks for any hints.

Answer 1

The notation ü has nothing particular to do with UTF-8. The use of character references is a common way of avoiding the need to use UTF-8; they can be used with any encoding, but if you use UTF-8, you don’t need them.

The notation ü is an HTML notation, not JavaScript. Whether it gets interpreted by HTML rules when it appears inside your JavaScript code depends on the context (like JavaScript inside an HTML document vs. separate JavaScript file). This problem is best avoided by using either characters as such or by using JavaScript notations for characters.

For example, ü means the same as ü, i.e. U+00FC, ü (u with diaeresis). The JavaScript notation, for use inside string literals, for this is \u00fc (\u followed by exactly four hexadecimal digits). E.g., the following sets the value to “Für”:

document.getElementById('myInputField').value = "F\u00fcr";