Workaround for issue using HTML entities in Virtual Devices

[Adam.Bewsher 2]

Hi everyone,

I've noticed a few places on the forum and spoken with a couple of people who have had issues with using HTML entities in virtual devices. This thread explains the workaround.

What is an HTML entity?

(From

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)

Some characters are reserved in HTML.

If you use the less than (<) or greater than (>) signs in your text, the browser might mix them with tags.

Character entities are used to display reserved characters in HTML.

A character entity looks like this:

&entity_name;

OR

entity_number;

To display a less than sign we must write: < or <

The problem in Virtual Devices

If you want to write a string or Lua code which has an HTML entity (like & for example) in it, it will work the first time you save the virtual device. But when you open the device, all the HTML entities will be decoded into their single character form - & will become &, > will become > etc. So the next time you save it, everything will break. In fact, it doesn't even need the semicolon, so &gt will also become >.

The workaround

Do you remember that mystical string we put at the end of some virtual device button code? It looks like this:

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This is a sequence of hexadecimal escape codes which represent the characters Carriage Return (CR) and Line Feed (LF) repeated twice. In other words, two new lines.

We can use hexadecimal escape sequences to represent any character. And... it just so happens that 0x26 represents the character &.

So, if we replace all the ampersands (&) in our strings with 0x26, then they will still be output as & but when they are loaded into the browser for editing they will appear as 0x26. And 0x26gt; will not be decoded into >.

For example:

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Should be written as:

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otherwise, when you save the virtual device and reload it, it will become:

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But what about Lua?

If you have some Lua code like this:

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You may find it clearer (and simpler) not to use hexadecimal escape codes, but to change it to this:

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All this is doing is breaking the string up and joining it back together again. But now instead of &amp it has &".."amp and so it will not decode.

And that's it!

Now you will be able to edit and save your virtual devices as much as you like - without strange things happening causing them to break.

Happy Automating!

Adam Bewsher