Replace a specific char in a string

[TroubleAllWays]

I am looking for a solution to replace a char (in my case the space) when entering a string in a field .
Here's my example:
I shift copy a sting like this: AGT TAA CCA ATA TAG
In the saved data the spaces should be remove, so this should be in the field after saving the dataset: AGTTAACCAATATAG

Is there anybody, who got an idea to solve this problem? Would be great.

Tom

 

[troester]

You can add a php validation with "Replace"

 

[TroubleAllWays]

I already tried in the Validation section:
________
Action: php
published - both - both -
Must validate: yes

PHP Code:
$str = ' ';
echo str_replace(' ', '', $str);

(I've read somewhere, that <?PHP has to be omitted)

Replace
________

But nothing happens when I copy a string with space into the field.

 

[juuser]

Something like this should do for just spaces:

return str_replace(' ', '', $data);

For all whitespaces including tabs and line ends etc:

return preg_replace('/\s+/', '', $data);

PS. Not tested.