Problem:
String Translation - domain is missing from the list when using HAML
Solution:
The 4.0.7 version is an older version and since then there have been plenty of changes made to our code.
As WPML itself does not scan or officially support HAML files I wouldn't be able to point out what change was made that could have caused this behavior with HAML files.
One of the functions that scan the templates has changed. It's possible the new function does not scan non-PHP files
Line 31 of wpml-string-translation\classes\strings-scanning\wpml-st-theme-plugin-scan-dir-ajax.php will allow .haml files to be scanned by changing:
$file_type = array( 'php', 'inc' );
to
$file_type = array( 'php', 'inc', 'haml' );
However, I tried this and it doesn't catch the strings in Haml.
You might want to examine the following file which should be where all the actual processing is happening:
wpml-string-translation\inc\potx.php
NOTE: I did test with version 4.0.7 of WPML and its version at the time of String Translation and it still does not scan HAML files.
Once you go to WPML->Themes and Plugins localization-> Scan your theme and then you get a list of all the files scanned, only .php files are scanned.
My suggestion would be to create a .mo file with your strings
https://wordpress.stackexchange.com/questions/127917/generating-po-mo-translating-files-from-scratch-in-a-wordpress-theme
Relevant Documentation: