Update composer.js

Wrong compare to "undefined" and name.length of undefined.
Update compose.html.twig

I need to bind event before block form is submitted but i don't have access to composer. I propose this solution.
Update composer.js

Changed with typeof.
Merge pull request #372 from Th3Mouk/master

[ADD] i18n labels for composer template
Merge pull request #367 from piron4o/master

Update composer.js
Merge pull request #368 from piron4o/patch-2

Update compose.html.twig