Redirect to HTTP non-www to HTTPS www htaccess
The answer by Prix works. To make it more dynamic lets use SERVER_NAME and REQUEST_URI instead of a static domain name.
RewriteEngine On
#we replace domain.com/$1 with %{SERVER_NAME}%{REQUEST_URI}.
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*) https://www.%{SERVER_NAME}%{REQUEST_URI} [L,R=301]
#here we dont use www as non www was already redirected to www.
RewriteCond %{HTTPS} off
RewriteRule ^(.*) https://%{SERVER_NAME}%{REQUEST_URI} [L,R=301]
Try it like this:
RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://www.example.com/$1 [L,R=301]
The only real difference here is that first we redirect from non-WWW to WWW then we check for HTTPS and redirect it.
If it does not work, try this one:
RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]
RewriteCond %{SERVER_PORT} !^443$
RewriteRule ^(.*)$ https://www.example.com/$1 [L,R=301]