I am trying to add a drop-down containing taxonomy terms to my site's basic search. I have created a taxonomy term category and used search auto-complete module for providing auto-complete search functionality. Can anyone suggest me how to add taxonomy drop-down besides the search button on the search block and relate the drop-down selection with search text.
I think you will need to use custom search module. For auto-complete feature i think it is better to go with custom development rather than depending on contributed modules which will come with lot of unwanted features.
To preface :
You will need to use
hook_form_alter() for add you custom field.
Then with the help of
hook_search you can inject your custom search criteria using search query extract and search query insert.