Implement category functionalities
Today’s goal was adding the functionalities for setting and unsetting categories on each individual article.
I started off with what would be the first thing that a user could interact with, so obviously I’m talking about the checkboxes on the create article form. To achieve this I first of all had to create a small function in DBConnect which simply returns all available categories, it’s just a simple SELECT that returns all entries in the categories-table.
Displaying the categories is not much more than a foreach-loop that creates div’s for each available category (div’s because I already got some styling wandering around my head).
Done that I had to improve the processing of the create-form. This again is a small loop (this time a while-loop) that was added to the create_entry.php-File and just calls the new linkCategoriesToArticle-DBConnect-function.
Ok, creating articles and setting the categories on the fly works now, so next step is handling the categories on updating/editing existing articles.
So now I need to now which categories are already set for the article the user is editing, this means it’s time for another DBConnect-function „getCategoriesForArticle“ which is another SELECT, enhanced by a simple JOIN that returns all categories that are already linked to the article with the given id.
On the edit-form I added the same foreach-loop that is used on the creation-form, but in this case the checkboxes for the already set categories will be pre-checked (which is what I needed the new function for).
On the processing script I also added the same loop as for creating new articles, but to be able to unlink categories again I also call to the getCategoriesForArticle-function and check whether all of this categories are still activated for the article. If there are differences the newly selected categories will be added and the unselected categories will be unlinked for the article.
In total not much of a hassle and didn’t took to much time to implement.
So long
Sven