WordPress - Add data to the database with AJAX from front-end forms.

## INTRODUCTION I need this to act as a start for something bigger, which I will build upon. So it is crucial that the work carried out has clean, maintainable code that is easy to understand and well commented throughout. You will be given access (admin login and FTP details) to an existing fresh clean WordPress instance where the project files already exist. A custom taxonomy and custom post type have already been set up. There is basic 'demo' theme for you to work with. ## REQUIREMENTS - the use of WordPress AJAX function on the front-end. - can not use any WordPress plugins to assist. - no proprietary scripts. - where possible, use jQuery instead of regular JavaScript. ## DESCRIPTION I have 4 forms already created on the front-end. These are basic hand-coded forms (not generated by any plugins or framework) so feel free to make edits to them if required. The forms are... - Create animal species - Edit animal species - Create animal - Edit animal ...each of which contains text inputs, radio buttons, select and textareas. ## HOW THE FORMS NEED TO WORK # Create Animal Species form - User fills in the form details, clicks submit. - The animated spinner graphic is to appear while the form is submitting. - The form data is added to the database into the 'animal_species' taxonomy (which already exists). - Upon success, a message will appear on screen saying "You added an animal species". # Edit Animal Species form - User makes edits to the details in the form fields, clicks submit. - The animated spinner graphic is to appear while the form is submitting. - The form data is updated in the database. - Upon success, a message will appear on screen saying "You updated the animal species". # Create Animal form - User fills in the form details, clicks submit. - The animated spinner graphic is to appear while the form is submitting. - The form data is added to the database into the 'animal' custom post type (which already exists). - Upon success, a message will appear on screen saying "You added an animal". # Edit Animal form - User makes edits to the details in the form fields, clicks submit. - The animated spinner graphic is to appear while the form is submitting. - The form data is updated in the database. - Upon success, a message will appear on screen saying "You updated the animal". ## OTHER STUFF - Please make the form processing happen in [login to view URL], or create a new file for this purpose. I would like to keep it separate from the form HTML files. - I already have a div called 'ajax-message' (currently hidden with CSS) where the returned messages need to appear. It just needs to only show after the form has been successfully submitted and data added to the database. - I already have the animated spinner graphic in place (currently hidden with CSS). It just needs to only show while the form is processing. - If anything goes wrong with the form processing, the ajax-message returned should say 'error -please try again'. - Keep security in mind. Maybe add nonce to the forms if that helps.