How to add javascript function in the "save()" of gutenberg block?

Question

I have created a custom Gutenberg block that creates a form. This form contains a button and I want to attach a script to this button to do form validation and then make an AJAX call to back end to submit the form.

I have all this working correctly in the "edit" function. And things work as expected in Gutenberg edit mode.

What question is about the save function. First of all I am not able to use Button component in save mode. If I use button element and attach function to onclick as onclick ={OnHandleSubmit}, the curly brackets do not resolve and I get the text as is in the final html.

If I write my own function in save render html the curly brackets in the script cause a problem.

I tried writing my function in separate js file and en-queuing that, but I get function not defined error.

Finally, I had to resort to using & # 123; etc in place of special characters in the script in the "save" function. I feel that there must be a better way to handle the script in save mode.

Please help with this.

Thanks.

Answer 1

WordPress is using React only on it's backend editor not on frontend. Gutenberg work as follows:

• You create a block and interacts with it. (edit function)
• While saving gutenberg put your attributes in save function which in end returns just html
• WordPress uses comments to identify blocks and storing data related to it. You can view these comments if you switch to Code Editor from Visual Editor. Menu on top right can help you with switching.
• When you save the post then WordPress take all of the output of save functions in blocks, merge them together and save it to database.
• This simple html is loading on front end therefore none of your code is working.
• While on other end if WordPress load that same post in Edit then it redo all the steps take html, read comments and give you an interactive layout.

Gutenberg blocks mostly handles the backend behavior as you can suggest from it's common name which is backend editor. On front end you are still left with the same old logic which is enqueuing scripts separately and handles front end interactions there.

If you don't like then you can use an extra file like frontend.js with in each of your block and then use webpack to bundle them and php to enqueue them to the wp_enqueue_scripts. This how WordPress works as of now.

I have found some people using this method to use React on front-end but didn't find anything on it in docs of gutenberg.

• In save return an custom react element instead of actual html like <CustomElement />
• Define a component just like react in your scripts which enqueue on front-end and while enqueuing add wp-element dependency, as we'll need react on front and wp-element is a wrapper of React so no need to use any external library.
• When WordPress load html on frontend then your custom element will be present there and your script that we loaded on above point can then take control of it.