Module development and code questions

Hi All,

Whats the best way to learn drupal module development?

I am guessing this comes up a fair bit.  But if I was looking to learn drupal 8 module development, does anyone have any recommendations for books to learn from?  Or am I better off with online courses?

I am currently going through the freecodecamp tutorials (which don't cover PHP nevermind drupal module dev).  Therefore I am a complete new comer to Drupal (although I did dabble making a module under Drupal 5),

Any advice highly appreciated!

Thanks in advance,

Mark.

Hi,

I am trying to add a "Save & Send Email" button to both the Node Add and Node Edit forms of a Content Type to give the Current User the option of sending themselves an email after saving the content.  I have put together code that works to add the button and to generate the email, but I cannot figure out how to have the button (#submit) trigger sending the email.  Could someone please help me tie them together?  I am also not sure how (if?) to implement both the hook_entity_insert and hook_entity_update in the same module.  The code I have so far is:

One of the elements of my webform is a dropdown list that has a Jquery function assigned that when changing its value shows a message where the form will be sent depending on the chosen value.
The email value is also assigned to a hidden field that is used in the submission of the form to send the email.
This works correctly when all required values are entered and the form is successfully submitted.

Trying to build a field(or fields) that allows the content person to select one of three scenarios for listing nodes from a specific content type.

1. By default list the latest entries (whatever the limit would be like 3)

2. Pull the latest three entries that are tagged with a specific category. (uses a taxonomy list)

3. Manually add 3 entries

Just looking for ideas on how this could be put together in an easy to use way. Any ideas? 

I am looking for a good Drupal 8 module that provides private messaging functions.  I have tried private messages, which gives an error when you send a message. And I have tried Drupal chat, which doesn't let me view the message inbox.  Does anyone have any suggestions for a good module, or have successfully used either of what I mentioned above?

Hello together, I've got a question about my drupal installation. I changed the password in my MySQL database. After that I changed the password in the settings.php too. But after that my site disappeared and I could not log in. When I changed the password again to the old one the site was back again. Can somebody help me with that problem? I changed my password the same way before and it worked. I don't understand why it's not working now.