Module development and code questions

I installed the "Private Message" module on Drupal 8.

There is a link to send a message that I want to transform into a Bootstrap button.

How to customize a link on Drupal 8 ?

Here is the HTML code of the link :

<div class="private_message_link_wrapper"><a href="/private_messages/9" class="private_message_link">Envoyer un message</a></div>

The developer of "Private Message" gave me this code, but I do not know what to do with it.

Control block visibility based on custom condition, I can achieve this via blockAccess or Plugin evaluate. could you please suggest which approach is best for performance vise?

I have a Content type with some fields. In that I have two text fields(Text A & Text B) and Geofield(Lat&Lng). So I need to store that text field values into geofield (Text A->Lat & Text B->Lng).

I have tried some entity based logic but it didn't help.

Can anyone let me know how to do this programmatically?

Hi, I would like to call functions from other modules in my own. This works fine if the modules I want to call a function from are loaded before mine. I have no access to modules that are loaded after my own. Also adding dependencies doesn't change anything. Apparently I'm doing something wrong. Can someone possibly explain to me how to solve this properly? Greetings.

Hi all, 

I am new to Drupal and I have one question.

Previously I have created a view under certain name, and decided to change the name of that view and the path but it only changed pages path of that view.

My question is, how can I change the path of edit page path of that view?

For example 

Current:

/views/view/testing-view-1/edit

For later to be

/views/view/final-view/edit

If there is a way please explain it step by step because I really lack of knowledge in Drupal.

Thank you.

Hi There,

I'm using the Google Maps Review Module in one of my sites. Could someone please assist with calling "site_id" (which is defined in "google_site_place_id" field) through a node field rather than the block field? 

Thus, I want to assign different Id's to different node's on a custom node field.

Here the current module code: