How do I alter a view and add/change the form action in Entity View Attachment (eva) with table format?

Question

I have 2 related content types (Order and Proposals). In the Order Detail page, I attach the proposals for that order using EVA with table format.

I want to add an action button (vote) in EVA output (orange colored box buttons), so that when it's clicked, it updates the Vote field in the corresponding proposal node. I don't know where to start.

I've tried using hook_view_pre_render() but I can't find the corresponding object because the dpm() breaks the site.

This is the code I am using.

function mymodule_views_pre_render(\Drupal\views\ViewExecutable $view) {
  if ($view->id() == 'order_proposal_list') {
    $results = $view->result;
    dpm($view); // This breaks the site.
    ddm($view); // This outputs 300000 and more lines in drupal_debug.txt.
  }
}

Somehow, I can get that field value using this code, but it's still not enough.

function mymodule_preprocess_views_view_field(&$variables)  {
  $view = $variables['view'];
  if ($view->id() == 'order_quotation_list') {
    if ($variables['field']->field == 'edit_node') {
      dpm($variables['output']);
    }
  }
}

Answer 1

It's too late to change field plugins at this stage. You have to configure them in the View.

You could create a custom field handler plugin providing the button link and make it available in Views via hook_views_data().

On a higher level of the Entity API entities define operations. You can add your own in hook_entity_operation() or alter them in the corresponding alter hook. To use them in a View add the field Operation Links. The existing core operations edit/delete are only displayed for users who have access.

On a lower level, directly adding the HTML markup of the button to the field, use the rewrite input box of the Views field UI. See How can I theme individual fields in a row?