RoR新手求助：如何结合link_to与JS传递双参数至控制器create方法

Hey there! I remember struggling with exactly this kind of thing when I was new to Rails and DataTables—let's walk through how to get this working properly.

First: Fixing the AJAX ($.get) Approach #

Your initial AJAX attempt had two main issues: you were passing current_user.id as a string instead of the actual value, and using GET for a create action (which should use POST per RESTful conventions). Here's how to fix it:

1. Update your JS to pass the correct values:
   Make sure your JS file is an .erb file (like your_view.js.erb) so you can embed Rails variables directly, or add this script inside your ERB view file:

   // Bind to your button's click event
   $('.add-btn').on('click', function() {
     // Get the selected row's h_id (adjust this to match how you store the ID in your row)
     const selectedHId = $('.dataTable').DataTable().row('.selected').data().h_id;
     // Or if you're using data attributes on the row:
     // const selectedHId = $('.dataTable .selected').data('h-id');
   
     // Send a POST request to your create action
     $.post('/mycontroller/create', {
       h: {
         user_id: <%= current_user.id %>,
         h_id: selectedHId
       }
     })
     .done(function() {
       alert('Successfully added to your list!');
       // Optional: Refresh your DataTable or update the UI
       $('.dataTable').DataTable().ajax.reload();
     })
     .fail(function() {
       alert('Oops, something went wrong.');
     });
   });
   

Second: Fixing the link_to Approach #

The problem with link_to is that it's rendered on the server, so it can't access the dynamically selected row's h_id from the frontend. We can work around this by using JS to inject the h_id when the button is clicked:

1. Create the link with a base URL:

   <%= link_to "Add to h-list", "#", method: :post, class: "btn btn-default add-link", data: { base_url: my_controller_create_path } %>
   

2. Add JS to handle the click:

   $('.add-link').on('click', function(e) {
     e.preventDefault(); // Stop the default link behavior
     const selectedHId = $('.dataTable').DataTable().row('.selected').data().h_id;
     const baseUrl = $(this).data('base_url');
   
     // Send the POST request with both parameters
     $.post(baseUrl, {
       h: {
         user_id: <%= current_user.id %>,
         h_id: selectedHId
       }
     })
     .done(function() {
       // Handle success (e.g., show a notification)
     });
   });
   

Third: Handling Parameters in the Controller #

You need to use strong parameters to safely accept the values and create your model instance. Here's how to update your controller:

def create
  @h = H.new(h_params) # Make sure your model name is capitalized (H, not h)
  
  if @h.save
    # Redirect or send a success response
    redirect_to your_target_path, notice: 'Added to your list successfully!'
  else
    # Handle errors (e.g., validation failures)
    redirect_to :back, alert: "Couldn't add: #{@h.errors.full_messages.join(', ')}"
  end
end

private

# Strong parameters to whitelist allowed inputs
def h_params
  params.require(:h).permit(:user_id, :h_id)
end

Key Notes: #

• Always use POST for create actions (Rails routes expect this for RESTful resources).
• Nesting parameters under h: matches how Rails expects model attributes, making strong parameters easier to handle.
• Double-check that you're correctly fetching h_id from your DataTable row—adjust the JS selector if your row stores the ID differently (e.g., data attributes, hidden columns).

内容的提问来源于stack exchange，提问作者Awesome