SignalR + MVC: "TypeError: can't access property "value", event.target.attributes['data-id'] is undefined"

Question

Hi, I am newbie recently taking a tutorial on SignaR with Asp MVC, I encountered a bug in voting.js that I could not able to solve it by myself, here is error:

(Idk why it cant get "data-id" from .cshtml display code T.T)

This is my VotingHub:

My .cshtml display code:

And here is voting function:

   csharp  
   public int Vote(int id, bool direction)  
       {  
           var item = GetByID(id);  
           if (item == Character.NotFound) return 0;  
                    
           System.Console.WriteLine($"Voting for {item.Name}");  
     
           if (direction) item.Votes++;  
           else item.Votes--;  
             
           _ctx.Characters.Update(item);  
           _ctx.SaveChanges();  
     
           return item.Votes;  
       }  

What i try wanna do is wire up voting but it seem my signalR code couldn't connect through, all other feature of app work just fine except this voting feature, i hope some one could give me some instruction or point me to somewhere to learn so i able to understand it.

Much appreciated your time for help !

Answer 1

Hi @Tiger Ser ,

TypeError: can't access property "value", event.target.attributes['data-id'] is undefined"

About this issue, try to find the custom attribute via the votingButtons, instead of the event.

Code like this:

let itemId = votingButtons[i].attributes["data-id"].value;  

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