Check if an ID exists on a data-list

Question

I’m doing an ajax crud where user chooses a result coming from a data-list to be added to a table(html).

data-list

     <div class="list_details">
       <ul>
        <li id="valor"><img src="..."><p>Nome</p></li>
        <hr>
        <li id="valor"><img src="..."><p>Nome</p></li>
        <hr>
        <li id="valor"><img src="..."><p>Nome</p></li>
        <hr>
      </ul>      
    </div>

By clicking on one of the li an event is triggered:

$('.list_details li').on('click',function(){
   if(! $('.tab_aluno').find('tr').attr('id') == $(this).attr('id') ){
      $('.tab_aluno').before('<tr class='+$(this).attr("id")+'><td><img src="'+$(this).find('img').attr('src')+'"></td><td>'+$(this).find('p').text()+'</td><td class="remove">X</td></tr>');  
   }
   $('.list_details').hide();
});

The code to do Insert in the tables works, but I want to check in the table itself if the id has already been included. There where the bug picks up, at the time to do this "IF THE ID EXISTS IN THE TABLE"

The code above will generate something like:

<table class="tab_aluno">
  <tr id="id">
     <td><img src="..."></td>
     <td>Nome</td>
     <td class='remove'>X</td>
  </tr>
  <tr id="id">
     <td><img src="..."></td>
     <td>Nome</td>
     <td class='remove'>X</td>
  </tr>
</table>

Therefore, I am looking for a logic for the if, so that it searches on all <tr> already existing in the <table> and make sure the id has already been included to avoid duplicate results

Answer 1

Is this what you want?

$('.list_details li').on('click',function(){
   var cliked = $(this);
   var found = false;
   $('.tab_aluno tr').each(function(){
     if($(this).attr('id') == cliked.attr('id')) {
         found = true;
         return false; // sair do loop
     }
   });
   if(found) {
      alert('id existe');
   }
   else {
       $('.tab_aluno').before('<tr id="'+cliked.attr("id")+'" class="'+cliked.attr("id")+'"><td><img src="'+cliked.find('img').attr('src')+'"></td><td>'+cliked.find('p').text()+'</td><td>X</td></tr>');  
   }
   $('.list_details_a').hide();
});