Question

I’m learning jquery and wrote this so I can do two seperate $.GET to a php file, retrieve some info and do some calculations on it. I understand I could create one specific php file that does everything and returns the value I need, but I thought it would make more sense to reuse this php file any time I need to retrieve info.

I have this in a function and I wasn’t sure how to do the first $.GET, wait for it to finish, attach it to a variable, then execute the second $.GET pass the variable to it and do the calculation. Instead I nested them together which I don’t think is right. Here is the code.

    $.get('selectdb.php', { 'id':nsname, 'q':'basecomplexity','table':'switchers'  }, function(data)     {          $('#switchtotal'+lastIndex).html(data); //sets data to #switchtotal          $.get('selectdb.php', { 'id':nsname, 'q':'sources','table':'switchers'  }, function(data)         {             var val1 = $('#switchtotal'+lastIndex).html();             var answer = ((parseFloat(nszones)*parseFloat(data))+parseFloat(val1))*parseFloat(nsquant);             $('#switchtotal'+lastIndex).html(answer.toFixed(2)); //calculates formula and displays          });       }); 

Is there an easier way to do this?

Answer 1

You have to nest them at some level.

Due to the asynchronous nature of Ajax ( The A = Asynchronous ) , there’s no way to really just stop the code¹. So you have to do the processing in the callback.

The best you can get is by implementing a function that gets called in the callbacks instead, so they’re not nested, but the logic is still nested.

jQuery(function($){   function dbselect( opts, callback ){     $.get('select.php', opts, callback );  }  function  handle_sources( data ){     var val1 = $('#switchtotal'+lastIndex).html();    var answer = ((parseFloat(nszones)*parseFloat(data))+parseFloat(val1))*parseFloat(nsquant);    $('#switchtotal'+lastIndex).html(answer.toFixed(2)); //calculates formula and displays } function handle_basecomplex ( data ){       $('#switchtotal'+lastIndex).html(data); //sets data to #switchtotal      dbselect( { 'id':nsname, 'q':'sources','table':'switchers'  } , handle_sources );  }  dbselect( { 'id':nsname, 'q':'basecomplexity','table':'switchers'  }, handle_basecomplex );   }); 

_{1. well you can, with synchronous mode, but that’s nasty, it stops everything}