How to check variables with jQuery so that they are not sent empty?

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I am learning about jQuery and have already started making Ajax requests to register the information in the mysql database. I have a code that has several variables and I would like to ask how I can check at once if there is an empty variable. I was thinking about doing this with array but I don’t know how to use it. These variables will be captured from the form Submit. I ask for help!

    var empresa;        
    var username;       
    var ativado;            
    var tipousuario;        
    var senha;              
    var nome;               
    var cpf;                
    var cnpj;
php javascript jquery ajax
  • 1

    You can use if as seen [in this reply][1]. 
 
 
 [1]: http://stackoverflow.com/a/6003920

  • I would put them in an if and check them one by one by returning a single answer or do several if’s with a custom response for each certain variable?

  • 1

    checks the server side and returns the error message to show in ajax.

  • 1

    You can validate in JS, but inevitably you will need to validate ALSO with PHP, since JS may be disabled.

1 answer

1


Sometimes validation is done on the client side and the server side. There are always several ways to do this.

To do a customer side check you will need to search for element.value, element.checked depending on the type of element, and in the case of input type="radio" you have to go through them all and see if one of them is selected. You can make it a little easier by joining a class to these elements, but otherwise test like this:

var validado = true, erros = 0;
$('input, select, textarea').each(function () {
    var nomeTag = this.tagName.toLowerCase()
    if (nomeTag == 'select' || nomeTag == 'textarea') validado = !!this.value;
    else if (this.type == 'checkbox') validado = !!this.checked;
    else if (this.type == 'radio') validado = !!$('input').filter(function () {
        return this.checked
    })[0];
    else validado = !!this.value

    if (!validado) {
        this.addClass('incompleto');
        erros++;
    } else {
        this.removeClass('incompleto');
    }
});
if (erros) // validacao falhou!

If the erros don’t give 0 after this code then there are empty fields. I joined an optional part to give a class to the empty elements for user visibility.

On the PHP side all fields go within $_GET or $_POST, it depends on how you are using it. There you can do a simple check with a for cycle:

foreach ($post as $chave=>$valor) if (!$valor) die('O campo '.$chave.' está  vazio!');

There are more complex methods to check the content type. In these examples, and in the sequence of what you asked, this only checks if there are empty fields.

Until: this check does nothing to make the content safe, that is, this check must follow another that prepares the content to be inserted in the database.

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