jQuery Form Validation before Ajax submit

Question

JavaScript bit:

$(document).ready(function()
    {
            $('#form').submit(function(e)
            {     

                e.preventDefault();
                var $form = $(this);

                // check if the input is valid
                if(! $form.valid()) return false;
                    $.ajax(
                    {
                    type:'POST',
                    url:'add.php',
                    data:$('#form').serialize(),
                    success:function(response)
                    {
                        $("#answers").html(response);
                    }
                });     

            })
    });

HTML bit:

So this is the code I am trying to use. The idea is to get all my inputs validated before I send my form with Ajax. I've tried numerous versions of this now but every time I end up with submitting even though the form is not entirely filled out. All my inputs are of the "required" class. Can anyone see what I am doing wrong?

Also, I depend on class-based requirements as my input names are generated with php so I can never be sure what name[id] or input types I get.

I show/hide questions as I go through it in "pages".

JS:

function toggleVisibility(newSection) 
        {
            $(".section").not("#" + newSection).hide();
            $("#" + newSection).show();
        }

user_9852764 · Answer

function validateForm()
{
    var a=document.forms["Form"]["firstname"].value;
    var b=document.forms["Form"]["midname"].value;
    var c=document.forms["Form"]["lastname"].value;
    var d=document.forms["Form"]["tribe"].value;
    if (a==null || a=="",b==null || b=="",c==null || c=="",d==null || d=="")
    {
        alert("Please Fill All Required Field");
        return false;
    }
    else{

        $.ajax({
        type: 'post',
        url: 'add.php',
        data: $('form').serialize(),
        success: function () {
          alert('Patient added');
          document.getElementById("form").reset();
        }
      });

    }
}

  $(function () {

    $('form').on('submit', function (e) {
      e.preventDefault();

      validateForm();


    });
  });

user_576153 · Answer

You need to trigger form validation before checking if it is valid. Field validation runs after you enter data in each field. Form validation is triggered by the submit event but at the document level. So your event handler is being triggered before jquery validates the whole form. But fret not, there's a simple solution to all of this.

You should validate the form:

if ($(this).validate().form()) {
  // do ajax stuff
}

https://jqueryvalidation.org/Validator.form/#validator-form()

You should validate the form:

if ($(this).validate().form()) {
  // do ajax stuff
}

https://jqueryvalidation.org/Validator.form/#validator-form()

user_14344959 · Answer

$("#myformId").submit(function (event) {
    // submit modal form of create & edit 
    event.preventDefault();
    formObj = $(this);
        
    // check the form input is valid or not if not valid then return false;
    if (!formObj.validate().form()) return false;

    data = $(formObj).serializeArray();

    // do stuff with ajax or anything else what you wants 
});

explainantion:- first validate form and if validation will pass, then call ajax request otherwise stop execution using return false;

var validator = $( "#myform" ).validate(); Validates the form, returns true if it is valid, false otherwise. So, we need to check just if (!formObj.validate().form())

for more details see here documentation

I share customization option of validate function

$(function () {
    $('form.needs-validation').each(function() {   // <- selects every  on page which contains .needs-validation class
        var validator = $(this).validate({
            errorElement: 'span',
            errorPlacement: function (error, element) {
                error.addClass('invalid-feedback');
                element.closest('.form-group').append(error);
            },
            highlight: function (element, errorClass, validClass) {
                $(element).addClass('is-invalid');
            },
            unhighlight: function (element, errorClass, validClass) {
                $(element).removeClass('is-invalid');
            }
        });
    });
});

for more details about to customize the JQuery validation see here

for Customizing the default Validation Messages see below answers URLs that was really helpful to me

jQuery Form Validation before Ajax submit

11 Answers