Sending multiple forms data through jQuery Ajax

Question

I have two forms for which I want to send the data through jQuery Ajax call. I managed to send it successfully for one form but I am not able to send the data from both of them through the same Ajax call.

My forms are:

<form id="filter-group1"  method="post" name="filtergroup1">
<input type="checkbox" name="colour1" value="Value1" onclick="filterBy()" /><label>Option 1</label>
<input type="checkbox" name="colour2" value="Value2" onclick="filterBy()" /><label>Option 2</label>
<input type="checkbox" name="colour3" value="Value3" onclick="filterBy()" /><label>Option 3</label>
</form>
<form id="filter-group2" method="post" name="filtergroup2">
<input type="checkbox" name="size1" value="Value1" onclick="filterBy()" /><label>Option 1</label>
<input type="checkbox" name="size2" value="Value2" onclick="filterBy()" /><label>Option 2</label>
<input type="checkbox" name="size3" value="Value3" onclick="filterBy()" /><label>Option 3</label>
</form>

And the function is:

function filterBy() { 
    var fgroup1 = document.filtergroup1;
    var fgroup2 = document.filtergroup2;
    var dataString1 = $(fgroup1).serialize();
    var dataString2 = $(fgroup2).serialize();
    var filterdata = [];
    filterdata.push(dataString1,dataString2);
    $.ajax( {
        type: 'POST',
        url: 'filter.php',
        data: filterdata,
        success: function(data) {
            console.log(data);
            $('#message').html(data);
        }
    });
}

I have this in the php file:

echo var_export($_POST);

The function works fine for one form if I replace data: with

data: dataString1,

I am trying to achieve the same result with the data from both forms but I don't want to use a different function for each form.

I appreciate any help. Thank you.

Answer 1

jQuery's serialize() method concatenates your input values with an '&' symbol - therefore when you are pushing two serialized form data, you are creating an array and not concatenating the values in two forms with '&' (which is the one that will be parsed correctly). You can either: (1) concatenate the items in the array into a string with '&' or (2) use $("#form1, #form2").serialize() to do it:

function filterBy() { 
    // Construct data string
    var dataString = $("#filter-group1, #filter-group2").serialize();

    // Log in console so you can see the final serialized data sent to AJAX
    console.log(dataString);

    // Do AJAX
    $.ajax( {
        type: 'POST',
        url: 'filter.php',
        data: dataString,
        success: function(data) {
            console.log(data);
            $('#message').html(data);
        }
    });
}

[Edit]: On a side note, I highly discourage using inline JavaScript. You should separate content from function. Instead, use the .click() function, like:

$("form input[type='checkbox']").click(function() {
    var dataString = $("#filter-group1, #filter-group2").serialize();
    // (and more...)
});

I also don't exactly understand the reasoning behind using two separate forms...