"click" listener gets execute multiple time

Question

I am trying to create the table which creates rows using ajax. the problem is that when i assigned the "click" listener based on the class name it is getting called multiple time

my code is

function fn_getAlertRules(parentRowId) {
    $.ajax({
        type: "GET",
        url: anyURL,
        contentType: "application/json",
        dataType: "json"
    }).done(function(data) {
        // create row to add to parent table's row
        var s_rulesHtmlString = '<tr><td colspan="3" class="rules-parent-tr"><table><tbody>';
        $.each(data, function(i, name) {
        s_rulesHtmlString += '<tr class="rule-tr">';
        s_rulesHtmlString += '<td class="eventid-td">Rule ID:'+ name.RuleId+'<span>' + name.OccuredEventId + '</span></td>';
        s_rulesHtmlString += '<td>' + name.Name + '</td><td>' + name.RuleDate + '</td>';
        s_rulesHtmlString += '</tr>';
        });
        s_rulesHtmlString += '</tbody></table></td></tr>';
        // add row below parent tr
        $(parentRowId).parent().after(s_rulesHtmlString);
        $(".rule-tr").on("click", "td", function(event) {
            // this code blocks get executed multiple times
        });
    });
}

can anybody please tell me, why it is getting called multiple time ?

Answer 1

You are binding click event in each (loop) and event is binded as many times as loop is executed, that is why you get repeated click events. You can delegate the click event to parent of elements to be added or document before ajax call and event will be binded automatically to dynamically added element being added in done function. You can read more about event delegation using on here

Delegated events have the advantage that they can process events from descendant elements that are added to the document at a later time. By picking an element that is guaranteed to be present at the time the delegated event handler is attached, you can use delegated events to avoid the need to frequently attach and remove event handlers. Reference.

function fn_getAlertRules(parentRowId) {
    $(document).on("click", ".rule-tr td", function(event) {
       // this code blocks get executed multiple times 
    });

    $.ajax({
        type: "GET",
        url: anyURL,
        contentType: "application/json",
        dataType: "json"
    }).done(function(data) {
        // create row to add to parent table's row
        var s_rulesHtmlString = '<tr><td colspan="3" class="rules-parent-tr"><table><tbody>';
        $.each(data, function(i, name) {
        s_rulesHtmlString += '<tr class="rule-tr">';
        s_rulesHtmlString += '<td class="eventid-td">Rule ID:'+ name.RuleId+'<span>' + name.OccuredEventId + '</span></td>';
        s_rulesHtmlString += '<td>' + name.Name + '</td><td>' + name.RuleDate + '</td>';
        s_rulesHtmlString += '</tr>';
        });
        s_rulesHtmlString += '</tbody></table></td></tr>';
        // add row below parent tr
        $(parentRowId).parent().after(s_rulesHtmlString);       
    });
}

Answer 2

That's because you have multiple table rows with the same class assigned to it. If you want to get it executed only for the item that is clicked, assign a unique id to it.