jQuery .change（）事件仅触发一次

Question

So I'm fairly novice with jquery and js, so I apologise if this is a stupid error but after researching I can't figure it out.

So I have a list of data loaded initially in a template, one part of which is a dropdown box that lets you filter the data. My issue is that the filtering only works once? As in, the .change function inside $(document).ready() only fires the once.

There are two ways to reload the data, either click the logo and reload it all, or use the search bar. Doing either of these at any time also means the .change function never fires again. Not until you refresh the page.

    var list_template, article_template, modal_template;
var current_article = list.heroes[0];


function showTemplate(template, data)
{
    var html = template(data);
    $("#content").html(html);
}

$(document).ready(function()
{
  var source = $("#list-template").html();
  list_template = Handlebars.compile(source);

  source = $("#article-template").html();
  article_template = Handlebars.compile(source);

    source = $("#modal-template").html();
    modal_template = Handlebars.compile(source);

  showTemplate(list_template,list);
    $(".articleButton").click(function()
    {
        var index = $(this).data("id");
        current_article = list.heroes[index];
        showTemplate(article_template,current_article);
        $('.poseThumb').click(displayModal);
    });

    $("#classFilter").change(function()
    {
        console.log("WOW!");
        var classToFilter = this.value;
        var filteredData =
        {
            heroes: list.heroes.filter(function(d)
            {
                if (d.heroClass.search(classToFilter) > -1)
                {
                    return true;
                }
                return false;
            })
        };
        console.log(filteredData);
        showTemplate(list_template,filteredData);
        $(".articleButton").click(function()
        {
            var index = $(this).data("id");
            current_article = filteredData.heroes[index];
            showTemplate(article_template,current_article);
            $('.poseThumb').click(displayModal);
        });
    });

    $("#searchbox").keypress(function (e)
    {
        if(e.which == 13)
            {
                var rawSearchText = $('#searchbox').val();
                var search_text = rawSearchText.toLowerCase();
                var filteredData =
                {
                    heroes: list.heroes.filter(function(d)
                    {
                        if (d.name.search(search_text) > -1)
                        {
                            return true;
                        }
                        return false;
                    })
                };
                console.log(filteredData);
                showTemplate(list_template,filteredData);
                $(".articleButton").click(function()
                {
                    var index = $(this).data("id");
                    current_article = filteredData.heroes[index];
                    showTemplate(article_template,current_article);
                    $('.poseThumb').click(displayModal);
                });
            }
    });

    $("#logo").click(function()
    {
            showTemplate(list_template,list);

            $(".articleButton").click(function()
            {
        var index = $(this).data("id");
                current_article = list.heroes[index];
                showTemplate(article_template,current_article);
                $('.poseThumb').click(displayModal);
            });
    });
    //$("#logo").click();
});

function displayModal(event)
{
        var imageNumber = $(this).data("id");
        console.log(imageNumber);
        var html    = modal_template(current_article.article[0].vicPose[imageNumber]);
        $('#modal-container').html(html);
        $("#imageModal").modal('show');
}

I should note two things: first, that the search bar works perfectly, and the anonymous function inside both of them is nearly identical, and like I said, the filtering works perfectly if you try it after the initial load. The second is that the same problem occurs replacing .change(anonymous function) with .on("change",anonymous function)

Any help or advice would be greatly appreciated. Thanks.

Answer 1

Try to use some reference like 'body' in the event listeners inside your DOM like:

  $('body').on('click','.articleButton', function() {
        //Do your stuff...
    })


    $('body').on('click','#classFilter', function() {
        //Do your stuff...  
    })


    $('body').on('keypress','#searchbox', function() {
       //Do your stuff...   
    })

    $('body').on('click','#logo', function() {
        //Do your stuff...  
    })

This will work that you can fire it more than once.

Answer 2

I agree with Fernando Urban's answer, but it doesn't actually explain what's going on.

You've created a handler attached to an HTML element ( id="classFilter" ) which causes part of the HTML to be rewritten. I suspect that the handler overwrites the HTML which contains the element with the handler on it. So after this the user is clicking on a new HTML element, which looks like the old one but doesn't have a handler.

There are two ways round this. You could add code inside the handler which adds the handler to the new element which has just been created. In this case, that would mean making the handler a named function which refers to itself. Or (the easier way) you could do what Fernando did. If you do this, the event handler is attached to the body , but it only responds to clicks on the #classFilter element inside the body . In other words, when the user clicks anywhere on the body, jQuery checks whether the click happened on a body #classFilter element. This way, it doesn't matter whether the #classFilter existed when the handler was set. See "Direct and delegated events" in jQuery docs for .on method .