Jquery : swap two value and change style

问题:

i need to make a script for select a black div by click(go red), and put black div value into a white div value by another click, this is ok but when i try to swap values of two white case, the change do correctly one time, but if i retry to swap two value of white case the values swap correctly but whitout the background color red.

This is my code :

var lastClicked = '';
var lastClicked2 = '';

$(".blackcase").click(function(e) {
    var i = 0;
    if ($(this).html().length == 0) {
        return false;
    } else {
        e.preventDefault();
        $('.blackcase').removeClass('red');

        if (lastClicked != this.id) {
            $(this).addClass('red');
            var currentId = $(this).attr('id');
            var currentVal = $(this).html();

            $(".whitecase").click(function(e) {
                $('.blackcase').removeClass('red');
                var currentId2 = $(this).attr('id');

                if (i <= 0 && $("#" + currentId2).html().length == 0) {
                    $("#" + currentId2).html(currentVal);
                    $("#" + currentId).html("");
                    i = 1;
                }
            });
        } else {
            lastClicked = this.id;
        }
    }
});

$(".whitecase").click(function(e) {
    var j = 0;
    if ($(this).html().length == 0) {
        return false;
    } else {
        e.preventDefault();
        $('.whitecase').removeClass('red');

        if (lastClicked2 != this.id) {
            $(this).addClass('red');
            var currentId0 = $(this).attr('id');
            var currentVal0 = $(this).html();

            $(".whitecase").click(function(e) {
                e.preventDefault();
                var currentId02 = $(this).attr('id');
                var currentVal02 = $(this).html();

                if (j <= 0 && currentVal0 != currentVal02) {
                    $('.whitecase').removeClass('red');
                    $("#" + currentId02).html(currentVal0);
                    $("#" + currentId0).html(currentVal02);
                    j = 1;

                    return false;
                }
            });
        } else {
            lastClicked2 = this.id;
        }
    }
});

This is JSfiddle : https://jsfiddle.net/12gwq95u/12/

Try to take 12 and put into first white case, put 39 into second white case, click on the white case with 12 (go red) then click on the white case with 39, the values swap correctly with the red color when it's select, but if you try to reswap two whitecase values thats work but without the red color.

Thanks a lot

回答1:

I have spent some time to rewrite your code to make it more clear. I don't know what exactly your code should do but according to the information you have already provided, my version of your code is the following:

var selectedCase = {color: "", id: ""};

function removeSelectionWithRed() {
   $('div').removeClass('red'); 
}

function selectWithRed(element) {
    removeSelectionWithRed();
    element.addClass('red');
}

function updateSelectedCase(color, id) {
    selectedCase.color = color;
    selectedCase.id = id;
}

function moveValueFromTo(elemFrom, elemTo) {
    elemTo.html(elemFrom.html());
    setValueToElem("", elemFrom);
}

function setValueToElem(value, elem) {
    elem.html(value);
}

function swapValuesFromTo(elemFrom, elemTo) {
    var fromValue = elemFrom.html();
    var toValue = elemTo.html();
    setValueToElem(fromValue, elemTo);
    setValueToElem(toValue, elemFrom);
}

function isSelected(color) {
    return selectedCase.color == color;
}

function clearSelectedCase() {
    selectedCase.color = "";
    selectedCase.id = "";
}

function elemIsEmpty(elem) {
   return elem.html().length == 0;
}

$(".blackcase").click(function (e) {
    if (elemIsEmpty($(this))) {
        return;
    }

    alert("black is selected");
    selectWithRed($(this));
    updateSelectedCase("black", $(this).attr("id"), $(this).html());
});

$(".whitecase").click(function (e) {    
    removeSelectionWithRed();

    if (isSelected("black")) {
        alert("moving black to white");

        moveValueFromTo($("#"+selectedCase.id), $(this));

        clearSelectedCase();
        return;
    }

    if(isSelected("white") && selectedCase.id !== $(this).attr("id")) {
        alert("swap whitecase values");

        swapValuesFromTo($("#"+selectedCase.id), $(this));

        clearSelectedCase();
        return;
    }

    alert("white is selected");
    selectWithRed($(this));
    updateSelectedCase("white", $(this).attr("id"), $(this).html());
});

Link to jsfiddle: https://jsfiddle.net/12gwq95u/21/

If my answers were helpful, please up them.

回答2:

It happens because you have multiple $(".whitecase").click() handlers and they don't override each other but instead they all execute in the order in which they were bound.

I advise you to debug your code in browser console by setting breakpoints in every click() event you have (in browser console you can find your file by navigating to the Sources tab and then (index) file in the first folder in fiddle.jshell.net).

In general I think you should rewrite you code in such a way that you won't have multiple handlers to the same events and you can be absolutely sure what your code does.