Question

如果表单中的所有字段为脏，则返回true，否则返回false。这是我的代码。

function getHasChanges() {
    var hasChanges = false;

    $(":input:not(:button):not([type=hidden])").each(function () {
        if ((this.type == "text" || this.type == "textarea" || this.type == "hidden") && this.defaultValue != this.value) {
            hasChanges = true;
            return false;             }
        else {
            if ((this.type == "radio" || this.type == "checkbox") && this.defaultChecked != this.checked) {
                hasChanges = true;
                return false;                 }
            else {
                if ((this.type == "select-one" || this.type == "select-multiple")) {
                    for (var x = 0; x < this.length; x++) {
                        if (this.options[x].selected != this.options[x].defaultSelected) {
                            hasChanges = true;
                            return false;
                        }
                    }
                }
            }
        }
    });

    return hasChanges;
}

我使用了这段代码并试图操纵它，但我无法理解它。

我的问题是：如何检查表单上的所有字段是否都是脏的？

Answer 1

我认为你做错了。您在任何地方都返回false，因此输出将始终为false，无论它是否有更改。即使您有hasChanges = true;，也要返回false更改您的代码：

function getHasChanges() {
    var hasChanges = false;

    $(":input:not(:button):not([type=hidden])").each(function () {
        if ((this.type == "text" || this.type == "textarea" || this.type == "hidden") && this.defaultValue != this.value) {
            hasChanges = true;
         }
        else 
         {
            if ((this.type == "radio" || this.type == "checkbox") && this.defaultChecked != this.checked) {
                hasChanges = true;
             }
            else 
            {
                if ((this.type == "select-one" || this.type == "select-multiple")) {
                    for (var x = 0; x < this.length; x++) {
                        if (this.options[x].selected != this.options[x].defaultSelected) {
                            hasChanges = true;
                       }
                    }
                }
            }
        }
    });

    return hasChanges;
}

修改

即使上面的代码也会有问题;因为一旦我们将其设置为true，即使下面查询中的字段未更改，我们也不会将其设置为false。你需要使用这个：

function getHasChanges() { var hasChanges = false; $(":input:not(:button):not([type=hidden])").each(function () { if ((this.type == "text" || this.type == "textarea" || this.type == "hidden")) { if(this.defaultValue != this.value) { hasChanges = true; } else { hasChanges = false; } return hasChanges; } else { if ((this.type == "radio" || this.type == "checkbox")) { if(this.defaultChecked != this.checked) { hasChanges = true; } else { hasChanges = false; } } return hasChanges; else { if ((this.type == "select-one" || this.type == "select-multiple")) { for (var x = 0; x < this.length; x++) { if (this.options[x].selected != this.options[x].defaultSelected) { hasChanges = true; } } } return hasChanges; } } }); return hasChanges; }

希望这会有所帮助：）

错过了一个支架。请检查一下：

function getHasChanges() { var hasChanges = false; $(":input:not(:button):not([type=hidden])").each(function () { if ((this.type == "text" || this.type == "textarea" || this.type == "hidden")) { if(this.defaultValue != this.value) { hasChanges = true; } else { hasChanges = false; } return hasChanges; } else if ((this.type == "radio" || this.type == "checkbox")) { if(this.defaultChecked != this.checked) { hasChanges = true; } else { hasChanges = false; } return hasChanges; } else if (this.type == "select-one" || this.type == "select-multiple") { for (var x = 0; x < this.length; x++) { if (this.options[x].selected != this.options[x].defaultSelected) { hasChanges = true; } } return hasChanges; } }); return hasChanges; }

Answer 2

如果您想知道所有字段是否已更改，我会反转逻辑。将hasChanges初始化为true，并在没有进行更改时立即设置为false。

像这样：

function getHasChanges() {
    var hasChanges = true;

    $(":input:not(:button):not([type=hidden])").each(function () {
        if ((this.type == "text" || this.type == "textarea" || this.type == "hidden") && this.defaultValue == this.value) {
            hasChanges = false;
        }
        else if ((this.type == "radio" || this.type == "checkbox") && this.defaultChecked == this.checked) {
            hasChanges = false;
        }
        else if ((this.type == "select-one" || this.type == "select-multiple")) {
            for (var x = 0; x < this.length; x++) {
                if (this.options[x].selected == this.options[x].defaultSelected) {
                    hasChanges = false;
                }
            }
        }
    });

    return hasChanges;
}

Answer 3

这是我的刺：

如果所有字段都具有非默认的非空字符串值，则返回false。如果所有字段都设置为默认值或为空字符串，则返回true。

注意：即使语法错误也没有测试过，所以YMMV。

编辑：已更新：已检查语法，现在就运行。

编辑2 ：再次更新以更智能地考虑选择框。目前尚不清楚多选应如何处理，但你原来的方式肯定会产生意想不到的结果。

供参考，my jsbin为此。

function getHasChanges() {
    var incomplete = false;

    var ch = {
      text: {
            list: ['text', 'textarea', 'hidden'],
            defaultProp: 'defaultValue',
            valueProp: 'value'
        },
      check: {
            list: ['radio', 'checkbox'],
            defaultProp: 'defaultChecked',
            valueProp: 'checked'
        },
      select: {
            list: ['select-one', 'select-multiple'],
            defaultProp: 'defaultSelected',
            valueProp: 'selected',
            multi: 'options'
        }
    };

    $(':input:not(:button):not([type=hidden])').each(function () {
        for(kind in ch){
            for(k in ch[kind].list){
                var type = ch[kind].list[k];
                if(this.type == type){
                    if(ch[kind].multi){
                        for (var i = 0; i < this.length; i++) {
                            if(type == 'select-one'){
                                // for single select the default needs to have changed 
                                if(this[ch[kind].multi][i][ch[kind].defaultProp] && this[ch[kind].multi][i][ch[kind].valueProp]){
                                    // this defaulted to selected and is still selected
                                    incomplete = true;
                                    return;
                                }
                            } else if(type == 'select-multiple'){
                                // it's not clear what's correct here.
                                // do you want each selected item to change?
                                // for now do nothing.
                            }
                        }
                    } else {
                        if(this[ch[kind].valueProp] === '' || this[ch[kind].defaultProp] == this[ch[kind].valueProp]){
                            incomplete = true;
                            return;
                        }
                    }
                    break;
                }
            }
        }
    });

    return incomplete;
}

Answer 4

问题是您设置了hasChanges = true，然后设置了return false。

function getHasChanges() {
    var hasChanges = false;

    $(":input:not(:button):not([type=hidden])").each(function () {
        if ((this.type == "text" || this.type == "textarea" || this.type == "hidden") && this.defaultValue != this.value) {
            hasChanges = true;
        else {
            if ((this.type == "radio" || this.type == "checkbox") && this.defaultChecked != this.checked) {
                hasChanges = true;
            else {
                if ((this.type == "select-one" || this.type == "select-multiple")) {
                    for (var x = 0; x < this.length; x++) {
                        if (this.options[x].selected != this.options[x].defaultSelected) {
                            hasChanges = true;
                        }
                    }
                }
            }
        }
    });

    return hasChanges;
}

如果所有输入字段都是脏的，则返回true，如何？

4 个答案: