我有一个有很多变量的工作视图模型.
我在文本框中使用autoNumeric(http://www.decorplanit.com/plugin/)进行文本格式化.我想在计算的observable中使用输入字段的观察数据,但是如果具有格式的可观察文本字段被修改,格式化也会保存在变量中.
如何在没有格式化的情况下仅观察输入字段的值？
我认为最好的方法可能是observable的getter / setter,并在设置值时删除格式.我无法在knockout文档中找到为ko.observable()编写get / set方法的解决方案,而ko.computed()无法存储值.
我不想使用隐藏字段或额外变量.
没有它可能吗？
最佳答案
解决方案,如http://knockoutjs.com/documentation/extenders.html所示
ko.extenders.numeric = function(target,precision) {
//create a writeable computed observable to intercept writes to our observable
var result = ko.computed({
read: target,//always return the original observables value
write: function(newValue) {
var current = target(),roundingMultiplier = Math.pow(10,precision),newValueAsNum = isNaN(newValue) ? 0 : parseFloat(+newValue),valueToWrite = Math.round(newValueAsNum * roundingMultiplier) / roundingMultiplier;
//only write if it changed
if (valueToWrite !== current) {
target(valueToWrite);
} else {
//if the rounded value is the same,but a different value was written,force a notification for the current field
if (newValue !== current) {
target.notifySubscribers(valueToWrite);
}
}
}
});
//initialize with current value to make sure it is rounded appropriately
result(target());
//return the new computed observable
return result;
};
后来
function Appviewmodel(one,two) {
this.myNumberOne = ko.observable(one).extend({ numeric: 0 });
this.myNumberTwo = ko.observable(two).extend({ numeric: 2 });
}
