![](/img/trans.png)
[英]Knockout.js - how do I get the value of an observable property inside a computed observable?
[英]How do I append to a mapped observable array in Knockout.js?
如何在Knockout.js中的可編輯表中添加行?
var data = {
"Lines": [
{"Entries": [{"Hours": 5.5},{"Hours": 2.50},{"Hours": 3.75}]},
{"Entries": [{"Hours": 5.1},{"Hours": 2.00},{"Hours": 4.75}]},
{"Entries": [{"Hours": 1.2},{"Hours": 3.00},{"Hours": 2.12}]}
]
}
var data1 = {"Entries": [{"Hours": 0},{"Hours": 0},{"Hours": 0}],Total:0};
該表顯示self.List()
是映射到data.Lines
與self.List(ko.mapping.fromJS(data.Lines)())
[{"Entries":[{"Hours":"33.5"},{"Hours":2.5},{"Hours":3.75}],"Total":39.75},{"Entries":[{"Hours":5.1},{"Hours":2},{"Hours":4.75}],"Total":11.85},{"Entries":[{"Hours":1.2},{"Hours":3},{"Hours":2.12}],"Total":6.32}]
當我單擊addRow按鈕時,我想我需要重新計算self.List()
。 我已經嘗試了為什么不能將數據連接到可觀察到的陣列中
self.addRow =function(){
self.List(self.List().concat(data1))
self.applyTotals();
}
如果我不添加行, applyTotoals
效果很好。
self.applyTotals = function(){
ko.utils.arrayForEach(self.List(), function(vm){
vm.Total = ko.computed(function(){
var s = 0;
ko.utils.arrayForEach(this.Entries(), function(entry){
var p = parseFloat(entry.Hours(), 10);
if (!isNaN(p)) {
s += p;
}
});
return s;
}, vm);
});
}
但是我沒有得到uncaught TypeError:this.Entries is not a function
,新行將不計算總數。 所以我嘗試了
self.addRow =function(){
self.List = ko.computed(function(){
var orig = self.List();
var os= ko.toJS(orig);
os.push(data1)
console.log(JSON.stringify(os))
var oa = ko.observableArray([]);
return oa(ko.mapping.fromJS(os)());
})
}
如何修改映射的observableArrray?
@mcktimo好,您沒有有效地使用mapping
插件。 您可以在fromJS函數中使用2nd paramter Mapper
,並有效地構建viewModel。
viewModel:
function model(data) {
var self = this;
self.Entries = ko.observableArray();
self.Total = ko.computed(function () {
var sum = 0;
ko.utils.arrayForEach(self.Entries(), function (entry) {
var value = parseFloat(entry.Hours(), 10);
if (!isNaN(value)) {
sum += value;
}
});
return sum;
});
ko.mapping.fromJS(data, {}, self);
}
var mapping = { //everything goes through this point
create: function (options) {
return new model(options.data);
}
}
function ViewModel() {
var self = this
self.List = ko.observableArray([])
self.LoadData = function (data) {
ko.mapping.fromJS(data.Lines, mapping, self.List)
}
self.LoadData(data);
self.addRow = function () {
self.List.push(ko.mapping.fromJS(data1, mapping));
}
}
ko.applyBindings(new ViewModel(), document.getElementById('ko'))
這里的工作樣本
我建議更深入地研究映射文檔
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.