在TypeScript中计算(ko.computed in TypeScript)

在TypeScript中计算(ko.computed in TypeScript)

我有以下问题。 以下代码适用于JS：

Application1.Trackers = function (params) { var viewModel = { dsTrackers: new DevExpress.data.DataSource({ store: Application1.db, searchExpr: "Bezeichnung" }), searchString: ko.observable(''), find: function () { viewModel.showSearch(!viewModel.showSearch()); viewModel.searchString(''); }, showSearch: ko.observable(false), }; ko.computed(function () { return viewModel.searchString(); }).extend({ throttle: 500 }).subscribe(function (value) { viewModel.dsTrackers.filter("Bezeichnung", "contains", value); viewModel.dsTrackers.pageIndex(0); viewModel.dsTrackers.load(); }); return viewModel;

};

在Typescript中我尝试过这种方式，但这不起作用：

module MyExtremeApp { export function Trackers(params: { id: any }) { return { dsTrackers: new DevExpress.data.DataSource({ store: MyGlobals.oTrackerManager.getTrackerCustomStore(), searchExpr: "Bezeichnung" }), searchString: ko.observable(''), find: function () { this.showSearch(!this.showSearch()); this.searchString(''); }, showSearch: ko.observable(false), }; ko.computed(() => { return this.searchString(); }).extend({ throttle: 500 }).subscribe(function (value) { this.dsTrackers.filter("Bezeichnung", "contains", value); this.dsTrackers.pageIndex(0); this.dsTrackers.load(); }); }

}

它永远不会跳转到ko.computed（）。 有没有人知道为什么不呢？ 我是打字稿的新手

非常感谢你。 最好的祝福

I've the following problem. The following code works in JS:

Application1.Trackers = function (params) { var viewModel = { dsTrackers: new DevExpress.data.DataSource({ store: Application1.db, searchExpr: "Bezeichnung" }), searchString: ko.observable(''), find: function () { viewModel.showSearch(!viewModel.showSearch()); viewModel.searchString(''); }, showSearch: ko.observable(false), }; ko.computed(function () { return viewModel.searchString(); }).extend({ throttle: 500 }).subscribe(function (value) { viewModel.dsTrackers.filter("Bezeichnung", "contains", value); viewModel.dsTrackers.pageIndex(0); viewModel.dsTrackers.load(); }); return viewModel;

};

In Typescript I tried it this way, but this doesn't work:

module MyExtremeApp { export function Trackers(params: { id: any }) { return { dsTrackers: new DevExpress.data.DataSource({ store: MyGlobals.oTrackerManager.getTrackerCustomStore(), searchExpr: "Bezeichnung" }), searchString: ko.observable(''), find: function () { this.showSearch(!this.showSearch()); this.searchString(''); }, showSearch: ko.observable(false), }; ko.computed(() => { return this.searchString(); }).extend({ throttle: 500 }).subscribe(function (value) { this.dsTrackers.filter("Bezeichnung", "contains", value); this.dsTrackers.pageIndex(0); this.dsTrackers.load(); }); }

}

It never jumps into ko.computed(). Does anyone has an idea why not? I'm new to typescript

Thank you very much. Best Regards

最满意答案

由于您要转移到TypesSript，您应该使用opertunity来思考面向对象并使用类和模块。 这样你就可以生成更易读的代码。 你的课可能如下：

import mm_data = require('pathToMyDataClass'); import mm_globals = require('pathToMyGlobals'); export interface ITrackerParms { id: any; } export class Trackers { constructor(parms: ITrackerParms) { this.parms = parms; this.dsTrackers = new DevExpress.data.DataSource({ store: mm_globals.MyGlobals.oTrackerManager.getTrackerCustomStore(), searchExpr: "Bezeichnung" }); this.searchString.extend({ throttle: 500 }); this.searchString.subscribe((val: string) => { this.dsTrackers.filter("Bezeichnung", "contains", val); this.dsTrackers.pageIndex(0); this.dsTrackers.load(); }, this); } public parms: ITrackerParms; public dsTrackers: mm_data.ITrackerSource; //interface from your datasource module public showSearch = ko.observable(false); public searchString = ko.observable(''); public find() : void { this.showSearch(!this.showSearch()); this.searchString(''); } }

但是你的问题是基于确保在类的构造函数中设置subscrptions和computed（或者在你的例子中等于构造函数）。 事实上，你不需要在你的例子中使用compuded，因为你可以扩展Knockout observable以进行throtteling。

Since you are moving to TypesSript you should use the opertunity to think object oriented and use classes and modules. That way you produce much more readable code. Your class could look like this:

import mm_data = require('pathToMyDataClass'); import mm_globals = require('pathToMyGlobals'); export interface ITrackerParms { id: any; } export class Trackers { constructor(parms: ITrackerParms) { this.parms = parms; this.dsTrackers = new DevExpress.data.DataSource({ store: mm_globals.MyGlobals.oTrackerManager.getTrackerCustomStore(), searchExpr: "Bezeichnung" }); this.searchString.extend({ throttle: 500 }); this.searchString.subscribe((val: string) => { this.dsTrackers.filter("Bezeichnung", "contains", val); this.dsTrackers.pageIndex(0); this.dsTrackers.load(); }, this); } public parms: ITrackerParms; public dsTrackers: mm_data.ITrackerSource; //interface from your datasource module public showSearch = ko.observable(false); public searchString = ko.observable(''); public find() : void { this.showSearch(!this.showSearch()); this.searchString(''); } }

But your problem is based on making sure that the subscrptions and computeds are set in the constructor of the class (or what in your example equals constructor). In fact you do not need to use compuded in your example since you can extend the Knockout observable for throtteling.