如何从 Durandal shell 监控路线？

Question

我所需要的只是监控当前路线，以便一些计算出的 observables 相应地更新。 cmets中带解释的相关代码：

define(['durandal/plugins/router', 'durandal/app','services/dataservice'], function (router, app, dataservice) {

    // TODO: I need to make these computed observables that monitor the route, but I can't monitor the route until after it's been activated, so I just define these guys as observables here
    this.isViewingFolder = ko.observable();
    this.isViewingSet = ko.observable();

    // These don't evaluate correctly because isViewingFolder() doesn't get defined until after the DOM loads (I think)
    var displayAddForFolder = ko.computed(function () {
        return selectedItemsCount() == 0 && isViewingFolder() && !isViewingSet();
    });
    var displayAddForSet = ko.computed(function () {
        return selectedItemsCount() == 0 isViewingSet() && !isViewingFolder();
    }); 

    // The ONLY way I've been able to get this to work is with the following (putting a computed into an observable??)
    var viewAttached = function () {
        isViewingFolder(ko.computed(function() {
            return router.activeRoute().moduleId == 'viewmodels/folder';
        }));
        isViewingSet(ko.computed(function () {
            return router.activeRoute().moduleId == 'viewmodels/set';
        }));
    }

    // If I try this the value updates once but only once, never again:
    var viewAttached = function () {
        isViewingFolder(router.activeRoute().moduleId == 'viewmodels/folder');
        isViewingSet(ko.computed(router.activeRoute().moduleId == 'viewmodels/set');
    }

任何帮助将不胜感激。整个周末都在为此头疼。

Answer 1

这不是您的问题Durandal: Determining if a view is currently active (possibly using Router)? 的变体。 同样的答案也适用于此。

假设您的 shell 返回一个单例，如下所示应该可以满足您的需求。

define(['durandal/plugins/router', 'durandal/app','services/dataservice'], function (router, app, dataservice) {

var isViewingFolder = ko.observable(false);
var isViewingSet = ko.observable(false);

router.activeRoute.subscribe(function( val ) {
      isViewingFolder(val.moduleId === 'viewmodels/folder');
      isViewingSet(val.moduleId === 'viewmodels/set');
      console.log('isViewingFolderOrSet', isViewingFolder(), isViewingSet());

  });
...


return {
    router: router,
    isViewingFolder: isViewingFolder,
    isViewingSet: isViewingSet,
    ...
   }
});