kickout.js外部模型js文件

Question

I have an MVC.NET app which using Knockout.js (+ knockout.mapping) to deal with some cascading dropdowns. The data for these comes from a WebAPI call to an external service. As it happens this service requires an authentication token which expires after 2 hours, so I have the MVC app put the data from the service in a System.Web.Caching.Cache and return it from there unless the token has expired where it will grab it again from the service. This is working fine. However when I need to get this to the View, I am currently using the following method, which is to have a property of the ViewModel that I assign the service/Cache data to and then do this in the view:

var model = new ViewModel(@Html.Raw(Json.Encode(Model.ReferenceData)))
ko.applyBindings(model); 

where Model.ReferenceData is the data from the service. again this is working fine, but... the thing is with this, that the page then has all that Json data dumped in it on each request. I would like to use an external JS file for the ReferenceData as then at least it can be cached by the browser and lessen the weight of the page on future requests. However, I imagine that the overhead of generating a JS file is not that small, along with – what I really need is it to generate a link to that file that changes in much the same way that the built in MVC bundling of js files works – generating a link with a querystring. My question is: is there an easy way of doing this? For sure I can, when the cache is filled that first time, generate a js file and reference that from the View, but as I say getting that to change its link each time it is refreshed – or at least working out whether the data in it has changed and updating it only then is where the problem lies.

Any insight to this would be of great help

Thanks

Nat

Answer 1

1. Version the JS file (you can keep a GUID in the file it-self).
2. In Application_Start() get this version ID to a static variable.
3. In your controller pass this static variable data to ViewBag.
4. Ref your script with this ID

When you regenerate the file, update the version in file as well as your static variable. Next request from the client get the new version with new key.

Now if you want to update clients on the new version you have to use bi-directional protocol like web sockets or long-polling.