CODEWITHSUNDEEP
asp.netajaxjsonasp.net-mvc-3
Ingó Vals
Ingó Vals

Reputation: 4898

Why have a separate call to get Json?

I need to get some Json to the client side from the server and it's somewhat troublesome as almost all tutorials assume an Ajax call to a separate action to get the Json.

This led me to think that there must be some reason why it is done this way. In Asp.Net MVC we can pass a Model along with the view to get the information but we can't seem to easily pass a Json object. Instead you are supposed to make a separate call to get this information.

What if the Json info is known when the page is generated, why not generate it at the same time?

I'm sorry if I wasn't clear enough. While it's nice to hear of ways to get Json to the client, the question is actually whether there is a specific reason the Ajax call method is much more popular, like security or anything like that.

Upvotes: 1

Views: 121

Answers (4)

Simon Halsey
Simon Halsey

Reputation: 5480

No reason why you can't. You could use the javacript serializer to create a JSON string that drop on the page. You could also create an action that return the json string that you called from a script tag.

What you want if you're using KnockOut, would be the Mapping plugin that turns an ordinary JS object, like that generated above, into an observable ready for KnockOut to use. See here from info. http://knockoutjs.com/documentation/plugins-mapping.html

Upvotes: 1

Rich O'Kelly
Rich O'Kelly

Reputation: 41767

Because you do not need both at the same time... on the first call will be to get html (the view of the data - represented by a view model), and any ajax calls will be to get the possibly updated data (json serialized view model).

Upvotes: 1

DaveRead
DaveRead

Reputation: 3413

Can you put something like this into your view? (rough pseudo code, assuming using a Razor view)

< script >

var myJSON = { Field: @model.Field, Field2: @model.Field2 };

< /script >

Upvotes: 1

Aliostad
Aliostad

Reputation: 81680

You can use content-negotiation by setting accept header. This is considered a best practice (and according to some RESTful).

This needs to be supported and implemented at server as well. ASP NET MVC does not make it easy to support content-negotiation and you have to implement it yourself by if-else or using ActionFilter and implementing action selector.

Upvotes: 0

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