# Hypothetical Question about Views **URL:** \ **Category:** Rails\ **Created:** [September 14, 2009, 10:44pm UTC](https://www.ruby-forum.com/t/hypothetical-question-about-views/175505 "2009-09-14T22:44:58Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![mercurykjb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9adbd/32.png) [@mercurykjb](https://www.ruby-forum.com/u/mercurykjb)\ **Post date:** [September 14, 2009, 10:44pm UTC](https://www.ruby-forum.com/t/hypothetical-question-about-views/175505/1 "2009-09-14T22:44:58Z")
This is purely for curiosity’s sake: If I have a simple controller method: def index @thing = Thing.all respond\_to do |format| format.js end end And I’d like to call the ‘index’ controller method from three different locations, all with AJAX, to return three entirely different views. Currently I use this: def index @thing = Thing.all respond\_to do |format| format.first\_view format.second\_view format.third\_view end end I have a hunch, however, that separate mime types for different views is inappropriate, or is this good? Any thoughts? ---
**Author:** ![mercurykjb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9adbd/32.png) [@mercurykjb](https://www.ruby-forum.com/u/mercurykjb)\ **Post date:** [September 14, 2009, 11:12pm UTC](https://www.ruby-forum.com/t/hypothetical-question-about-views/175505/2 "2009-09-14T23:12:38Z")
On Sep 14, 9:44 pm, Kendall B. \ wrote: > I have a hunch, however, that separate mime types for different views is > inappropriate, or is this good? Any thoughts? Sounds like a needless complication to me - I don’t see what this buys you. Fred ---
**Author:** ![mercurykjb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9adbd/32.png) [@mercurykjb](https://www.ruby-forum.com/u/mercurykjb)\ **Post date:** [September 14, 2009, 11:54pm UTC](https://www.ruby-forum.com/t/hypothetical-question-about-views/175505/3 "2009-09-14T23:54:19Z")
Frederick C. wrote: > On Sep 14, 9:44�pm, Kendall B. \ [s.net](http://s.net)\> wrote: > > > I have a hunch, however, that separate mime types for different views is > > inappropriate, or is this good? Any thoughts? > > Sounds like a needless complication to me - I don’t see what this buys > you. > > Fred How do you deal with wanting three different views for the same data? Do you use three separate controller actions? ---
**Author:** ![mercurykjb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9adbd/32.png) [@mercurykjb](https://www.ruby-forum.com/u/mercurykjb)\ **Post date:** [September 15, 2009, 2:19am UTC](https://www.ruby-forum.com/t/hypothetical-question-about-views/175505/4 "2009-09-15T02:19:13Z")
If it is 3 views of the same data, then the controller could just look at a params[:which\_format] value to determine where to route the view for rendering. Creating mime types for different views _all destined for the same recipient format_ is, in my opinion, an inappropriate use of the mime types. And just a niggle… Thing.all implies you are retrieving @things, plural. ---
**Author:** ![mercurykjb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9adbd/32.png) [@mercurykjb](https://www.ruby-forum.com/u/mercurykjb)\ **Post date:** [September 15, 2009, 4:13pm UTC](https://www.ruby-forum.com/t/hypothetical-question-about-views/175505/5 "2009-09-15T16:13:45Z")
Kendall B. wrote: > def index > @thing = Thing.all > > respond\_to do |format| > format.first\_view > format.second\_view > format.third\_view > end > end > > I have a hunch, however, that separate mime types for different views is > inappropriate, or is this good? Any thoughts? I have a hunch that your hunch is correct. At least in the sense that you present here. There is a fundamental concept of the REST architecture that I believe Rails tends to make somewhat obscure. The concept I’m referring to is the fundamental definitions of resources and representations. It is tempting to think of a “resource” (in Rails) as the combination of a controller and a model, but that is not really the case. Take for example this table from Fielding’s Dissertation on REST: ``` Table 5-1: REST Data Elements ``` ## Data Element | Modern Web Examples resource | the intended conceptual target of a hypertext reference resource identifier | URL, URN representation | HTML document, JPEG image representation metadata | media type, last-modified time resource metadata | source link, alternates, vary control data | if-modified-since, cache-control Notice the definition of a resource, “The intended conceptual target of a hypertext reference.” The concept of a resource by definition is a conceptual target not a specific controller. In my mind this means that there is not a one-to-one correspondence between a resource and a controller/model. Therefore, if there are three separate, and independent views, they each deserve their own “conceptual target,” and hence their own set of resource identifiers. In Rails this means they might have their own controllers and their own routes to map URLs to controller actions. The responds\_to block (and hence mime-types) are intended to provide access to the representations of a resource. Again these are representations of the conceptual concept of a resource. As indicated in the table above this might be in the form of an HTML document, JPEG image, XML document, JSON, etc. The types also do not have to be a one-to-one correspondence. One could very well have multiple representations in HTML. A good use case for this is to provide alternate layouts for different target devices. One might define a mime-type for an iPhone representation of a resource along with a desktop browser version both using HTML. ---
**Author:** ![mercurykjb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9adbd/32.png) [@mercurykjb](https://www.ruby-forum.com/u/mercurykjb)\ **Post date:** [September 15, 2009, 5:01pm UTC](https://www.ruby-forum.com/t/hypothetical-question-about-views/175505/6 "2009-09-15T17:01:32Z")
On Sep 14, 10:54 pm, Kendall B. \ wrote: > Frederick C. wrote: > How do you deal with wanting three different views for the same data? Do > you use three separate controller actions? I would. Sounds like it would be clearer than fiddling with respond\_to. Obviously you’d want to share the data generation stuff between the various actions. Fred