Return partial from a xhr request

[Gregory Mar]

Hi,
I am working on a mobile device dev using javascript and I use a remote
Rails app for the backend.
I query the backend using Ajax, and I would like to know if from my
controller I can return a partial in response to the ajax request?

Greg
--
Posted via http://www.ruby-forum.com/.

[Ivan Nastyukhin]

yep u can

index.js.erb

and in it, render your response

buts its worse idea, return json, and build dom

Ivan Nastyukhin
diei...@me.com

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[Gregory Ma]

Ivan Nastyukhin wrote:
> yep u can
>
> index.js.erb
>
> and in it, render your response
>
> buts its worse idea, return json, and build dom
>
>
> Ivan Nastyukhin
> diei...@me.com

I'm not sure to understand.
You think it's better to return json and than build the dom from the
javascript?

[Andy Jeffries]

> yep u can
>
> index.js.erb
>
> and in it, render your response
>
> buts its worse idea, return json, and build dom

I'm not sure to understand.
You think it's better to return json and than build the dom from the
javascript?

It's faster/lighter to do it that way.

However, you often break DRY* as you have two sets of logic used to create markup from a dataset (one in Rails and one is JS).  So I'm not sure I agree with Ivan.

Cheers,

Andy

* http://en.wikipedia.org/wiki/Don%27t_repeat_yourself

[Bill Walton]

Hi Greg,

On Thu, Jun 3, 2010 at 8:05 AM, Gregory Mar <li...@ruby-forum.com> wrote:
> Hi,
> I am working on a mobile device dev using javascript and I use a remote
> Rails app for the backend.
> I query the backend using Ajax, and I would like to know if from my
> controller I can return a partial in response to the ajax request?
>

If you're asking if you can return it specifically from the controller
rather than through an rjs template / view, the answer is yes.

render :update do |page|
page.which_ever_method_you_need
end

But I tend to agree with Ivan. If you're trying to get html to your
javascript app, it'll probably be easier in the long run to send json
and build the html on the client.

HTH,
Bill

[Ivan Nastyukhin]

yes
its better choise

Ivan Nastyukhin
diei...@me.com

[Gregory Ma]

Andy Jeffries wrote:
> It's faster/lighter to do it that way.
>
> However, you often break DRY* as you have two sets of logic used to
> create
> markup from a dataset (one in Rails and one is JS). So I'm not sure I
> agree
> with Ivan.
> Cheers,
> Andy

If you don't agree how would you do it?

[Ivan Nastyukhin]

people
not use rjs, its ugly

Ivan Nastyukhin
diei...@me.com

[Andy Jeffries]

> It's faster/lighter to do it that way.
>
> However, you often break DRY* as you have two sets of logic used to
> create
> markup from a dataset (one in Rails and one is JS).  So I'm not sure I
> agree
> with Ivan.

If you don't agree how would you do it?

I'd do it as the OP requested, have a partial used in both places and return that.

It depends on the amount of data/size of partial to be displayed - but as it's a mobile device I can't imagine it will be huge...

Cheers,

Andy

[Andy Jeffries]

I'd do it as the OP requested, have a partial used in both places and return that.

Sorry, just realised you were the OP :-)

In particular I'd use jQuery's load method to load the URL in to an element (the original page's container for this section):

http://api.jquery.com/load/

And from within the controller just render the partial:

render :partial => "my_data"

(having a view called _my_data.html.erb).

Cheers,

Andy

[Ivan Nastyukhin]

mm, u can do it

but 

1) u should write yet anothe action at controller, its not like REST

2) its will be more slower, than render at mobile device, from json

Ivan Nastyukhin

diei...@me.com

[Gregory Ma]

Andy Jeffries wrote:
> Sorry, just realised you were the OP :-)
>
> In particular I'd use jQuery's load method to load the URL in to an
> element
> (the original page's container for this section):
>
> http://api.jquery.com/load/
>
> And from within the controller just render the partial:
>
> render :partial => "my_data"
>
> (having a view called _my_data.html.erb).
>
> Cheers,
>
>
> Andy

This is exactly what I planned to do until you said it would be better
to return json

[Andy Jeffries]

This is exactly what I planned to do until you said it would be better
to return json

Ivan said it would be better, not me :-)

I said that it is faster/lighter weight - but not better and said I disagreed with him.

Cheers,

Andy

[Andy Jeffries]

mm, u can do it

but 

1) u should write yet anothe action at controller, its not like REST

No reason why you should...

def show

   ...blah...blah...blah

   if request.xhr?

     render :partial => "whatever"

  end

end

 

2) its will be more slower, than render at mobile device, from json

How much slower is a big thing though.  If you can cache the response then it should remove the load from Rails, if the content is small/gzipped over the air time should be negligibly larger than JSON and if it takes a few milliseconds longer than JSON parsing/DOM creation on a client device it's not the end of the world.

Optimal performance isn't necessarily the only criteria in success...

Cheers,

Andy

[Ivan Nastyukhin]

   if request.xhr?

     render :partial => "whatever"

  end

 

if developers, from my team, write this, i curse too much for such)

How much slower is a big thing though.  If you can cache the response then it should remove the load from Rails, if the content is small/gzipped over the air time should be negligibly larger than JSON and if it takes a few milliseconds longer than JSON parsing/DOM creation on a client device it's not the end of the world.

yep, if u will be cache the render time, will be good. but data with u send, will be huge.

Insert big html into dom, is slower then build its in js.

Optimal performance isn't necessarily the only criteria in success...

yep agree with u

code readability, and understandable to developers, probably two main factors

Ivan Nastyukhin

diei...@me.com

[Andy Jeffries]

On 3 June 2010 15:17, Ivan Nastyukhin <diei...@me.com> wrote:

   if request.xhr?

     render :partial => "whatever"

  end

if developers, from my team, write this, i curse too much for such)

If a developer from my team makes a judgement/technical direction based on incomplete facts I'd curse too much too :-)

Out of interest, what's your problem with the above code?

 

yep, if u will be cache the render time, will be good. but data with u send, will be huge.

Insert big html into dom, is slower then build its in js.

That's the important fact - we don't know how much data/html will be returned.  I'm assuming it will be relatively small (the OP said mobile device), you're assuming it will be huge.

Neither of us know, so I'd prefer to go with the simpler solution (that keeps display logic/markup generation in one place) and optimise to a JSON/DOM insertion later *IF* it's found to be required.  Premature optimisation is the root of all evil...

Cheers,

Andy

[Ivan Nastyukhin]

Out of interest, what's your problem with the above code?

its crutch, for incomprehensible thing

Premature optimisation is the root of all evil...

yep, but i'm thinking, that write 1-10 LOC in js, witch will be build partial for each json element, its not optimisation, its "by default" use case, 

this is my opinion

of course, i will not be try to convince u) 

Ivan Nastyukhin

diei...@me.com

[Andy Jeffries]

Out of interest, what's your problem with the above code?

its crutch, for incomprehensible thing

Sorry, I don't understand - could you rephrase...

Premature optimisation is the root of all evil...

yep, but i'm thinking, that write 1-10 LOC in js, witch will be build partial for each json element, its not optimisation, its "by default" use case, 

The problem is we don't know how complex his logic is that converts the data structure to HTML.  I think you have a fairly simple display if it's only 10 LOC in JS to build it.

This shows how we're obviously working on different projects :-)

In my world the logic to display data is large/complicated but the data displayed (per page) is relatively small.

 

this is my opinion

of course, i will not be try to convince u) 

I'm happy for you to convince me, I'm also happy to debate it (debates help everyone clarify their own thoughts/opinions).  And I don't necessarily disagree with you that your solution is faster (for the client) and may be better (if a large data set and simple display logic), but it's just that it's not the first step I'd take, I'd go with a partial first and optimise to JSON/JS rendering if required later.

Cheers,

Andy

[Ivan Nastyukhin]

Out of interest, what's your problem with the above code?

its crutch, for incomprehensible thing

Sorry, I don't understand - could you rephrase...

U should not insert if request.xhr?

 u can create view, with build js ( show.js.erb)

and in its view call render, but with js escape

The problem is we don't know how complex his logic is that converts the data structure to HTML.  I think you have a fairly simple display if it's only 10 LOC in JS to build it.

10LOC, yep its for simple results, such twitter post, github notify, or something else

in my project, we use haml, we can simplify use jshaml tools, for simplify create dom elements in js

This shows how we're obviously working on different projects :-)

I would say, as far as we are working on projects with a completely different level of thoughtfulness interface ;-)

I'd take, I'd go with a partial first and optimise to JSON/JS rendering if required later.

in phase of prototyping, i thing we can completely remove all ajax, calls if we can.

Ivan Nastyukhin

diei...@me.com

[Andy Jeffries]

Out of interest, what's your problem with the above code?

its crutch, for incomprehensible thing

Sorry, I don't understand - could you rephrase...

U should not insert if request.xhr?

 u can create view, with build js ( show.js.erb)

and in its view call render, but with js escape

Fair point.  I don't often do this... :-)

The problem is we don't know how complex his logic is that converts the data structure to HTML.  I think you have a fairly simple display if it's only 10 LOC in JS to build it.

10LOC, yep its for simple results, such twitter post, github notify, or something else

in my project, we use haml, we can simplify use jshaml tools, for simplify create dom elements in js

 In my project we have very complex display logic (major sports betting site), so I certainly wouldn't want to rewrite the 15-20 classes that determine display logic in to JS :-)

This shows how we're obviously working on different projects :-)

I would say, as far as we are working on projects with a completely different level of thoughtfulness interface ;-)

 Not sure how to take that, but as there's a smiley I assume you meant no offence...

Cheers,

Andy