On Thu, Feb 11, 2010 at 12:58 PM, Marnen Laibow-Koser
[email protected] wrote:
Why do you prefer RJS to writing JavaScript?
RJS is a template rendering system that also happens to execute JS. I
do not prefer one over the other, it’s apples and oranges.
Controller action:
def get_user
if request.xhr?
@user = User.find( params[:id] )
end
end
get_user.rjs:
if @user
page.replace_html ‘user_tab’, :partial => ‘user/user_form’
page << “$j( ‘#user_tab’ ).fadeIn(‘slow’);”
end
How do you keep the generated JavaScript out of your HTML?
Partials.
Wouldn’t that still put the JavaScript into your HTML files?
Yup.
–
Greg D.
destiney.com | gregdonald.com
Ok, does anyone know how to do a page[:div].replace_html on every ajax
call, helper or something like that?
Greg D. wrote:
On Thu, Feb 11, 2010 at 12:58 PM, Marnen Laibow-Koser
[email protected] wrote:
Why do you prefer RJS to writing JavaScript?
RJS is a template rendering system that also happens to execute JS. I
do not prefer one over the other, it’s apples and oranges.
OK. Perhaps I should have asked when you prefer RJS.
Controller action:
def get_user
if request.xhr?
@user = User.find( params[:id] )
end
end
get_user.rjs:
if @user
page.replace_html ‘user_tab’, :partial => ‘user/user_form’
page << “$j( ‘#user_tab’ ).fadeIn(‘slow’);”
end
Hmm. Why the visual effect here, rather than in the completion handler
for the Ajax call? I guess I don’t see the point of Rails writing JS,
rather than simply handing a JSON packet to the client.
I’ll think about this further, though.
How do you keep the generated JavaScript out of your HTML?
Partials.
Wouldn’t that still put the JavaScript into your HTML files?
Yup.
Which I don’t like to do. Thanks for confirming that this is actually
the case.
–
Greg D.
destiney.com | gregdonald.com
Best,
–Â
Marnen Laibow-Koser
http://www.marnen.org
[email protected]
Hi Marnen,
On Thu, 2010-02-11 at 20:33 +0100, Marnen Laibow-Koser wrote:
I guess I don’t see the point of Rails writing JS,
rather than simply handing a JSON packet to the client.
Reduced application complexity.
Best regards,
Bill
On Thu, Feb 11, 2010 at 1:33 PM, Marnen Laibow-Koser
[email protected] wrote:
Wouldn’t that still put the JavaScript into your HTML files?
Yup.
Which I don’t like to do. Thanks for confirming that this is actually
the case.
link_to_remote, button_to_remote, periodically_call_remote,
submit_to_remote, and remote_form_for all write JS directly into the
HTML. Good thing you don’t use those.
–
Greg D.
destiney.com | gregdonald.com
Greg D. wrote:
On Thu, Feb 11, 2010 at 1:33 PM, Marnen Laibow-Koser
[email protected] wrote:
Wouldn’t that still put the JavaScript into your HTML files?
Yup.
Which I don’t like to do. �Thanks for confirming that this is actually
the case.
link_to_remote, button_to_remote, periodically_call_remote,
submit_to_remote, and remote_form_for all write JS directly into the
HTML. Good thing you don’t use those.
Exactly. I’m looking forward to being able to use them in Rails 3, but
till then I can’t.
–
Greg D.
destiney.com | gregdonald.com
Best,
–Â
Marnen Laibow-Koser
http://www.marnen.org
[email protected]
On Thu, Feb 11, 2010 at 1:33 PM, Marnen Laibow-Koser
[email protected] wrote:
get_user.rjs:
if @user
page.replace_html ‘user_tab’, :partial => ‘user/user_form’
page << “$j( ‘#user_tab’ ).fadeIn(‘slow’);”
end
Hmm. Why the visual effect here, rather than in the completion handler
for the Ajax call?
Because I build more than just toy apps. Sometimes I have complex
logic for what effect to show, or what to do when an exception is
raised. Sometimes the JS is generated, like:
page << “$j(function(){ $j.notifyBar({ html: ‘#{ “Enrollment goals
updated” }’, delay: #{ FLASH_EXPIRE_DELAY }, animationSpeed: ‘normal’
}); });”
I guess I don’t see the point of Rails writing JS,
I agree, you do not.
–
Greg D.
destiney.com | gregdonald.com
On Feb 11, 4:57 pm, Me [email protected] wrote:
Is there a way to use any kind of helper or something if you do the
same thing on every rjs call? Like render a flash box div?
if in a helper you stick something like
def rjs_flash
update_page do |page|
…
end
end
Then in your templates you can do
page << rjs_flash
You can also do stuff like link_to_function(‘Foo’, rjs_flash) if you
use those helpers. (First saw this trick at rails conf europ a few
years ago, slides to the talk are here:
Fred
Thanks. I was not sure if there was a totally transparent way to do.
On Thu, Feb 11, 2010 at 3:41 PM, Frederick C. <
Greg D. wrote:
On Thu, Feb 11, 2010 at 1:33 PM, Marnen Laibow-Koser
[email protected] wrote:
get_user.rjs:
if @user
� page.replace_html ‘user_tab’, :partial => ‘user/user_form’
� page << “$j( ‘#user_tab’ ).fadeIn(‘slow’);”
end
Hmm. �Why the visual effect here, rather than in the completion handler
for the Ajax call?
Because I build more than just toy apps.
So do I.
Sometimes I have complex
logic for what effect to show, or what to do when an exception is
raised. Sometimes the JS is generated, like:
page << “$j(function(){ $j.notifyBar({ html: ‘#{ “Enrollment goals
updated” }’, delay: #{ FLASH_EXPIRE_DELAY }, animationSpeed: ‘normal’
}); });”
I’d consider that problematic application design, but again, I’ll think
about it further. I’d rather let the client-side JS make this decision.
I guess I don’t see the point of Rails writing JS,
I agree, you do not.
–
Greg D.
destiney.com | gregdonald.com
Best,
–Â
Marnen Laibow-Koser
http://www.marnen.org
[email protected]
Greg D. wrote:
link_to_remote, button_to_remote, periodically_call_remote,
submit_to_remote, and remote_form_for all write JS directly into the
HTML. Good thing you don’t use those.
In Rails3 these have all been made unobtrusive.
On Thu, Feb 11, 2010 at 2:19 PM, Marnen Laibow-Koser
[email protected] wrote:
I’d rather let the client-side JS make this decision.
The client side wouldn’t yet know if my record was successfully saved
to the db or not.
–
Greg D.
destiney.com | gregdonald.com
On Fri, Feb 12, 2010 at 4:44 AM, Andrew P. [email protected]
wrote:
Greg D. wrote:
link_to_remote, button_to_remote, periodically_call_remote,
submit_to_remote, and remote_form_for all write JS directly into the
HTML. Good thing you don’t use those.
In Rails3 these have all been made unobtrusive.
Yup, but it doesn’t mean the old way is suddenly wrong.
–
Greg D.
destiney.com | gregdonald.com
On Feb 11, 7:46 pm, Greg D. [email protected] wrote:
On Thu, Feb 11, 2010 at 1:33 PM, Marnen Laibow-Koser
Because I build more than just toy apps. Sometimes I have complex
logic for what effect to show, or what to do when an exception is
raised. Sometimes the JS is generated, like:
page << "$j(function(){ $j.notifyBar({ html: ‘#{ “Enrollment goals
updated” }’, delay: #{ FLASH_EXPIRE_DELAY }, animationSpeed: ‘normal’
}); });"
I guess I don’t see the point of Rails writing JS,
Personally I use rjs when it’s a good fit, and when it’s not I don’t -
RJS is fine for the simple stuff but sometimes it just doesn’t feel
like it’s worth the effort to massage something into RJS language
instead of writing plain javascript - plain old js.erb is easier
there. I also don’t like writing anything too complicated like this
(rjs or js.erb) because I find it awkward to test. It’s way simpler to
write unit tests that assert that the server side code produces the
correct json fragments and then some javascript unit tests to assert
that the various possible json payloads are consumed properly.
Greg D. wrote:
Yup, but it doesn’t mean the old way is suddenly wrong.
–
Greg D.
destiney.com | gregdonald.com
RJS is difficult to test and especially difficult to debug when things
go wrong. I would have to agree with Fred that it’s just less
complicated to stay away from RJS.
When you need javascript, just write javascript.
And, yes, Marnen has a style of writing that may seem elitist at times,
but his arguments serve a purpose. He wants to force a definitive
answer if it can exist. I’ve gotten into many arguments (most positive)
with him and in many of those, sometimes I want to yank the strings out
of his violin. But, then I calm down and slowly re-read what he’s
posting and remove any and all tones I might see in the argument.
What I got from Marnen’s arguments in this topic were that RJS is more
complicated, more often it is clearly unnecessary to use, and it’s just
better to write … javascript. All of those points are pretty clear and
true.
Greg, some of your own points are pretty clear as well and if you’ve
perfected your RJS templates and they work great in your projects, I see
no reason not to reuse them again, if you are happy with them. However,
everything changes and RJS is becoming less used. Just keep that in
mind.
On Fri, Feb 12, 2010 at 12:16 PM, Alpha B. [email protected]
wrote:
Greg, some of your own points are pretty clear as well and if you’ve
perfected your RJS templates and they work great in your projects, I see
no reason not to reuse them again, if you are happy with them.
Thank goodness… I’ll be able to sleep tonight.
–
Greg D.
destiney.com | gregdonald.com
Greg D. wrote:
On Thu, Feb 11, 2010 at 2:19 PM, Marnen Laibow-Koser
[email protected] wrote:
�I’d rather let the client-side JS make this decision.
The client side wouldn’t yet know if my record was successfully saved
to the db or not.
Then that information could be in the JSON packet, because the server
would know at the appropriate time. All it would need is one more
field.
It seems to me that in most cases, there’s something conceptually wrong
with sending behavior in the way you’re describing, rather than
data. I tend to think that if the client sends an Ajax request for
(say) a record to the server, it should get back data for that record,
which it can then decide how to render. This would also presumably make
it easier to use the same JSON API for both internal Ajax and external
Web-service consumers. It also means that JS files can be static, and
thus cacheable by the browser.
I like the simplicity of the RJS approach for certain trivial cases (and
perhaps for cases where behavior, rather than data, is primarily what
the client is requesting), but I’m finding difficulty in seeing how it
can scale well or be maintainable. I’ll probably play around with it at
some point soon and see if I’m missing something that would change my
mind.
–
Greg D.
destiney.com | gregdonald.com
Best,
Marnen Laibow-Koser
http://www.marnen.org
[email protected]