Guys,
I''ve been chasing a problem with country_select for the past few hours
now. My intention was pretty simple...use the following line in a form:
<p><label for="country_region">Country</label>
<%= f.country_select :country_region, "United States"
%></p>
However, for the life of me, I couldn''t get it to work. I kept getting
|can''t convert nil into String|
Turns out, after much heartache, that my problem was I wasn''t passing
it
as an array. It *should* have been
<%= f.country_select :country_region, ["United States"]
%></p>
Now, looking at the api docs, it says:
----
*country_select*(object, method, priority_countries = nil, options = {},
html_options = {})
Return select and option tags for the given object and method, using
country_options_for_select
<http://api.rubyonrails.com/classes/ActionView/Helpers/FormOptionsHelper.html#M000406>
to generate the list of option tags.
----
How was I to know it should have been an array? Had I not been so tired,
I would''ve probably infrerred it from the parameter''s
pluralization.
Additionally, after figuring out the problem, I noted
country_options_for_selects doc does say priority_countries should be an
array. Still, I feel beaten. How do you know, from looking at the api
docs or method signature, what kind of variables the method takes? This
is one instance where I miss static typing...if this were Java code I
would''ve known in two seconds what the method expected.
I''m honestly seeking your advice here...how do you keep the various
different ways methods, paritcularly ActionView helpers, can be called
straight?
Compounding the problem (and confusing me) was this method further down
in the call stack:
----
module ActionView::Helpers
class InstanceTag
def to_country_select_tag(priority_countries, options, html_options)
html_options = html_options.stringify_keys
add_default_name_and_id(html_options)
content_tag("select",
add_options(country_options_for_select(value, priority_countries),
options, value), html_options)
end
end
end
----
Can anyone tell me how value here could *ever* have a value?
Thanks for listening. I feel better somehow, but still not clean.
John
Sometimes, I get frustrated too (I miss intellisense :). Usually, a method is a related closely to another. As in the case of country_select, I see that there''s a related method, "country_options_for_select", which mentions the array of countries. You have to do a little lookup, which I really hate. I would rather have the docs be repetitive as long as each parameter is explained well. "John Wells" <lists@sourceillustrated.com> wrote in message news:44B041F9.5000003@sourceillustrated.com...> Guys, > > I''ve been chasing a problem with country_select for the past few hours > now. My intention was pretty simple...use the following line in a form: > > <p><label for="country_region">Country</label> > <%= f.country_select :country_region, "United States" %></p> > > However, for the life of me, I couldn''t get it to work. I kept getting > > |can''t convert nil into String| > > Turns out, after much heartache, that my problem was I wasn''t passing it > as an array. It *should* have been > > <%= f.country_select :country_region, ["United States"] %></p> > > Now, looking at the api docs, it says: > ---- > *country_select*(object, method, priority_countries = nil, options = {}, > html_options = {}) > > Return select and option tags for the given object and method, using > country_options_for_select > <http://api.rubyonrails.com/classes/ActionView/Helpers/FormOptionsHelper.html#M000406> > to generate the list of option tags. > ---- > How was I to know it should have been an array? Had I not been so tired, I > would''ve probably infrerred it from the parameter''s pluralization. > Additionally, after figuring out the problem, I noted > country_options_for_selects doc does say priority_countries should be an > array. Still, I feel beaten. How do you know, from looking at the api docs > or method signature, what kind of variables the method takes? This is one > instance where I miss static typing...if this were Java code I would''ve > known in two seconds what the method expected. > > I''m honestly seeking your advice here...how do you keep the various > different ways methods, paritcularly ActionView helpers, can be called > straight? > > Compounding the problem (and confusing me) was this method further down in > the call stack: > ---- > module ActionView::Helpers > class InstanceTag def to_country_select_tag(priority_countries, > options, html_options) > html_options = html_options.stringify_keys > add_default_name_and_id(html_options) > content_tag("select", add_options(country_options_for_select(value, > priority_countries), options, value), html_options) > end > end end ---- > > Can anyone tell me how value here could *ever* have a value? > > Thanks for listening. I feel better somehow, but still not clean. > > John
> I''m honestly seeking your advice here...how do you keep the various > different ways methods, paritcularly ActionView helpers, can be called > straight?It seems pretty rare to me that this sort of ambiguity happens, clearly it does but I hadn''t run into it personally since I started. So my answer is that I don''t remember the intricacies. I don''t know how one would push this up the stack to DHH himself but it seems like a good thing to change asap.> Can anyone tell me how value here could *ever* have a value?InstanceTag is much more complex than the api would have you believe. There is a function called value in the InstanceTag class which fills this role. For reference, InstanceTag is around 150 lines of code. The source on the api is hidden for a reason I think. :) Don''t give up, Rails is extremely new. Each release changes subtle things like this and makes it much better in my opinion. The difference between 0.13, 1.0.0, and 1.1.12 has been like night and day but the change seemed to happen in no time at all. Ta, Chuck Vose
On 7/8/06, John Wells <lists@sourceillustrated.com> wrote:> Guys, > > I''ve been chasing a problem with country_select for the past few hours > now. My intention was pretty simple...use the following line in a form: > > <p><label for="country_region">Country</label> > <%= f.country_select :country_region, "United States" %></p> > > However, for the life of me, I couldn''t get it to work. I kept getting > > |can''t convert nil into String| > > Turns out, after much heartache, that my problem was I wasn''t passing it > as an array. It *should* have been > > <%= f.country_select :country_region, ["United States"] %></p> > > Now, looking at the api docs, it says: > ---- > *country_select*(object, method, priority_countries = nil, options = {}, > html_options = {}) > > Return select and option tags for the given object and method, using > country_options_for_select > <http://api.rubyonrails.com/classes/ActionView/Helpers/FormOptionsHelper.html#M000406> > to generate the list of option tags. > ---- > How was I to know it should have been an array? Had I not been so tired, > I would''ve probably infrerred it from the parameter''s pluralization. > Additionally, after figuring out the problem, I noted > country_options_for_selects doc does say priority_countries should be an > array. Still, I feel beaten. How do you know, from looking at the api > docs or method signature, what kind of variables the method takes? This > is one instance where I miss static typing...if this were Java code I > would''ve known in two seconds what the method expected. > > I''m honestly seeking your advice here...how do you keep the various > different ways methods, paritcularly ActionView helpers, can be called > straight? > > Compounding the problem (and confusing me) was this method further down > in the call stack: > ---- > module ActionView::Helpers > class InstanceTag > def to_country_select_tag(priority_countries, options, html_options) > html_options = html_options.stringify_keys > add_default_name_and_id(html_options) > content_tag("select", > add_options(country_options_for_select(value, priority_countries), > options, value), html_options) > end > end > end > ---- > > Can anyone tell me how value here could *ever* have a value? > > Thanks for listening. I feel better somehow, but still not clean. > > John > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >I feel your pain, and I think there room for a lot of improvement in the docs for cases like this. I suggest you write a patch with added documentation, and submit it on the dev site: http://dev.rubyonrails.org/ - also include the specific problem you had due to the lack of docs, to explain why the patch is needed. Documentation patches are pretty easy to get applied if they make sense - send a msg to the rails-core list to spur it on. This _is_ open source, after all =). - Rob http://www.robsanheim.com http://www.seekingalpha.com http://www.ajaxian.com
On Jul 8, 2006, at 4:38 PM, John Wells wrote:> module ActionView::Helpers > class InstanceTag def to_country_select_tag > (priority_countries, options, html_options) > html_options = html_options.stringify_keys > add_default_name_and_id(html_options) > content_tag("select", add_options(country_options_for_select > (value, priority_countries), options, value), html_options) > end > end end ---- > > Can anyone tell me how value here could *ever* have a value? > > Thanks for listening. I feel better somehow, but still not clean.Do you believe that value is a local variable, rather than a method call on self? -- -- Tom Mornini
Tom Mornini wrote:> Do you believe that value is a local variable, rather than a method call > on self?Yes, I did. Looking at the code, I can''t for the life of me find a "value" method. Am I looking in the wrong place? I appreciate the discussion. However, this thread illustrates what I feel is a real weakness in Rails. In a language as dynamic as Ruby, you really *have* to have documentation with each method specifying the contract of that method...what the method expects, and what the method returns. Without this, claims of productivity may be somewhat premature...if you have to research code for methods to determine what sort of values they expect and can handle, your producivity will go down quickly...trust me. I understand lack of documentation (sometimes) if you''re writing a framework for internal consumption, but if you''re writing it for public consumption the game changes. It seems perhaps the Rails team should develop a set of loose coding standards, where no code will be excepted unless a proper method contract is included for each one. Just my two cents...I think it would help tremendously. PHP and Java have already conquered this problem...surely Ruby/Rails can? Thanks, John -- Posted via http://www.ruby-forum.com/.
I made the same mistake of assuming that value was a local variable,
while it is indeed a method. It''s defined in:
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.3/lib/action_view/helpers/form_helper.rb
def value
unless object.nil?
object.send(@method_name)
end
end
On 7/10/06, John Wells <lists@sourceillustrated.com>
wrote:> Tom Mornini wrote:
> > Do you believe that value is a local variable, rather than a method
call
> > on self?
>
> Yes, I did. Looking at the code, I can''t for the life of me find a
> "value" method. Am I looking in the wrong place?
>
> I appreciate the discussion. However, this thread illustrates what I
> feel is a real weakness in Rails. In a language as dynamic as Ruby, you
> really *have* to have documentation with each method specifying the
> contract of that method...what the method expects, and what the method
> returns. Without this, claims of productivity may be somewhat
> premature...if you have to research code for methods to determine what
> sort of values they expect and can handle, your producivity will go down
> quickly...trust me.
>
> I understand lack of documentation (sometimes) if you''re writing a
> framework for internal consumption, but if you''re writing it for
public
> consumption the game changes. It seems perhaps the Rails team should
> develop a set of loose coding standards, where no code will be excepted
> unless a proper method contract is included for each one.
>
> Just my two cents...I think it would help tremendously. PHP and Java
> have already conquered this problem...surely Ruby/Rails can?
>
> Thanks,
> John
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
On Jul 10, 2006, at 8:01 AM, John Wells wrote:> Tom Mornini wrote: >> Do you believe that value is a local variable, rather than a >> method call >> on self? > > Yes, I did. Looking at the code, I can''t for the life of me find a > "value" method. Am I looking in the wrong place?snip...> Just my two cents...I think it would help tremendously. PHP and Java > have already conquered this problem...surely Ruby/Rails can?Since Rails is a community based open source project, feel free to contribute where you think it needs improvement. -- -- Tom Mornini
John Wells wrote:> module ActionView::Helpers > class InstanceTag > def to_country_select_tag(priority_countries, options, > html_options) > html_options = html_options.stringify_keys > add_default_name_and_id(html_options) > content_tag("select", > add_options(country_options_for_select(value, priority_countries), > options, value), html_options) > end > end > end > ---- > > Can anyone tell me how value here could *ever* have a value? >I think ''value'' is a method call, not a variable. A. -- Posted via http://www.ruby-forum.com/.
Tom Mornini wrote:> On Jul 10, 2006, at 8:01 AM, John Wells wrote: > Since Rails is a community based open source project, feel free to > contribute where you think it needs improvement.Tom, While I agree with you that it is indeed an open project and that, if one sees issues, one should take up cause and contribute, I think enforcing proper documentation of methods (expected parameters and returns) is something that has to be done an enforced by the project leads. I cannot personally dictate that all contributed code or implemented code have this...but DHH and the commit gatekeepers can. Understand, I''m not trying to criticize...more, I''m trying to suggest what would help developers like me and yourself leverage the framework in a more efficient way. I am a cheerleader for Rails and want to see it succeed. I think just saying it''s open source, go contribute is not really addressing the problem. Thanks, John -- Posted via http://www.ruby-forum.com/.
Mike Garey wrote:> I made the same mistake of assuming that value was a local variable, > while it is indeed a method. It''s defined in: > > /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.3/lib/action_view/helpers/form_helper.rbAha...thanks Mike. I made the wrong assumption that the definition of InstanceTag in form_options_helper.rb was the only definition...need to remember to grep "class ClassName" from all possible source files. John -- Posted via http://www.ruby-forum.com/.