What I wish to do is to have a construct like this in a view:
<%= link_to_if , “New Model View”, new_model_path -%>
has to return true if new_model_path is defined and false
otherwise. What is the proper idiom to do this in rails 2?
James B. wrote:
defined? new_model_path
I do not know why I can spend so much time on something only to find the
answer after I have asked for help.
Hi –
On Mon, 24 Mar 2008, James B. wrote:
What I wish to do is to have a construct like this in a view:
<%= link_to_if , “New Model View”, new_model_path -%>
has to return true if new_model_path is defined and false
otherwise. What is the proper idiom to do this in rails 2?
I guess you could do:
<% if respond_to?(:new_model_path) %>
<%= link_to … %>
<% end %>
but that seems very brittle to me. By the time you’re writing a view,
you should know what helper methods and named routes exist, and which
ones don’t.
David
–
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James B. wrote:
But I could not get it to work with link_to_if.
This does not work (syntax error)
<%= link_to_if((defined?(new_vendor_path)), ‘New Vendor’,
new_vendor_path) -%>
but this does
<%= link_to(‘New Vendor’, new_vendor_path) if (defined?
(new_vendor_path)) -%>
Why?
David A. Black wrote:
Hi –
but that seems very brittle to me. By the time you’re writing a view,
you should know what helper methods and named routes exist, and which
ones don’t.
Yes and I do/will. But for the moment I am writing one side of a
bilaterally symmetrical application tree. I therefor wish to make this
functionality dynamic since I am frequently adding and deleting that
specific branch. It is not intended for production code.
On Mon, Mar 24, 2008 at 1:09 PM, James B.
[email protected] wrote:
James B. wrote:
But I could not get it to work with link_to_if.
This does not work (syntax error)
<%= link_to_if((defined?(new_vendor_path)), ‘New Vendor’,
new_vendor_path) -%>
I wonder if you would have to write that as:
<%= link_to_if(defined?(:new_vendor_path), …
(notice the “:”)?
newbies $.02
–wpd
Hi –
On Mon, 24 Mar 2008, James B. wrote:
Yes and I do/will. But for the moment I am writing one side of a
bilaterally symmetrical application tree. I therefor wish to make this
functionality dynamic since I am frequently adding and deleting that
specific branch. It is not intended for production code.
I also converted your example to a plain if (instead of link_to_if) –
just an artifact of having been playing around with it, but I imagine
you could translate it back 
But my main point was about knowing
the helpers, etc., and I understand your point about just trying it
out.
David
–
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ADVANCING WITH RAILS April 14-17 New York City
INTRO TO RAILS June 9-12 Berlin
ADVANCING WITH RAILS June 16-19 Berlin
CORE RAILS June 24-27 London (Skills Matter)
See http://www.rubypal.com for more info!
Patrick D. wrote:
I wonder if you would have to write that as:
<%= link_to_if(defined?(:new_vendor_path), …
(notice the “:”)?
I tried your suggestion and it does not change anything. I seemingly
cannot get link_to_if to work in this instance.
On Mar 24, 2008, at 1:46 PM, James B. wrote:
Patrick D. wrote:
I wonder if you would have to write that as:
<%= link_to_if(defined?(:new_vendor_path), …
(notice the “:”)?
I tried your suggestion and it does not change anything. I seemingly
cannot get link_to_if to work in this instance.
In order to call the link_to_if method, its arguments must first be
evaluated.
With David’s change to
link_to(…) if defined? new_vendor_path
the arguments to the link_to() are only evaluated after the “defined?
new_vendor_path” has returned true.
-Rob