ERb question: Embedding <%= %> in helper method calls

I had a situation where I wanted to use a <%= %> (scriptlet) in my
text_field call to set the “disabled” attribute on the text field, like
so:

<%= text_field(:current_job, ‘removeLinkPos’, :value => ‘’, :id =>
‘offset’, :maxlength => 2, :disabled => <%= sometest ? ‘true’ : ‘false’
%>) %>

however, this caused a compile error.

I ended up with an if/else statement to generate my text_field
differently based on the boolean test for “disabledness”.

It kind of makes sense to me that doing <%= … <%= … %> …%> might
cause problems.

However, is there an alternative way to achieve this behavior, when you
want to use <%= %> to generate dynamic attributes within the call to a
helper method?

Thanks,
Wes

How about:

def text_field_with_conditional_options(object, method, options={})
text_field(object, method, options.merge(yield))
end

And the call would be:

<%= text_field_with_conditional_options(:current_job, ‘removeLinkPos’,
:value => ‘’, :id => ‘offset’, :maxlength => 2) {{:disabled =>
sometest}} %>

I don’t know if this makes things better or worse :expressionless:

How I intended it was that you call it exactly like text_field but
specify
any additional options as a hash. These options are merged with the
existing
options hash you¹ve provided in the original call. The reason for the
two
options hashes is that the function signature is what you¹re familiar
with.
But, now that you mention it, the code should probably be:

def text_field_with_conditional_options(object, method, options={})
block_given? ?
text_field(object, method, options.merge(yield)) :
text_field(object, method, options)
end

That way it doesn¹t upchuck if you fail to provide a block.

Steve R. wrote:

How about:

def text_field_with_conditional_options(object, method, options={})
text_field(object, method, options.merge(yield))
end

And the call would be:

<%= text_field_with_conditional_options(:current_job, ‘removeLinkPos’,
:value => ‘’, :id => ‘offset’, :maxlength => 2) {{:disabled =>
sometest}} %>

I don’t know if this makes things better or worse :expressionless:

How does this work? Would each hash element get looked at to see if it
was a code block and then, if so, the yield happens?

So options would have keys value, id, maxlength, and then the last key
would be a code block containing a hash, the yield would happen and when
complete, you end up with another hash element (with whatever value got
determined in the block)?

Just trying to make sure I get it.

Interesting. I agree - not sure if this helps anything :).

Wes

%>) %>
However, is there an alternative way to achieve this behavior,
when you
want to use <%= %> to generate dynamic attributes within the call
to a
helper method?

Thanks,
Wes

On Jul 6, 2006, at 4:35 PM, s.ross wrote:

sometest}} %>

I don’t know if this makes things better or worse :expressionless:

What’s wrong with: (note the trailing . on the 2nd line

<%= text_field(:current_job, ‘removeLinkPos’,
{ :value => ‘’, :id => ‘offset’, :maxlength => 2 }.
merge!(sometest ? { :disabled => ‘disabled’ } : {})
) %>

No need to get complicated about it. You’re already doing Ruby in
the <%= … %> so just add the code you need.

Now, if you were using this all over the place, then a helper might
be useful. In particular, the HTML ‘disabled’ attribute really needs
to be ‘disabled=“disabled”’ if you want to be XHTML 1.0. If your
only conditional was to set a field disabled or not, I’d make the
helper know specifically about the :disabled key and set the options
hash given to text_field similarly to how I’ve done it above.

-Rob

Rob B. http://agileconsultingllc.com
[email protected]

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