Rails - Jun 2006 - What does => mean ?

I see => is a hash in ruby so is #   ,,, errrg But then I see in Rails 
#=>
and then
    render :action => ''list.rhtml''

and other uses to it ,, I just need some sort of definition to what it 
mean, is it redirect send_to ''then'' no wait : is then ,,,
help...


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

trip dragon wrote:
> I see => is a hash in ruby so is #   ,,, errrg But then I see in Rails 
> #=>
> and then
>     render :action => ''list.rhtml''
> 
> and other uses to it ,, I just need some sort of definition to what it 
> mean, is it redirect send_to ''then'' no wait : is then ,,,
help...
When creating a hash, => is used to relate the keys to the values.

Anywhere you see =>, a hash is being created.  Lots of Rails methods 
take hashes as input.

Wes

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

Ah! many thanks! ...

mhh note to self need more books... and need to make a real cheat sheet

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

trip dragon wrote:
> Ah! many thanks! ...
> 
> mhh note to self need more books... and need to make a real cheat sheet
You need the following books:

Programming Ruby - Thomas ("pickaxe")
Ruby for Rails - Black
Agile Web Development with Rails - Thomas, Heinemeier Hansson (2nd ed.)
[ optional: Rails Recipes - Fowler ]

plus a browser and a little patience, and you''ll be all set.

Good luck!  It''s a lot of fun once you get into it.

Wes

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

Wes Gamble wrote:
> trip dragon wrote:
>> I see => is a hash in ruby so is #   ,,, errrg But then I see in
Rails
>> #=>
>> and then
>>     render :action => ''list.rhtml''
>> 
>> and other uses to it ,, I just need some sort of definition to what it 
>> mean, is it redirect send_to ''then'' no wait : is then
,,, help...
> 
> When creating a hash, => is used to relate the keys to the values.
> 
> Anywhere you see =>, a hash is being created.  Lots of Rails methods 
> take hashes as input.
> 
> Wes
Also you should know that hashes provided to method calls don''t always 
need the {}''s around it to be a hash.  For example, lets say I have a 
method foo:

  def foo(name, options = {})
    puts "#{name} is #{options[:is]}"
  end

Now as long the hash is the last element in the method arguments then 
you can just string key/value pairs along as if they where individual 
arguments:

  foo(''Sally'', :is => ''hot'')

  produces: Sally is hot

Which is exactly the same as:

  foo(''Sally'', {:is => ''hot''})

So anytime you see a => remember its a hash and mentally put {}''s
around
it.  So in your example, render method excepts a hash.

  render :action => ''list.rhtml''

is the same as

  render {:action => ''list.rhtml''}

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