# A question about rails view code

**URL:** <https://www.ruby-forum.com/t/a-question-about-rails-view-code/153939>\
**Category:** Rails\
**Created:** [November 23, 2008, 1:06pm UTC](https://www.ruby-forum.com/t/a-question-about-rails-view-code/153939 "2008-11-23T13:06:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\
**Post date:** [November 23, 2008, 1:06pm UTC](https://www.ruby-forum.com/t/a-question-about-rails-view-code/153939/1 "2008-11-23T13:06:00Z")

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I am new to rails. I read some examples and don’t understand rails erb  
syntax. There is a piece of code I am not familiar:

\<% form\_for(@bay\_info) do |f| %\>  
\<%= f.error\_messages %\>

\<%= f.label :HostName %\>  
 \<%= f.text\_field :HostName %\>

...

I wander what f mean. What is its type? How can I find its definition?

thanks.

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<div class="post-metadata">

**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\
**Post date:** [November 23, 2008, 1:26pm UTC](https://www.ruby-forum.com/t/a-question-about-rails-view-code/153939/2 "2008-11-23T13:26:48Z")

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Sent from my iPhone

On 23 Nov 2008, at 12:06, Zhao Yi [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> I am new to rails. I read some examples and don’t understand rails erb  
> syntax. There is a piece of code I am not familiar:
> 
> \<% form\_for(@bay\_info) do |f| %\>  
> \<%= f.error\_messages %\>

f is a form builder. If my memory is correct the docs for form\_for  
should have some details.

Fred