What's the right way to define an anchor tag in rails?

Question

It's obvious from the documentation (and google) how to generate a link with a segment e.g. `podcast/5#comments`. You just pass a value for `:anchor` to `link_to`. My concern is about the much simpler task of generating the `Comments` tag i.e. the destination of the first link. I've tried the following, and although they seemed to work, the markup was not what I expected: ``` link_to "Comments", :name => "comments" link_to "Comments", :anchor => "comments" ``` I think I'm missing something obvious. Thanks.

Accepted Answer

You are getting confused by Ruby's syntactic sugar (which Rails uses profusely). Let me explain this briefly before answering your question.

When a ruby function takes a single parameter that is a hash:

```
def foo(options)
  #options is a hash with parameters inside
end
```

You can 'forget' to put the parenthesis/brackets, and call it like this:

```
foo :param => value, :param2 => value
```

Ruby will fill out the blanks and understand that what you are trying to accomplish is this:

```
foo({:param => value, :param2 => value})
```

Now, to your question: `link_to` takes two optional hashes - one is called `options` and the other `html_options`. You can imagine it defined like this (this is an approximation, it is much more complex)

```
def link_to(name, options, html_options)
...
end
```

Now, if you invoke it this way:

```
link_to 'Comments', :name => 'Comments'
```

Ruby will get a little confused. It will try to "fill out the blanks" for you, but incorrectly:

```
link_to('Comments', {:name => 'Comments'}, {}) # incorrect
```

It will think that `name => 'Comments'` part belongs to options, not to `html_options`!

You have to help ruby by filling up the blanks yourself. Put all the parenthesis in place and it will behave as expected:

```
link_to('Comments', {}, {:name => 'Comments'}) # correct
```

You can actually remove the last set of brackets if you want:

```
link_to("Comments", {}, :name => "comments") # also correct
```

In order to use html_options, you must leave the first set of brackets, though. For example, you will need to do this for a link with confirmation message and name:

```
link_to("Comments", {:confirm => 'Sure?'}, :name => "comments")
```

Other rails helpers have a similar construction (i.e. `form_for`, `collection_select`) so you should learn this technique. In doubt, just add all the parenthesis.

What's the right way to define an anchor tag in rails?

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