Writing javascript function from ruby string in hash - ruby-on-rails

Question

I have ROR Helper that build some Javascript code.
In the helper I have Hash of options and variables that define this javascript code.
One of them is string that holds JS function, the problem is it rendered as a string and not as function when using to_json.
How can I make it work?
Example:
In my helper I have this code:
h = {url: '/some/url', async: false}
h[success] = "function(result) {alert(result);}"
"<script type='text/javascript'> jQuery.ajax(#{h.to_json}); </script>"html_safe
This code will generates:
<script type='text/javascript'>
jQuery.ajax({
url: '/some/url',
async: false,
success: "function(result) {alert(result);}"
});
</script>
What I wont to to achieve is that code (without the ".." in success part):
<script type='text/javascript'>
jQuery.ajax({
url: '/some/url',
async: false,
success: function(result) {alert(result);}
});
</script>

Answer 1

You could create a string out of h hash instead of using to_json; for example:
def js_code
h = {url: '"/some/url"', async: false}
h[:success] = "function(result) { alert(result); }"
s = h.map { |k, v| "#{k}: #{v}" }.join(",")
"<script type='text/javascript'> jQuery.ajax({#{s}}); </script>".html_safe
end
Notice that additional double quotes (") were added to '"/some/url"' in order to keep them in the final string.
Output:
<script type='text/javascript'> jQuery.ajax({url: "/some/url",async: false, success: function(result) { alert(result); }}); </script>

Answer 2

I would do that using heredoc syntax and string interpolation:
def some_helper_method
h = { url: '/some/url', async: false }
<<-HTML
<script type='text/javascript'>
jQuery.ajax({
url: '#{ h[:url] }',
async: #{ h[:async] },
success: function(result) {
alert(result);
}
});
</script>
HTML
end

Answer 3

The easiest way would be to remove the surrounding quotes with a regular expression like this.
"<script type='text/javascript'> jQuery.ajax(#{h.to_json}); </script>".gsub(/"success":"(.*)"/, '"success":\1')
which gives
<script type='text/javascript'> jQuery.ajax({"url":"/some/url","async":false,"success":function(result) {alert(result);}}); </script>
Which is not complety what you want.
I would just build a string instead of using the json approach.
html = %Q{
<script type='text/javascript'>
jQuery.ajax({
url: '#{h[:url]}',
async: #{h[:async]},
success: #{h[:success]}
});
</script>
}