stuck with haml templates - ruby-on-rails

I want to transform some haml (*.html.haml files) into xhtml. The haml command says "Usage: haml [options] [INPUT] [OUTPUT]". So I tried it with the following response:
Exception on line 1: undefined method `content_for' for #<Object:0xb730af2c>
I noticed that there are different formats which are all called haml. I noticed one which uses angle brackets a lot. Do I need some kind of preprocessing?
Here is a sample html.haml file that I want to transform:
- content_for :head do
= stylesheet_link_tag 'jquery.autocomplete'
= javascript_include_tag 'jquery.autocomplete'
- javascript_behaviour '$("input#user_full_name").autocomplete("project_roles/auto_complete_for_user_full_name")'
Note: I know how to google so I am looking for specific advice.


You are using a rails helper, content_for, so when you invoke haml using the command line program it doesn't know what does it stands for.
So either add the haml gem to your gemfile and save the template in a .html.haml template and try to render it or replace the content_for with the html result generated by rails.


What you wanted is to convert Haml to Erb - the Ruby templating language which looks like HTML. Haml doesn't do that, so it tried to render your haml template into xhtml instead of converting it to another template.
You could have used the haml2erb gem to do the conversion. It would go like this:
Dir["**/*.haml"].each do |filename|
File.open(filename.gsub(/haml$/, 'erb'),'w') do |f|
f.puts Haml2Erb.convert( File.read(filename) )
end
end

Related

Why naming convention of views files in rails are considered as action.html.erb only?

Why naming convention of views files in rails are considered as action.html.erb only ( instead of action.erb.html ) ?
What will happen if we write views files as action.erb.html ?

What will happen if we write views files as action.erb.html?
The first thing that will happen is that the Ruby syntax highlighting in your editor will stop working as the file extension is now .html instead of .erb. On almost every file system in use the file extension is the rightmost part of the file name.
The second thing that will happen is that Rails will no longer be able to lookup the template and even if it could it would no longer process it through ERB as it no longer has the .erb file extension.
.html is just a segment of the file name that lets the rails template resolver distinguish between templates for different formats when looking up a template for a given request format. Its not really technically part of the extension. For example:
show.html # just HTML - no processing
show.html.erb # a HTML ERB template
show.html.slim # a HTML Slim template
show.html.haml # a HTML Haml template
show.xml.erb # a XML ERB template
show.xml.slim # a XML Slim template
show.xml.haml # a XML Haml template
show.json.erb # a JSON ERB template
show.json.jbuilder # a JSON jBuilder template
TRDL; changing the file extension is a dumb idea. Especially when you consider that Rails actually supports multiple template engines such as jbuilder, Slim and Haml in addition to ERB.

How do I pass script name to layout from separate haml file

This is what I'm currently using:
haml :login_signup, :layout => :'main'
From the login_signup haml file, I would like to pass the name of the JS file to be parsed inside the :main haml file.
Reason? layout main.haml contains jquery reference. Rest of the haml files use different JS scripts that require jquery to be sourced first.

What you describe sounds like content_for.
Here is how this works add something like this to your main (source):
= yield(:somejs)
And then fill it from the login_signup view:
- content_for(:somejs) do
= javascript_include_tag :foo
Since you tagged also Sinatra there is a plugin for that functionality: https://github.com/foca/sinatra-content-for

Use HTML instead of HAML with Ruby on Rails Happy Seed

How can I use html.erb instead of haml when using a rails application that is generated using happy seed?

You dont have to do anything special.
You could convert your haml code to erb using https://haml2erb.org and then create an erb file pasting the code. Also delete the haml file. This should work.

CoffeeScript in Rails does not correctly render partial

$('#some').append('<%= render 'my_partial' %>')
And it renders it as text. It always escapes html. I have tried in all ways to avoid escaping.
$('#some').append('<%= j render('my_partial') %>')
$('#some').append('<%= raw render('my_partial') %>')
Result is the same.

If you want your coffee (or any files) to be interpreted as ERB, then you need to append the file name with .erb ie app.coffee.erb.
But a better question is why? Doing so will tightly couple your coffee to both rails and ruby making re-use much harder - much like putting css inline in HTML.
There are two better options IMO:
Use data attributes in HTML and access them with javascript
If you only have a single variable to pass, try something like <%= javascript_tag "my_func(#{#my_var})" %>. This will invoke a javascript function with that variable.

Rails with backbone-rails: asset helpers (image_path) in EJS files

I have a Rails 3.1 app that uses the codebrew/backbone-rails. In a .jst.ejs template, I would like to include an image, like so:
<img src="<%= image_path("foo.png") %>"/>
But of course the asset helpers are not available in JavaScript.
Chaining ERB (.jst.ejs.erb) does not work, because the EJS syntax conflicts with ERB.
Here is what I know:
The asset helpers are not available in the browser, so I need to run them on the server side.
I can work around the problem by making the server dump various asset paths into the HTML (through data attributes or <script> and JSON) and reading them back in JS, but this seems rather kludgy.
Is there a way to somehow use the asset helpers in EJS files?

There is a way, actually, to chain a .jst.ejs.erb file, although it's fairly undocumented, and I only found it through looking at the EJS test cases. You can tell EJS to use {{ }} (or [% %] or whatever else you want) instead of <% %>, and then ERB won't try to evaluate your EJS calls.
Make sure to require EJS somewhere in your code (I just included gem 'ejs' in my Gemfile), and then create an initializer (I called it ejs.rb) that includes the following:
EJS.evaluation_pattern = /\{\{([\s\S]+?)\}\}/
EJS.interpolation_pattern = /\{\{=([\s\S]+?)\}\}/
Then just make sure to rename your templates to .jst.ejs.erb, and replace your existing <% %> EJS-interpreted code with {{ }}. If you want to use something other than {{ }}, change the regular expressions in the initializer.
I wish there were an option in Sprockets to handle this through the config rather than having to explicitly include EJS, but as of the moment, there's no way to do that that I know of.

I can see two ways. Neither are great.
When you say <%%= variable %> then this is rendered by ERB as <%= variable %>, so you could double percent escape everything but the asset_tags and that would survive the trip through one ERB pass on the way to EJS.
If you find that too gross...
How about making a different javascript file, with an ERB extension, that defines your asset paths? And then use the asset pipeline to require that.
So say assets.js.erb defines something like:
MyAssets = {
'foo': <%= image_path("foo.png") %>,
...
}
And then require this somewhere near the top of your manifest. And then reference the globals however that works in EJS.

For those willing to try HAML instead of EJS: Using haml-coffee through haml_coffee_assets has worked well for me as well.
You can have the following in a .hamlc.erb file:
%img(src="<%= image_path('foo.png') %>")
(It still doesn't give you routing helpers though, only asset helpers.)

Ryan Fitzgerald was kind enough to post a gist of his JavaScript asset helpers (which get precompiled with ERB): https://gist.github.com/1406349

You can use corresponding Javascript helper via the following gem:
https://github.com/kavkaz/js_assets
Finally (after installing and configuring) you will be able to use it like this:
<img src="<%= asset_path("foo.png") %>"/>

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