Rails: pass data to javascript -

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• passing ruby variables javascript function in rails view 5 answers
• ruby on rails - send javascript variable controller external javascript asset file 2 answers

i'm new in rails , in controller have:

class pagescontroller < applicationcontroller    def home       @temp = "hello"    end end 

i have read must put javascript code in application.js (tell me if true) , have:

window.onload=function(){alert("<%= j @temp %>")} 

obviously alert print string "<%= j @temp %>" how can pass variable @temp javascript alert can print hello?

thanks

i wrote article on how pass ruby objects client. ryan bates has excellent railscast on passing data js.

add div view corresponds pagescontrolle#home action not visible when load page contain data stored in ruby objects:

# views/pages_controllers/home.html.erb <%= content_tag :div, class: "temp_information", data: {temp: @temp} %> <% end %> 

load page div included , view page source. can see ruby objects stored in .temp_information div. open javascript console access ruby objects javascript objects:

$('.temp_information').data('temp') 

you not need add js js partial, can use asset pipeline.