Notice: this needs to be admin/development only, since it can be really dangerous in the wrong hands… (uses eval or param…)
- Developers see what they are dooing (just hit Refresh)
- Livesaver for HTML Emails
- Non-developers can check alignment/spelling/… sooo easy
- Generated mails can be shared through url so no need for forwarding/screenshots
View
Just make a form that submits:
- the method you want to call
- list of arguments to use
<%form_tag({:action=>'make_mail'}, :method=>:get) do%>
<%=select_tag :method_name, options_for_select(UserMailer.public_instance_methods(false).sort)%>
Models: Product.find(12322) / String: "abc" / Numbers: 123 / Array: [1,2,3]
<table>
<%5.times do |i|%>
<tr>
<td><%=i%></td>
<td><%=text_field_tag "args[]", '', :style=>'width:300px'%></td>
</tr>
<%end%>
</table>
<%=submit_tag 'Preview'%>
<%=submit_tag 'Send'%>
<%end%>
<%end%>
Controller
Evals the ‘args’ and send or previews the mail.
def make_mail
args = params[:args].map{|arg| eval arg}.compact
if params[:commit]=='Preview' #preview button
@text = UserMailer.send("create_#{params[:method_name]}", *args).body
if @text =~ /<body>/
render :text=>@text
else
render :text=>"<pre>#{@text}</pre>"
end
else #Send button
UserMailer.send("deliver_#{params[:method_name]}", *args)
flash[:notice] = 'Mail sent!'
redirect_to params.merge(:action=>:index)
end
end
Happy mail preview too you 😀
Michael Grosser, the Blog 
While the idea is nice, “eval”ing arguments submitted by a user is an incredibly large security thread.
You cannot be serious to post this code on a website. Someone might actually use it!
Its only meant to be used by programmers/admins that know what they do, no real user should ever use it of course, this would be madness 😉
e.g. I have it disabled when not in development mode.