#2034 Exceptions in views hard to catch - Ruby on Rails

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#2034 ✓resolved

Exceptions in views hard to catch

Reported by pedz | February 21st, 2009 @ 02:54 AM | in 3.0.2

I had a ticket open in the old Rails bug system about this along with a patch. That patch no longer works.

I have a couple of questions / concerns.

First, if a template encounters an exception during "compile" time, the original exception is caught and wrapped in a TemplateError exception. Thats fine but if an exception occurs during "run" time, the exception is also caught and also wrapped in a TemplateError. It would be nice if those two wrappers were different.

Second, I set a catch for a particular exception but if that exception happens while in a view, then the view code catches it and wraps it. When it gets to action controller, now my exception handler is not used because it looks like a TemplateError exception.

Third, the second item above would not be too bad if there was a defined way to catch a TemplateError exception (or any exception), examine it, and if I don't want to really catch it, return "false" or something like that from my exception handler and have it be caught by the default handlers. (I guess calling rescue_action_without_handler would work but is that "stable"?)

I would not mind working on a patch for all this but it gets frustrating submitting patches for the same issue over and over again.

Comments and changes to this ticket

You flagged this item as spam.
pedz April 14th, 2009 @ 09:31 PM
The diff fixes my issue.
- fix-view-rescue.diff 1.9 KB
Michael Koziarski July 27th, 2009 @ 04:27 AM
- Milestone cleared.
- Assigned user set to “Michael Koziarski”
I was bitten by this myself today, marking for 3.0

I'd prefer to investigate changing AV to not swallow the exceptions before making this change in rescue_from
Michael Koziarski June 1st, 2010 @ 10:25 PM
- Milestone cleared.
Yehuda Katz (wycats) June 8th, 2010 @ 02:09 AM
- State changed from “new” to “invalid”
I cannot reproduce. If anyone can, please provide better repro information.

Evgeniy Dolzhenko June 8th, 2010 @ 04:49 AM

Hopefully this sufficiently illustrates the problem we're having

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  layout 'application'
  
  rescue_from ActionView::TemplateError, :with => :rescue_template_error

  def rescue_template_error(template_error)
    # any exception raised from views will be wrapped in TemplateError
    # so that you have to examine `template_error.original_exception` and
    # then use `rescue_action_without_handler` if exception should propagate 
    render :text => "rescued TemplateError"
  end

  rescue_from ArgumentError, :with => :rescue_argument_error

  def rescue_argument_error(argument_error)
    # this will get called only when raised from controller level
    render :text => "rescued ArgumentError"
  end
end

posts/index.html.erb

<%# will get caught by `rescue_from ActionView::TemplateError` clause  %>
<% raise ArgumentError, "test ArgumentError" %>

posts_controller.rb

class PostsController < ApplicationController
  def index
    # will get caught by `rescue_from ArgumentError, :with => :rescue_argument_error` clause
    raise ArgumentError, "test ArgumentError"
  end
end

Neeraj Singh June 8th, 2010 @ 10:22 AM
- Tag changed from “action_view, exception, templateerror” to “3.x, action_view, exception, patch, templateerror”
Attached is a patch with test.
- 2034_fix_against_master.diff 2.6 KB
Neeraj Singh June 8th, 2010 @ 02:40 PM
José Valim provided feedback on the patch. Will be providing a better patch and test soon.
Neeraj Singh June 8th, 2010 @ 05:09 PM
Attached is modified patch with test.
- 2034_fix_against_master.diff 4 KB
José Valim July 19th, 2010 @ 01:00 PM
- State changed from “invalid” to “open”
- Assigned user changed from “Michael Koziarski” to “José Valim”
- Importance changed from “” to “”
Repository July 19th, 2010 @ 01:51 PM
- State changed from “open” to “resolved”
(from [33c5689e2d04aa08759903bc5d1e4de3bf6c35dd]) Exceptions from views should be rescued based on the original exception. If a handler for original exception is missing then apply ActiveView::TemplateError

[#2034 state:resolved]

Signed-off-by: José Valim jose.valim@gmail.com
http://github.com/rails/rails/commit/33c5689e2d04aa08759903bc5d1e4d...
Jon Leighton August 4th, 2010 @ 10:58 AM
Here is a workaround for those who are using Rails 2.3. Place in your ApplicationController:
```
rescue_from ActionView::TemplateError do |exception|
  rescue_action(exception.original_exception)
end
```
Jeremy Kemper October 15th, 2010 @ 11:01 PM
- Milestone set to “3.0.2”
[bulk edit]