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Diffstat (limited to 'guides/source/debugging_rails_applications.md')
| -rw-r--r-- | guides/source/debugging_rails_applications.md | 82 |
1 files changed, 71 insertions, 11 deletions
diff --git a/guides/source/debugging_rails_applications.md b/guides/source/debugging_rails_applications.md index 1a647f8375..a9715fb837 100644 --- a/guides/source/debugging_rails_applications.md +++ b/guides/source/debugging_rails_applications.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + Debugging Rails Applications ============================ @@ -309,7 +311,7 @@ For example: ```bash => Booting WEBrick -=> Rails 4.2.0 application starting in development on http://0.0.0.0:3000 +=> Rails 5.0.0 application starting in development on http://0.0.0.0:3000 => Run `rails server -h` for more startup options => Notice: server is listening on all interfaces (0.0.0.0). Consider using 127.0.0.1 (--binding option) => Ctrl-C to shutdown server @@ -422,11 +424,11 @@ then `backtrace` will supply the answer. --> #0 ArticlesController.index at /PathTo/project/test_app/app/controllers/articles_controller.rb:8 #1 ActionController::ImplicitRender.send_action(method#String, *args#Array) - at /PathToGems/actionpack-4.2.0/lib/action_controller/metal/implicit_render.rb:4 + at /PathToGems/actionpack-5.0.0/lib/action_controller/metal/implicit_render.rb:4 #2 AbstractController::Base.process_action(action#NilClass, *args#Array) - at /PathToGems/actionpack-4.2.0/lib/abstract_controller/base.rb:189 + at /PathToGems/actionpack-5.0.0/lib/abstract_controller/base.rb:189 #3 ActionController::Rendering.process_action(action#NilClass, *args#NilClass) - at /PathToGems/actionpack-4.2.0/lib/action_controller/metal/rendering.rb:10 + at /PathToGems/actionpack-5.0.0/lib/action_controller/metal/rendering.rb:10 ... ``` @@ -438,7 +440,7 @@ context. ``` (byebug) frame 2 -[184, 193] in /PathToGems/actionpack-4.2.0/lib/abstract_controller/base.rb +[184, 193] in /PathToGems/actionpack-5.0.0/lib/abstract_controller/base.rb 184: # is the intended way to override action dispatching. 185: # 186: # Notice that the first argument is the method to be dispatched @@ -542,7 +544,7 @@ This way an irb session will be started within the context you invoked it. But be warned: this is an experimental feature. The `var` method is the most convenient way to show variables and their values. -Let's let `byebug` to help us with it. +Let's let `byebug` help us with it. ``` (byebug) help var @@ -655,7 +657,7 @@ instruction to be executed. In this case, the activesupport's `week` method. ``` (byebug) step -[50, 59] in /PathToGems/activesupport-4.2.0/lib/active_support/core_ext/numeric/time.rb +[50, 59] in /PathToGems/activesupport-5.0.0/lib/active_support/core_ext/numeric/time.rb 50: ActiveSupport::Duration.new(self * 24.hours, [[:days, self]]) 51: end 52: alias :day :days @@ -780,10 +782,10 @@ will be stopped and you will have to start it again. `byebug` has a few available options to tweak its behaviour: -* `set autoreload`: Reload source code when changed (default: true). -* `set autolist`: Execute `list` command on every breakpoint (default: true). +* `set autoreload`: Reload source code when changed (defaults: true). +* `set autolist`: Execute `list` command on every breakpoint (defaults: true). * `set listsize _n_`: Set number of source lines to list by default to _n_ -(default: 10) +(defaults: 10) * `set forcestep`: Make sure the `next` and `step` commands always move to a new line. @@ -798,6 +800,63 @@ set forcestep set listsize 25 ``` +Debugging with the `web-console` gem +------------------------------------ + +Web Console is a bit like `byebug`, but it runs in the browser. In any page you +are developing, you can request a console in the context of a view or a +controller. The console would be rendered next to your HTML content. + +### Console + +Inside any controller action or view, you can then invoke the console by +calling the `console` method. + +For example, in a controller: + +```ruby +class PostsController < ApplicationController + def new + console + @post = Post.new + end +end +``` + +Or in a view: + +```html+erb +<% console %> + +<h2>New Post</h2> +``` + +This will render a console inside your view. You don't need to care about the +location of the `console` call; it won't be rendered on the spot of its +invocation but next to your HTML content. + +The console executes pure Ruby code. You can define and instantiate +custom classes, create new models and inspect variables. + +NOTE: Only one console can be rendered per request. Otherwise `web-console` +will raise an error on the second `console` invocation. + +### Inspecting Variables + +You can invoke `instance_variables` to list all the instance variables +available in your context. If you want to list all the local variables, you can +do that with `local_variables`. + +### Settings + +* `config.web_console.whitelisted_ips`: Authorized list of IPv4 or IPv6 +addresses and networks (defaults: `127.0.0.1/8, ::1`). +* `config.web_console.whiny_requests`: Log a message when a console rendering +is prevented (defaults: `true`). + +Since `web-console` evaluates plain Ruby code remotely on the server, don't try +to use it in production. + Debugging Memory Leaks ---------------------- @@ -830,7 +889,7 @@ application. Here is a list of useful plugins for debugging: * [Footnotes](https://github.com/josevalim/rails-footnotes) Every Rails page has footnotes that give request information and link back to your source via TextMate. -* [Query Trace](https://github.com/ntalbott/query_trace/tree/master) Adds query +* [Query Trace](https://github.com/ruckus/active-record-query-trace/tree/master) Adds query origin tracing to your logs. * [Query Reviewer](https://github.com/nesquena/query_reviewer) This rails plugin not only runs "EXPLAIN" before each of your select queries in development, but @@ -854,6 +913,7 @@ References * [ruby-debug Homepage](http://bashdb.sourceforge.net/ruby-debug/home-page.html) * [debugger Homepage](https://github.com/cldwalker/debugger) * [byebug Homepage](https://github.com/deivid-rodriguez/byebug) +* [web-console Homepage](https://github.com/rails/web-console) * [Article: Debugging a Rails application with ruby-debug](http://www.sitepoint.com/debug-rails-app-ruby-debug/) * [Ryan Bates' debugging ruby (revised) screencast](http://railscasts.com/episodes/54-debugging-ruby-revised) * [Ryan Bates' stack trace screencast](http://railscasts.com/episodes/24-the-stack-trace) |