Module | ActionController::Rescue |
In: |
vendor/rails/actionpack/lib/action_controller/rescue.rb
|
Actions that fail to perform as expected throw exceptions. These exceptions can either be rescued for the public view (with a nice user-friendly explanation) or for the developers view (with tons of debugging information). The developers view is already implemented by the Action Controller, but the public view should be tailored to your specific application.
The default behavior for public exceptions is to render a static html file with the name of the error code thrown. If no such file exists, an empty response is sent with the correct status code.
You can override what constitutes a local request by overriding the local_request? method in your own controller. Custom rescue behavior is achieved by overriding the rescue_action_in_public and rescue_action_locally methods.
LOCALHOST | = | '127.0.0.1'.freeze |
DEFAULT_RESCUE_RESPONSE | = | :internal_server_error |
DEFAULT_RESCUE_RESPONSES | = | { 'ActionController::RoutingError' => :not_found, 'ActionController::UnknownAction' => :not_found, 'ActiveRecord::RecordNotFound' => :not_found, 'ActiveRecord::StaleObjectError' => :conflict, 'ActiveRecord::RecordInvalid' => :unprocessable_entity, 'ActiveRecord::RecordNotSaved' => :unprocessable_entity, 'ActionController::MethodNotAllowed' => :method_not_allowed, 'ActionController::NotImplemented' => :not_implemented, 'ActionController::InvalidAuthenticityToken' => :unprocessable_entity |
DEFAULT_RESCUE_TEMPLATE | = | 'diagnostics' |
DEFAULT_RESCUE_TEMPLATES | = | { 'ActionView::MissingTemplate' => 'missing_template', 'ActionController::RoutingError' => 'routing_error', 'ActionController::UnknownAction' => 'unknown_action', 'ActionView::TemplateError' => 'template_error' |
True if the request came from localhost, 127.0.0.1. Override this method if you wish to redefine the meaning of a local request to include remote IP addresses or other criteria.
# File vendor/rails/actionpack/lib/action_controller/rescue.rb, line 169 169: def local_request? #:doc: 170: request.remote_addr == LOCALHOST && request.remote_ip == LOCALHOST 171: end
Overwrite to implement custom logging of errors. By default logs as fatal.
# File vendor/rails/actionpack/lib/action_controller/rescue.rb, line 132 132: def log_error(exception) #:doc: 133: ActiveSupport::Deprecation.silence do 134: if ActionView::TemplateError === exception 135: logger.fatal(exception.to_s) 136: else 137: logger.fatal( 138: "\n\n#{exception.class} (#{exception.message}):\n " + 139: clean_backtrace(exception).join("\n ") + 140: "\n\n" 141: ) 142: end 143: end 144: end
Attempts to render a static error page based on the status_code thrown, or just return headers if no such file exists. For example, if a 500 error is being handled Rails will first attempt to render the file at public/500.html. If the file doesn‘t exist, the body of the response will be left empty.
# File vendor/rails/actionpack/lib/action_controller/rescue.rb, line 156 156: def render_optional_error_file(status_code) 157: status = interpret_status(status_code) 158: path = "#{Rails.public_path}/#{status[0,3]}.html" 159: if File.exist?(path) 160: render :file => path, :status => status 161: else 162: head status 163: end 164: end
Exception handler called when the performance of an action raises an exception.
# File vendor/rails/actionpack/lib/action_controller/rescue.rb, line 114 114: def rescue_action(exception) 115: log_error(exception) if logger 116: erase_results if performed? 117: 118: # Let the exception alter the response if it wants. 119: # For example, MethodNotAllowed sets the Allow header. 120: if exception.respond_to?(:handle_response!) 121: exception.handle_response!(response) 122: end 123: 124: if consider_all_requests_local || local_request? 125: rescue_action_locally(exception) 126: else 127: rescue_action_in_public(exception) 128: end 129: end
Overwrite to implement public exception handling (for requests answering false to local_request?). By default will call render_optional_error_file. Override this method to provide more user friendly error messages.s
# File vendor/rails/actionpack/lib/action_controller/rescue.rb, line 148 148: def rescue_action_in_public(exception) #:doc: 149: render_optional_error_file response_code_for_rescue(exception) 150: end
Render detailed diagnostics for unhandled exceptions rescued from a controller action.
# File vendor/rails/actionpack/lib/action_controller/rescue.rb, line 175 175: def rescue_action_locally(exception) 176: add_variables_to_assigns 177: @template.instance_variable_set("@exception", exception) 178: @template.instance_variable_set("@rescues_path", File.dirname(rescues_path("stub"))) 179: @template.send!(:assign_variables_from_controller) 180: 181: @template.instance_variable_set("@contents", @template.render_file(template_path_for_local_rescue(exception), false)) 182: 183: response.content_type = Mime::HTML 184: render_for_file(rescues_path("layout"), response_code_for_rescue(exception)) 185: end
Tries to rescue the exception by looking up and calling a registered handler.
# File vendor/rails/actionpack/lib/action_controller/rescue.rb, line 188 188: def rescue_action_with_handler(exception) 189: if handler = handler_for_rescue(exception) 190: if handler.arity != 0 191: handler.call(exception) 192: else 193: handler.call 194: end 195: true # don't rely on the return value of the handler 196: end 197: end