Class: Coach::Handler
- Inherits:
-
Object
- Object
- Coach::Handler
- Defined in:
- lib/coach/handler.rb
Constant Summary collapse
- STATUS_CODE_FOR_EXCEPTIONS =
0
Instance Attribute Summary collapse
-
#name ⇒ Object
readonly
Returns the value of attribute name.
Instance Method Summary collapse
-
#build_request_chain(sequence, context) ⇒ Object
Given a middleware sequence, filter out items not applicable to the current request, and set up a chain of instantiated middleware objects, ready to serve a request.
-
#build_sequence(item, context) ⇒ Object
Traverse the middlware tree to build a linear middleware sequence, containing only middlewares that apply to this request.
-
#call(env) ⇒ Object
The Rack interface to handler - builds a middleware chain based on the current request, and invokes it.
-
#initialize(middleware, config = {}) ⇒ Handler
constructor
A new instance of Handler.
- #inspect ⇒ Object
Constructor Details
#initialize(middleware, config = {}) ⇒ Handler
Returns a new instance of Handler.
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# File 'lib/coach/handler.rb', line 12 def initialize(middleware, config = {}) @config = config if middleware.is_a?(String) @name = middleware else @middleware = middleware @name = middleware.name # This triggers validation of the middleware chain, to raise any errors early on. root_item end end |
Instance Attribute Details
#name ⇒ Object (readonly)
Returns the value of attribute name.
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# File 'lib/coach/handler.rb', line 10 def name @name end |
Instance Method Details
#build_request_chain(sequence, context) ⇒ Object
Given a middleware sequence, filter out items not applicable to the current request, and set up a chain of instantiated middleware objects, ready to serve a request.
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# File 'lib/coach/handler.rb', line 73 def build_request_chain(sequence, context) sequence.reverse.reduce(nil) do |successor, item| item.build_middleware(context, successor) end end |
#build_sequence(item, context) ⇒ Object
Traverse the middlware tree to build a linear middleware sequence, containing only middlewares that apply to this request.
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# File 'lib/coach/handler.rb', line 62 def build_sequence(item, context) sequence = item.middleware.middleware_dependencies.map do |child_item| build_sequence(child_item.set_parent(item), context) end dedup_sequence([*sequence, item].flatten) end |
#call(env) ⇒ Object
The Rack interface to handler - builds a middleware chain based on the current request, and invokes it. rubocop:disable Metrics/MethodLength
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# File 'lib/coach/handler.rb', line 29 def call(env) context = { request: ActionDispatch::Request.new(env) } sequence = build_sequence(root_item, context) chain = build_request_chain(sequence, context) event = build_event(context) publish("start_handler.coach", event.dup) instrument("finish_handler.coach", event) do response = chain.instrument.call rescue StandardError => e raise ensure # We want to populate the response and metadata fields after the middleware # chain has completed so that the end of the instrumentation can see them. The # simplest way to do this is pass the event by reference to ActiveSupport, then # modify the hash to contain this detail before the instrumentation completes. # # This way, the last finish_handler.coach event will have all the details. status = response.try(:first) || STATUS_CODE_FOR_EXCEPTIONS event.merge!( response: { status: status, exception: e, }.compact, metadata: context.fetch(:_metadata, {}), ) end end |
#inspect ⇒ Object
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# File 'lib/coach/handler.rb', line 79 def inspect "#<Coach::Handler[#{name}]>" end |