Module: Mbeditor::MountPath

Defined in:
lib/mbeditor/mount_path.rb

Overview

Resolves the active URL prefix mbeditor serves from.

At break-time the host route table is wiped, so it is the wrong place to ask “where am I mounted?”. MountPath answers from a resolution chain that never touches the route table directly:

1. explicit Mbeditor.configuration.mount_path (override)
2. the cached detected value (populated from a healthy route load)
3. the "/mbeditor" default

The cache is guarded by a mutex because it is read at break-time from whatever request thread happens to be serving mbeditor.

Constant Summary collapse

DEFAULT = 
'/mbeditor'

Class Method Summary collapse

Class Method Details

.cached ⇒ Object

The cached detected prefix, or nil if nothing has been detected yet.



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# File 'lib/mbeditor/mount_path.rb', line 52

def cached
  @mutex.synchronize { @cached }
end

.cached=(value) ⇒ Object

Stores the detected prefix. Passing nil clears the cache.



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# File 'lib/mbeditor/mount_path.rb', line 57

def cached=(value)
  @mutex.synchronize { @cached = value }
end

.detect(route_set) ⇒ Object

Scans a route set for the route that mounts Mbeditor::Engine and returns its path-spec prefix (e.g. “/mbeditor”), or nil if the engine is not mounted in this set. A mounted engine’s route.app is a Constraints wrapper whose #app is the engine; an unmounted route’s app is something else, so an unwrap-once-then-compare is enough.



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# File 'lib/mbeditor/mount_path.rb', line 32

def detect(route_set)
  route_set.routes.each do |route|
    app = route.app
    target = app.respond_to?(:app) ? app.app : app
    return route.path.spec.to_s if target == Mbeditor::Engine
  end
  nil
end

.refresh!(route_set) ⇒ Object

Re-detects from a route set and caches the result. Called from the engine’s after_routes_loaded hook, which fires only on a healthy route load — never at break-time, when the table is wiped. A nil detection is left as a no-op so a stray refresh from an engine-less set can never clobber a good prefix cached from an earlier healthy load.



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# File 'lib/mbeditor/mount_path.rb', line 46

def refresh!(route_set)
  detected = detect(route_set)
  self.cached = detected if detected
end

.resolve ⇒ Object 



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# File 'lib/mbeditor/mount_path.rb', line 23

def resolve
  Mbeditor.configuration.mount_path || cached || DEFAULT
end