Class: Impression::Resource

Inherits:
Object
  • Object
show all
Defined in:
lib/impression/resource.rb

Overview

The ‘Resource` class represents an abstract web resource. Resources are organized in tree like structure, with the structure normally corresponding to the URL path hierarchy. Other ways of organising resources, according to other taxonomies, can be implemented as long as the resources implement the same interface as the `Resource` class, which includes the following methods:

  • ‘Resource#route` - returns the resource which should respond to the request.

  • ‘Resource#respond` - responds to the request.

Direct Known Subclasses

FileTree, RackApp

Constant Summary collapse

FIRST_PATH_SEGMENT_REGEXP = 
/^(\/[^\/]+)\//.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parent: nil, path:, &block) ⇒ void

Initalizes a new resource instance. If a block is given, it is used as the request handler instead of the default one, which returns ‘404 NOT FOUND`.

Parameters:

  • parent (Impression::Resource, nil) (defaults to: nil) —

    the parent resource (or nil)

  • path (String) —

    the resource’s relative path

  • &block (Proc) —

    default request handler



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# File 'lib/impression/resource.rb', line 36

def initialize(parent: nil, path:, &block)
  @parent = parent
  @path = normalize_route_path(path)
  @route_regexp = @path == '/' ? nil : /^#{@path}(\/.*)?$/.freeze
  @children = {}

  @parent&.add_child(self)

  if block
    singleton_class.define_method(:call, &block)
  end
end

Instance Attribute Details

#children ⇒ Object (readonly)

A hash mapping relative paths to child resources



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# File 'lib/impression/resource.rb', line 27

def children
  @children
end

#parent ⇒ Object (readonly)

Reference to the parent resource



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# File 'lib/impression/resource.rb', line 21

def parent
  @parent
end

#path ⇒ Object (readonly)

The resource’s path relative to its parent



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# File 'lib/impression/resource.rb', line 24

def path
  @path
end

Instance Method Details

#absolute_path ⇒ String

Returns the resource’s absolute path, according to its location in the resource hierarchy.

Returns:

  • (String) —

    absolute path



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# File 'lib/impression/resource.rb', line 64

def absolute_path
  @absoulte_path ||= File.join(@parent ? @parent.absolute_path : '/', @path)
end

#add_child(child) ⇒ Impression::Resource

Adds a child reference to the children map.

Parameters:

Returns:



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# File 'lib/impression/resource.rb', line 82

def add_child(child)
  @children[child.path] = child
  self
end

#call(req) ⇒ void

This method returns an undefined value.

Responds to the given request by rendering a 404 Not found response.

Parameters:



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# File 'lib/impression/resource.rb', line 100

def call(req)
  req.respond(nil, ':status' => Qeweney::Status::NOT_FOUND)
end

#each(&block) ⇒ Impression::Resource

Iterates over the resource and any of its sub-resources, passing each to the given block.

Returns:



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# File 'lib/impression/resource.rb', line 72

def each(&block)
  block.(self)
  @children.values.each { |c| c.each(&block) }
  self
end

#html_response(html, **headers) ⇒ Object

Returns a callable that responds with HTML using the given parameters.

Parameters:

  • html (String) —

    response body

  • **headers (Hash) —

    additional response headers



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# File 'lib/impression/resource.rb', line 169

def html_response(html, **headers)
  ->(req) { req.respond_html(html, **headers) }
end

#json_response(object, **headers) ⇒ Object

Returns a callable that responds with JSON using the given parameters.

Parameters:

  • object (any) —

    object to be converted to JSON

  • **headers (Hash) —

    additional response headers



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# File 'lib/impression/resource.rb', line 178

def json_response(object, **headers)
  ->(req) { req.respond_json(object, **headers) }
end

#remount(parent, path) ⇒ void

This method returns an undefined value.

Remounts the resource on a different parent and path.

Parameters:

  • parent (Resource, nil) —

    new parent

  • path (String) —

    new path relative to new parent



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# File 'lib/impression/resource.rb', line 54

def remount(parent, path)
  @parent&.remove_child(self)
  @parent = parent
  @path = normalize_route_path(path)
end

#remove_child(child) ⇒ Impression::Resource

Removes a child reference from the children map.

Parameters:

Returns:



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# File 'lib/impression/resource.rb', line 91

def remove_child(child)
  @children.delete(child.path)
  self
end

#render_tree_to_static_files(base_path) ⇒ Impression::Resource

Renders the resource and all of its sub-resources to static files.

Parameters:

  • base_path (String) —

    base path of target directory

Returns:



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# File 'lib/impression/resource.rb', line 135

def render_tree_to_static_files(base_path)
  each do |r|
    path = File.join(base_path, r.relative_static_file_path)
    dir = File.dirname(path)
    FileUtils.mkdir_p(dir) if !File.directory?(dir)
    File.open(path, 'w') { |f| r.render_to_file(f) }
  end
  self
end

#route(req) ⇒ Impression::Resource?

Routes the request by matching self and any children against the request path, returning the target resource, or nil if there’s no match.

Parameters:

Returns:



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# File 'lib/impression/resource.rb', line 111

def route(req)
  case (relative_path = req.match_resource_path?(@route_regexp))
  when nil
    return nil
  when '/'
    return self
  else
    # naive case
    child = @children[relative_path]
    return child.route(req) if child

    if (m = relative_path.match(FIRST_PATH_SEGMENT_REGEXP))
      child = @children[m[1]]
      return child.route(req) if child
    end

    return self
  end
end

#text_response(text, **headers) ⇒ Object

Returns a callable that responds with plain text using the given parameters.

Parameters:

  • text (String) —

    response body

  • **headers (Hash) —

    additional response headers



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# File 'lib/impression/resource.rb', line 160

def text_response(text, **headers)
  ->(req) { req.respond_text(text, **headers) }
end

#to_proc ⇒ Proc

Converts the resource to a Proc, for use as a Qeweney app.

Returns:

  • (Proc) —

    web app proc



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# File 'lib/impression/resource.rb', line 148

def to_proc
  ->(req) do
    resource = route(req) || self
    resource.call(req)
  end
end