Module: GraphQL::Client::ViewModule

Defined in:
lib/graphql/client/view_module.rb

Overview

Allows a magic namespace to map to app/views/*/.erb files to retrieve statically defined GraphQL definitions.

# app/views/users/show.html.erb
<%grapql
  fragment UserFragment on User { }
%>

# Loads graphql section from app/views/users/show.html.erb
Views::Users::Show::UserFragment

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#clientObject

Returns the value of attribute client


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# File 'lib/graphql/client/view_module.rb', line 20

def client
  @client
end

#load_pathObject Also known as: path

Public: Directory to retrieve nested GraphQL definitions from.

Returns absolute String path under app/views.


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# File 'lib/graphql/client/view_module.rb', line 79

def load_path
  @load_path
end

#source_pathObject

Public: if this module was defined by a view

Returns absolute String path under app/views.


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# File 'lib/graphql/client/view_module.rb', line 86

def source_path
  @source_path
end

Class Method Details

.extract_graphql_section(src) ⇒ Object

Public: Extract GraphQL section from ERB template.

src - String ERB text

Returns String GraphQL query and line number or nil or no section was defined.


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# File 'lib/graphql/client/view_module.rb', line 28

def self.extract_graphql_section(src)
  query_string = src.scan(/<%graphql([^%]+)%>/).flatten.first
  return nil unless query_string
  [query_string, Regexp.last_match.pre_match.count("\n") + 1]
end

.valid_constant_name?(name) ⇒ Boolean

Internal: Check if name is a valid Ruby constant identifier.

name - String or Symbol constant name

Examples

valid_constant_name?("Foo") #=> true
valid_constant_name?("404") #=> false

Returns true if name is a valid constant, otherwise false if name would result in a “NameError: wrong constant name”.

Returns:

  • (Boolean)

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# File 'lib/graphql/client/view_module.rb', line 72

def self.valid_constant_name?(name)
  name.to_s =~ /^[A-Z][a-zA-Z0-9_]*$/
end

Instance Method Details

#const_missing(name) ⇒ Object

Public: Implement constant missing hook to autoload View ERB statics.

name - String or Symbol constant name

Returns module or raises NameError if missing.


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# File 'lib/graphql/client/view_module.rb', line 145

def const_missing(name)
  load_and_set_module(name) || super
end

#eager_load!Object

Public: Eager load module and all subdependencies.

Use in production when cache_classes is true.

Traverses all app/views/*/.erb and loads all static constants defined in ERB files.

Examples

Views.eager_load!

Returns nothing.


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# File 'lib/graphql/client/view_module.rb', line 46

def eager_load!
  return unless File.directory?(load_path)

  Dir.entries(load_path).sort.each do |entry|
    next if entry == "." || entry == ".."
    name = entry.sub(/(\.\w+)+$/, "").camelize.to_sym
    if ViewModule.valid_constant_name?(name)
      mod = const_defined?(name, false) ? const_get(name) : load_and_set_module(name)
      mod.eager_load! if mod
    end
  end

  nil
end

#load_and_set_module(name) ⇒ Object


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# File 'lib/graphql/client/view_module.rb', line 127

def load_and_set_module(name)
  placeholder = placeholder_module(name)
  const_set(name, placeholder) if placeholder

  mod = load_module(name)
  return placeholder unless mod

  remove_const(name) if placeholder
  const_set(name, mod)
  mod.unloadable
  mod
end

#load_module(name) ⇒ Object

Internal: Initialize new module for constant name and load ERB statics.

name - String or Symbol constant name.

Examples

Views::Users.load_module(:Profile)
Views::Users::Profile.load_module(:Show)

Returns new Module implementing Loadable concern.


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# File 'lib/graphql/client/view_module.rb', line 98

def load_module(name)
  pathname = ActiveSupport::Inflector.underscore(name.to_s)
  path = Dir[File.join(load_path, "{#{pathname},_#{pathname}}{.*}")].sort.map { |fn| File.expand_path(fn) }.first

  return if !path || File.extname(path) != ".erb"

  contents = File.read(path)
  query, lineno = ViewModule.extract_graphql_section(contents)
  return unless query

  mod = client.parse(query, path, lineno)
  mod.extend(ViewModule)
  mod.load_path = File.join(load_path, pathname)
  mod.source_path = path
  mod.client = client
  mod
end

#placeholder_module(name) ⇒ Object


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# File 'lib/graphql/client/view_module.rb', line 116

def placeholder_module(name)
  dirname = File.join(load_path, ActiveSupport::Inflector.underscore(name.to_s))
  return nil unless Dir.exist?(dirname)

  Module.new.tap do |mod|
    mod.extend(ViewModule)
    mod.load_path = dirname
    mod.client = client
  end
end