Class: Line::Message::Builder::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/line/message/builder/context.rb

Overview

The Context class is a crucial component of the Line::Message::Builder DSL, enabling a flexible and dynamic environment for message construction. It acts as a wrapper around an optional user-provided context object and manages a separate hash of assigns (local variables for the DSL).

The primary purposes of the Context are:

  1. To provide access to helper methods: If a user passes a context object (e.g., a Rails view context, a presenter, or any custom object) during builder initialization, methods defined on that object become directly callable within the DSL blocks.
  2. To allow local data storage: The assigns hash allows for setting and retrieving temporary data that can be shared across different parts of a complex message construction block, without needing to pass it explicitly or pollute the user-provided context.

Method calls within the DSL that are not defined on the builder objects themselves are resolved by Context in the following order:

  • First, it checks if the method name corresponds to a key in the assigns hash.
  • If not found in assigns, it checks if the wrapped user-context object responds to the method.
  • If neither, the call proceeds up the normal Ruby method lookup chain.

This mechanism allows for a clean and powerful way to integrate external logic and data into the message building process.

Example: Using a custom context

class MyContext
def current_user_name
  "Alice"
end
end

context = MyContext.new
Line::Message::Builder.with(context) do
# current_user_name is resolved from context by Context
text "Hello, #{current_user_name}!"
end

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(context, mode: :api) ⇒ Context

Initializes a new Context object.

[context] An optional object whose methods will be made available within the DSL. If nil, only assigns and standard builder methods will be available. [mode] The mode of the context, which can be :api (default) for direct LINE Messaging API format or :sdkv2 for LINE Bot SDK v2 compatible format.

Example

# With a custom context object
my_context = MyHelpers.new
context = Line::Message::Builder::Context.new(my_context, mode: :api)

Example: Without context

# Without context, using only assigns
context = Line::Message::Builder::Context.new(nil)
context.assigns[:user_name] = "Alice"


80
81
82
83
84
 
# File 'lib/line/message/builder/context.rb', line 80

def initialize(context, mode: :api)
  @context = context
  @assigns = {}
  @mode = mode
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name) ⇒ Object

:nodoc:



92
93
94
95
96
97
98
 
# File 'lib/line/message/builder/context.rb', line 92

def method_missing(method_name, ...) # :nodoc:
  return @assigns[method_name] if @assigns.key?(method_name)
  # Check @context directly
  return @context.public_send(method_name, ...) if @context.respond_to?(method_name)

  super
end

Instance Attribute Details

#assigns ⇒ Object

A hash for storing arbitrary data that can be accessed within the builder DSL. This is useful for temporary variables or shared state during message construction.

Example

context.assigns[:user_id] = 123
puts context.assigns[:user_id] # => 123


53
54
55
 
# File 'lib/line/message/builder/context.rb', line 53

def assigns
  @assigns
end

#mode ⇒ Object (readonly)

The mode in which the builder is operating. This affects how messages are formatted in the final output. Either :api for direct LINE Messaging API format or :sdkv2 for LINE Bot SDK v2 compatible format.



58
59
60
 
# File 'lib/line/message/builder/context.rb', line 58

def mode
  @mode
end

Instance Method Details

#respond_to_missing?(method_name, include_private = false) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


86
87
88
89
90
 
# File 'lib/line/message/builder/context.rb', line 86

def respond_to_missing?(method_name, include_private = false) # :nodoc:
  @assigns.key?(method_name) ||
    @context.respond_to?(method_name, include_private) || # Check @context directly
    super
end

#sdkv2? ⇒ Boolean

Checks if the current mode is set to SDK v2 compatibility.

Returns true if the mode is :sdkv2, false otherwise.

Example

if context.sdkv2?
# Format message for LINE Bot SDK v2
else
# Format message for direct API use
end

Returns:

  • (Boolean) 


111
112
113
 
# File 'lib/line/message/builder/context.rb', line 111

def sdkv2?
  mode == :sdkv2
end