Class: LaunchDarkly::LDContext

Inherits:
Object
  • Object
show all
Defined in:
lib/ldclient-rb/context.rb

Overview

LDContext is a collection of attributes that can be referenced in flag evaluations and analytics events.

To create an LDContext of a single kind, such as a user, you may use LDContext.create or LDContext.with_key.

To create an LDContext with multiple kinds, use LDContext.create_multi.

Each factory method will always return an LDContext. However, that LDContext may be invalid. You can check the validity of the resulting context, and the associated errors by calling #valid? and #error

Constant Summary collapse

KIND_DEFAULT = 
"user"
KIND_MULTI = 
"multi"
ERR_PRIVATE_NON_ARRAY = 
'context private attributes must be an array'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key, fully_qualified_key, kind, name = nil, anonymous = nil, attributes = nil, private_attributes = nil, error = nil, contexts = nil) ⇒ LDContext

Returns a new instance of LDContext.

Parameters:

  • key (String, nil)
  • fully_qualified_key (String, nil)
  • kind (String, nil)
  • name (String, nil) (defaults to: nil)
  • anonymous (Boolean, nil) (defaults to: nil)
  • attributes (Hash, nil) (defaults to: nil)
  • private_attributes (Array<String>, nil) (defaults to: nil)
  • error (String, nil) (defaults to: nil)
  • contexts (Array<LDContext>, nil) (defaults to: nil) 


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# File 'lib/ldclient-rb/context.rb', line 62

def initialize(key, fully_qualified_key, kind, name = nil, anonymous = nil, attributes = nil, private_attributes = nil, error = nil, contexts = nil)
  @key = key
  @fully_qualified_key = fully_qualified_key
  @kind = kind
  @name = name
  @anonymous = anonymous || false
  @attributes = attributes
  @private_attributes = Set.new
  (private_attributes || []).each do |attribute|
    reference = Reference.create(attribute)
    @private_attributes.add(reference) if reference.error.nil?
  end
  @error = error
  @contexts = contexts
  @is_multi = !contexts.nil?
end

Instance Attribute Details

#error ⇒ String? (readonly)

Returns the error associated with this LDContext if invalid

Returns:

  • (String, nil) —

    Returns the error associated with this LDContext if invalid



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# File 'lib/ldclient-rb/context.rb', line 48

def error
  @error
end

#fully_qualified_key ⇒ String? (readonly)

Returns the fully qualified key for this context

Returns:

  • (String, nil) —

    Returns the fully qualified key for this context



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# File 'lib/ldclient-rb/context.rb', line 42

def fully_qualified_key
  @fully_qualified_key
end

#key ⇒ String? (readonly)

Returns the key for this context

Returns:

  • (String, nil) —

    Returns the key for this context



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# File 'lib/ldclient-rb/context.rb', line 39

def key
  @key
end

#kind ⇒ String? (readonly)

Returns the kind for this context

Returns:

  • (String, nil) —

    Returns the kind for this context



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# File 'lib/ldclient-rb/context.rb', line 45

def kind
  @kind
end

Class Method Details

.create(data) ⇒ LDContext

Create a single kind context from the provided hash.

The provided hash must match the format as outlined in the SDK documentation.

Parameters:

  • data (Hash)

Returns:



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# File 'lib/ldclient-rb/context.rb', line 446

def self.create(data)
  return create_invalid_context(ERR_NOT_HASH) unless data.is_a?(Hash)

  kind = data[:kind]
  if kind == KIND_MULTI
    contexts = []
    data.each do |key, value|
      next if key == :kind
      contexts << create_single_context(value, key.to_s)
    end

    return create_multi(contexts)
  end

  create_single_context(data, kind)
end

.create_multi(contexts) ⇒ LDContext

Create a multi-kind context from the array of LDContexts provided.

A multi-kind context is comprised of two or more single kind contexts. You cannot include a multi-kind context instead another multi-kind context.

Additionally, the kind of each single-kind context must be unique. For instance, you cannot create a multi-kind context that includes two user kind contexts.

If you attempt to create a multi-kind context from one single-kind context, this method will return the single-kind context instead of a new multi-kind context wrapping that one single-kind.

Parameters:

Returns:



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# File 'lib/ldclient-rb/context.rb', line 481

def self.create_multi(contexts)
  return create_invalid_context(ERR_KIND_MULTI_NON_CONTEXT_ARRAY) unless contexts.is_a?(Array)
  return create_invalid_context(ERR_KIND_MULTI_WITH_NO_KINDS) if contexts.empty?

  kinds = Set.new
  contexts.each do |context|
    if !context.is_a?(LDContext)
      return create_invalid_context(ERR_KIND_MULTI_NON_CONTEXT_ARRAY)
    elsif !context.valid?
      return create_invalid_context(ERR_KIND_MULTI_NON_CONTEXT_ARRAY)
    elsif context.multi_kind?
      return create_invalid_context(ERR_KIND_MULTI_CANNOT_CONTAIN_MULTI)
    elsif kinds.include? context.kind
      return create_invalid_context(ERR_KIND_MULTI_DUPLICATES)
    end

    kinds.add(context.kind)
  end

  return contexts[0] if contexts.length == 1

  full_key = contexts.sort_by(&:kind)
                     .map { |c| LaunchDarkly::Impl::Context::canonicalize_key_for_kind(c.kind, c.key) }
                     .join(":")

  new(nil, full_key, "multi", nil, false, nil, nil, nil, contexts)
end

.with_key(key, kind = KIND_DEFAULT) ⇒ Object

Convenience method to create a simple single kind context providing only a key and kind type.

Parameters:

  • key (String)
  • kind (String) (defaults to: KIND_DEFAULT) 


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# File 'lib/ldclient-rb/context.rb', line 432

def self.with_key(key, kind = KIND_DEFAULT)
  create({key: key, kind: kind})
end

Instance Method Details

#==(other) ⇒ Boolean Also known as: eql?

An LDContext can be compared to other LDContexts or to a hash object. If a hash is provided, it is first converted to an LDContext using the ‘LDContext.create` method.

Parameters:

Returns:

  • (Boolean) 


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# File 'lib/ldclient-rb/context.rb', line 312

def ==(other)
  other = LDContext.create(other) if other.is_a? Hash
  return false unless other.is_a? LDContext

  return false unless self.kind == other.kind
  return false unless self.valid? == other.valid?
  return false unless self.error == other.error

  return false unless self.individual_context_count == other.individual_context_count

  if self.multi_kind?
    self.kinds.each do |kind|
      return false unless self.individual_context(kind) == other.individual_context(kind)
    end

    return true
  end

  return false unless self.key == other.key
  return false unless self.name == other.name
  return false unless self.anonymous == other.anonymous
  return false unless self.attributes == other.attributes

  # TODO(sc-227265): Calling .to_set is unnecessary once private_attributes are sets.
  return false unless self.private_attributes.to_set == other.private_attributes.to_set

  true
end

#[](key) ⇒ Object

For a single-kind context, the provided key will return the attribute value specified. This is the same as calling ‘LDCotnext.get_value`.

For multi-kind contexts, the key will be interpreted as a context kind. If the multi-kind context has an individual context of that kind, it will be returned. Otherwise, this method will return nil. This behaves the same as calling ‘LDContext.individual_context`.

Parameters:

  • key (Symbol, String) 


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# File 'lib/ldclient-rb/context.rb', line 352

def [](key)
  return nil unless key.is_a? Symbol or key.is_a? String
  multi_kind? ? individual_context(key.to_s) : get_value(key)
end

#get_custom_attribute_names ⇒ Array<Symbol>

Return an array of top level attribute keys (excluding built-in attributes)

Returns:

  • (Array<Symbol>) 


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# File 'lib/ldclient-rb/context.rb', line 153

def get_custom_attribute_names
  return [] if @attributes.nil?

  @attributes.keys
end

#get_value(attribute) ⇒ any

get_value looks up the value of any attribute of the Context by name. This includes only attributes that are addressable in evaluations– not metadata such as private attributes.

For a single-kind context, the attribute name can be any custom attribute. It can also be one of the built-in ones like “kind”, “key”, or “name”.

For a multi-kind context, the only supported attribute name is “kind”. Use #individual_context to inspect a Context for a particular kind and then get its attributes.

This method does not support complex expressions for getting individual values out of JSON objects or arrays, such as “/address/street”. Use #get_value_for_reference for that purpose.

If the value is found, the return value is the attribute value; otherwise, it is nil.

Parameters:

  • attribute (String, Symbol)

Returns:

  • (any) 


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# File 'lib/ldclient-rb/context.rb', line 181

def get_value(attribute)
  reference = Reference.create_literal(attribute)
  get_value_for_reference(reference)
end

#get_value_for_reference(reference) ⇒ any

get_value_for_reference looks up the value of any attribute of the Context, or a value contained within an attribute, based on a Reference instance. This includes only attributes that are addressable in evaluations– not metadata such as private attributes.

This implements the same behavior that the SDK uses to resolve attribute references during a flag evaluation. In a single-kind context, the Reference can represent a simple attribute name– either a built-in one like “name” or “key”, or a custom attribute – or, it can be a slash-delimited path using a JSON-Pointer-like syntax. See Reference for more details.

For a multi-kind context, the only supported attribute name is “kind”. Use #individual_context to inspect a Context for a particular kind and then get its attributes.

If the value is found, the return value is the attribute value; otherwise, it is nil.

Parameters:

Returns:

  • (any) 


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# File 'lib/ldclient-rb/context.rb', line 209

def get_value_for_reference(reference)
  return nil unless valid?
  return nil unless reference.is_a?(Reference)
  return nil unless reference.error.nil?

  first_component = reference.component(0)
  return nil if first_component.nil?

  if multi_kind?
    if reference.depth == 1 && first_component == :kind
      return kind
    end

    # Multi-kind contexts have no other addressable attributes
    return nil
  end

  value = get_top_level_addressable_attribute_single_kind(first_component)
  return nil if value.nil?

  (1...reference.depth).each do |i|
    name = reference.component(i)

    return nil unless value.is_a?(Hash)
    return nil unless value.has_key?(name)

    value = value[name]
  end

  value
end

#individual_context(kind) ⇒ LDContext?

Returns the single-kind LDContext corresponding to one of the kinds in this context.

The ‘kind` parameter can be either a number representing a zero-based index, or a string representing a context kind.

If this method is called on a single-kind LDContext, then the only allowable value for ‘kind` is either zero or the same value as #kind, and the return value on success is the same LDContext.

If the method is called on a multi-context, and ‘kind` is a number, it must be a non-negative index that is less than the number of kinds (that is, less than the return value of #individual_context_count, and the return value on success is one of the individual LDContexts within. Or, if `kind` is a string, it must match the context kind of one of the individual contexts.

If there is no context corresponding to ‘kind`, the method returns nil.

Parameters:

  • kind (Integer, String) —

    the index or string value of a context kind

Returns:

  • (LDContext, nil) —

    the context corresponding to that index or kind, or null if none.



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# File 'lib/ldclient-rb/context.rb', line 280

def individual_context(kind)
  return nil unless valid?

  if kind.is_a?(Integer)
    unless multi_kind?
      return kind == 0 ? self : nil
    end

    return kind >= 0 && kind < @contexts.count ? @contexts[kind] : nil
  end

  return nil unless kind.is_a?(String)

  unless multi_kind?
    return self.kind == kind ? self : nil
  end

  @contexts.each do |context|
    return context if context.kind == kind
  end

  nil
end

#individual_context_count ⇒ Integer

Returns the number of context kinds in this context.

For a valid individual context, this returns 1. For a multi-context, it returns the number of context kinds. For an invalid context, it returns zero.

Returns:

  • (Integer) —

    the number of context kinds



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# File 'lib/ldclient-rb/context.rb', line 250

def individual_context_count
  return 0 unless valid?
  return 1 if @contexts.nil?
  @contexts.count
end

#keys ⇒ Hash<Symbol, String>

Returns a hash mapping each context’s kind to its key.

Returns:

  • (Hash<Symbol, String>) 


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# File 'lib/ldclient-rb/context.rb', line 129

def keys
  return {} unless valid?
  return Hash[kind, key] unless multi_kind?

  @contexts.map { |c| [c.kind, c.key] }.to_h
end

#kinds ⇒ Array<String>

Returns an array of context kinds.

Returns:

  • (Array<String>) 


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# File 'lib/ldclient-rb/context.rb', line 141

def kinds
  return [] unless valid?
  return [kind] unless multi_kind?

  @contexts.map { |c| c.kind }
end

#multi_kind? ⇒ Boolean

Returns Is this LDContext a multi-kind context?.

Returns:

  • (Boolean) —

    Is this LDContext a multi-kind context?



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# File 'lib/ldclient-rb/context.rb', line 93

def multi_kind?
  @is_multi
end

#private_attributes ⇒ Array<Reference>

Returns the private attributes associated with this LDContext

Returns:

  • (Array<Reference>) —

    Returns the private attributes associated with this LDContext



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# File 'lib/ldclient-rb/context.rb', line 85

def private_attributes
  # TODO(sc-227265): Return a set instead of an array.
  @private_attributes.to_a
end

#to_h ⇒ Hash

Convert the LDContext to a hash. If the LDContext is invalid, the hash will contain an error key with the error message.

Returns:

  • (Hash) 


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# File 'lib/ldclient-rb/context.rb', line 373

def to_h
  return {error: error} unless valid?
  return hash_single_kind unless multi_kind?

  hash = {kind: 'multi'}
  @contexts.each do |context|
    single_kind_hash = context.to_h
    kind = single_kind_hash.delete(:kind)
    hash[kind] = single_kind_hash
  end

  hash
end

#to_json(*args) ⇒ String

Convert the LDContext to a JSON string.

Parameters:

  • args (Array)

Returns:

  • (String) 


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# File 'lib/ldclient-rb/context.rb', line 363

def to_json(*args)
  JSON.generate(to_h, *args)
end

#valid? ⇒ Boolean

Returns Determine if this LDContext is considered valid.

Returns:

  • (Boolean) —

    Determine if this LDContext is considered valid



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# File 'lib/ldclient-rb/context.rb', line 100

def valid?
  @error.nil?
end

#without_anonymous_contexts ⇒ Object

For a multi-kind context:

A multi-kind context is made up of two or more single-kind contexts. This method will first discard any single-kind contexts which are anonymous. It will then create a new multi-kind context from the remaining single-kind contexts. This may result in an invalid context (e.g. all single-kind contexts are anonymous).

For a single-kind context:

If the context is not anonymous, this method will return the current context as is and unmodified.

If the context is anonymous, this method will return an invalid context.



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# File 'lib/ldclient-rb/context.rb', line 117

def without_anonymous_contexts
  contexts = multi_kind? ? @contexts : [self]
  contexts = contexts.reject { |c| c.anonymous }

  LDContext.create_multi(contexts)
end