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

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 href="https://docs.launchdarkly.com/sdk/features/user-config">https://docs.launchdarkly.com/sdk/features/user-config 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