Class: Lti2Commons::JsonWrapper

Inherits:
Object
  • Object
show all
Defined in:
lib/lti2_commons/lib/lti2_commons/json_wrapper.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(json_str_or_obj) ⇒ JsonWrapper

Returns a new instance of JsonWrapper.



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 9

def initialize(json_str_or_obj)
  @root = JsonPath.new('$').on(json_str_or_obj).first
end

Instance Attribute Details

#root ⇒ Object

Returns the value of attribute root.



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 7

def root
  @root
end

Instance Method Details

#at(path) ⇒ Object 



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 13

def at(path)
  JsonPath.new(path).on(@root)
end

#deep_copy ⇒ JsonObject

Deep copy through reserialization. Only used to preserve immutability of source.

Returns:

  • (JsonObject) —

    A full new version of self



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 20

def deep_copy
  JsonWrapper.new(@root.to_json)
end

#each_leaf ⇒ Object 



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 24

def each_leaf
  JsonPath.new('$..*').on(@root).each do |node|
    yield node if node.is_a? String
  end
end

#first_at(path) ⇒ Object 



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 30

def first_at(path)
  at(path).first
end

#get_matching_node(candidate, constraint_hash) ⇒ TreeNode

Does this node, possibly repeating, match all elements of the constraint_hash

Returns:

  • (TreeNode) —

    Either self or immediate child that matches constraint_hash



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 39

def get_matching_node(candidate, constraint_hash)
  if candidate.is_a? Hash
    return candidate if is_hash_intersect(candidate, constraint_hash)
  elsif candidate.is_a? Array
    candidate.each do |child|
      # are there extraneous keys in constraint_hash
      return child if is_hash_intersect(child, constraint_hash)
    end
  end
  nil
end

#search(path, constraint_hash, return_path) ⇒ Object

Convenience method to find a particular node with matching attributes to constraint_hash and then return specific element of that node. e.g., search for ‘path’ within the ‘resource_handler’ with constraint_hash attributes.

Returns:

  • (Object) —

    result_path within matching node or nil



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 59

def search(path, constraint_hash, return_path)
  candidate = JsonPath.new(path).on(@root)
  candidate = get_matching_node(candidate.first, constraint_hash)
  return nil unless candidate
  JsonPath.new(return_path).on(candidate).first
end

#select(path, selector, value, return_path) ⇒ Object

Convenience method to find a particular node with matching attributes to constraint_hash and then return specific element of that node. e.g., search for ‘path’ within the ‘resource_handler’ with constraint_hash attributes.

Returns:

  • (Object) —

    result_path within matching node or nil



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 74

def select(path, selector, value, return_path)
  candidates = JsonPath.new(path).on(@root)
  now_candidate = nil
  candidates.each do |candidate|
    now_candidate = candidate
    selector_node = JsonPath.new(selector).on(candidate.first)
    break if selector_node.include? value
  end
  if now_candidate
    JsonPath.new(return_path).on(now_candidate.first).first
  else
    nil
  end
end

#substitute_text_in_all_nodes(token_prefix, token_suffix, hash) ⇒ Object 



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 89

def substitute_text_in_all_nodes(token_prefix, token_suffix, hash)
  self.each_leaf do |v|
    substitute_template_values_from_hash(v, token_prefix, token_suffix, hash)
  end
end

#to_pretty_json ⇒ Object 



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# File 'lib/lti2_commons/lib/lti2_commons/json_wrapper.rb', line 95

def to_pretty_json
  JSON.pretty_generate(root)
end