Class: JSONP3::JSONPath

Inherits:
Object
  • Object
show all
Defined in:
lib/json_p3/path.rb

Overview

A compiled JSONPath expression ready to be applied to JSON-like values.

Instance Method Summary collapse

Constructor Details

#initialize(env, segments) ⇒ JSONPath

Returns a new instance of JSONPath.



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# File 'lib/json_p3/path.rb', line 8

def initialize(env, segments)
  @env = env
  @segments = segments
end

Instance Method Details

#empty? ⇒ Boolean

Return true if this JSONPath expression has no segments.

Returns:

  • (Boolean) 


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# File 'lib/json_p3/path.rb', line 68

def empty?
  @segments.empty?
end

#find(root) ⇒ Array<JSONPathNode> Also known as: apply

Apply this JSONPath expression to JSON-like value root.

Parameters:

  • root (Array, Hash, String, Integer, nil) —

    the root JSON-like value to apply this query to.

Returns:

  • (Array<JSONPathNode>) —

    the sequence of nodes found while applying this query to root.



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# File 'lib/json_p3/path.rb', line 20

def find(root)
  nodes = [JSONPathNode.new(root, [], root)]
  @segments.each { |segment| nodes = segment.resolve(nodes) }
  JSONPathNodeList.new(nodes) # TODO: use JSONPathNodeList internally?
end

#find_enum(root) ⇒ Enumerable<JSONPathNode>

Apply this JSONPath expression to JSON-like value root.

Parameters:

  • root (Array, Hash, String, Integer, nil) —

    the root JSON-like value to apply this query to.

Returns:

  • (Enumerable<JSONPathNode>) —

    the sequence of nodes found while applying this query to root.



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# File 'lib/json_p3/path.rb', line 31

def find_enum(root)
  nodes = [JSONPathNode.new(root, [], root)] # : Enumerable[JSONPathNode]
  @segments.each { |segment| nodes = segment.resolve_enum(nodes) }
  nodes
end

#first(root) ⇒ JSONPathNode | nil

Return the first node from applying this JSONPath expression to JSON-like value root.

Parameters:

  • root (Array, Hash, String, Integer, nil) —

    the root JSON-like value to apply this query to.

Returns:

  • (JSONPathNode | nil) —

    the first available node or nil if there were no matches.



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# File 'lib/json_p3/path.rb', line 54

def first(root)
  find_enum(root).first
end

#match(root) ⇒ JSONPathNode | nil

Return the first node from applying this JSONPath expression to JSON-like value root.

Parameters:

  • root (Array, Hash, String, Integer, nil) —

    the root JSON-like value to apply this query to.

Returns:

  • (JSONPathNode | nil) —

    the first available node or nil if there were no matches.



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# File 'lib/json_p3/path.rb', line 40

def match(root)
  find_enum(root).first
end

#match?(root) ⇒ bool

Return true if this query results in at least one node, or false otherwise.

Parameters:

  • root (Array, Hash, String, Integer, nil) —

    the root JSON-like value to apply this query to.

Returns:

  • (bool) —

    true if this query results in at least one node, or false otherwise.



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# File 'lib/json_p3/path.rb', line 47

def match?(root)
  !find_enum(root).first.nil?
end

#singular? ⇒ Boolean

Return true if this JSONPath expression is a singular query.

Returns:

  • (Boolean) 


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# File 'lib/json_p3/path.rb', line 59

def singular?
  @segments.each do |segment|
    return false if segment.instance_of? RecursiveDescentSegment
    return false unless segment.selectors.length == 1 && segment.selectors[0].singular?
  end
  true
end

#to_s ⇒ Object 



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# File 'lib/json_p3/path.rb', line 13

def to_s
  "$#{@segments.map(&:to_s).join}"
end