Module: Sequel::Plugins::JsonSerializer::InstanceMethods

Defined in:

lib/sequel/plugins/json_serializer.rb

Instance Method Summary

• #from_json(json, opts = {}) ⇒ Object

  Parse the provided JSON, which should return a hash, and process the hash with from_json_node.

• #from_json_node(hash, opts = {}) ⇒ Object

  Using the provided hash, update the instance with data contained in the hash.

• #to_json(*a) ⇒ Object

  Return a string in JSON format.

Instance Method Details

#from_json(json, opts = {}) ⇒ Object

Parse the provided JSON, which should return a hash, and process the hash with from_json_node.

# File 'lib/sequel/plugins/json_serializer.rb', line 190

def from_json(json, opts={})
  from_json_node(Sequel.parse_json(json), opts)
end

#from_json_node(hash, opts = {}) ⇒ Object

Using the provided hash, update the instance with data contained in the hash. By default, just calls set with the hash values.

Options:

:all_associations

Indicates that all associations supported by the model should be tried. This option also cascades to associations if used. It is better to use the :associations option instead of this option. This option only exists for backwards compatibility.

:all_columns

Overrides the setting logic allowing all setter methods be used, even if access to the setter method is restricted. This option cascades to associations if used, and can be reset in those associations using the :all_columns=>false or :fields options. This option is considered a security risk, and only exists for backwards compatibility. It is better to use the :fields option appropriately instead of this option, or no option at all.

:associations

Indicates that the associations cache should be updated by creating a new associated object using data from the hash. Should be a Symbol for a single association, an array of symbols for multiple associations, or a hash with symbol keys and dependent association option hash values.

:fields

Changes the behavior to call set_fields using the provided fields, instead of calling set.

# File 'lib/sequel/plugins/json_serializer.rb', line 213

def from_json_node(hash, opts={})
  unless hash.is_a?(Hash)
    raise Error, "parsed json doesn't return a hash"
  end
  hash.delete(JSON.create_id)

  unless assocs = opts[:associations]
    if opts[:all_associations]
      assocs = {}
      model.associations.each{|v| assocs[v] = {:all_associations=>true}}
    end
  end

  if assocs
    assocs = case assocs
    when Symbol
      {assocs=>{}}
    when Array
      assocs_tmp = {}
      assocs.each{|v| assocs_tmp[v] = {}}
      assocs_tmp
    when Hash
      assocs
    else
      raise Error, ":associations should be Symbol, Array, or Hash if present"
    end

    if opts[:all_columns]
      assocs.each_value do |assoc_opts|
        assoc_opts[:all_columns] = true unless assoc_opts.has_key?(:fields) || assoc_opts.has_key?(:all_columns)
      end
    end

    assocs.each do |assoc, assoc_opts|
      if assoc_values = hash.delete(assoc.to_s)
        unless r = model.association_reflection(assoc)
          raise Error, "Association #{assoc} is not defined for #{model}"
        end

        associations[assoc] = if r.returns_array?
          raise Error, "Attempt to populate array association with a non-array" unless assoc_values.is_a?(Array)
          assoc_values.map{|v| v.is_a?(r.associated_class) ? v : r.associated_class.new.from_json_node(v, assoc_opts)}
        else
          raise Error, "Attempt to populate non-array association with an array" if assoc_values.is_a?(Array)
          assoc_values.is_a?(r.associated_class) ? assoc_values : r.associated_class.new.from_json_node(assoc_values, assoc_opts)
        end
      end
    end
  end

  if fields = opts[:fields]
    set_fields(hash, fields, opts)
  elsif opts[:all_columns]
    meths = methods.collect{|x| x.to_s}.grep(Model::SETTER_METHOD_REGEXP) - Model::RESTRICTED_SETTER_METHODS
    hash.each do |k, v|
      if meths.include?(setter_meth = "#{k}=")
        send(setter_meth, v)
      else
        raise Error, "Entry in JSON does not have a matching setter method: #{k}"
      end
    end
  else
    set(hash)
  end

  self
end

#to_json(*a) ⇒ Object

Return a string in JSON format. Accepts the following options:

:except

Symbol or Array of Symbols of columns not to include in the JSON output.

:include

Symbol, Array of Symbols, or a Hash with Symbol keys and Hash values specifying associations or other non-column attributes to include in the JSON output. Using a nested hash, you can pass options to associations to affect the JSON used for associated objects.

:naked

Not to add the JSON.create_id (json_class) key to the JSON output hash, so when the JSON is parsed, it will yield a hash instead of a model object.

:only

Symbol or Array of Symbols of columns to only include in the JSON output, ignoring all other columns.

:root

Qualify the JSON with the name of the object. Implies :naked since the object name is explicit.

# File 'lib/sequel/plugins/json_serializer.rb', line 300

def to_json(*a)
  if opts = a.first.is_a?(Hash)
    opts = model.json_serializer_opts.merge(a.first)
    a = []
  else
    opts = model.json_serializer_opts
  end
  vals = values
  cols = if only = opts[:only]
    Array(only)
  else
    vals.keys - Array(opts[:except])
  end
  h = (JSON.create_id && !opts[:naked] && !opts[:root]) ? {JSON.create_id=>model.name} : {}
  cols.each{|c| h[c.to_s] = send(c)}
  if inc = opts[:include]
    if inc.is_a?(Hash)
      inc.each do |k, v|
        v = v.empty? ? [] : [v]
        h[k.to_s] = case objs = send(k)
        when Array
          objs.map{|obj| Literal.new(obj.to_json(*v))}
        else
          Literal.new(objs.to_json(*v))
        end
      end
    else
      Array(inc).each{|c| h[c.to_s] = send(c)}
    end
  end
  h = {model.send(:underscore, model.to_s) => h} if opts[:root]
  h.to_json(*a)
end