Class: Dynamoid::Transactions::Mutation::Builders::UpdateRequestBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/dynamoid/transactions/mutation/builders/update_request_builder.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(model_class) ⇒ UpdateRequestBuilder

Returns a new instance of UpdateRequestBuilder.



11
12
13
14
15
16
17
18
19
20
21
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 11

def initialize(model_class)
  @model_class = model_class

  @attributes_to_set = {}
  @attributes_to_add = {}
  @attributes_to_delete = {}
  @attributes_to_remove = []
  @condition_expression = nil
  @extra_attribute_names = {}
  @extra_attribute_values = {}
end

Instance Attribute Details

#condition_expression=(value) ⇒ Object (writeonly)

Sets the attribute condition_expression

Parameters:

  • value —

    the value to set the attribute condition_expression to.



9
10
11
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 9

def condition_expression=(value)
  @condition_expression = value
end

#hash_key=(value) ⇒ Object (writeonly)

Sets the attribute hash_key

Parameters:

  • value —

    the value to set the attribute hash_key to.



9
10
11
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 9

def hash_key=(value)
  @hash_key = value
end

#range_key=(value) ⇒ Object (writeonly)

Sets the attribute range_key

Parameters:

  • value —

    the value to set the attribute range_key to.



9
10
11
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 9

def range_key=(value)
  @range_key = value
end

Instance Method Details

#add_expression_attribute_name(placeholder, name) ⇒ Object 



23
24
25
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 23

def add_expression_attribute_name(placeholder, name)
  @extra_attribute_names[placeholder] = name
end

#add_expression_attribute_value(placeholder, value) ⇒ Object 



27
28
29
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 27

def add_expression_attribute_value(placeholder, value)
  @extra_attribute_values[placeholder] = value
end

#add_value(name, value) ⇒ Object 



35
36
37
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 35

def add_value(name, value)
  @attributes_to_add[name] = value
end

#delete_value(name, value) ⇒ Object 



39
40
41
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 39

def delete_value(name, value)
  @attributes_to_delete[name] = value
end

#remove_attributes(names) ⇒ Object 



43
44
45
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 43

def remove_attributes(names)
  @attributes_to_remove.concat(names)
end

#request ⇒ Object 



47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 47

def request
  key = { @model_class.hash_key => @hash_key }
  key[@model_class.range_key] = @range_key if @model_class.range_key?

  # Build UpdateExpression and keep names and values placeholders mapping
  # in ExpressionAttributeNames and ExpressionAttributeValues.
  update_expression_statements = []
  expression_attribute_names = @extra_attribute_names.dup
  expression_attribute_values = @extra_attribute_values.dup
  name_placeholder = '#_n0'
  value_placeholder = ':_v0'

  unless @attributes_to_set.empty?
    statements = []

    @attributes_to_set.each do |name, value|
      statements << "#{name_placeholder} = #{value_placeholder}"

      expression_attribute_names[name_placeholder] = name
      expression_attribute_values[value_placeholder] = value

      name_placeholder = name_placeholder.succ
      value_placeholder = value_placeholder.succ
    end

    update_expression_statements << "SET #{statements.join(', ')}"
  end

  unless @attributes_to_add.empty?
    statements = []

    @attributes_to_add.each do |name, value|
      statements << "#{name_placeholder} #{value_placeholder}"

      expression_attribute_names[name_placeholder] = name
      expression_attribute_values[value_placeholder] = value

      name_placeholder = name_placeholder.succ
      value_placeholder = value_placeholder.succ
    end

    update_expression_statements << "ADD #{statements.join(', ')}"
  end

  unless @attributes_to_delete.empty?
    statements = []

    @attributes_to_delete.each do |name, value|
      statements << "#{name_placeholder} #{value_placeholder}"

      expression_attribute_names[name_placeholder] = name
      expression_attribute_values[value_placeholder] = value

      name_placeholder = name_placeholder.succ
      value_placeholder = value_placeholder.succ
    end

    update_expression_statements << "DELETE #{statements.join(', ')}"
  end

  unless @attributes_to_remove.empty?
    name_placeholders = []

    @attributes_to_remove.each do |name|
      name_placeholders << name_placeholder

      expression_attribute_names[name_placeholder] = name

      name_placeholder = name_placeholder.succ
      value_placeholder = value_placeholder.succ
    end

    update_expression_statements << "REMOVE #{name_placeholders.join(', ')}"
  end

  update_expression = update_expression_statements.join(' ')

  {
    update: {
      key: key,
      table_name: @model_class.table_name,
      update_expression: update_expression,
      expression_attribute_names: expression_attribute_names,
      expression_attribute_values: expression_attribute_values,
      condition_expression: @condition_expression
    }
  }
end

#set_attributes(attributes) ⇒ Object

rubocop:disable Naming/AccessorMethodName



31
32
33
 
# File 'lib/dynamoid/transactions/mutation/builders/update_request_builder.rb', line 31

def set_attributes(attributes) # rubocop:disable Naming/AccessorMethodName
  @attributes_to_set.merge!(attributes)
end