1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
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
|
# frozen_string_literal: true
module Gitlab
module Graphql
module Pagination
module Keyset
class QueryBuilder
def initialize(arel_table, order_list, decoded_cursor, before_or_after)
@arel_table = arel_table
@order_list = order_list
@decoded_cursor = decoded_cursor
@before_or_after = before_or_after
if order_list.empty?
raise ArgumentError.new('No ordering scopes have been supplied')
end
end
# Based on whether the main field we're ordering on is NULL in the
# cursor, we can more easily target our query condition.
# We assume that the last ordering field is unique, meaning
# it will not contain NULLs.
# We currently only support two ordering fields.
#
# Example of the conditions for
# relation: Issue.order(relative_position: :asc).order(id: :asc)
# after cursor: relative_position: 1500, id: 500
#
# when cursor[relative_position] is not NULL
#
# ("issues"."relative_position" > 1500)
# OR (
# "issues"."relative_position" = 1500
# AND
# "issues"."id" > 500
# )
# OR ("issues"."relative_position" IS NULL)
#
# when cursor[relative_position] is NULL
#
# "issues"."relative_position" IS NULL
# AND
# "issues"."id" > 500
#
def conditions
attr_values = order_list.map do |field|
name = field.try(:attribute_name) || field
decoded_cursor[name]
end
if order_list.count == 1 && attr_values.first.nil?
raise Gitlab::Graphql::Errors::ArgumentError.new('Before/after cursor invalid: `nil` was provided as only sortable value')
end
if order_list.count == 1 || attr_values.first.present?
Keyset::Conditions::NotNullCondition.new(arel_table, order_list, attr_values, operators, before_or_after).build
else
Keyset::Conditions::NullCondition.new(arel_table, order_list, attr_values, operators, before_or_after).build
end
end
private
attr_reader :arel_table, :order_list, :decoded_cursor, :before_or_after
def operators
order_list.map { |field| field.operator_for(before_or_after) }
end
end
end
end
end
end
|
