47 lines
1.4 KiB
Ruby
47 lines
1.4 KiB
Ruby
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# frozen_string_literal: true
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module Gitlab
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module Graphql
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# This module allows your class to easily defer and force values.
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# Its methods are just sugar for calls to the Gitlab::Graphql::Lazy class.
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#
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# example:
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#
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# class MyAwesomeClass
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# include ::Gitlab::Graphql::Laziness
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#
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# # takes a list of id and list of factors, and computes
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# # sum of [SomeObject[i]#value * factor[i]]
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# def resolve(ids:, factors:)
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# ids.zip(factors)
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# .map { |id, factor| promise_an_int(id, factor) }
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# .map(&method(:force))
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# .sum
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# end
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#
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# # returns a promise for an Integer
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# def (id, factor)
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# thunk = SomeObject.lazy_find(id)
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# defer { force(thunk).value * factor }
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# end
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# end
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#
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# In the example above, we use defer to delay forcing the batch-loaded
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# item until we need it, and then we use `force` to consume the lazy values
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#
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# If `SomeObject.lazy_find(id)` batches correctly, calling
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# `resolve` will only perform one batched load for all objects, rather than
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# loading them individually before combining the results.
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#
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module Laziness
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def defer(&block)
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::Gitlab::Graphql::Lazy.new(&block)
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end
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def force(lazy)
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::Gitlab::Graphql::Lazy.force(lazy)
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end
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end
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end
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end
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