77 lines
1.4 KiB
Ruby
77 lines
1.4 KiB
Ruby
class Object
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# An object is blank if it's false, empty, or a whitespace string.
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# For example, "", " ", +nil+, [], and {} are blank.
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#
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# This simplifies:
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#
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# if !address.nil? && !address.empty?
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#
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# ...to:
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#
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# if !address.blank?
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def blank?
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respond_to?(:empty?) ? empty? : !self
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end
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# An object is present if it's not blank.
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def present?
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!blank?
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end
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# Returns object if it's #present? otherwise returns nil.
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# object.presence is equivalent to object.present? ? object : nil.
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#
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# This is handy for any representation of objects where blank is the same
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# as not present at all. For example, this simplifies a common check for
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# HTTP POST/query parameters:
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#
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# state = params[:state] if params[:state].present?
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# country = params[:country] if params[:country].present?
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# region = state || country || 'US'
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#
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# ...becomes:
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#
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# region = params[:state].presence || params[:country].presence || 'US'
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def presence
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self if present?
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end
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end
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class NilClass #:nodoc:
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def blank?
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true
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end
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end
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class FalseClass #:nodoc:
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def blank?
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true
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end
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end
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class TrueClass #:nodoc:
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def blank?
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false
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end
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end
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class Array #:nodoc:
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alias_method :blank?, :empty?
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end
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class Hash #:nodoc:
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alias_method :blank?, :empty?
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end
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class String #:nodoc:
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def blank?
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self !~ /\S/
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end
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end
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class Numeric #:nodoc:
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def blank?
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false
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end
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end
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