instance method
try
Ruby on Rails edge
Since v2.3.18Signature
try(*args, &block)
Invokes the public method whose name goes as first argument just like public_send does, except that if the receiver does not respond to it the call returns nil rather than raising an exception.
This method is defined to be able to write
“‘ruby @person.try(:name) “`
instead of
“‘ruby @person.name if @person “`
try calls can be chained:
“‘ruby @person.try(:spouse).try(:name) “`
instead of
“‘ruby @person.spouse.name if @person && @person.spouse “`
try will also return nil if the receiver does not respond to the method:
“‘ruby @person.try(:non_existing_method) # => nil “`
instead of
“‘ruby @person.non_existing_method if @person.respond_to?(:non_existing_method) # => nil “`
try returns nil when called on nil regardless of whether it responds to the method:
“‘ruby nil.try(:to_i) # => nil, rather than 0 “`
Arguments and blocks are forwarded to the method if invoked:
“‘ruby @posts.try(:each_slice, 2) do |a, b|
...
end “‘
The number of arguments in the signature must match. If the object responds to the method the call is attempted and ArgumentError is still raised in case of argument mismatch.
If try is called without arguments it yields the receiver to a given block unless it is nil:
“‘ruby @person.try do |p|
...
end “‘
You can also call try with a block without accepting an argument, and the block will be instance_eval’ed instead:
“‘ruby @person.try { upcase.truncate(50) } “`
Please also note that try is defined on Object. Therefore, it won’t work with instances of classes that do not have Object among their ancestors, like direct subclasses of BasicObject.
Source
# File activesupport/lib/active_support/core_ext/object/try.rb, line 37
Defined in activesupport/lib/active_support/core_ext/object/try.rb line 37
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Defined in Object