Improved try documentation [ci skip]

- better `if` example
- Added chaining example to the try method description
- Documented the `respond_to?` check to the try method description
- Clearer wording to explain that argument error is raised on argument mismatch to responding method, rather than to non-responding method (which is handled without exception by `try`)
- `.any?` is more precise than `! .blank?`
 - Don't need to use `try` on `children` as (for regular associations) they will always be a collection or array that responds to `first`
- Fix typos/grammar

1 files changed, 25 insertions, 8 deletions

diff --git a/activesupport/lib/active_support/core_ext/object/try.rb b/activesupport/lib/active_support/core_ext/object/try.rb
index 09b8a19789..0bc675329d 100644
--- a/activesupport/lib/active_support/core_ext/object/try.rb
+++ b/activesupport/lib/active_support/core_ext/object/try.rb
@@ -9,7 +9,23 @@ class Object
   #
   # instead of
   #
-  #   @person ? @person.name : nil
+  #   @person.name if @person
+  #
+  # +try+ calls can be chained:
+  #
+  #   @person.try(:spouse).try(:name)
+  #
+  # instead of
+  #
+  #   @person.spouse.name if @person && @person.spouse
+  #
+  # +try+ will also return +nil+ if the receiver does not respond to the method:
+  #
+  #   @person.try(:non_existing_method)
+  #
+  # instead of
+  #
+  #   @person.non_existing_method if @person.respond_to?(:non_existing_method)
   #
   # +try+ returns +nil+ when called on +nil+ regardless of whether it responds
   # to the method:
@@ -24,7 +40,7 @@ class Object
   #
   # 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
-  # otherwise.
+  # in case of argument mismatch.
   #
   # If +try+ is called without arguments it yields the receiver to a given
   # block unless it is +nil+:
@@ -38,17 +54,18 @@ class Object
   #
   #   @person.try { upcase.truncate(50) }
   #
-  # Please also note that +try+ is defined on +Object+, therefore it won't work
+  # 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+. For example, using +try+ with
   # +SimpleDelegator+ will delegate +try+ to the target instead of calling it on
-  # delegator itself.
+  # the delegator itself.
   def try(*a, &b)
     try!(*a, &b) if a.empty? || respond_to?(a.first)
   end
 
-  # Same as #try, but will raise a NoMethodError exception if the receiving is not nil and
+  # Same as #try, but will raise a NoMethodError exception if the receiver is not +nil+ and
   # does not implement the tried method.
+  
   def try!(*a, &b)
     if a.empty? && block_given?
       if b.arity.zero?
@@ -64,15 +81,15 @@ end
 
 class NilClass
   # Calling +try+ on +nil+ always returns +nil+.
-  # It becomes specially helpful when navigating through associations that may return +nil+.
+  # It becomes especially helpful when navigating through associations that may return +nil+.
   #
   #   nil.try(:name) # => nil
   #
   # Without +try+
-  #   @person && !@person.children.blank? && @person.children.first.name
+  #   @person && @person.children.any? && @person.children.first.name
   #
   # With +try+
-  #   @person.try(:children).try(:first).try(:name)
+  #   @person.try(:children).first.try(:name)
   def try(*args)
     nil
   end