diff options
| -rw-r--r-- | lib/erb.rb | 54 |
1 files changed, 32 insertions, 22 deletions
diff --git a/lib/erb.rb b/lib/erb.rb index c90ce855ec..2cd134a6f1 100644 --- a/lib/erb.rb +++ b/lib/erb.rb @@ -25,13 +25,6 @@ require 'erb/util' # Like method [sprintf][sprintf], \ERB can format run-time data into a string. # \ERB, however,s is *much more powerful*. # -# In simplest terms: -# -# - You can create an \ERB object to store a text *template* that includes specially formatted *tags*; -# each tag specifies data that at run-time is to replace the tag in the produced result. -# - You can call instance method ERB#result to get the result, -# which is the string formed by replacing each tag with run-time data. -# # \ERB is commonly used to produce: # # - Customized or personalized email messages. @@ -49,24 +42,41 @@ require 'erb/util' # # ## In Brief # -# ``` -# # Expression tag: begins with '<%', ends with '%>'. -# # This expression does not need the local binding. -# ERB.new('Today is <%= Date::DAYNAMES[Date.today.wday] %>.').result # => "Today is Monday." -# # This expression tag does need the local binding. -# magic_word = 'xyzzy' -# template.result(binding) # => "The magic word is xyzzy." +# Here's how \ERB works: # -# Execution tag: begins with '<%=', ends with '%>'. -# s = '<% File.write("t.txt", "Some stuff.") %>' -# ERB.new(s).result -# File.read('t.txt') # => "Some stuff." +# - You can create an \ERB object (a *template*) to store text that includes specially formatted *tags*. +# - You can call instance method ERB#result to get the *result*. # -# # Comment tag: begins with '<%#', ends with '%>'. -# s = 'Some stuff;<%# Note to self: figure out what the stuff is. %> more stuff.' -# ERB.new(s).result # => "Some stuff; more stuff." -# ``` +# \ERB supports tags of three kinds: +# +# - [Expression tags][expression tags]: +# each begins with `'<%'`, ends with `'%>'`; contains a Ruby expression; +# in the result, the value of the expression replaces the entire tag: +# +# magic_word = 'xyzzy' +# template.result(binding) # => "The magic word is xyzzy." +# +# ERB.new('Today is <%= Date::DAYNAMES[Date.today.wday] %>.').result # => "Today is Monday." +# +# The first call to #result passes argument `binding`, +# which contains the binding of variable `magic_word` to its string value `'xyzzy'`. +# +# The second call need not pass a binding, +# because its expression `Date::DAYNAMES` is globally defined. +# +# - [Execution tags][execution tags]: +# each begins with `'<%='`, ends with `'%>'`; contains Ruby code to be executed: +# +# s = '<% File.write("t.txt", "Some stuff.") %>' +# ERB.new(s).result +# File.read('t.txt') # => "Some stuff." +# +# - [Comment tags][comment tags]: +# each begins with `'<%#'`, ends with `'%>'`; contains comment text; +# in the result, the entire tag is omitted. # +# s = 'Some stuff;<%# Note to self: figure out what the stuff is. %> more stuff.' +# ERB.new(s).result # => "Some stuff; more stuff." # # ## Some Simple Examples # |