Class: FlexColumns::Util::StringUtils

Inherits:
Object
  • Object
show all
Defined in:
lib/flex_columns/util/string_utils.rb

Overview

Contains a single method for abbreviating strings.

Yes, this is very un-Ruby-like – to define a separate utility function, rather than just adding a method to String. However, this method is used in such limited context (generating exception messages) that polluting the namespace of one of the most important classes in Ruby is probably a pretty bad idea.

Constant Summary collapse

MAX_LENGTH_FOR_ABBREVIATED_STRING = 
100
ABBREVIATED_STRING_SEPARATOR = 
"..."

Class Method Summary collapse

Class Method Details

.abbreviated_string(s) ⇒ Object

Returns a string of length no more than MAX_LENGTH_FOR_ABBREVIATED_STRING, by eliding, if necessary, characters from the middle. This is used when throwing exceptions: flex_columns can generate very long strings of JSON data, and having many kilobytes (or even megabytes) of JSON make its way into an exception message is probably a really bad idea.



17
18
19
20
21
22
23
24
25
26
27
 
# File 'lib/flex_columns/util/string_utils.rb', line 17

def abbreviated_string(s)
  if s && s.length > MAX_LENGTH_FOR_ABBREVIATED_STRING
    before_separator_length = ((MAX_LENGTH_FOR_ABBREVIATED_STRING - ABBREVIATED_STRING_SEPARATOR.length) / 2.0).floor
    out = s[0..(before_separator_length - 1)] + ABBREVIATED_STRING_SEPARATOR
    remaining = MAX_LENGTH_FOR_ABBREVIATED_STRING - out.length
    out << s[(-remaining + 1)..-1]
    out
  else
    s
  end
end