MorningHacker MorningHacker - 9 days ago 8
JSON Question

What is a JSON octet and why are two required?

I have incoming data, which I store in a variable

messages
:

connection = ContextIO::Connection.new(key, secret)
messages = connection.all_messages(:account => account, :limit => 100, :since => (Time.now - 3000.day ))


The variable
messages
is formatted in JSON. Then I execute this:

foo = JSON.parse(messages)['data']


Most of the time this works. Every now and again, I get this error message:

A JSON text must at least contain two octets!


That error message then refers to the line
JSON.parse(messages)['data']



  1. What is an octet?

  2. Why must JSON text contain at least two octets?

  3. How do I prevent my code from breaking every time
    messages
    does not have two octets?



Thanks!

Answer
  1. An octet is a group of 8 bits. Today, octet is synonymous with byte, but byte historically referred to any "native" grouping of bits, and that could mean 4,6,7, or 8 bits.
  2. Because the top-level structure of a JSON document is an array or object, and the shortest representations of those are [] and {}, respectively.
  3. Check the value messages. It is probably empty, unset or consists of a single digit (like 4), which is not valid JSON, but accepted by many JSON implementations.