Fantasy fiction book recommendation. The Red Knight http://www.goodreads.com/book/show/13616278-the-red-knight
It talks about memory palace which was actualy used in ancient greece and in modern memory tournaments
It is a core part of their magic system
http://en.wikipedia.org/wiki/Method_of_loci
http://www.wikihow.com/Build-a-Memory-Palace
Using JSON Schema's
Lets suppose you are recieving a json message roughly of format:
{
'id' : 'abc-123',
'account' : {
'id' : 'acc-123',
'name' : 'Codemancers'
},
'resource' : {
'id' : 'srv-123',
'name' : 'Codemancers CI server'
}
}
When processing this incoming json you know that 'id' field must be present, similary
account field must have and id and there must be a resouce field and that field
must have an id field too. Traditionally we solve this by using if/elses and rejecting
the json if it is missing some fields. For example:
json_data = JSON.parse(imcoming_string)
return if json_data['id'].blank || json_data['account'].blank? || ...
A really nice approach of solving this problem is to use json schemas. With them I can define a schema for above json:
{
'type' : 'object',
'properties' : {
'id' : { 'type' : 'string'},
'account': {
'type' : 'object',
'properties' : {
'id' : {'type' : 'string'},
'name': {'type' : 'string'}
},
'required': ['id']
}
},
required: ['id', 'account', 'resource']
}
And then rather than playing whack-a-mole with incoming json, using the gem https://github.com/hoxworth/json-schema we can do:
JSON::Validator.validate(schema, data)
and boom code is much simpler and more exhaustive.