JSON
JSON is a subset of Javascript that is specifically for data exchange. See http://www.json.org/ for the specification.
Contents
Relationship with YAML
With a little care, JSON is also a valid subset of YAML. All JSON is valid YAML if you take care to strip the comments, don't use single quoted strings, and ensure a space after the commas and colons.
See why's post for more details.
JSON instead of YAML
Pros: Javascript Compatibility
- The browser can instantiate objects using eval (very fast) without any server side translations
- We're already using JSON in a number of places
- It doesn't do much, but you can reason through what it does
Cons: Requires work in Ruby and Rails
- We have to handle serialization to/from the database ourselves (rather than rails doing it for us)
- Doesn't support loopy data structures
- Doesn't encode the classes of objects
- Only allows string keys
YAML instead of JSON
Pros: Rails Compatibility, Ruby Compatibility
- ActiveRecord makes serialized database fields work transparently
- The differences between symbols and strings in hashes are preserved
- Can transparently replace our current use of serialize
Cons: Requires work in Javascript, Must convert existing code
- YAML must be converted to JSON before sending to the browser
- Must rewrite everywhere we've already serialized
- Would need to understand what we'd be saving
- Less reliable as a serialization format because it's optimized for human readability
- Doesn't handle utf-32
Use both YAML and JSON
Pros:
- Already using both ... don't have to change things we've already written and that work
- Don't even have to talk about it
Cons:
- Additional complexity akin to technical debt
Decision
- Which do we prefer for new development?
- Is it worth switching any places we already use the other?
