Ruby JSON convert Time

Developers Ruby API
#1

So I just noticed that when parsing JSON Time objects end up as strings.

a = { 'time' => Time.now }
b = JSON.parse(a.to_json)
puts "a is a #{a['time'].class} object."
puts "b is a #{b['time'].class} object."
#< a is a Time object.
#< b is a String object.

What is the best way to work around this? The only way I can think of requires parsing each value.

require 'time'
a = { 'time' => Time.now }
b = JSON.parse(a.to_json)
b['time'] = Time.parse(b['time'])
puts "a is a #{a['time'].class} object."
puts "b is a #{b['time'].class} object."
#< a is a Time object.
#< b is a Time object.

Update; Ok from a bit more searching it doesn’t look like there is an easy fix available.

#2

Basically, you do not store the Time object, you store the number of it’s seconds since to start of the epoch. You can use #to_i (or #to_f if you want to be more precise than integer seconds.)

t = Time.now
a = { 'time' => t.to_i }
j = a.to_json
# Send to a Html Dialog,
# Later get it back:
b = JSON.parse(j)
t = Time::at(b['time'])
1 Like
#3

JSON supports strings, null, true, false and numbers, as well as arrays and hashmaps/objects containing these types of elements. Time, Sketchup::Material and other kind of objects need to be serialized into the supported units.

2 Likes
#4

That makes perfect sense. I guess now that I think of it, I was already doing that with lengths.

hash['length'].to_l
1 Like
#5

We have discussed in the past some SketchUp API additions to the JSON library.

See:
Module JSON: Extended rendering and loading of Ruby objects