Parsing Nested JSON and Manipulating It in Ruby - arrays

Question

This is my first attempt at parsing nested JSON with Ruby. I need to go through the JSON to pull out specific values for "_id", "name", and "type" for instance. I then need to create a reference table so that I can refer to each "_id" and associated information. I also need to combine information from multiple JSON responses. I've been able to get basic information and have tried a few things I've found online. I just need a little assistance with a starting point. If anyone has any ideas of where to start with this I'd really appreciate it.
Devices JSON response hash. Each device starts with _id.
{
"api": "1.0",
"error": null,
"id": "60b5d4c3077862123cfa4443",
"result": {
"devices": [
{
"_id": "123456787786211fd31f3dd",
"batteryPowered": true,
"category": "door_lock",
"deviceTypeId": "144_1_1",
"firmware": [
{
"id": "us.144.1_1.0",
"version": "2.6"
}
],
"gatewayId": "1234567807786214fbc6bd4e",
"info": {
"firmware.stack": "3.28",
"hardware": "0",
"manufacturer": "Kwikset",
"model": "912",
"protocol": "zwave",
"zwave.node": "2",
"zwave.smartstart": "no"
},
"name": "Garage Door",
"parentDeviceId": "",
"persistent": false,
"reachable": false,
"ready": true,
"roomId": "1234567807786211fd31f3eb",
"security": "middle",
"status": "idle",
"subcategory": "",
"type": "doorlock"
},
{
"_id": "1234567897786211fd31f3ed",
"batteryPowered": true,
"category": "door_lock",
"deviceTypeId": "59_1_1129",
"firmware": [
{
"id": "us.59.18064.0",
"version": "3.3"
},
{
"id": "us.59.18065.1",
"version": "11.0"
}
],
"gatewayId": "1234567897786214fbc6bd4e",
"info": {
"firmware.stack": "6.3",
"hardware": "3",
"manufacturer": "Schlage",
"model": "BE469ZP",
"protocol": "zwave",
"zwave.node": "3",
"zwave.smartstart": "no"
},
"name": "Front Door",
"parentDeviceId": "",
"persistent": false,
"reachable": true,
"ready": true,
"roomId": "1234567807786211fd31f3ec",
"security": "high",
"status": "idle",
"subcategory": "",
"type": "doorlock"
},
{
"_id": "1234567897786211fd31f40a",
"batteryPowered": false,
"category": "switch",
"deviceTypeId": "57_20562_12344",
"firmware": [
{
"id": "us.57.29240.0",
"version": "5.25"
}
],
"gatewayId": "1234567807786214fbc6bd4e",
"info": {
"firmware.stack": "4.54",
"hardware": "255",
"manufacturer": "Honeywell",
"model": "ZW4103/39337",
"protocol": "zwave",
"zwave.node": "4",
"zwave.smartstart": "no"
},
"name": "Lamp Switch",
"parentDeviceId": "",
"persistent": false,
"reachable": true,
"ready": true,
"roomId": "1234567807786211fd31f416",
"security": "no",
"status": "idle",
"subcategory": "interior_plugin",
"type": "switch.outlet"
},
{
"_id": "1234567b07786211fd31f40e",
"batteryPowered": false,
"category": "dimmable_light",
"deviceTypeId": "57_20548_12339",
"firmware": [
{
"id": "us.57.29747.0",
"version": "5.21"
}
],
"gatewayId": "1234567d07786214fbc6bd4e",
"info": {
"firmware.stack": "4.34",
"hardware": "255",
"manufacturer": "Honeywell",
"model": "39339/ZW3107",
"protocol": "zwave",
"zwave.node": "5",
"zwave.smartstart": "no"
},
"name": "Lamp Dimmer",
"parentDeviceId": "",
"persistent": false,
"reachable": true,
"ready": true,
"roomId": "1234567807786211fd31f416",
"security": "no",
"status": "idle",
"subcategory": "dimmable_plugged",
"type": "dimmer.outlet"
}
]
}
}
There is then also a JSON response that lists the functions for each device in the same format above. However instead of "devices"=> it is "items"=> and the beach function is the _id key again.
I'd like to combine function _id tags and descriptions with the device JSON, so I can create a way to send my script "unlock door lock 1" and it subs the number with the _id of the device and the function _id.

Answer 1

You can start with a very rough navigator function like this:
def find_device(data, name, index)
# Filter through the device list...
data['result']['devices'].select do |device|
# ...for matching names.
device.name == name
end[index] # Take indexed entry
end
Where now you can do find_device(data, 'door_lock', 0) to dig up that entry.
Converting "door lock 1" to [ 'door_lock', 0 ] should be pretty trivial:
def to_location(str)
# Split off the name component(s) and index number
*name, index = str.split(/\s+/)
# Reassemble with underscores and -1 to account for 0-index
[ name.join('_'), index.to_i - 1 ]
end