How do I get images from a particular project using the OpenAsset REST API? - rest

Question

I asked a while ago about how to get the actual image file from the File noun using the OA REST API.
I'm confused as to how to retrieve images related to a specific project.

Answer 1

Thanks to a helpful nudge from Jason I've discovered that the secret password is filtering using the params.
This still feels a bit unpleasant as it requires 4 trips to the OA server, so I'm probably still missing something that would allow me to concatenate these requests into one.
I wrote a short Ruby programme that will go and get a single image to illustrate the principle:
baseURL = "http://IP.A.DDR.ESS"
password = "password"
username = "login"
require 'net/http'
require "uri"
require 'json'
def ask_oa(request, baseURL, params, username, password, useParams)
#This constructs a REST request, makes it, and returns the JSON response.
uri = URI.parse(baseURL + request)
if useParams
uri.query = URI.encode_www_form(params)
end
puts uri
http = Net::HTTP.new(uri.host, uri.port)
request = Net::HTTP::Get.new(uri.request_uri)
request.basic_auth(username, password)
response = Net::HTTP.start(uri.hostname, uri.port) {|http|
http.request(request)
}
json_response = JSON.parse(response.body)
puts JSON.pretty_generate(json_response)
return json_response
end
puts "Step 1"
#You'll need to change this for *your* project name
project_name = "M020707"
puts "go and get a project where the project number is "+project_name+":"
request = "/REST/1/Projects"
params = { :textMatching => "exact",
:code => project_name
}
projectJSON = ask_oa(request, baseURL, params, username, password, true)
projectNumber = projectJSON[0]["id"]
#This ID is the ID of the Project. You use this as the Project_id to
#key into the Files list that we access next
puts "Step 2"
puts "go and get the files that have a project_id of "+projectNumber+":"
request = "/REST/1/Files"
params = { :textMatching => "exact",
:project_id => projectNumber
}
fileJSON = ask_oa(request, baseURL, params, username, password, true)
#You'd want a more exciting way of picking a file out of that list
#probably based on the ranking of the files or some other secret knowledge
the_file_I_want = 0
fileID = fileJSON[the_file_I_want]["id"]
#This is a single file, picked from a list of all the files associated
#with the project that we pulled in step 1. Now that we have a file id
#we're back to where we were when I asked my last question on SO.
#To OA, File means the source file, we now need to pick a
#processed/formatted version of it:
puts "Step 3"
puts "go and get the size options for the file with the ID "+fileID+":"
request = "/REST/1/Files/"+fileID+"/Sizes"
params = {}
sizeJSON = ask_oa(request, baseURL, params, username, password, false)
#implement a picker in here to get the format that you want. 0 is just
#the first, and I don't know if the order that they are provided in is
#deterministic
s = sizeJSON[0]
#This gets to the list of actual files that you can now construct a URL from
puts "Step 4"
puts "Request an image with this URL:"
puts baseURL + s["http_root"] + s["relative_path"]
#Now we can just request the file at the end of
#this url and we'll see a picture!