topic Re: Using JSON in a "GET" HTTP Request in Discussions

Using JSON in a "GET" HTTP Request

vt_sailor — Fri, 26 Apr 2019 15:18:05 GMT

I'm working to interface with our data retrieval engine. I can submit a job perfectly fine using a POST request like this:

request = New HTTP Request(
url( "http://fc8tdbitmapconvs07:11111/daas/" ),
Method( "POST" ),
Json( Load Text File( ctfn ) )
);
data = request << Send;

'data' contains the response from the server and all is well.

-------------------------------------------

However, when I try and check on the status of the running job with a 'GET' request the json does not get included in the HTTP request to the server:

Attempt#1:

request2 = New HTTP Request(
url( "http://fc8tdbitmapconvs07:11111/daas/status/" ),
Method( "GET" ),
headers( {"Content-Type:application/json"} ), // add your custom headers
Json( Load Text File( ctfn2 ) )
);

data2 = request2 << Send;

Attempt#2

request2 = New HTTP Request(
url( "http://fc8tdbitmapconvs07:11111/daas/status/" ),
Method( "GET" ),
headers( {"Content-Type:application/json"} ) // add your custom headers
);
request2 <<Json( Load Text File( ctfn2 ) );
data2 = request2 << Send;

In both cases the JSON fails to load. The header information makes it to the server just fine but the spot where the JSON should be in the request is empty. What am I missing?

Thanks

Re: Using JSON in a "GET" HTTP Request

bryan_boone — Fri, 26 Apr 2019 17:50:35 GMT

"GET"

and "POST"

are two different HTTP request methods (https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods)

"GET" typically reads data from a server while

"Post" typically submits data to a server.

These are Web Server/Web Service defined outside of JMP/JSL

In your first example, you are "POST"-ing (aka submitting) data to "http://fc8tdbitmapconvs07:11111/daas/" and telling the service that ctfn is the JSON content to use.

In Attempt#1, the goal is "GET"-ting the status of a running job. I'm not sure what the service is, but if the endpoint is "http://fc8tdbitmapconvs07:11111/daas/status/", then you'd want something like:

request2 = New HTTP Request(
url( "http://fc8tdbitmapconvs07:11111/daas/status/" ),
Method( "GET" )
);

data2 = request2 << Send;

Since you wouldn't be submitting anything to the server in a GET.

Additionaly, "Content-Type:application/json" is used to describe the content you are sending (not really appropriate in a GET since you are recieving data and probably ignored by the web server)

Content-Type: headers are what you are sending (these are automatically set by HTTP Request)

Accept: headers are what you tell the web server you'd like.

request << Get MIME Type

will tell you what the web server sent. (most web servers set this, but it can be empty)

Keep in mind, too that after any

request << Send

You can do

request << Get Status; //this is the http status code
request << Get Status Message; //this is the message from the server

to investigate any error message the Web Service emits.

HTH

Re: Using JSON in a "GET" HTTP Request

vt_sailor — Fri, 26 Apr 2019 18:00:13 GMT

bryan_boone,

Thank you for the quick response. According to the developer who wrote the
REST API the JSON is required. Here's the working version in Python

status_info = get(
'http://fc8tdbitmapconvs07:11111/daas/status/',
json={'_id': '5cc311a97925b1000ce4fd54', 'include_complete':
True}
).json()

>> the long number in red is the job number which of course varies. This
bit works fine running in a python notebook or running inside JMP using the
following JSL. But, how do I get it to work with the HTTP Request protocol?

Thanks!
-----------------------------------------------------------------------------------------------------------------------------
Python Init();
Python Execute(
{x},
{status_info},
"
import getpass
from io import BytesIO
from time import sleep

import pandas as pd
from requests import get, post

status_info = get(
'http://fc8tdbitmapconvs07:11111/daas/status/',
json={'_id': '5cc311a97925b1000ce4fd54', 'include_complete':
True}
).json()

"
);
Python Term();

Re: Using JSON in a "GET" HTTP Request

bryan_boone — Fri, 26 Apr 2019 18:09:10 GMT

Is the JSON embedded in a request header? (Dropbox, Onedrive, and many others do that)

The JSON argument in the HTTP Request used in a POST/PATCH/PUT where the content is sent with the JSON content type. It is a "submit" action.

GET are "read" and arguments are either query strings or embeded in a request header.

Re: Using JSON in a "GET" HTTP Request

bryan_boone — Fri, 26 Apr 2019 22:20:21 GMT

After reading up on the HTTP Spec, I see that sending data with a GET is discouraged and that servers usually ignore it.

I found this discussion on stackoverflow, which links to the relevant HTTP specs.

Is this statement correct? HTTP GET method always has no message body

It basically boils do to some custom webservice implementations might use it and the spec is pretty nebulous about it.

Maybe I can get something in for JMP 15 if the need still exists.

Are there any other avenues to interact with this serviece?

Re: Using JSON in a "GET" HTTP Request

vt_sailor — Tue, 30 Apr 2019 11:58:04 GMT

Bryon,

Thank you for the quick reply. I'm working directly with the developer for the REST API and packaging the JSON in a GET request is their documented way of requesting data. You're correct that the spec is not clear and packaging JSON in a GET request is what is taught in some CS curriculums. In this instance the idea is to pass in a job number which will return either a code indicating the job is not yet complete (poll & response) or a code indicating that it is complete, the data file names and a zip file containing these files. If you could get something into JMP 15 that would be very helpful.

Re: Using JSON in a "GET" HTTP Request

bryan_boone — Tue, 30 Apr 2019 19:26:29 GMT

One last thing (or 2). can the Job Number, etc be passed as a query string parameter (or even JSON can be embedded in the request header)

and 2, be sure to add the get with a "body" to the wish list. That way we can keep track and you can be notified when it's there.

Thanks.

-Bryan

Re: Using JSON in a "GET" HTTP Request

bryan_boone — Tue, 26 Nov 2019 19:12:58 GMT

This feature (using "GET" while sending JSON) should be available in JMP 15.