What's a complete API call to /partstudios/../featurescript look like?

johnsogg

I think I have all the puzzle pieces for making an authenticated api call to evaluate a featurescript function, but I'm having trouble with cryptic error messages like "Error in input". I get the same error if I make the call via the API Explorer (using API key/secret) or from command line (using OAuth).

Here's the raw request with oauth key scrubbed (I can confirm it works using GET requests). I am hitting https://cad.onshape.com.

POST /api/partstudios/d/491cd510f26b33c86c3b1079/w/138c990145cb0318d3d0b43a/e/6c93e73cf1134e1ede7ece51/featurescript HTTP/1.1

Authorization: bearer <scrubbed>

Content-Type: application/json

Cookie: _u=websvc-c1ee691a

Host: cad.onshape.com

Connection: close

User-Agent: Paw/3.0.14 (Macintosh; OS X/10.12.1) GCDHTTPRequest

Content-Length: 167

{

  "script": "scribble",

  "queries": "",

  "serializationVersion": "1.1.9",

  "sourceMicroversion": "8ac4dc66d1e60d79bec44977",

  "rejectMicroversionSkew": "false"

} 

I've tried variations on the queries field (using [] and {}, for example). I'm using the feature name "scribble" (see below) and the serializationVersion and sourceMicroversion out of the results of GET /partstudios/../features.

I have a FeatureScript installed on that document (as confirmed by GET /partstudios/../features). In case there's something wrong with the FS, here it is:

<div></div>

<div></div>

FeatureScript 455;

import(path : "onshape/std/geometry.fs", version : "455.0");

annotation { "Feature Type Name" : "scribble" }

export const scribble = defineFeature(function(context is Context, id is Id, definition is map)

    precondition

    {

        // Define the parameters of the feature type

    }

    {

        return "42";

    });

The response from making the featurescript API call is:

HTTP/1.1 400 Bad Request

Server: nginx

Date: Mon, 12 Dec 2016 18:23:03 GMT

Content-Type: application/json;charset=utf-8

Content-Length: 91

Connection: close

On-Version: 1.55.16903.482b9b8ea9c5

Strict-Transport-Security: max-age=31536000; includeSubDomains

X-Content-Type-Options: nosniff

X-XSS-Protection: 1; mode=block

{

  "moreInfoUrl" : "",

  "code" : 9999,

  "message" : "Error in input",

  "status" : 400

}

Any ideas?

(Apologies for the formatting. The 'code' format doesn't work on render...)

mark_noyes

First, you can find examples of complete featurescript evaluation calls in the developer portal help section (https://dev-portal.onshape.com/help) in the Feature list API section. In summary, the "script" field is expected to be a function definition where the functions arguments must be a Context and a map. The "queries" field in the post body is a list of topology references, which are supplied to the function in the map argument.

Second, you appear to be trying to call a feature, but FeatureScript evaluation calls have no persistent side-effects, so you can't use this to alter your model. You can only call these functions to extract information, though you can feed that information back into features.

Lastly, in your example you are making reference to custom featurescript code. That is not currently supported, but whatever logic you need can be supplied in the FeatureScript that you pass in. So, although your example is presumably not what you are really trying to achieve, the working example for your test case is:

{

  "script" : "function (context is Context, queries is map) { return \"42\"; }",

  "queries" : [ ]

}

johnsogg

Thanks. I was treating this as more of an RPC thing (sending the function *name*) rather than sending the function *definition*. Yesterday I did try sending something similar to what you wrote, but it failed with the message "Error in input". Most likely I had some unescaped character, a newline maybe.