Struggling with a seemingly simple REST call that has left me completely stuck. I have a node-based restful service that requires an array of strings as input. However, every time I make the call with what seems like a valid parameter, the server throws an error indicating it's trying to interpret the string as an integer. This leads me to believe that somewhere along the line, the quotes around the string are being lost.
Below is the original Swift (3) code snippet along with two additional variants at the end. The function takes in "id" and "parmvalue" as parameters:
let url = URL(string: "\(root)path/\(id)/myendpoint")
var request = URLRequest(url:url!)
request.httpMethod = "POST"
request.addValue("application/json",forHTTPHeaderField: "Content-Type")
let params = [ "parm" : [ parmvalue ] ]
do {
let jsonParams = try JSONSerialization.data(withJSONObject: params)
request.httpBody = jsonParams
let task = URLSession.shared.dataTask(with: request, completionHandler: {(data, response, error) -> Void in
...etc
On the server side, here's the corresponding code snippet:
app.post('/path/:id/myendpoint', globals.authentication, function(req, res){
var param = JSON.parse(req.param('parm', "[]"));
var Id = req.param('id', -1);
...etc
When passing in a parmvalue = "898e1ac8-4892-4e6e-89cb-4b2ea9306f75.jpg", the server responds with a 500 error, and the data received by the completionHandler for the dataTask shows:
SyntaxError: Unexpected token e
This error occurs right at the line where "var param" is defined. The unexpected token usually corresponds to the first non-numeric value in the guid.
Variant 1 attempted to hardcode the JSON:
let url = URL(string: "\(root)path/\(id)/myendpoint")
var request = URLRequest(url:url!)
request.httpMethod = "POST"
request.addValue("application/json",forHTTPHeaderField: "Content-Type")
let testparamsString = "{ \"photos\" : [ \"\(filename)\" ] }"
let testparams = testparamsString.data(using: .utf8)
request.httpBody = testparams
...etc
Variant 2 tried using query param format if JSON didn't work:
let url = URL(string: "\(root)path/\(id)/myendpoint")
var request = URLRequest(url:url!)
request.httpMethod = "POST"
let queryparams = "parm[]=\(filename.stringByAddingPercentEncodingForFormUrlencoded()!)"
request.httpBody = queryparams.data(using: .utf8)
Note that variable names and values have been anonymized in the code snippets provided. All three variations in Swift resulted in the same response from the server, suggesting any issues aren't due to manual anonymizing.
Just for reference, here's a snippet from a C# application that successfully calls this endpoint using the RestSharp library:
var request = new RestRequest($"/path/{id}/myendpoint", Method.POST);
var parmArray = new JArray();
parmArray.Add(parmvalue);
var jsonParms = JsonConvert.SerializeObject(parmArray, Formatting.None);
request.AddParameter("parm", jsonParms);