BTW, this is no about Zinc, but about NeoJSON. This is what I meant with variability that is hard to capture with a simple static type schema.
I have no time to try myself right now, but a custom mapping for ivar result (as in a block) might be able to see the difference and act accordingly. > On 13 Dec 2017, at 07:59, Ben Coman <b...@openinworld.com> wrote: > > > With... > Object subclass: #BittrexResponse > instanceVariableNames: 'success message result' > classVariableNames: '' > package: 'Bittrex' > > Object subclass: #BittrexMarketSummary > instanceVariableNames: 'MarketName High Low Volume Last > BaseVolume TimeStamp Bid Ask OpenBuyOrders > OpenSellOrders PrevDay Created DisplayMarketName' > classVariableNames: '' > package: 'Bittrex' > > this code works great when the response holds good data... > ZnClient new > url: > 'https://bittrex.com/api/v1.1/public/getmarketSummary?market=BTC-LTC'; > enforceHttpSuccess: true; > accept: ZnMimeType applicationJson; > contentReader: [ :entity | |reader| > reader := (NeoJSONReader on: entity readStream). > reader for: BittrexResponse do: [:m| > m mapInstVar: #success. > m mapInstVar: #message. > (m mapInstVar: #result) valueSchema: #ResultArray]. > reader for: #ResultArray customDo: [ :mapping | > mapping listOfElementSchema: BittrexMarketSummary ]. > reader mapInstVarsFor: BittrexMarketSummary. > reader nextAs: BittrexResponse ]; > get. > > i.e. a raw response looking like this.... > (ZnClient new > url: > 'https://bittrex.com/api/v1.1/public/getmarketsummary?market=BTC-LTC'; > get) inspect. > ==> > "'{""success"":true,""message"":"",""result"":[{""MarketName"":""BTC-LTC"",""High"":0.01982450,""Low"":0.01285257,""Volume"":1436429.81313360,""Last"":0.01842000,""BaseVolume"":24841.17217724,""TimeStamp"":""2017-12-13T05:56:25.937"",""Bid"":0.01840001,""Ask"":0.01842000,""OpenBuyOrders"":10140,""OpenSellOrders"":6306,""PrevDay"":0.01439800,""Created"":""2014-02-13T00:00:00""}]}'" > > > But for bad response looking like this... > (ZnClient new > url: > 'https://bittrex.com/api/v1.1/public/getmarketsummary?market=INVALID'; > get) inspect. > ==> {"success":false,"message":"INVALID_MARKET","result":null} > > the JSON handling code fails deep in the call stack with an error > "NeoJSONParseError: [ expected" > which is not so friendly for users of the Bittrex library. > > What are the different/recommended approaches with Zinc > for catching JSON errors such that I can pass "message" > as a higher level Error up the stack to the Bittrex user. > > cheers -ben
