hi Sven, > 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 >
On 13 December 2017 at 15:37, Sven Van Caekenberghe <s...@stfx.eu> wrote: > 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. okay. So I played around tracing this through the debugger and for anyone else with a similar need later, I ended up with the following... response := (ZnClient new url: 'https://bittrex.com/api/v1.1/public/getticker?market=INVALID'; 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: BittrexTicker ]. reader mapInstVarsFor: BittrexTicker. reader nextAs: BittrexResponse ] on: Error do: [ :err | |json| json := NeoJSONReader fromString: entity contents. (json at: 'success') ifFalse: [ self error: (json at: 'message') ] ifTrue: [ self error: 'UKNOWN ERROR' ] ] ]) get. for which I get a nice pre-debug window titled "Error: INVALID_MARKET" cheers -ben
