Tappy Communication Messaging Protocol (TCMP) commany family for commands and responses that specifically interact with Type 4 tags.

Installation

Bower

bower install tappy-type4family

NPM

npm install @taptrack/tappy-type4family

Commands

varType4Family=require('tappy-type4family');varCommands=Type4Family.Commands;// Send an Application Protocol Data Unit (APDU) // to a Type 4 tagvarcmd=newCommands.TransceiveApdu(apdu)// Request that the Tappy poll for a Type 4 tag using// Type B modulationcmd=newCommands.DetectType4B(timeout)// Request that the Tappy poll for a Type 4 tag using Type B // modulation and having a specific Application Family Idefntifer (AFI)cmd=newCommands.DetectType4BSpecificAfi(timeout,afi)// Request that the Tappy poll for a Type 4 tag using // Type A modulationcmd=newCommands.DetectType4(timeout)// Request that the Tappy report the version of the // Type 4 family that it supportscmd=newCommands.GetLibraryVersion()

Responses

Note, you should only manually construct responses as below for testing purposes. in practise, please use the resolver described later to convert raw tcmp messages received from the tappy into their corresponding concrete response types with the payloads parsed appropriately.

varType4Family=require('tappy-type4family');varResponses=Type4Family.Responses;// the tag was successfully sent an APDU and repliedvarapduResp=newResponses.ApduTransceiveSuccessful();// retrieve the apdu the tag responded withapduResp.getApdu();// a type 4b tag was detectedvartype4BDetected=newResponses.Type4BDetected();// get the tag's ATTRIBtype4BDetected.getAttrib();// get the tag's ATQBtype4BDetected.getAtqb();// a type 4a tag was detectedvartype4Detected=newResponses.Type4Detected();// get the tag's UIDtype4Detected.getUid();// get the tag's ATStype4Detected.getAts();// an error occured when the Tappy was in the process// of detecting a tag such as when a tag is removed from// the Tappy's range part way through detectionvartype4PollingError=newResponses.Type4PollingError();// Tag polling finished without any tag being detectedvartype4Timeout=newResponses.Type4Timeout();// the version of the library varlibVersion=newResponses.Type4LibraryVersion();libVersion.getMajorVersion();libVersion.getMinorVersion();// an error occured executing a command vartype4Error=newResponses.Type4Error();// retrieve the command family-specific error code as per Type4Family.ErrorCodes type4Error.getErrorCode();// retrieve the internal-use error code type4Error.getInternalErrorCode();// retrieve the status reported by the Tappy's NFC Controllertype4Error.getReaderStatusCode();// retrieve the text message describing the error (may be empty string)type4Error.getErrorMessage();

Resolver

While you can manually resolve raw TCMP messages received from the Tappy using getCommandFamily(), getCommandCode(), getPayload(), and parsePayload(), it is much more convenient to use the built-in resolvers and isTypeOf().

varresolver=newType4Family.Resolver();// first check to see if the family matches this can be used to multiplex // multiple resolvers from different familiesif(resolver.checkFamily(responseMsg){// resolution will throw if the command family doesn't match, so it is// advisable to check that first. additionally, resolution will return// null if there is no matching command code in the libraryvarresolved=resolver.resolveResponse(responseMsg);if(Type4Family.Responses.Type4LibraryVersion.isTypeOf(resolved)){console.log("Library version v"+resolved.getMajorVersion()+"."+resolved.getMinorVersion());}}

There is a corresponding resolveCommand for commands in case you are storing commands in a raw form. Note that commands and responses have overlapping commandCode space, so keep track of whether the message was sent to the Tappy or received from it and use the appropriate resolution function.