marco-loche/saw

//     saw.js v0.0.1
//     (c) 2014 Marco Loche
//     SAW may be freely distributed under the MIT license.
//     http://marco-loche.mit-license.org/
"use strict";

(function () {

  var findAPITries = 0;
  // The function charged to locate the API adapter object presented by the LMS.
  // As described in section 3.3.6.1 of the documentation.
  var findAPI = function (win) {
    if (win == null) {
      return null;
    }
    while ((win.API == null) && (win.parent != null) && (win.parent != win)) {
      findAPITries++;
      if (findAPITries > 7) {
        return null;
      }
      win = win.parent;
    }

    return win.API;
  };

  var scormStatusCodeString = {
    '0':   'NoError',
    '101': 'GeneralException',
    '102': 'ServerBusy',
    '201': 'InvalidArgumentError',
    '202': 'ElementCannotHaveChildren',
    '203': 'ElementIsNotAnArray',
    '301': 'NotInitialized',
    '401': 'NotImplementedError',
    '402': 'InvalidSetValue',
    '403': 'ElementIsReadOnly',
    '404': 'ElementIsWriteOnly',
    '405': 'IncorrectDataType'
  };

  var saw = {
    LMSInitialized: false,
    API:            null,
    sessionLogs:    [],

    unset: function() {
      this.LMSInitialized = false;
      this.API = null;
    },

    configure: function () {
      this.API = findAPI(window);
      if ((this.API == null) && (window.opener != null) && (typeof(window.opener) != "undefined")) {
        this.API = findAPI(window.opener);
      }

      if (this.API == null) {
        throw new Error("A valid SCORM API Adapter can not be found in the window or in the window.opener");
      }
    },

    isConfigured: function () {
      return !(this.API == null);
    },

    isInitialized: function () {
      return this.LMSInitialized;
    },

    lmsInitialize: function () {
      //see 3.2.2.1 LMSInitialize
      this.LMSInitialized = "true" === String(this.API.LMSInitialize(""));
      this.logOperation('LMSInitialize');
      if (!this.isInitialized()) {
        this.abort("LMSInitialize");
      }
    },

    lmsCommit: function () {
      var succeeded= "true" === String(this.API.LMSCommit(""));
      this.logOperation('LMSCommit');
      if (!succeeded) {
        this.abort("LMSCommit");
      }
    },

    lmsFinish: function () {
      var succeeded= "true" === String(this.API.LMSFinish(""));
      this.logOperation('LMSFinish');
      if (!succeeded) {
        this.abort("LMSFinish");
      }

      this.unset();
    },

    setScormValue: function (parameter, value) {

      var succeeded= "true" === String(this.API.LMSSetValue(parameter, value));
      this.logOperation('LMSSetValue', {'parameter' : parameter, 'value' : value} );
      if (!succeeded) {
        this.abort("LMSSetValue");
      }
    },

    getScormValue: function (parameter) {
      var value = this.API.LMSGetValue(parameter);
      this.logOperation('LMSGetValue', {'parameter' : parameter, 'value' : value} );
      return value;
    },

    // A convenience method that do the correct sequence of calls to initialize the communication with the lms
    initialize:       function () {
      this.configure();
      this.lmsInitialize();
    },

    // A convenience method with a more
    commit: function() {
      this.lmsCommit();
    },

    // A convenience method that do the correct sequence of calls to close the communication with the lms
    finish:       function () {
      this.lmsCommit();
      this.lmsFinish();
    },

    abort: function (action) {
      this.LMSInitialized = false;
      this.API = null;

      throw new Error(action + " failed");
    },
    
    getLastError: function () {
      var error = this.API.LMSGetLastError();
      
      return {
        code: parseInt(error, 10),
        message: scormStatusCodeString[error]
      };
    },

    logOperation: function (scormAPIFn, scormAPIFnArguments) {
      var scormLastErrCode = this.API.LMSGetLastError();
      var log = {
        'timestamp':          Date.now(),
        'scormFn':            scormAPIFn,
        'scormFnArgs':        scormAPIFnArguments,
        'errorCode':          scormLastErrCode,
        'errorCodeString':    scormStatusCodeString[scormLastErrCode],
        'errorCodeStringLMS': this.API.LMSGetErrorString(scormLastErrCode),
        'diagnostic':         this.API.LMSGetDiagnostic("")
      };

      this.sessionLogs.push(log);
    }

  };

  if (typeof module === 'object' && typeof module.exports === 'object') {
    module.exports = saw;
  }
  else if (typeof define === 'function' && define.amd) {
    define(saw);
  }
}.call(this));