User:Abel/PersonalData.js

// License: GPL
// Indexeddb JavaScript 
console.log('Indb loading');

function IndexedDBContainer(ww) {

  // suppress console.log, switch to true for debug
  var Debug_switch = false;
  // seemingly the Safari engine uses a somewhat different implementation of arguments for db.transaction and index.get
  // because no browser on any mac / ios is allowed to use a different engine, rather than user agent, platform can be tested
  var iOS = !!navigator.platform && /iPad|iPhone|iPod/.test(navigator.platform);
  var Safari = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);
  debuglog("iOS:" + iOS + " & Saf:" + Safari);

  // deterministic hash generator for creating user id#s from usernames, should be replaced by something more functional (guaranteed to be transitively different)
  hashCode = function(s) {
    if (s == undefined) {
      s = '00'
    }
    var h = 0,
      l = s.length,
      i = 0;
    if (l > 0)
      while (i < l)
        h = (h << 5) - h + s.charCodeAt(i++) | 0;
    return h;
  };


  if (ww.user != undefined) {
    // if user exists in object passed to constructor, get username		
    var self = ww.user.getName();
    // create userid by hashing username
    var idgen = hashCode(self);
    debuglog(idgen);

    // Take username for standard databasename format:
    // Our current convention for personal databasename (separate dbname for each user)
    var PersonalDataDataBaseName = "PD.IO" + idgen + "Database";
    // Use username in user to get up to date version of self
    // Blank object for personal data Record with id and username included
    this.CurrentPerson = {
      id: idgen,
      name: {
        user: self
      },
      age: 0
    };
    debuglog(PersonalDataDataBaseName);
    debuglog(this.CurrentPerson);
  }

  // ADD MORE DOC

  // EnqueuePDIO a PDIOLocalDatabase:User database access function with modes
  // Externally accessible wrapper for Enquire with current user / db preloaded

  this.EnqueuePDIO = async function(sw, c1, c2, c3) {
    debuglog("enquing pdio db " + PersonalDataDataBaseName + " with user " + JSON.stringify(this.CurrentPerson));
    var k = await Enquire(PersonalDataDataBaseName, this.CurrentPerson, sw, c1, c2, c3);
    return k;
  }

  // Enquire, a general purpose indexeddb update function with modes

  // Mode 'aggressive push':
  // parameter record is pushed to database, overwriting whatever is there

  // Mode 'checkin':
  // record is retrieved from database, parameter record is pushed if not found

  // Mode 'get record'
  // updates record given as argument

  // Mode 'update record' field1 field2 field3
  // retrieve record, make record.field1.field2 = field3, push back

  // Mode 'update record' field1 field2
  // retrieve record, make record.field1 = field2, push back

  // Mode 'remove from record' field1 
  // retrieve record, splice/delete record.field1, push back

  // Mode 'remove from record' field1 field2 
  // retrieve record, splice/delete record.field1.field2, push back

  // Mode 'import record' field1
  // retrieve record, add all fields from field1, push back

  async function Enquire(pddbname, record, sqitch, control_1, control_2, control_3) {
    return new Promise(
      function(resolve, reject) {

        var pddb = window.indexedDB.open(pddbname, 3);
        var inp_obj;

        pddb.onerror = function() {
          console.log("Warning: Access to IndexedDB for application has been rejected.");
        };

        // indexeddb internal mechanism for version tracking of schema
        pddb.onupgradeneeded = function() {
          console.log('upgrading database');
          var db = pddb.result;
          var store = db.createObjectStore(pddbname, {
            keyPath: "id"
          });
          var index = store.createIndex("NameIndex", ["id"]);

        };
        // Database successfully opened function.
        pddb.onsuccess = function() {
          debuglog(pddb.result);
          var db = pddb.result;
          var tx;

          if (iOS || Safari) {
            tx = db.transaction([pddbname], "readwrite");
          } else {
            tx = db.transaction(pddbname, "readwrite");
          }

          var store = tx.objectStore(pddbname);
          var index = store.index("NameIndex");

          // Get the original record from the db...
          var getRecord;
          if (iOS || Safari) {
            getRecord = index.get(record.id);
          } else {
            getRecord = index.get([record.id]);
          }

          getRecord.onsuccess = function() {
            debuglog("Record in database: \n <<");
            debuglog(getRecord.result);
            debuglog(">>");
            // Essential recordAdd																													
            if (sqitch === "aggressive push") {
              // Mode 'aggressive push':
              // parameter record is pushed to database, overwriting whatever is there
              inp_obj = record;
              store.put(inp_obj);
              return inp_obj;
            } else if (sqitch === "checkin") {
              // Mode 'checkin':
              // record is retrieved from database, parameter record is pushed if not found
              if (getRecord.result != undefined) {
                debuglog("getting from store");
                inp_obj = getRecord.result;
              } else {
                debuglog("overriding whatever in there");
                inp_obj = record;
                store.put(inp_obj);
              }

            } else {
              // Methods manipulationg the actual record come here
              // Update & Remove from
              // If we got the record from store, use that version to be manipulated
              if (getRecord.result !== undefined) {
                inp_obj = getRecord.result;

                if (sqitch === "get record") {

                  debuglog("Getting record");
                  // we will return later

                }

                // endof onsuccess
              } else {

                debuglog("Record not found");

                if (sqitch === "update record") {
                  // Update record will use supplied copy to update it
                  inp_obj = record;
                } else {
                  if (sqitch === "get record") {
                    inp_obj = undefined;
                  } else if (sqitch === "remove from record") {
                    inp_obj = record;
                  } else {
                    // any other method ...... would quit as record was not even foun
                    return undefined;
                  }
                }
              }
            }

            if (sqitch === "update record") { // Record Update															
              if (control_1 != undefined) {
                if (control_2 != undefined) {
                  if (control_3 != undefined) {

                    // Mode 'update record' field1 field2 field3
                    // retrieve record, make record.field1.field2 = field3, push back

                    if (inp_obj[control_1] == undefined) {
                      inp_obj[control_1] = (isNaN(control_2)) ? {} : []
                    };
                    inp_obj[control_1][control_2] = control_3; // => "Bob"
                    store.put(inp_obj);
                  } else {

                    // Mode 'update record' field1 field2
                    // retrieve record, make record.field1 = field2, push back

                    inp_obj[control_1] = inp_obj[control_1] || {};
                    if (Array.isArray(inp_obj[control_1])) {
                      inp_obj[control_1].push(control_2);
                    } else {
                      inp_obj[control_1] = control_2;
                    }
                    store.put(inp_obj);

                  }
                } else {
                  // Only one control defined. We will return that part of the record, and change nothing
                  inp_obj = inp_obj[control_1];
                }
              } else {

                // There's not even control_1, we will just return the record itself

              }
              debuglog("return 3")
              // return inp_obj;

            };

            if (sqitch === "remove from record") { // Record Update															
              if (control_1 != undefined) {
                if (control_2 != undefined) {

                  // Mode 'remove from record' field1 field2 
                  // retrieve record, splice/delete record.field1.field2, push back

                  if (Array.isArray(inp_obj[control_1]) && !isNaN(control_2)) {
                    inp_obj[control_1].splice(control_2, 1);
                  } else {
                    delete inp_obj[control_1][control_2];
                  }

                } else {

                  // Mode 'remove from record' field1 
                  // retrieve record, splice/delete record.field1, push back

                  delete inp_obj[control_1];
                }
              }
              debuglog("putting object to store:");
              debuglog(inp_obj);
              store.put(inp_obj);
            }

            if (sqitch === "import record") {
              debuglog("import command");
              if (control_1 != undefined) {
                // Only import if control_1 is a non-empty object
                if ((!Array.isArray(control_1)) && (Object.keys(control_1).length > 0)) {
                  debuglog("command is obj");
                  Object.keys(control_1).forEach(function(importkey) {
                    debuglog("importing " + importkey);
                    if (control_1.hasOwnProperty(importkey)) {
                      inp_obj[importkey] = control_1[importkey]
                    };
                  })
                  store.put(inp_obj);
                }
              }
            }

            // We are past all methodic code, Async return						

            resolve(inp_obj);

          };

          // Indexeddb internal mechanism, close db

          tx.oncomplete = function() {
            debuglog("return 1")
            db.close();
          };
        };
        debuglog("return 0")

        // End of promise

      }).then(function(result) {
      debuglog("Mark 3");
      debuglog(result);
      return result;
    });
  }

  function debuglog(l0g) {
    if (Debug_switch) {
      console.log(l0g);
    }
  }
};