1. module mysql-events
   1. function mysql-events (dsn, settings)

module mysql-events

function mysql-events (dsn, settings)

• description and source-code

  mysql-events = function (dsn, settings) {
    var mySQLEvents = {
      //Watching - to check whether the zongji.on() has been called or not
      started: false,
  
      //zongji instance
      zongji: {},
  
      //db list which are currenly watching
      databases: [],
  
      //table list, key will be dbname
      tables: {},
  
      //column list - 2D Array of objects, [dbname][table][column]
      columns: {},
  
      //events - unique list of events, thats passed to includeEvents to zongji
      events: ['tablemap', 'writerows', 'updaterows', 'deleterows'],
  
      //triggers - each MySQLEvents.add() generate an object, stored here
      triggers: [],
  
      dsn,
  
      //settings available - serverId, startAtEnd, binlogName, binlogNextPos, includeEvents, excludeEvents, includeSchema, excludeSchema
      settings: settings || {},
  
      //connect - instantiate an ZongJi Class
      connect: function(dsn) {
        if (!_underScore.isUndefined(dsn.host) &&
          !_underScore.isUndefined(dsn.user) &&
          !_underScore.isUndefined(dsn.password)
        ) {
          this.dsn = dsn;
  
        }
        else {
          throw new Error('Error: MySQLEvents connect() needs host, user & password');
        }
      },
  
      //Add a watcher
      add: function(watchon, callback, columnValue) {
  
        var trigger = {
          trigger: watchon,
          callback: callback
        };
        if (!_underScore.isUndefined(columnValue)) {
          _underScore.extend(trigger, {
            value: columnValue
          });
        }
  
        this.triggers.push(trigger);
        this.reload();
  
        return trigger;
      },
  
      //unset watcher - this is the stop() method on the returned object of add() call
      remove: function(trigger) {
        this.triggers = _underScore.reject(this.triggers, function(obj) {
          return _underScore.isEqual(obj, trigger);
        });
        this.reload();
      },
  
      //Stop all watchers
      stop: function() {
        this.zongji.stop();
      },
  
      //set the zongji includeSchema based on current watcher list
      reload: function() {
  
        var map = {
          startAtEnd: true,
          includeEvents: this.events,
          includeSchema: this.includeSchema()
        };
        //override default settings
        Object.assign(map, this.settings);
  
        //check whether ZongJi started
        if (!this.started) {
          this.zongji = zongjiManager(this.dsn, map, function(evt) {
            if (
              evt.getEventName() === 'writerows' ||
              evt.getEventName() === 'updaterows' ||
              evt.getEventName() === 'deleterows'
            ) {
              //console.log(evt.getEventName());
              //console.log("zongji ctrlConnection", mySQLEvents.zongji.ctrlConnection.state);
  
              var database = evt.tableMap[evt.tableId].parentSchema;
              var table = evt.tableMap[evt.tableId].tableName;
              var columns = evt.tableMap[evt.tableId].columns;
              var oldRow = {};
              var newRow = {};
              var changedColumns = [];
  
              _underScore.each(evt.rows, function(row) {
                //console.log(row);
                if (evt.getEventName() == 'writerows') {
                  oldRow = null;
                  newRow = {
                    database: database,
                    table: table,
                    affectedColumns: columns,
                    changedColumns: changedColumns,
                    fields: row
                  };
                }
                if (evt.getEventName() == 'deleterows') {
                  newRow = null;
                  oldRow = {
                    database: database,
                    table: table,
                    affectedColumns: columns,
                    changedColumns: changedColumns,
                    fields: row
                  };
                }
                if (evt.getEventName() == 'updaterows') {
                  //get the changed rows list
                  _underScore.each(row.before, function(val, key) {
                    if (row.before[key] != row.after[key]) {
                      changedColumns.push(key);
                    }
                  });
  
                  oldRow = {
                    database: database, ...

• example usage

  n/a