src/fragments.js
function(context, expr, callback, callbackContext) {
    if (typeof context === 'string') {
      callbackContext = callback;
      callback = expr;
      expr = context;
      context = null;
    }
    var observer = this.observations.createObserver(expr, callback, callbackContext);
    if (context) {
      observer.bind(context, true);
    }
    return observer;
  }
function(context, expr, callback, callbackContext) {
    if (typeof context === 'string') {
      callbackContext = callback;
      callback = expr;
      expr = context;
      context = null;
    }
    var observer = this.observations.createObserver(expr, callback, callbackContext);
    if (context) {
      observer.bind(context, true);
    }
    return observer;
  }
function ( context , expr , callback , callbackContext ) { if ( typeof context === 'string' ) { callbackContext = callback ; callback = expr ; expr = context ; context = null ; } var observer = this . observations . createObserver ( expr , callback , callbackContext ) ; if ( context ) { observer . bind ( context , true ) ; } return observer ; }
Observes an expression within a given context, calling the callback when it changes and returning the observer.
Observes an expression within a given context calling the callback when it changes and returning the observer .