Example: handling user changed records (simulating math on user changes, change rippling to another record)

Handle a list of user-changed records that simulates doing some work on the data before saving:

• Calculating a value based on the user-submitted data

• Causing a change in a record the user didn't modify

  <button id="eg3">Change the data!</button> <script> // The silly user changed some numbers!!! function fake_user_changing_data(){ var raw_record_list = []; for( var i=0; i<4; i++ ) { raw_record_list[i] = { id : i , name : 'Record ' + i }; }; console.log( 'You changed the data to ' );console.log( raw_record_list ); handle_changes( raw_record_list ); }

    /** Save all the change records and then display the results
    */
    var handle_changes = function( raw_record_list ) {
    	var record_list = doMathOnChangedData( raw_record_list  );
    	
    	// concurrently run the save changes
    	// 	returned_records is what we're promised
    	var returned_records = record_list.map(function( record ){
    		// console.log( 'map: ' );console.log( record );
    		return save_record( record ).then(function( returned_record ){
    			// funnel it back to returned_records array
    			return returned_record;
    		}); 
    	}); 
    	
    	return Q.all( returned_records ).done(function( a ){
    		// print the record_list when the lookups and processing are done
    		display_changes( returned_records );
    	}); 
    }
    
    /**	Do calcs... including "updating" the record after the last user-updated one
    */
    var doMathOnChangedData = function( record_list  ) {
    	for( var i=0; i<record_list  .length; i++ ) {
    		record_list[i].s = 
    			record_list[i].id + 
    			Math.floor(Math.random() * (100 + record_list[i].id)) + record_list[i].id;
    	}
    	id = record_list.length+1;
    	record_list[ id ] = {
    		id 		: id
    	,	name	: 'Record ' + i
    	, s		: 0
    	};
    	return record_list;
    }
    
    function saveUrl( record ) {
    	var url = '/?id=' + record.id;
    	for( var key in record ) {
    		if( key == 'id' )	continue;
    		url += '&' + key + '=' + record[key];
    	}
    	url = url.split(' ').join('%20');	// lazy cleanup
    	// console.log( url );
    	
    	// okay... just in case your localhost go boom on the url
    	url = '/';
    	return url;
    }
  
    /** Save a changed record
    */
    function save_record( _record ) {
    	var record = _record;
    	console.log( 'saving record: ' );console.log( record );
    	var deferred = Q.defer();
    	$.ajax( {
    		url: saveUrl( record ),
    		success: function( resultRecordIThink ) {
    			// fake a return record
    			var return_record = {};
    			for( var key in record ) {
    				return_record[key] = record[key];
    			}
    			return_record['bob'] = 'bob ' + return_record.id;
    			var max = 100.0; var min =0.0;
    			return_record.percent_done = Math.round( Math.random() * (max - min) + min, 2);
    			
    			console.log( 'save record ' + record.id + ' returned ' );console.log( return_record );
    			deferred.resolve( return_record );
    		}
    	});
    	
    	return deferred.promise;
    }
  
    var display_changes = function( returned_records ) {
    	console.log( 'returned_records (same as a): ' );console.log( returned_records );
    }
  
  
  
    $('#eg3').on( 'click', function() {
    	fake_user_changing_data();
    } );
  

  </script>