lumberjack - Developer IT

From the Sys Admin Toolbox: Logwatch

<b>Linux Magazine: </b>"Q: What did one lumberjack say to the other lumberjack? A: Watch those logs. Now, what will you, as a system administrator, use to watch logs? Logwatch, of course."

Is my class structure good enough?

So I wanted to try out this challenge on reddit which is mostly about how you structure your data the best you can. I decided to challenge my C++ skills. Here's how I planned this. First, there's the Game class. It deals with time and is the only class main has access to. A game has a Forest. For now, this class does not have a lot of things, only a size and a Factory. Will be put in better use when it will come to SDL-stuff I guess A Factory is the thing that deals with the Game Objects (a.k.a. Trees, Lumberjack and Bears). It has a vector of all GameObjects and a queue of Events which will be managed at the end of one month. A GameObject is an abstract class which can be updated and which can notify the Event Listener The EventListener is a class which handles all the Events of a simulation. It can recieve events from a Game Object and notify the Factory if needed, the latter will manage correctly the event. So, the Tree, Lumberjack and Bear classes all inherits from GameObject. And Sapling and Elder Tree inherits from Tree. Finally, an Event is defined by an event_type enumeration (LUMBERJACK_MAWED, SAPPLING_EVOLUTION, ...) and an event_protagonists union (a GameObject or a pair of GameObject (who killed who ?)). I was quite happy at first with this because it seems quite logic and flexible. But I ended up questionning this structure. Here's why : I dislike the fact that a GameObject need to know about the Factory. Indeed, when a Bear moves somewhere, it needs to know if there's a Lumberjack ! Or it is the Factory which handles places and objects. It would be great if a GameObject could only interact with the EventListener... or maybe it's not that much of a big deal. Wouldn't it be better if I separate the Factory in three vectors ? One for each kind of GameObject. The idea would be to optimize research. If I'm looking do delete a dead lumberjack, I would only have to look in one shorter vector rather than a very long vector. Another problem arises when I want to know if there is any particular object in a given case because I have to look for all the gameObjects and see if they are at the given case. I would tend to think that the other idea would be to use a matrix but then the issue would be that I would have empty cases (and therefore unused space). I don't really know if Sapling and Elder Tree should inherit from Tree. Indeed, a Sapling is a Tree but what about its evolution ? Should I just delete the sapling and say to the factory to create a new Tree at the exact same place ? It doesn't seem natural to me to do so. How could I improve this ? Is the design of an Event quite good ? I've never used unions before in C++ but I didn't have any other ideas about what to use. Well, I hope I have been clear enough. Thank you for taking the time to help me !

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LINQ Query to DataTable.DataSource

- by lumberjack

I am trying to perform a LINQ query on a DataTable and show the result in another DataTable. My source DataTable looks something like this: DataTable myDataTable = new DataTable(); myDataTable.Columns.Add("OrderID", typeof(int)); myDataTable.Columns.Add("Date", typeof(DateTime)); myDataTable.Columns.Add("UnitsPurchased", typeof(int)); The resulting DataTable looks like this when filled: Order ID Date Units Purchased 16548 10/15/09 250 17984 11/03/09 512 20349 01/11/10 213 34872 01/15/10 175 My current LINQ query looks like this: IEnumerable<DataRow> query = (from row in myDataTable.AsEnumerable() where row.UnitsPurchased > 200 select new { row.OrderID, row.Date, row.UnitsPurchased }) as IEnumerable<DataRow>; resultDataTable.DataSource = query.CopyToDataTable<DataRow>(); Every time I run this code query is null. I can see that that the as IEnumerable<DataRow> is the culprit, but it makes no since to me since DataTable.AsEnumerable() returns an IEnumerable<DataRow>. Any help would be appreciated.

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jQuery DataTables: Problems with POST Server Side JSON output

- by Tim

Hello Everyone, I am trying to get my datatable to take a POST JSON output from my server. This is my client side code <script> $(document).ready(function() { $('#example').dataTable( { "bProcessing": true, "bServerSide": true, "sAjaxSource": "http://localhost/staff/jobs/my_jobs", "fnServerData": function ( sSource, aoData, fnCallback ) { $.ajax( { "dataType": 'json', "type": "POST", "url": sSource, "data": aoData, "success": fnCallback } ); } } ); } ); </script> Now I have copied and pasted the server side code found in the DataTables examples found here. When I change my sAjaxSource to view this page the table doesn't move beyond 'processing'. When I view the JSON directly I see this output. {"sEcho": 1, "iTotalRecords": 1, "iTotalDisplayRecords": 1, "aaData": [ ["Trident","First Ever Job"]] } Just for fun I went to the POST server-side example and copied some of the JSON they are using for their example and just PHP echoed it straight out of another page. This is the output of that page. {"sEcho": 1, "iTotalRecords": 1, "iTotalDisplayRecords": 1, "aaData": [ ["Trident","Internet Explorer 4.0"]] } Here is where it gets interesting. The JSON that has been processed by the server fails to work yet the JSON simply echo'd by the same server on a different page does work... yet both are almost identical in outputs. I hope someone can shed some light on this because as the tree said to the lumberjack... I'm stumped. Thanks, Tim

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CoreData: managedObjectContext not being created

- by PruitIgoe

I had to add core data to an existing project but I am having issues with the managedObjectContext... in prefix.pch I have this: #import <Availability.h> #ifndef __IPHONE_5_0 #warning "This project uses features only available in iOS SDK 5.0 and later." #endif #ifdef __OBJC__ #import <UIKit/UIKit.h> #import <Foundation/Foundation.h> #import <CoreData/CoreData.h> #endif ... in my appDelegate.h I have this: #import <UIKit/UIKit.h> #import "AppViewController.h" #import "DDLog.h" #import "DDASLLogger.h" #import "DDFileLogger.h" #import "DDTTYLogger.h" #import "KIP_LogManager.h" @interface AppDelegate : UIResponder <UIApplicationDelegate> { DDFileLogger* fileLogger; /*coredata*/ NSManagedObjectModel* managedObjectModel; NSManagedObjectContext* managedObjectContext; NSPersistentStoreCoordinator* persistentStoreCoordinator; } @property (strong, nonatomic) UIWindow *window; @property (strong, nonatomic) AppViewController* viewController; @property (readonly, strong, nonatomic) NSManagedObjectContext* managedObjectContext; @property (readonly, strong, nonatomic) NSManagedObjectModel* managedObjectModel; @property (readonly, strong, nonatomic) NSPersistentStoreCoordinator* persistentStoreCoordinator; - (void)setupLogging; - (NSString *)applicationDocumentsDirectory; in appDelegate.m this: @synthesize managedObjectContext = _managedObjectContext; @synthesize managedObjectModel = _managedObjectModel; @synthesize persistentStoreCoordinator = _persistentStoreCoordinator; ... - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { //establish lumberjack logging [self setupLogging]; DDLogVerbose(@"\n\n*********************\nNEW LOG SESSION\n**********************\n\n"); //set root view controller self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; self.viewController = [[AppViewController alloc] init]; self.window.rootViewController = self.viewController; self.viewController.managedObjectContext = _managedObjectContext; return YES; } ... #pragma mark - CoreData Stack - (NSManagedObjectContext *)managedObjectContext { if (_managedObjectContext != nil) { return _managedObjectContext; } NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator]; if (coordinator != nil) { _managedObjectContext = [[NSManagedObjectContext alloc] init]; [_managedObjectContext setPersistentStoreCoordinator:coordinator]; } return _managedObjectContext; } // Returns the managed object model for the application. // If the model doesn't already exist, it is created from the application's model. - (NSManagedObjectModel *)managedObjectModel { if (_managedObjectModel != nil) { return _managedObjectModel; } NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"SPI_PAC" withExtension:@"momd"]; _managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL]; return _managedObjectModel; } - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { if (persistentStoreCoordinator != nil) { return persistentStoreCoordinator; } NSMutableString* strDocsDirector = [[NSMutableString alloc] initWithString:[self applicationDocumentsDirectory]]; [strDocsDirector appendString:@"/SPI_PAC.sqlite"]; NSURL* storeURL = [NSURL URLWithString:strDocsDirector]; NSError *error = nil; persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; if(![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) { /*Error for store creation should be handled in here*/ } return persistentStoreCoordinator; } - (NSString *)applicationDocumentsDirectory { return [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]; } in the view controller, viewDidLoad I am logging the passed managedObjectContext and am getting null returned. Obviously I am missing something but not sure what? In viewcontroller.h I have: @property (nonatomic, retain) NSManagedObjectModel* managedObjectModel; @property (nonatomic, retain) NSManagedObjectContext* managedObjectContext; @property (nonatomic, retain) NSPersistentStoreCoordinator* persistentStoreCoordinator; and in the viewcontroller.m: @synthesize managedObjectContext = managedObjectContext; ... DDLogVerbose(@"%@", managedObjectContext);

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