Search Results

Search found 10533 results on 422 pages for 'task organization'.

Page 1/422 | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • Task scheduler "hidden" only hides task, not process

    - by Brandi
    I am trying to make an application that acts like a desktop application for all the computers in our network. I have already got a windows forms app that works like I want it to, and I'm using the task scheduler to start it on login. We would really like it if the process as well as the task is hidden from the task manager in order to avoid accidental deletion. Selecting "Hidden" in the task scheduler hides the task (good!) but the process is still visible (not good enough). I tried using the option to run as "SYSTEM" or "LOCAL SERVICE" so that the user would get "access denied" when trying to delete or just wouldn't even view it by default. However, running as a service makes the process invisible on Vista and 7, and the point of my app is to display information interactively. (User can click, sort, etc). Is there any other alternatives to either run the process as someone/something besides the logged in user and still have the logged on user be able to see and interact with it? (Therefore it would list as someone else's app?) From what I've read on the internet, the only ways to actually hide something from the task manager seem hacky and/or difficult and rather involved. I don't really want to write a bunch of C or whatever only to maybe not have it work on Vista/7 anyway. Besides which, for a legitimate app with a legitimate use, I shouldn't have to go to those extremes... I see "Access Denied" all the time for system processes... why is it so hard for me to do the same? So does anyone have any simple solutions? Is it easier than I think to just list something in the task manager as another user? Thanks in advance for any replies.

    Read the article

  • The Best Free Alternatives to the Windows Task Manager

    - by Lori Kaufman
    The Windows Task Manager is a built-in tool that allows you to check which services are running in the background, how much resources are being used by which software programs, and the all-to-common task of killing programs that are not responding. Even though the Windows Task Manager has several useful tools, there are many free alternatives available that provide additional or expanded features, allowing you to more closely monitor and tweak your system. How To Play DVDs on Windows 8 6 Start Menu Replacements for Windows 8 What Is the Purpose of the “Do Not Cover This Hole” Hole on Hard Drives?

    Read the article

  • Windows Server 2008 Task Scheduler Tasks Not Executing

    - by omatase
    I've been having an intermittent problem for some time now with the Windows Task Scheduler that I can't work out. I use the task scheduler to run a C# app I've written that has various plugins used to ensure production systems are working. This task scheduler itself is actually a production system so I have one simple task that executes every 8 minutes to notify an external monitoring system that the task scheduler is still up. If this external service fails to receive an "all-clear" at least once every 15 minutes (or so I don't remember the exact number right now) it will message us that the monitoring system is down. In the past we've had intermittent "down" messages from time to time and each time I've investigated the cause I was unable to find any problems. So this time I wanted to ask the StackOverflow community since it doesn't look like I'll have luck on my own. This morning at 2:32 AM the task fired (exactly 8 minutes after the previous firing) however the task didn't fire again until 3:28. There are no errors that I can see in the Event Viewer at this time. When I look at the Task Scheduler log there are no errors there either. Here is what the log looks like though: Information 6/11/2011 3:28:56 AM 102 Task completed (2) d6cf2412-269e-48bf-9f40-4a863347baad Information 6/11/2011 3:28:56 AM 201 Action completed (2) d6cf2412-269e-48bf-9f40-4a863347baad Information 6/11/2011 3:28:55 AM 129 Created Task Process Info Information 6/11/2011 3:28:55 AM 200 Action started (1) d6cf2412-269e-48bf-9f40-4a863347baad Information 6/11/2011 3:28:55 AM 100 Task Started (1) d6cf2412-269e-48bf-9f40-4a863347baad Information 6/11/2011 3:28:55 AM 319 Task Engine received message to start task (1) Information 6/11/2011 3:28:55 AM 107 Task triggered on scheduler Info d6cf2412-269e-48bf-9f40-4a863347baad Information 6/11/2011 3:28:15 AM 102 Task completed (2) b91fe5ce-39ef-42fb-adbe-bd8be012c00a Information 6/11/2011 3:28:15 AM 201 Action completed (2) b91fe5ce-39ef-42fb-adbe-bd8be012c00a Information 6/11/2011 3:28:15 AM 102 Task completed (2) 556c07dc-2724-4a21-a97e-dc4abd56f94d Information 6/11/2011 3:28:15 AM 201 Action completed (2) 556c07dc-2724-4a21-a97e-dc4abd56f94d Information 6/11/2011 3:28:15 AM 102 Task completed (2) 79328289-f742-49dd-aa0d-c3d05db50895 Information 6/11/2011 3:28:15 AM 201 Action completed (2) 79328289-f742-49dd-aa0d-c3d05db50895 Information 6/11/2011 3:28:15 AM 102 Task completed (2) 19743755-47b6-4b98-9bec-052193be9496 Information 6/11/2011 3:28:15 AM 201 Action completed (2) 19743755-47b6-4b98-9bec-052193be9496 Information 6/11/2011 3:28:15 AM 102 Task completed (2) c165754f-e3e6-4176-a327-11f9c06c39a5 Information 6/11/2011 3:28:15 AM 201 Action completed (2) c165754f-e3e6-4176-a327-11f9c06c39a5 Information 6/11/2011 3:28:15 AM 102 Task completed (2) 0e62ad3e-1f6e-40c0-9155-19f0108dee22 Information 6/11/2011 3:28:15 AM 201 Action completed (2) 0e62ad3e-1f6e-40c0-9155-19f0108dee22 Information 6/11/2011 3:28:10 AM 129 Created Task Process Info Information 6/11/2011 3:28:10 AM 200 Action started (1) 0e62ad3e-1f6e-40c0-9155-19f0108dee22 Information 6/11/2011 3:28:10 AM 129 Created Task Process Info Information 6/11/2011 3:28:10 AM 200 Action started (1) c165754f-e3e6-4176-a327-11f9c06c39a5 Information 6/11/2011 3:28:10 AM 129 Created Task Process Info Information 6/11/2011 3:28:10 AM 200 Action started (1) 19743755-47b6-4b98-9bec-052193be9496 Information 6/11/2011 3:28:10 AM 129 Created Task Process Info Information 6/11/2011 3:28:10 AM 200 Action started (1) 79328289-f742-49dd-aa0d-c3d05db50895 Information 6/11/2011 3:28:10 AM 129 Created Task Process Info Information 6/11/2011 3:28:10 AM 200 Action started (1) 556c07dc-2724-4a21-a97e-dc4abd56f94d Information 6/11/2011 3:28:10 AM 129 Created Task Process Info Information 6/11/2011 3:28:10 AM 200 Action started (1) b91fe5ce-39ef-42fb-adbe-bd8be012c00a Information 6/11/2011 3:28:10 AM 100 Task Started (1) 0e62ad3e-1f6e-40c0-9155-19f0108dee22 Information 6/11/2011 3:28:10 AM 319 Task Engine received message to start task (1) Information 6/11/2011 3:28:10 AM 100 Task Started (1) c165754f-e3e6-4176-a327-11f9c06c39a5 Information 6/11/2011 3:28:10 AM 319 Task Engine received message to start task (1) Information 6/11/2011 3:28:10 AM 100 Task Started (1) 19743755-47b6-4b98-9bec-052193be9496 Information 6/11/2011 3:28:10 AM 319 Task Engine received message to start task (1) Information 6/11/2011 3:28:10 AM 100 Task Started (1) 79328289-f742-49dd-aa0d-c3d05db50895 Information 6/11/2011 3:28:10 AM 319 Task Engine received message to start task (1) Information 6/11/2011 3:28:10 AM 100 Task Started (1) 556c07dc-2724-4a21-a97e-dc4abd56f94d Information 6/11/2011 3:28:10 AM 319 Task Engine received message to start task (1) Information 6/11/2011 3:28:10 AM 100 Task Started (1) b91fe5ce-39ef-42fb-adbe-bd8be012c00a Information 6/11/2011 3:28:10 AM 319 Task Engine received message to start task (1) Information 6/11/2011 3:28:10 AM 107 Task triggered on scheduler Info 0e62ad3e-1f6e-40c0-9155-19f0108dee22 Information 6/11/2011 3:28:10 AM 107 Task triggered on scheduler Info c165754f-e3e6-4176-a327-11f9c06c39a5 Information 6/11/2011 3:28:10 AM 107 Task triggered on scheduler Info 19743755-47b6-4b98-9bec-052193be9496 Information 6/11/2011 3:28:10 AM 107 Task triggered on scheduler Info 79328289-f742-49dd-aa0d-c3d05db50895 Information 6/11/2011 3:28:10 AM 107 Task triggered on scheduler Info 556c07dc-2724-4a21-a97e-dc4abd56f94d Information 6/11/2011 3:28:10 AM 107 Task triggered on scheduler Info b91fe5ce-39ef-42fb-adbe-bd8be012c00a Information 6/11/2011 2:32:56 AM 102 Task completed (2) 16e4f2c3-a340-410a-9c14-4bfe0861fdd5 Information 6/11/2011 2:32:56 AM 201 Action completed (2) 16e4f2c3-a340-410a-9c14-4bfe0861fdd5 Information 6/11/2011 2:32:55 AM 129 Created Task Process Info Information 6/11/2011 2:32:55 AM 200 Action started (1) 16e4f2c3-a340-410a-9c14-4bfe0861fdd5 Information 6/11/2011 2:32:55 AM 100 Task Started (1) 16e4f2c3-a340-410a-9c14-4bfe0861fdd5 Information 6/11/2011 2:32:55 AM 319 Task Engine received message to start task (1) Information 6/11/2011 2:32:55 AM 107 Task triggered on scheduler Info 16e4f2c3-a340-410a-9c14-4bfe0861fdd5 Seems kind of strange. I also have two other C# apps that run and check something each hour on the hour using task scheduler. If I look at the history for those I can see that they didn't execute at 3 AM either! They all waited until 3:28 to start as well. If I look at "tasks completed" in the Event Viewer it shows that only one task was able to run between the 2:32 AM to 3:28 AM time period. The task was "\Microsoft\Windows\RAC\RACAgent" And here's what it looked like: Information 6/11/2011 3:18:09 AM 102 Task completed (2) 00c53a85-ba20-4666-80db-fbbe2492c0ad Information 6/11/2011 3:18:09 AM 201 Action completed (2) 00c53a85-ba20-4666-80db-fbbe2492c0ad Information 6/11/2011 3:18:08 AM 129 Created Task Process Info Information 6/11/2011 3:18:08 AM 200 Action started (1) 00c53a85-ba20-4666-80db-fbbe2492c0ad Information 6/11/2011 3:18:08 AM 100 Task Started (1) 00c53a85-ba20-4666-80db-fbbe2492c0ad Information 6/11/2011 3:18:08 AM 319 Task Engine received message to start task (1) I appreciate any ideas anyone may have.

    Read the article

  • Windows Task Scheduler fails on EventData instruction

    - by Pete
    The Scheduled Task fails on the Event Data instruction in this XML: <ValueQueries> <Value name="eventChannel">Event/System/Channel</Value> <Value name="eventRecordID">Event/System/EventRecordID</Value> <Value name="eventData">Event/EventData/Data</Value> </ValueQueries> The other 2 fields can be passed as arguments and the EventData syntax matches other websites, so I don't know why it's failing. This is the Event Viewer XML: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="Aptify.ExceptionManagerPublishedException" /> <EventID Qualifiers="0">0</EventID> <Level>2</Level> <Task>0</Task> <Keywords>0x80000000000000</Keywords> <TimeCreated SystemTime="2013-11-07T19:39:14.000000000Z" /> <EventRecordID>97555</EventRecordID> <Channel>Application</Channel> <Computer>[Computer Name]</Computer> <Security /> </System> <EventData> <Data>General Information ********************************************* Additional Info: ExceptionManager.MachineName: [Computer Name] ExceptionManager.TimeStamp: 11/7/2013 12:39:14 PM ExceptionManager.FullName: AptifyExceptionManagement, Version=4.0.0.0, Culture=neutral, PublicKeyToken=[key] ExceptionManager.AppDomainName: Aptify Shell.exe ExceptionManager.ThreadIdentity: ExceptionManager.WindowsIdentity: ACA_DOMAIN\pbassett 1) Exception Information ********************************************* Exception Type: Aptify.Framework.BusinessLogic.GenericEntity.AptifyGenericEntityValidationException Entity: Tasks ErrorString: Task Type "Make Contact" is not active. MachineName: [machine] CreatedDateTime: 11/7/2013 12:39:14 PM AppDomainName: Aptify Shell.exe ThreadIdentityName: WindowsIdentityName: [identity] Severity: 0 ErrorNumber: 0 Message: Task Type "Make Contact" is not active. Data: System.Collections.ListDictionaryInternal TargetSite: Boolean Save(Boolean, System.String ByRef, Sys tem.String) HelpLink: NULL Source: AptifyGenericEntity StackTrace Information ********************************************* at Aptify.Framework.BusinessLogic.GenericEntity.AptifyGenericEntity.Save(Boolean AllowGUI, String& ErrorString, String TransactionID)</Data> </EventData> </Event>

    Read the article

  • Task scheduler ran a task twice

    - by Ross Buggins
    Update: This has now happened two days in a row. Update: XML of scheduled tasks and images now included. Two servers located in London, both Windows 2012, have a scheduled task set to run at 3pm Monday to Friday. This has been set up for the last 5 months without a problem. However, on Monday the 28th of August they both ran the scheduled task at 3pm and then again at 4pm. When it was first reported, I thought it was too much of a coincidence to be the day after the clocks had gone back an hour. However, I’m failing in being able to explain why it has happened and if it is related to the clock change at all. The relevant logs from one server (the logs for the other follow this pattern as well): Event 129 15:00:20 Task Scheduler launch task "\3pm", instance "C:\Program Files (x86)\PHP\v5.4\php.exe" with process ID 2388. Event 100 15:00:20 Task Scheduler started "{75a3590f-dec1-4dee-bd27-73d63a50a9d7}" instance of the "\3pm" task for user "x\y". Event 200 15:00:20 Task Scheduler launched action "C:\Program Files (x86)\PHP\v5.4\php.exe" in instance "{75a3590f-dec1-4dee-bd27-73d63a50a9d7}" of task "\3pm". Event 201 15:00:23 Task Scheduler successfully completed task "\3pm" , instance "{75a3590f-dec1-4dee-bd27-73d63a50a9d7}" , action "C:\Program Files (x86)\PHP\v5.4\php.exe" with return code 0. Event 129 16:00:20 Task Scheduler launch task "\3pm", instance "C:\Program Files (x86)\PHP\v5.4\php.exe" with process ID 1224. Event 100 16:00:20 Task Scheduler started "{3dd46ca9-c525-4796-86b5-5e513fd45f26}" instance of the "\3pm" task for user "x\y". Event 200 16:00:20 Task Scheduler launched action "C:\Program Files (x86)\PHP\v5.4\php.exe" in instance "{3dd46ca9-c525-4796-86b5-5e513fd45f26}" of task "\3pm". Event 201 16:00:23 Task Scheduler successfully completed task "\3pm" , instance "{3dd46ca9-c525-4796-86b5-5e513fd45f26}" , action "C:\Program Files (x86)\PHP\v5.4\php.exe" with return code 0. I've seen this question Scheduled task running twice from time to time which points to a bug at http://support.microsoft.com/kb/2461249 being the cause. However, this doesn't include Server 2012 in it's list of problem operating systems. I’m struggling to explain this, can anyone else? The XML export for the scheduled task is: <?xml version="1.0" encoding="UTF-16"?> <Task version="1.2" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task"> <RegistrationInfo> <Date>2013-04-16T14:04:17.4897806</Date> <Author>x\y</Author> </RegistrationInfo> <Triggers> <CalendarTrigger> <StartBoundary>2013-04-17T15:00:20</StartBoundary> <Enabled>true</Enabled> <ScheduleByWeek> <DaysOfWeek> <Monday /> <Tuesday /> <Wednesday /> <Thursday /> <Friday /> </DaysOfWeek> <WeeksInterval>1</WeeksInterval> </ScheduleByWeek> </CalendarTrigger> </Triggers> <Principals> <Principal id="Author"> <UserId>x\y</UserId> <LogonType>Password</LogonType> <RunLevel>LeastPrivilege</RunLevel> </Principal> </Principals> <Settings> <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy> <DisallowStartIfOnBatteries>true</DisallowStartIfOnBatteries> <StopIfGoingOnBatteries>true</StopIfGoingOnBatteries> <AllowHardTerminate>true</AllowHardTerminate> <StartWhenAvailable>false</StartWhenAvailable> <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable> <IdleSettings> <StopOnIdleEnd>true</StopOnIdleEnd> <RestartOnIdle>false</RestartOnIdle> </IdleSettings> <AllowStartOnDemand>true</AllowStartOnDemand> <Enabled>true</Enabled> <Hidden>false</Hidden> <RunOnlyIfIdle>false</RunOnlyIfIdle> <WakeToRun>false</WakeToRun> <ExecutionTimeLimit>P3D</ExecutionTimeLimit> <Priority>7</Priority> </Settings> <Actions Context="Author"> <Exec> <Command>"C:\Program Files (x86)\PHP\v5.4\php.exe"</Command> <Arguments>-f "c:\a.php"</Arguments> </Exec> </Actions> </Task> 29 October 17:00 - Update - Both servers have again run the scheduled task at 15:00 and 16:00. I've now updated the php file that is run by the scheduler to not actually do anything whilst I'm going through trying to solve this. I'm planning on restarting one server to see if this changes anything tomorrow. 30 October 08:25 - Update - When exporting the task XML I remembered that I hadn't included the fact that the scheduled task on second server was created by importing the XML of the task created on the first. The only difference between the two tasks is the path of the php file they are executing and the user account that they are running as.

    Read the article

  • Windows Server 2008 Task Scheduler: Task Started (Task=100) but did task did not complete (Task=102) when the result code is 2

    - by MacGyver
    Can someone give me a use case for setting up a Windows Server 2008 Task Scheduler task (we'll call this "test") that completes (action completed is task=201) with an error (result code=2)? This is event trigger code for another task (called "notification" that sends out an email based on the event history of the "test" task. I've got use cases for tasks that opens a program successfully and when a program fails to find the program. I'm just trying to think of how I can test a scenario when it finds the program, but something fails with warnings or errors. /* Failed - task started but had errors (result code of 2) */ <QueryList> <Query Id="0" Path="Microsoft-Windows-TaskScheduler/Operational"> <Select Path="Microsoft-Windows-TaskScheduler/Operational"> *[ System [ Provider[@Name='Microsoft-Windows-TaskScheduler'] and (Level=0 or Level=1 or Level=2 or Level=3 or Level=4 or Level=5) and (Task = 201) ] ] and *[ EventData [ Data [ @Name='TaskName' ]='\Tasks\test' ] ] and *[ EventData [ Data [ @Name='ResultCode' ]='2' ] ] </Select> </Query> </QueryList>

    Read the article

  • Parallelism in .NET – Part 14, The Different Forms of Task

    - by Reed
    Before discussing Task creation and actual usage in concurrent environments, I will briefly expand upon my introduction of the Task class and provide a short explanation of the distinct forms of Task.  The Task Parallel Library includes four distinct, though related, variations on the Task class. In my introduction to the Task class, I focused on the most basic version of Task.  This version of Task, the standard Task class, is most often used with an Action delegate.  This allows you to implement for each task within the task decomposition as a single delegate. Typically, when using the new threading constructs in .NET 4 and the Task Parallel Library, we use lambda expressions to define anonymous methods.  The advantage of using a lambda expression is that it allows the Action delegate to directly use variables in the calling scope.  This eliminates the need to make separate Task classes for Action<T>, Action<T1,T2>, and all of the other Action<…> delegate types.  As an example, suppose we wanted to make a Task to handle the ”Show Splash” task from our earlier decomposition.  Even if this task required parameters, such as a message to display, we could still use an Action delegate specified via a lambda: // Store this as a local variable string messageForSplashScreen = GetSplashScreenMessage(); // Create our task Task showSplashTask = new Task( () => { // We can use variables in our outer scope, // as well as methods scoped to our class! this.DisplaySplashScreen(messageForSplashScreen); }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This provides a huge amount of flexibility.  We can use this single form of task for any task which performs an operation, provided the only information we need to track is whether the task has completed successfully or not.  This leads to my first observation: Use a Task with a System.Action delegate for any task for which no result is generated. This observation leads to an obvious corollary: we also need a way to define a task which generates a result.  The Task Parallel Library provides this via the Task<TResult> class. Task<TResult> subclasses the standard Task class, providing one additional feature – the ability to return a value back to the user of the task.  This is done by switching from providing an Action delegate to providing a Func<TResult> delegate.  If we decompose our problem, and we realize we have one task where its result is required by a future operation, this can be handled via Task<TResult>.  For example, suppose we want to make a task for our “Check for Update” task, we could do: Task<bool> checkForUpdateTask = new Task<bool>( () => { return this.CheckWebsiteForUpdate(); }); Later, we would start this task, and perform some other work.  At any point in the future, we could get the value from the Task<TResult>.Result property, which will cause our thread to block until the task has finished processing: // This uses Task<bool> checkForUpdateTask generated above... // Start the task, typically on a background thread checkForUpdateTask.Start(); // Do some other work on our current thread this.DoSomeWork(); // Discover, from our background task, whether an update is available // This will block until our task completes bool updateAvailable = checkForUpdateTask.Result; This leads me to my second observation: Use a Task<TResult> with a System.Func<TResult> delegate for any task which generates a result. Task and Task<TResult> provide a much cleaner alternative to the previous Asynchronous Programming design patterns in the .NET framework.  Instead of trying to implement IAsyncResult, and providing BeginXXX() and EndXXX() methods, implementing an asynchronous programming API can be as simple as creating a method that returns a Task or Task<TResult>.  The client side of the pattern also is dramatically simplified – the client can call a method, then either choose to call task.Wait() or use task.Result when it needs to wait for the operation’s completion. While this provides a much cleaner model for future APIs, there is quite a bit of infrastructure built around the current Asynchronous Programming design patterns.  In order to provide a model to work with existing APIs, two other forms of Task exist.  There is a constructor for Task which takes an Action<Object> and a state parameter.  In addition, there is a constructor for creating a Task<TResult> which takes a Func<Object, TResult> as well as a state parameter.  When using these constructors, the state parameter is stored in the Task.AsyncState property. While these two overloads exist, and are usable directly, I strongly recommend avoiding this for new development.  The two forms of Task which take an object state parameter exist primarily for interoperability with traditional .NET Asynchronous Programming methodologies.  Using lambda expressions to capture variables from the scope of the creator is a much cleaner approach than using the untyped state parameters, since lambda expressions provide full type safety without introducing new variables.

    Read the article

  • Scheduled task does not run on WIndows 2003 server on VMWare unattened, runs fine otherwise

    - by lnm
    Scheduled task does not run on Windows 2003 server on VMWare. The same setup runs fine on standalone server. Test below explains the problem. We really need to run a more complex bat file, but this shows the issue. I have a bat file that copies a file from server A to server B. I use full path name, no drive mapping. Runs fine on server B from command prompt. I created a task that runs this bat file under a domain id with password that is part of administrator group on both servers. Task runs fine from Scheduled task screen, and as a scheduled task as long as somebody is logged into the server. If nobody is logged in, the task does not run. There is no error message in Task Scheduler log, just an entry that the task started, bit no entry for finish or an error code. To add insult to injury, if the task copies a file in the opposite direction, from server B to server A, it runs fine as a scheduled unattended task. If I copy a file from server B to server B, the task also runs fine unattended, I recreated exactly the same setup on a standalone server. No issues at all. I checked obvious things like the task has "run only as logged in" unchecked, domain id has run as a batch job privilege and logon rights, Task Scheduler service runs as a local system, automatic start. Any suggestions?

    Read the article

  • Parallelism in .NET – Part 13, Introducing the Task class

    - by Reed
    Once we’ve used a task-based decomposition to decompose a problem, we need a clean abstraction usable to implement the resulting decomposition.  Given that task decomposition is founded upon defining discrete tasks, .NET 4 has introduced a new API for dealing with task related issues, the aptly named Task class. The Task class is a wrapper for a delegate representing a single, discrete task within your decomposition.  We will go into various methods of construction for tasks later, but, when reduced to its fundamentals, an instance of a Task is nothing more than a wrapper around a delegate with some utility functionality added.  In order to fully understand the Task class within the new Task Parallel Library, it is important to realize that a task really is just a delegate – nothing more.  In particular, note that I never mentioned threading or parallelism in my description of a Task.  Although the Task class exists in the new System.Threading.Tasks namespace: Tasks are not directly related to threads or multithreading. Of course, Task instances will typically be used in our implementation of concurrency within an application, but the Task class itself does not provide the concurrency used.  The Task API supports using Tasks in an entirely single threaded, synchronous manner. Tasks are very much like standard delegates.  You can execute a task synchronously via Task.RunSynchronously(), or you can use Task.Start() to schedule a task to run, typically asynchronously.  This is very similar to using delegate.Invoke to execute a delegate synchronously, or using delegate.BeginInvoke to execute it asynchronously. The Task class adds some nice functionality on top of a standard delegate which improves usability in both synchronous and multithreaded environments. The first addition provided by Task is a means of handling cancellation via the new unified cancellation mechanism of .NET 4.  If the wrapped delegate within a Task raises an OperationCanceledException during it’s operation, which is typically generated via calling ThrowIfCancellationRequested on a CancellationToken, or if the CancellationToken used to construct a Task instance is flagged as canceled, the Task’s IsCanceled property will be set to true automatically.  This provides a clean way to determine whether a Task has been canceled, often without requiring specific exception handling. Tasks also provide a clean API which can be used for waiting on a task.  Although the Task class explicitly implements IAsyncResult, Tasks provide a nicer usage model than the traditional .NET Asynchronous Programming Model.  Instead of needing to track an IAsyncResult handle, you can just directly call Task.Wait() to block until a Task has completed.  Overloads exist for providing a timeout, a CancellationToken, or both to prevent waiting indefinitely.  In addition, the Task class provides static methods for waiting on multiple tasks – Task.WaitAll and Task.WaitAny, again with overloads providing time out options.  This provides a very simple, clean API for waiting on single or multiple tasks. Finally, Tasks provide a much nicer model for Exception handling.  If the delegate wrapped within a Task raises an exception, the exception will automatically get wrapped into an AggregateException and exposed via the Task.Exception property.  This exception is stored with the Task directly, and does not tear down the application.  Later, when Task.Wait() (or Task.WaitAll or Task.WaitAny) is called on this task, an AggregateException will be raised at that point if any of the tasks raised an exception.  For example, suppose we have the following code: Task taskOne = new Task( () => { throw new ApplicationException("Random Exception!"); }); Task taskTwo = new Task( () => { throw new ArgumentException("Different exception here"); }); // Start the tasks taskOne.Start(); taskTwo.Start(); try { Task.WaitAll(new[] { taskOne, taskTwo }); } catch (AggregateException e) { Console.WriteLine(e.InnerExceptions.Count); foreach (var inner in e.InnerExceptions) Console.WriteLine(inner.Message); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, our routine will print: 2 Different exception here Random Exception! Note that we had two separate tasks, each of which raised two distinctly different types of exceptions.  We can handle this cleanly, with very little code, in a much nicer manner than the Asynchronous Programming API.  We no longer need to handle TargetInvocationException or worry about implementing the Event-based Asynchronous Pattern properly by setting the AsyncCompletedEventArgs.Error property.  Instead, we just raise our exception as normal, and handle AggregateException in a single location in our calling code.

    Read the article

  • Build an Organization Chart In Visio 2010

    - by Mysticgeek
    With trying to manage a business these days, it’s very important to have an Organization Chart to keep everything manageable. Here we’ll show you how to build one in Visio 2010. This Guest Article was written by our friends over at Office 2010 Club. Need for Organization Charts The need of creating Organization Charts are becoming indispensable these days, as companies start focusing on extensive hiring for far reach availability, increase in productivity and targeting diverse markets. Considering this rigorous change, creating an organization chart can help stakeholders in comprehending the ever growing organization structure & hierarchy with an ease. It shows the basic structure of organization along with defining the relationships between employees working in different departments. Opportunely, Microsoft Visio 2010 offers an easy way to create Organization chart. As before now, orthodox ways of listing organization hierarchy have been used for defining the structure of departments along with communication possible including; horizontal and vertical communications. To transform these lists which defines organizational structure, into a detailed chart, Visio 2010 includes an add-in for importing Excel spreadsheet, which comes in handy for pulling out data from spreadsheet to create an organization chart. Importantly, you don’t need to indulge yourself in maze of defining organizational hierarchies and chalking-out structure, as you just need to specify the column & row headers, along with data you need to import and it will automatically create out chart defining; organizational hierarchies with specified credentials of each employee, categorized in their corresponding departments. Creating Organization Charts in Visio 2010 To start off with, we have created an Excel spreadsheet having fields, Name, Supervisor, Designation, Department and Phone. The Name field contains name of all the employees working in different departments, whereas Supervisor field contains name of supervisors or team leads. This field is vital for creating Organization Chart, as it defines the basic structure & hierarchy in chart. Now launch Visio 2010, head over to View tab, under Add-Ons menu, from Business options, click Organization Chart Wizard. This will start Organization Chart Wizard, in the first step, enable Information that’s already stored in a file or database option, and click Next. As we are importing Excel sheet, select the second option for importing Excel spreadsheet. Specify the Excel file path and click Next to continue. In this step, you need to specify the fields which actually defines the structure of an organization. In our case, these are Name & Supervisor fields. After specifying fields, click Next to Proceed further. As organization chart is primarily for showing the hierarchy of departments/employees working in organization along with how they are linked together, and who supervises whom. Considering this, in this step we will leave out Supervisor field, because it’s inclusion wouldn’t be necessary as Visio automatically chalks-out the basic structure defined in Excel sheet. Add the rest of the fields under Displayed fields category, and click Next. Now choose the fields which you want to include in Organization Chart’s shapes and click Next. This step is about breaking the chart into multiple pages, if you are dealing with 100+ employees, you may want to specify numbers of pages on which Organization Chart will be displayed. But in our case, we are dealing with much less amount of data, so we will enable I want the wizard to automatically break my organization chart across pages option. Specify the name you need to show on the top of the page. If you are having less than 20 hierarchies, enter the name of the highest ranked employee in organization and click Finish to end the wizard. It will instantly create an Organization chart out of specified Excel spreadsheet. Highest ranked employee will be shown on top of the organization chart, supervising various employees from different departments. As shown below, his immediate subordinates further manages other employees and so on. For advance customizations, head over to Org Chart tab, here you will find different groups for setting up the Org Chart’s hierarchy and manage other employees’ positions. Under Arrange group, shapes’ arrangements can be changed and it provides easy navigation through the chart. You can also change the type of the position and hide subordinates of selected employee. From Picture group, you can insert a picture of the employees, departments, etc. From synchronization group, you have the option of creating a synced copy and expanding subordinates of selected employee. Under Organization Data group, you can change whole layout of Organization chart from Display Options including; shape display, show divider, enable/disable imported fields, change block position, and fill colors, etc. If at any point of time, you need to insert new position or announce vacancy, Organization Chart stencil is always available on the left sidebar. Drag the desired Organization Chart shape into main diagram page, to maintain the structure integrity, i.e, for inserting subordinates for a specific employee, drag the position shape over the existing employee shape box. For instance, We have added a consultant in organization, who is directly under CEO, for maintaining this, we have dragged the Consultant box and just dropped it over the CEO box to make the immediate subordinate position. Adding details to new position is a cinch, just right-click new position box and click Properties. This will open up Shape Data dialog, start filling in all the relevant information and click OK. Here you can see the newly created position is easily populated with all the specified information. Now expanding an Organization Chart doesn’t require maintenance of long lists any more. Under Design tab, you can also try out different designs & layouts over organization chart to make it look more flamboyant and professional.  Conclusion An Organization Chart is a great way of showing detailed organizational hierarchies; with defined credentials of employees, departments structure, new vacancies, newly hired employees, recently added departments, and importantly shows most convenient way of interaction between different departments & employees, etc. Similar Articles Productive Geek Tips Geek Reviews: Using Dia as a Free Replacement for Microsoft VisioMysticgeek Blog: Create Appealing Charts In Excel 2007Create Charts in Excel 2007 the Easy Way with Chart AdvisorCreate a Hyperlink in a Word 2007 Flow Chart and Hide Annoying ScreenTipsCreate A Flow Chart In Word 2007 TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips HippoRemote Pro 2.2 Xobni Plus for Outlook All My Movies 5.9 CloudBerry Online Backup 1.5 for Windows Home Server Know if Someone Accessed Your Facebook Account Shop for Music with Windows Media Player 12 Access Free Documentaries at BBC Documentaries Rent Cameras In Bulk At CameraRenter Download Songs From MySpace Steve Jobs’ iPhone 4 Keynote Video

    Read the article

  • Simple task framework - building software from reusable pieces

    - by RuslanD
    I'm writing a web service with several APIs, and they will be sharing some of the implementation code. In order not to copy-paste, I would like to ideally implement each API call as a series of tasks, which are executed in a sequence determined by the business logic. One obvious question is whether that's the best strategy for code reuse, or whether I can look at it in a different way. But assuming I want to go with tasks, several issues arise: What's a good task interface to use? How do I pass data computed in one task to another task in the sequence that might need it? In the past, I've worked with task interfaces like: interface Task<T, U> { U execute(T input); } Then I also had sort of a "task context" object which had getters and setters for any kind of data my tasks needed to produce or consume, and it gets passed to all tasks. I'm aware that this suffers from a host of problems. So I wanted to figure out a better way to implement it this time around. My current idea is to have a TaskContext object which is a type-safe heterogeneous container (as described in Effective Java). Each task can ask for an item from this container (task input), or add an item to the container (task output). That way, tasks don't need to know about each other directly, and I don't have to write a class with dozens of methods for each data item. There are, however, several drawbacks: Each item in this TaskContext container should be a complex type that wraps around the actual item data. If task A uses a String for some purpose, and task B uses a String for something entirely different, then just storing a mapping between String.class and some object doesn't work for both tasks. The other reason is that I can't use that kind of container for generic collections directly, so they need to be wrapped in another object. This means that, based on how many tasks I define, I would need to also define a number of classes for the task items that may be consumed or produced, which may lead to code bloat and duplication. For instance, if a task takes some Long value as input and produces another Long value as output, I would have to have two classes that simply wrap around a Long, which IMO can spiral out of control pretty quickly as the codebase evolves. I briefly looked at workflow engine libraries, but they kind of seem like a heavy hammer for this particular nail. How would you go about writing a simple task framework with the following requirements: Tasks should be as self-contained as possible, so they can be composed in different ways to create different workflows. That being said, some tasks may perform expensive computations that are prerequisites for other tasks. We want to have a way of storing the results of intermediate computations done by tasks so that other tasks can use those results for free. The task framework should be light, i.e. growing the code doesn't involve introducing many new types just to plug into the framework.

    Read the article

  • Task scheduler does not kill task

    - by Andomar
    We have a scheduled task that sometimes hangs. It just stops responding. On Windows 2003, we had task scheduler configured to kill the task after 3 hours. It's a 32-bit process. On Windows 2008 R2, we've set "Stop the task if it runs longer than" and "If the running task does not end when requested, force it to stop". However, when the task hangs, it is never stopped, and stays in process explorer for days. Any clue why Windows Scheduler would not kill a process? (This post has a reproducible setup for this issue.)

    Read the article

  • The Execute SQL Task

    In this article we are going to take you through the Execute SQL Task in SQL Server Integration Services for SQL Server 2005 (although it appies just as well to SQL Server 2008).  We will be covering all the essentials that you will need to know to effectively use this task and make it as flexible as possible. The things we will be looking at are as follows: A tour of the Task. The properties of the Task. After looking at these introductory topics we will then get into some examples. The examples will show different types of usage for the task: Returning a single value from a SQL query with two input parameters. Returning a rowset from a SQL query. Executing a stored procedure and retrieveing a rowset, a return value, an output parameter value and passing in an input parameter. Passing in the SQL Statement from a variable. Passing in the SQL Statement from a file. Tour Of The Task Before we can start to use the Execute SQL Task in our packages we are going to need to locate it in the toolbox. Let's do that now. Whilst in the Control Flow section of the package expand your toolbox and locate the Execute SQL Task. Below is how we found ours. Now drag the task onto the designer. As you can see from the following image we have a validation error appear telling us that no connection manager has been assigned to the task. This can be easily remedied by creating a connection manager. There are certain types of connection manager that are compatable with this task so we cannot just create any connection manager and these are detailed in a few graphics time. Double click on the task itself to take a look at the custom user interface provided to us for this task. The task will open on the general tab as shown below. Take a bit of time to have a look around here as throughout this article we will be revisting this page many times. Whilst on the general tab, drop down the combobox next to the ConnectionType property. In here you will see the types of connection manager which this task will accept. As with SQL Server 2000 DTS, SSIS allows you to output values from this task in a number of formats. Have a look at the combobox next to the Resultset property. The major difference here is the ability to output into XML. If you drop down the combobox next to the SQLSourceType property you will see the ways in which you can pass a SQL Statement into the task itself. We will have examples of each of these later on but certainly when we saw these for the first time we were very excited. Next to the SQLStatement property if you click in the empty box next to it you will see ellipses appear. Click on them and you will see the very basic query editor that becomes available to you. Alternatively after you have specified a connection manager for the task you can click on the Build Query button to bring up a completely different query editor. This is slightly inconsistent. Once you've finished looking around the general tab, move on to the next tab which is the parameter mapping tab. We shall, again, be visiting this tab throughout the article but to give you an initial heads up this is where you define the input, output and return values from your task. Note this is not where you specify the resultset. If however you now move on to the ResultSet tab this is where you define what variable will receive the output from your SQL Statement in whatever form that is. Property Expressions are one of the most amazing things to happen in SSIS and they will not be covered here as they deserve a whole article to themselves. Watch out for this as their usefulness will astound you. For a more detailed discussion of what should be the parameter markers in the SQL Statements on the General tab and how to map them to variables on the Parameter Mapping tab see Working with Parameters and Return Codes in the Execute SQL Task. Task Properties There are two places where you can specify the properties for your task. One is in the task UI itself and the other is in the property pane which will appear if you right click on your task and select Properties from the context menu. We will be doing plenty of property setting in the UI later so let's take a moment to have a look at the property pane. Below is a graphic showing our properties pane. Now we shall take you through all the properties and tell you exactly what they mean. A lot of these properties you will see across all tasks as well as the package because of everything's base structure The Container. BypassPrepare Should the statement be prepared before sending to the connection manager destination (True/False) Connection This is simply the name of the connection manager that the task will use. We can get this from the connection manager tray at the bottom of the package. DelayValidation Really interesting property and it tells the task to not validate until it actually executes. A usage for this may be that you are operating on table yet to be created but at runtime you know the table will be there. Description Very simply the description of your Task. Disable Should the task be enabled or not? You can also set this through a context menu by right clicking on the task itself. DisableEventHandlers As a result of events that happen in the task, should the event handlers for the container fire? ExecValueVariable The variable assigned here will get or set the execution value of the task. Expressions Expressions as we mentioned earlier are a really powerful tool in SSIS and this graphic below shows us a small peek of what you can do. We select a property on the left and assign an expression to the value of that property on the right causing the value to be dynamically changed at runtime. One of the most obvious uses of this is that the property value can be built dynamically from within the package allowing you a great deal of flexibility FailPackageOnFailure If this task fails does the package? FailParentOnFailure If this task fails does the parent container? A task can he hosted inside another container i.e. the For Each Loop Container and this would then be the parent. ForcedExecutionValue This property allows you to hard code an execution value for the task. ForcedExecutionValueType What is the datatype of the ForcedExecutionValue? ForceExecutionResult Force the task to return a certain execution result. This could then be used by the workflow constraints. Possible values are None, Success, Failure and Completion. ForceExecutionValue Should we force the execution result? IsolationLevel This is the transaction isolation level of the task. IsStoredProcedure Certain optimisations are made by the task if it knows that the query is a Stored Procedure invocation. The docs say this will always be false unless the connection is an ADO connection. LocaleID Gets or sets the LocaleID of the container. LoggingMode Should we log for this container and what settings should we use? The value choices are UseParentSetting, Enabled and Disabled. MaximumErrorCount How many times can the task fail before we call it a day? Name Very simply the name of the task. ResultSetType How do you want the results of your query returned? The choices are ResultSetType_None, ResultSetType_SingleRow, ResultSetType_Rowset and ResultSetType_XML. SqlStatementSource Your Query/SQL Statement. SqlStatementSourceType The method of specifying the query. Your choices here are DirectInput, FileConnection and Variables TimeOut How long should the task wait to receive results? TransactionOption How should the task handle being asked to join a transaction? Usage Examples As we move through the examples we will only cover in them what we think you must know and what we think you should see. This means that some of the more elementary steps like setting up variables will be covered in the early examples but skipped and simply referred to in later ones. All these examples used the AventureWorks database that comes with SQL Server 2005. Returning a Single Value, Passing in Two Input Parameters So the first thing we are going to do is add some variables to our package. The graphic below shows us those variables having been defined. Here the CountOfEmployees variable will be used as the output from the query and EndDate and StartDate will be used as input parameters. As you can see all these variables have been scoped to the package. Scoping allows us to have domains for variables. Each container has a scope and remember a package is a container as well. Variable values of the parent container can be seen in child containers but cannot be passed back up to the parent from a child. Our following graphic has had a number of changes made. The first of those changes is that we have created and assigned an OLEDB connection manager to this Task ExecuteSQL Task Connection. The next thing is we have made sure that the SQLSourceType property is set to Direct Input as we will be writing in our statement ourselves. We have also specified that only a single row will be returned from this query. The expressions we typed in was: SELECT COUNT(*) AS CountOfEmployees FROM HumanResources.Employee WHERE (HireDate BETWEEN ? AND ?) Moving on now to the Parameter Mapping tab this is where we are going to tell the task about our input paramaters. We Add them to the window specifying their direction and datatype. A quick word here about the structure of the variable name. As you can see SSIS has preceeded the variable with the word user. This is a default namespace for variables but you can create your own. When defining your variables if you look at the variables window title bar you will see some icons. If you hover over the last one on the right you will see it says "Choose Variable Columns". If you click the button you will see a list of checkbox options and one of them is namespace. after checking this you will see now where you can define your own namespace. The next tab, result set, is where we need to get back the value(s) returned from our statement and assign to a variable which in our case is CountOfEmployees so we can use it later perhaps. Because we are only returning a single value then if you remember from earlier we are allowed to assign a name to the resultset but it must be the name of the column (or alias) from the query. A really cool feature of Business Intelligence Studio being hosted by Visual Studio is that we get breakpoint support for free. In our package we set a Breakpoint so we can break the package and have a look in a watch window at the variable values as they appear to our task and what the variable value of our resultset is after the task has done the assignment. Here's that window now. As you can see the count of employess that matched the data range was 2. Returning a Rowset In this example we are going to return a resultset back to a variable after the task has executed not just a single row single value. There are no input parameters required so the variables window is nice and straight forward. One variable of type object. Here is the statement that will form the soure for our Resultset. select p.ProductNumber, p.name, pc.Name as ProductCategoryNameFROM Production.ProductCategory pcJOIN Production.ProductSubCategory pscON pc.ProductCategoryID = psc.ProductCategoryIDJOIN Production.Product pON psc.ProductSubCategoryID = p.ProductSubCategoryID We need to make sure that we have selected Full result set as the ResultSet as shown below on the task's General tab. Because there are no input parameters we can skip the parameter mapping tab and move straight to the Result Set tab. Here we need to Add our variable defined earlier and map it to the result name of 0 (remember we covered this earlier) Once we run the task we can again set a breakpoint and have a look at the values coming back from the task. In the following graphic you can see the result set returned to us as a COM object. We can do some pretty interesting things with this COM object and in later articles that is exactly what we shall be doing. Return Values, Input/Output Parameters and Returning a Rowset from a Stored Procedure This example is pretty much going to give us a taste of everything. We have already covered in the previous example how to specify the ResultSet to be a Full result set so we will not cover it again here. For this example we are going to need 4 variables. One for the return value, one for the input parameter, one for the output parameter and one for the result set. Here is the statement we want to execute. Note how much cleaner it is than if you wanted to do it using the current version of DTS. In the Parameter Mapping tab we are going to Add our variables and specify their direction and datatypes. In the Result Set tab we can now map our final variable to the rowset returned from the stored procedure. It really is as simple as that and we were amazed at how much easier it is than in DTS 2000. Passing in the SQL Statement from a Variable SSIS as we have mentioned is hugely more flexible than its predecessor and one of the things you will notice when moving around the tasks and the adapters is that a lot of them accept a variable as an input for something they need. The ExecuteSQL task is no different. It will allow us to pass in a string variable as the SQL Statement. This variable value could have been set earlier on from inside the package or it could have been populated from outside using a configuration. The ResultSet property is set to single row and we'll show you why in a second when we look at the variables. Note also the SQLSourceType property. Here's the General Tab again. Looking at the variable we have in this package you can see we have only two. One for the return value from the statement and one which is obviously for the statement itself. Again we need to map the Result name to our variable and this can be a named Result Name (The column name or alias returned by the query) and not 0. The expected result into our variable should be the amount of rows in the Person.Contact table and if we look in the watch window we see that it is.   Passing in the SQL Statement from a File The final example we are going to show is a really interesting one. We are going to pass in the SQL statement to the task by using a file connection manager. The file itself contains the statement to run. The first thing we are going to need to do is create our file connection mananger to point to our file. Click in the connections tray at the bottom of the designer, right click and choose "New File Connection" As you can see in the graphic below we have chosen to use an existing file and have passed in the name as well. Have a look around at the other "Usage Type" values available whilst you are here. Having set that up we can now see in the connection manager tray our file connection manager sitting alongside our OLE-DB connection we have been using for the rest of these examples. Now we can go back to the familiar General Tab to set up how the task will accept our file connection as the source. All the other properties in this task are set up exactly as we have been doing for other examples depending on the options chosen so we will not cover them again here.   We hope you will agree that the Execute SQL Task has changed considerably in this release from its DTS predecessor. It has a lot of options available but once you have configured it a few times you get to learn what needs to go where. We hope you have found this article useful.

    Read the article

  • Windows Task Scheduler does not start task at next run time

    - by Dan C
    I have a Windows Server 2008 SP 2 Task Scheduler task that should run every 10 minutes. The trigger says "At 6:50 PM every day - After triggered, repeat every 10 minutes for a duration of 1 day." Looking at the Next Run Time, it says 6/18/2012 8:00 PM. However, when I let that time pass, the Next Run Time just changes to 8:10 PM but the task has not started and the Last Run Time is unchanged from yesterday. How can I get this task to run every 10 minutes when enabled no matter what. Similarly, I have other tasks that need to run on slightly different schedules: Every 30 minutes (5:30, 6:00, 6:30, etc) Every 30 minutes (5:35, 6:05, 6:35, etc) How can I define these intervals? And why does the task not start at the indicated Next Run Time?

    Read the article

  • Server 2008 Task Scheduler and a CMD file

    - by Mark Smith
    Task Scheduler - I have a .cmd file I'm trying to execute on a regular basis through Task Scheduler. I've set the task so that it points to the cmd file. I want the task to execute even when no one is logged in. I've set the credentials associated with the task to the local service account. When I execute the task, nothing happens. The Last Run Result shows 0x1, this means it didn't execute properly. When I run the file from a command prompt it executes just fine. Any help out there would be appreciated. I would post the code but it has sensitive information in it and I'm not allowed to let the code outside. Thanks

    Read the article

  • Why would Windows Task Scheduler spawn multiple instances of the same task that run into each other?

    - by swagner88
    Overview: I use Windows Task Scheduler to run automated tasks. Occasionally I will see that randomly a task has failed to perform its duties. When I check Task Scheduler to see what has occurred in the history log, I see that for some reason, when the tasks are triggered at their schedules, they are spawning several instances of themselves simultaneously which turns into a train wreck for the task and it either kills the other instances and tries to run the "first" one, or it just does not run at all as it believes another instance of itself is already running. Sometimes this occurs in the same tasks and then occasionally it happens with others. The fix is just to end all instances and start the task manually. Question: Why would one single task with one single schedule decide to spawn multiple instance of itself simultaneously? Note: I've got a separate user account set to run the tasks instead of myself. That user is indeed an admin on the machine that runs the tasks and the tasks are set to tun whether or not the user is logged on. Also, the machine is windows server 08 R2.

    Read the article

  • Use a Windows 8-Like Task Manager in Windows 7, Vista, and XP

    - by Lori Kaufman
    One of the new features in Windows 8 is the improved Task Manager, which provides access to more information and settings. If you don’t want to upgrade, there is a way you can use a simple Windows 8-like Task Manager in Windows 7, Vista, or XP. The Windows 8 Metro Task Manager does not need to be installed. Simply download the .zip file (see the download link at the end of this article), extract the files, and double-click the Windows 8 Task Manager.exe file. A window displays a list of tasks currently running with the status of each task listed. To end a task, select the task in the list and click End Task. Why Does 64-Bit Windows Need a Separate “Program Files (x86)” Folder? Why Your Android Phone Isn’t Getting Operating System Updates and What You Can Do About It How To Delete, Move, or Rename Locked Files in Windows

    Read the article

  • This task is currently locked by a running workflow and cannot be edited. Limitation to both Nintex and SPD workflow

    - by ybbest
    Note, this post is from Nintex Forum here. These limitations apply to both SharePoint designer Workflow and Nintex Workflow as Nintex using the SharePoint workflow engine. The common cause that I experience is that ‘parent’ workflow is generating more than one task at once. This is common as you can have multiple approvers for certain approval process. You could also have workflow running when the task is created, one of the common scenario is you would like to set a custom column value in your approval task. For me this is huge limitation, as Nintex lover I really hope Nintex could solve this problem with Microsoft going forward. Introduction “This task is currently locked by a running workflow and cannot be edited” is a common message that is seen when an error occurs while the SharePoint workflow engine is processing a task item associated with a workflow. When a workflow processes a task normally, the following sequence of events is expected to occur: 1.       The process begins. 2.       The workflow places a ‘lock’ on the task so nothing else can change the values while the workflow is processing. 3.       The workflow processes the task. 4.       The lock is released when the task processing is finished. When the message is encountered, it usually indicates that an error occurred between step 2 and 4. As a result, the lock is never released. Therefore, the ‘task locked’ message is not an error itself, rather a symptom of another error – the ‘task locked’ message does not indicate what went wrong. In most cases, once this message is encountered, the workflow cannot be made to continue and must be terminated and started again. The following is a guide that can help troubleshoot the cause of these messages.  Some initial observations to narrow down the potential causes are: Is the error consistent or intermittent? When the error is consistent, it will happen every time the workflow is run. When it is intermittent, it may happen regularly, but not every time. Does the error occur the first time the user tries to respond to a task, or do they respond and notice the workflow does not continue, and when they respond again the error occurs? If the message is present when the user first responds to the task, the issue would have occurred when the task was created. Otherwise, it would have occurred when the user attempted to respond to the task. Causes Modifying the task list A cause of this error appearing consistently the first time a user tries to respond to a task is a modification to the default task list schema. For example, changing the ‘Assigned to’ field in a task list to be a multiple selection will cause the behaviour. Deleting the workflow task then restoring it from the Recycle bin If you start a workflow, delete the workflow task then restore it from the Recycle Bin in SharePoint, the workflow will fail with the ‘task locked’ error.  This is confirmed behaviour whether using a SharePoint Designer or a Nintex workflow.  You will need to terminate the workflow and start it again. Parallel simultaneous responses A cause of this error appearing inconsistently is multiple users responding to tasks in parallel at the same time. In this scenario, one task will complete correctly and the other will not process. When the user tries again, the ‘task locked’ message will display. Nintex included a workaround for this issue in build 11000. In build 11000 and later, one of the users will receive a message on the task form when they attempt to respond, stating that they need to try again in a few moments. Additional processing on the task A cause of this error appearing consistently and inconsistently is having an additional system running on the items in the task list. Some examples include: a workflow running on the task list, an event receiver running on the task list or another automated process querying and updating workflow tasks. Note: This Microsoft help article (http://office.microsoft.com/en-us/sharepointdesigner/HA102376561033.aspx#5) explains creating a workflow that runs on the task list to update a field on the task. Our experience shows that this causes the ‘Task Locked’ issues when the ‘parent’ workflow is generating more than one task at once. Isolated system error If the error is a rare event, or a ‘one off’ event, then an isolated system error may have occurred. For example, if there is a database connectivity issue while the workflow is processing the task response, the task will lock. In this case, the user will respond to a task but the workflow will not continue. When they respond again, the ‘task locked’ message will display. In this case, there will be an error in the SharePoint ULS Logs at the time that the user originally responded. Temporary delay while workflow processes If the workflow is taking a long time to process after a user submits a task, they may notice and try to respond to the task again. They will see the task locked error, but after a number of attempts (or after waiting some time) the task response page eventually indicates the task has been responded to. In this case, nothing actually went wrong, and the error message gives an accurate indication of what is happening – the workflow temporarily locked the task while it was processing. This scenario may occur in a very large workflow, or after the SharePoint application pool has just started. Modifying the task via a web service with an invalid url If the Nintex Workflow web service is used to respond to or delegate a task, the site context part of the url must be a valid alternative access mapping url. For example, if you access the web service via the IP address of the SharePoint server, and the IP address is not a valid AAM, the task can become locked. The workflow has become stuck without any apparent errors This behaviour can occur as a result of a bug in the SharePoint 2010 workflow engine.  If you do not have the August 2010 Cumulative Update (or later) for SharePoint, and your workflow uses delays, “Flexi-task”, State machine”, “Task Reminder” actions or variables, you could be affected. Check the SharePoint 2010 Updates site here: http://technet.microsoft.com/en-us/sharepoint/ff800847.  The October CU is recommended http://support.microsoft.com/kb/2553031.   The fix is described as “Consider the following scenario. You add a Delay activity to a workflow. Then, you set the duration for the Delay activity. You deploy the workflow in SharePoint Foundation 2010. In this scenario, the workflow is not resumed after the duration of the Delay activity”. If you find this is occurring in your environment, install the October CU, terminate all the running workflows affected and run them afresh. Investigative steps The first step to isolate the issue is to create a new task list on the site and configure the workflow to use it.  Any customizations that were made to the original task list should not be made to the new task list. If the new task list eliminates the issue, then the cause can be attributed to the original task list or a change that was made to it. To change the task list that the workflow uses: In Workflow Designer select Settings -> Startup Options Then configure the task list as required If any of the scenarios above do not help, check the SharePoint logs for any messages with a category of ‘Workflow Infrastructure’. Conclusion The information in this article has been gathered from observations and investigations by Nintex. The sources of these issues are the underlying SharePoint workflow engine. This article will be updated if further causes are discovered. From <http://connect.nintex.com/forums/thread/6503.aspx>

    Read the article

  • Task Scheduler not running .bat or .vbs successfully

    - by Django Reinhardt
    Hi there, got this weird problem, which will hopefully have an obvious solution for some enlightened soul: We have several daily tasks we run via a .vbs script on our server (through the Task Scheduler), and for months it has been fine, but recently we've hit a problem. The .vbs script stopped successfully executing... but oddly it worked fine when ran manually! The error given in these circumstances was always "Timeout". We thought we try a little creative thinking, and run the .vbs another way: Via a .bat file. Again we hit weird issues, but with a little more debugging information, this time around. The .bat file is nothing more than... CScript "C:\location\script.vbs" > Log.txt But the Task Scheduler fails with the following error: 0x1: An incorrect function was called or an unknown function was called. The log.txt file says: CScript Error: Initialization of the Windows Script Host failed. (Not enough storage is available to process this command. ) But get this: The .bat file executes perfectly (vbs script and all) if it's executed with a double click! There's only a problem when it's run by Task Scheduler. What the hell? We're running Windows Server 2008 R2 (x64) and yes, the Task Sheduler's results are the same whether the user is logged in or not. Also, the user that can run the scripts successfully manually, is also the same user that runs the scripts in Task Scheduler. Thanks for any help for this weird problem!

    Read the article

  • WebCenter Spaces 11g PS2 Task Flow Customization

    - by Javier Ductor
    Previously, I wrote about Spaces Template Customization. In order to adapt Spaces to customers prototype, it was necessary to change template and skin, as well as the members task flow. In this entry, I describe how to customize this task flow.Default members portlet:Prototype Members Portlet:First thing to do, I downloaded SpacesTaskflowCustomizationApplication with its guide.This application allows developers to modify task flows in Spaces, such as Announcements, Discussions, Events, Members, etc. Before starting, some configuration is needed in jDeveloper, like changing role to 'Customization Developer' mode, although it is explained in the application guide. It is important to know that the way task flows are modified is through libraries, and they cannot be updated directly in the source code like templates, you must use the Structure panel for this. Steps to customize Members portlet:1. There are two members views: showIconicView and showListView. By default it is set to Iconic view, but in my case I preferred the View list, so I updated in table-of-members-taskflow.xml this default value.2. Change the TableOfMembers-ListView.jspx file. By editing this file, you can control the way this task flow is displayed. So I customized this list view using the structure panel to get the desired look&feel.3. After changes are made, click save all, because every time a library changes an xml file is generated with all modifications listed, and they must be saved.4. Rebuild project and deploy application.5. Open WLST command window and import this customization to MDS repository with the 'import' command.Eventually, this was the result:Other task flows can be customized in a similar way.

    Read the article

  • Who organizes your Matlab code?

    - by KE
    After reading How to organize MATLAB code?, I had a follow up question. If you work in a group of Matlab programmers, who enforces the organization of the shared Matlab code and project matfiles? For example do you have a dedicated Matlab IT person, or does the most senior programmer issue guidelines that everyone must follow, or does everyone agree to follow a system? In my small group, each person has their own 'system'. Matlab code and project matfiles are either piled into a shared drive or tucked away on people's own computers. Hard to recreate work done by another person, or even to locate their code. There were lots of good suggestions on how to get organized. But it seems like someone has to make the trains run on time. Who does it in your group?

    Read the article

  • File Watcher Task

    The task will detect changes to existing files as well as new files, both actions will cause the file to be found when available. A file is available when the task can open it exclusively. This is important for files that take a long time to be written, such as large files, or those that are just written slowly or delivered via a slow network link. It can also be set to look for existing files first (1.2.4.55). The full path of the found file is returned in up to three ways: The ExecValueVariable of the task. This can be set to any String variable. The OutputVariableName when specified. This can be set to any String variable. The FullPath variable within OnFileFoundEvent. This is a File Watcher Task specific event.   Advanced warning of a file having been detected, but not yet available is returned through the OnFileWatcherEvent. This event does not always coincide with the completion of the task, as completion and the OnFileFoundEvent is delayed until the file is ready for use. This event indicates that a file has been detected, and that file will now be monitored until it becomes available. The task will only detect and report on the first file that is created or changes, any subsequent changes will be ignored. Task properties and there usages are documented below: Property Data Type Description Filter String Default filter *.* will watch all files. Standard windows wildcards and patterns can be used to restrict the files monitored. FindExistingFiles Boolean Indicates whether the task should check for any existing files that match the path and filter criteria, before starting the file watcher. IncludeSubdirectories Boolean Indicates whether changes in subdirectories are accepted or ignored. OutputVariableName String The name of the variable into which the full file path found will be written on completion of the task. The variable specified should be of type string. Path String Path to watch for new files or changes to existing files. The path is a directory, not a full filename. For a specific file, enter the file name in the Filter property and the directory in the Path property. PathInputType FileWatcherTask.InputType Three input types are supported for the path: Connection - File connection manager, of type existing folder. Direct Input - Type the path directly into the UI or set on the property as a literal string. Variable – The name of the variable which contains the path. Timeout Integer Time in minutes to wait for a file. If no files are detected within the timeout period the task will fail. The default value of 0 means infinite, and will not expire. TimeoutAsWarning Boolean The default behaviour is to raise an error and fail the task on timeout. This property allows you to suppress the error on timeout, a warning event is raised instead, and the task succeeds. The default value is false.   Installation The task is provided as an MSI file which you can download and run to install it. This simply places the files on disk in the correct locations and also installs the assemblies in the Global Assembly Cache as per Microsoft’s recommendations. You may need to restart the SQL Server Integration Services service, as this caches information about what components are installed, as well as restarting any open instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. For 2005/2008 Only - Finally you will have to add the task to the Visual Studio toolbox manually. Right-click the toolbox, and select Choose Items.... Select the SSIS Control Flow Items tab, and then check the File Watcher Task in the Choose Toolbox Items window. This process has been described in detail in the related FAQ entry for How do I install a task or transform component? We recommend you follow best practice and apply the current Microsoft SQL Server Service pack to your SQL Server servers and workstations. Downloads The File Watcher Task  is available for SQL Server 2005, SQL Server 2008 (includes R2) and SQL Server 2012. Please choose the version to match your SQL Server version, or you can install multiple versions and use them side by side if you have more than one version of SQL Server installed. File Watcher Task for SQL Server 2005 File Watcher Task for SQL Server 2008 File Watcher Task for SQL Server 2012 Version History SQL Server 2012 Version 3.0.0.16 - SQL Server 2012 release. Includes upgrade support for both 2005 and 2008 packages to 2012. (5 Jun 2012) SQL Server 2008 Version 2.0.0.14 - Fixed user interface bug. A migration problem caused the UI type editors to reference an old SQL 2005 assembly. (17 Nov 2008) Version 2.0.0.7 - SQL Server 2008 release. (20 Oct 2008) SQL Server 2005 Version 1.2.6.100 - Fixed UI bug with TimeoutAsWarning property not saving correctly. Improved expression support in UI. File availability detection changed to use read-only lock, allowing reduced permissions to be used. Corrected installed issue which prevented installation on 64-bit machines with SSIS runtime only components. (18 Mar 2007) Version 1.2.5.73 - Added TimeoutAsWarning property. Gives the ability to suppress the error on timeout, a warning event is raised instead, and the task succeeds. (Task Version 3) (27 Sep 2006) Version 1.2.4.61 - Fixed a bug which could cause a loop condition with an unexpected exception such as incorrect file permissions. (20 Sep 2006) Version 1.2.4.55 - Added FindExistingFiles property. When true the task will check for an existing file before the file watcher itself actually starts. (Task Version 2) (8 Sep 2006) Version 1.2.3.39 - SQL Server 2005 RTM Refresh. SP1 Compatibility Testing. Property type validation improved. (12 Jun 2006) Version 1.2.1.0 - SQL Server 2005 IDW 16 Sept CTP. Futher UI enhancements, including expression indicator. Fixed bug caused by execution within loop Subsequent iterations detected the same file as the first iteration. Added IncludeSubdirectories property. Fixed bug when changes made in subdirectories, and folder change was detected, causing task failure. (Task Version 1) (6 Oct 2005) Version 1.2.0.0 - SQL Server 2005 IDW 15 June CTP. Changes made include an enhanced UI, the PathInputType property for greater flexibility with path input, the OutputVariableName property, and the new OnFileFoundEvent event. (7 Sep 2005) Version 1.1.2 - Public Release (16 Nov 2004) Screenshots   Troubleshooting Make sure you have downloaded the version that matches your version of SQL Server. We offer separate downloads for SQL Server 2005 and SQL Server 2008. If you an error when you try and use the task along the lines of The task with the name "File Watcher Task" and the creation name ... is not registered for use on this computer, this usually indicates that the internal cache of SSIS components needs to be updated. This cache is held by the SSIS service, so you need restart the the SQL Server Integration Services service. You can do this from the Services applet in Control Panel or Administrative Tools in Windows. You can also restart the computer if you prefer. You may also need to restart any current instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. The full error message is shown below for reference: TITLE: Microsoft Visual Studio ------------------------------ The task with the name "File Watcher Task" and the creation name "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask, Konesans.Dts.Tasks.FileWatcherTask, Version=1.2.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b" is not registered for use on this computer. Contact Information: File Watcher Task A similar error message can be shown when trying to edit the task if the Microsoft Exception Message Box is not installed. This useful component is installed as part of the SQL Server Management Studio tools but occasionally due to the custom options chosen during SQL Server 2005 setup it may be absent. If you get an error like Could not load file or assembly 'Microsoft.ExceptionMessageBox.. you can manually download and install the missing component. It is available as part of the Feature Pack for SQL Server 2005 release. The feature packs are occasionally updated by Microsoft so you may like to check for a more recent edition, but you can find the Microsoft Exception Message Box download links here - Feature Pack for Microsoft SQL Server 2005 - April 2006 If you encounter this problem on SQL Server 2008, please check that you have installed the SQL Server client components. The component is no longer available as a separate download for SQL Server 2008  as noted in the Microsoft documentation for Deploying an Exception Message Box Application The full error message is shown below for reference, although note that the Version will change between SQL Server 2005 and SQL Server 2008: TITLE: Microsoft Visual Studio ------------------------------ Cannot show the editor for this task. ------------------------------ ADDITIONAL INFORMATION: Could not load file or assembly 'Microsoft.ExceptionMessageBox, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91' or one of its dependencies. The system cannot find the file specified. (Konesans.Dts.Tasks.FileWatcherTask) Once installation is complete you need to manually add the task to the toolbox before you will see it and to be able add it to packages - How do I install a task or transform component? If you are still having issues then contact us, but please provide as much detail as possible about error, as well as which version of the the task you are using and details of the SSIS tools installed. Sample Code If you wanted to use the task programmatically then here is some sample code for creating a basic package and configuring the task. It uses a variable to supply the path to watch, and also sets a variable for the OutputVariableName. Once execution is complete it writes out the file found to the console. /// <summary> /// Create a package with an File Watcher Task /// </summary> public void FileWatcherTaskBasic() { // Create the package Package package = new Package(); package.Name = "FileWatcherTaskBasic"; // Add variable for input path, the folder to look in package.Variables.Add("InputPath", false, "User", @"C:\Temp\"); // Add variable for the file found, to be used on OutputVariableName property package.Variables.Add("FileFound", false, "User", "EMPTY"); // Add the Task package.Executables.Add("Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask, " + "Konesans.Dts.Tasks.FileWatcherTask, Version=1.2.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Set basic properties taskHost.Properties["PathInputType"].SetValue(taskHost, 1); // InputType.Variable taskHost.Properties["Path"].SetValue(taskHost, "User::InputPath"); taskHost.Properties["OutputVariableName"].SetValue(taskHost, "User::FileFound"); #if DEBUG // Save package to disk, DEBUG only new Application().SaveToXml(String.Format(@"C:\Temp\{0}.dtsx", package.Name), package, null); #endif // Display variable value before execution to check EMPTY Console.WriteLine("Result Variable: {0}", package.Variables["User::FileFound"].Value); // Execute package package.Execute(); // Display variable value after execution, e.g. C:\Temp\File.txt Console.WriteLine("Result Variable: {0}", package.Variables["User::FileFound"].Value); // Perform simple check for execution errors if (package.Errors.Count > 0) foreach (DtsError error in package.Errors) { Console.WriteLine("ErrorCode : {0}", error.ErrorCode); Console.WriteLine(" SubComponent : {0}", error.SubComponent); Console.WriteLine(" Description : {0}", error.Description); } else Console.WriteLine("Success - {0}", package.Name); // Clean-up package.Dispose(); } (Updated installation and troubleshooting sections, and added sample code July 2009)

    Read the article

  • How can I cause Task Scheduler to "fail" if a dialog box returns a certain result?

    - by Roger
    I'm working on a VBScript to do a weekly reboot of all machines on our network. I want to run this script via Task Scheduler. The script runs at 3:00 AM, but there is a small chance that users may still be on the network at that time, and I need to give them the option to terminate the reboot. If they do so, I would like the reboot to occur the next night at 3:00 AM. I've set Task Scheduler up to repeat in this way. So far, so good. The problem is that if the user selects "Cancel" in my script, the Task Scheduler does not see my task as failed, and won't run it again the next night. Any ideas? Can I pass an errorcode to task scheduler or otherwise abort the task via VBScript? My code is below: Option Explicit Dim objShell, intShutdown Dim strShutdown, strAbort ' -r = restart, -t 600 = 10 minutes, -f = force programs to close strShutdown = "shutdown.exe -r -t 600 -f" set objShell = CreateObject("WScript.Shell") objShell.Run strShutdown, 0, false 'go to sleep so message box appears on top WScript.Sleep 100 ' Input Box to abort shutdown intShutdown = (MsgBox("Computer will restart in 10 minutes. Do you want to cancel computer restart?",vbYesNo+vbExclamation+vbApplicationModal,"Cancel Restart")) If intShutdown = vbYes Then ' Abort Shutdown strAbort = "shutdown.exe -a" set objShell = CreateObject("WScript.Shell") objShell.Run strAbort, 0, false End if Wscript.Quit Appreciate any thoughts.

    Read the article

  • Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", “readwrite”); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", "readwrite"); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

    Read the article

1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >