Search Results

Search found 14 results on 1 pages for 'kian mayne'.

Page 1/1 | 1 

  • Getting overwhelmed after starting a new project

    - by Kian Mayne
    I started a project (a Windows based timetable program that helps you stay organised with your subjects and assignments). The problem is that I'm not sure how I should manage this project and what order to build things. I.e. Should I build all the different interface elements then write the code or should I make an interface, code it, make another interface then code that? So my question is; how do I split up this longish project into small, ordered pieces to complete; and how should I order this?

    Read the article

  • Using XML as data storage

    - by Kian Mayne
    I was thinking about the XML format and the following quote: “XML is not a database. It was never meant to be a database. It is never going to be a database. Relational databases are proven technology with more than 20 years of implementation experience. They are solid, stable, useful products. They are not going away. XML is a very useful technology for moving data between different databases or between databases and other programs. However, it is not itself a database. Don't use it like one.“ -Effective XML: 50 Specific Ways to Improve Your XML by Elliotte Rusty Harold (page 230, Part 4, Item 41, 2nd paragraph) This seems to really stress that XML should not be used for data storage and should only be used for program to program interoperability. Personally, I disagree and .NET's app.config file that's used to store a program's settings is an example of data storage in an XML file. However for databases rather than configurations etc XML should not be used. To develop my point, I will use two examples: A) Data about customers with fields that are all on one level i.e. there are a number of fields all relating to one customer with no children B) Data about configuration of an application where nested fields and properties make a lot of sense So my question is, Is this still a valid statement and is it now acceptable to store data using XML? EDIT: I've sent an email to the author of that quote to ask for his input/extra context.

    Read the article

  • Disallow all user agents except one using .htaccess?

    - by Kian Mayne
    I've been struggling to get this .htaccess working. The aim is to disallow all user agents besides my app. The app sends a GET request with a user agent of lets say 'AcmeUpdater'. Whenever I try to navigate to any file in the folder, I get a 500 - Internal Server Error. Here are the rules I'm using: <IfModule mod_rewrite.c> Options +FollowSymLinks RewriteEngine on RewriteBase / RewriteCond %{HTTP_USER_AGENT} !^KMUpdaterClient* RewriteRule .* - [F,L] </IfModule> I have updated the .htaccess file as suggested in the answer by Nick, and restarted Apache. After trying a couple of different things, it seems that just the presence of a .htaccess is causing the 500 error. I'm getting nothing in the error logs. The .htaccess file at the document root looks like the following: <IfModule mod_rewrite.c> Options +FollowSymLinks ErrorDocument 404 /index.php?error=404 RewriteEngine On RewriteBase / RewriteRule ^index\.php$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d </IfModule> So I realised that the error logs were in chronological order rather than the reverse chronological I expected (Oops!). The error I'm getting is: </IfModule> without matching <IfModule> section. I removed the </IfModule> and still I get that error. Ideas?

    Read the article

  • C++ strongly typed typedef

    - by Kian
    I've been trying to think of a way of declaring strongly typed typedefs, to catch a certain class of bugs in the compilation stage. It's often the case that I'll typedef an int into several types of ids, or a vector to position or velocity: typedef int EntityID; typedef int ModelID; typedef Vector3 Position; typedef Vector3 Velocity; This can make the intent of code more clear, but after a long night of coding one might make silly mistakes like comparing different kinds of ids, or adding a position to a velocity perhaps. EntityID eID; ModelID mID; if ( eID == mID ) // <- Compiler sees nothing wrong { /*bug*/ } Position p; Velocity v; Position newP = p + v; // bug, meant p + v*s but compiler sees nothing wrong Unfortunately, suggestions I've found for strongly typed typedefs include using boost, which at least for me isn't a possibility (I do have c++11 at least). So after a bit of thinking, I came upon this idea, and wanted to run it by someone. First, you declare the base type as a template. The template parameter isn't used for anything in the definition, however: template < typename T > class IDType { unsigned int m_id; public: IDType( unsigned int const& i_id ): m_id {i_id} {}; friend bool operator==<T>( IDType<T> const& i_lhs, IDType<T> const& i_rhs ); }; Friend functions actually need to be forward declared before the class definition, which requires a forward declaration of the template class. We then define all the members for the base type, just remembering that it's a template class. Finally, when we want to use it, we typedef it as: class EntityT; typedef IDType<EntityT> EntityID; class ModelT; typedef IDType<ModelT> ModelID; The types are now entirely separate. Functions that take an EntityID will throw a compiler error if you try to feed them a ModelID instead, for example. Aside from having to declare the base types as templates, with the issues that entails, it's also fairly compact. I was hoping anyone had comments or critiques about this idea? One issue that came to mind while writing this, in the case of positions and velocities for example, would be that I can't convert between types as freely as before. Where before multiplying a vector by a scalar would give another vector, so I could do: typedef float Time; typedef Vector3 Position; typedef Vector3 Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; With my strongly typed typedef I'd have to tell the compiler that multypling a Velocity by a Time results in a Position. class TimeT; typedef Float<TimeT> Time; class PositionT; typedef Vector3<PositionT> Position; class VelocityT; typedef Vector3<VelocityT> Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; // Compiler error To solve this, I think I'd have to specialize every conversion explicitly, which can be kind of a bother. On the other hand, this limitation can help prevent other kinds of errors (say, multiplying a Velocity by a Distance, perhaps, which wouldn't make sense in this domain). So I'm torn, and wondering if people have any opinions on my original issue, or my approach to solving it.

    Read the article

  • SSH: Port Forwarding, Firewalls, & Plesk

    - by Kian Mayne
    I edited my SSH configuration to accept connections on Port 213, as it was one of the few ports that my work firewall allows through. I then restarted sshd and everything was going well. I tested the ssh server locally, and checked the sshd service was listening on port 213; however, I still cannot get it to work outside of localhost. PuTTY gives a connection refused message, and some of the sites that allow check of ports I tried said the port was closed. To me, this is either firewall or port forwarding. But I've already added inbound and outbound exceptions for it. Is this a problem with my server host, or is there something I've missed? My full SSH config file, as requested: # $OpenBSD: sshd_config,v 1.73 2005/12/06 22:38:28 reyk Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options change a # default value. Port 22 Port 213 #Protocol 2,1 Protocol 2 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: # HostKey for protocol version 1 #HostKey /etc/ssh/ssh_host_key # HostKeys for protocol version 2 #HostKey /etc/ssh/ssh_host_rsa_key #HostKey /etc/ssh/ssh_host_dsa_key # Lifetime and size of ephemeral version 1 server key #KeyRegenerationInterval 1h #ServerKeyBits 768 # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH SyslogFacility AUTHPRIV #LogLevel INFO # Authentication: #LoginGraceTime 2m #PermitRootLogin yes #StrictModes yes #MaxAuthTries 6 #RSAAuthentication yes #PubkeyAuthentication yes #AuthorizedKeysFile .ssh/authorized_keys # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts #RhostsRSAAuthentication no # similar for protocol version 2 #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # RhostsRSAAuthentication and HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # To disable tunneled clear text passwords, change to no here! #PasswordAuthentication yes #PermitEmptyPasswords no PasswordAuthentication yes # Change to no to disable s/key passwords #ChallengeResponseAuthentication yes ChallengeResponseAuthentication no # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no # GSSAPI options #GSSAPIAuthentication no GSSAPIAuthentication yes #GSSAPICleanupCredentials yes GSSAPICleanupCredentials yes # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication mechanism. # Depending on your PAM configuration, this may bypass the setting of # PasswordAuthentication, PermitEmptyPasswords, and # "PermitRootLogin without-password". If you just want the PAM account and # session checks to run without PAM authentication, then enable this but set # ChallengeResponseAuthentication=no #UsePAM no UsePAM yes # Accept locale-related environment variables AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL #AllowTcpForwarding yes #GatewayPorts no #X11Forwarding no X11Forwarding yes #X11DisplayOffset 10 #X11UseLocalhost yes #PrintMotd yes #PrintLastLog yes #TCPKeepAlive yes #UseLogin no #UsePrivilegeSeparation yes #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #ShowPatchLevel no #UseDNS yes #PidFile /var/run/sshd.pid #MaxStartups 10 #PermitTunnel no #ChrootDirectory none # no default banner path #Banner /some/path # override default of no subsystems Subsystem sftp /usr/libexec/openssh/sftp-server

    Read the article

  • How do I calculate the amount of tuning needed for my server ?

    - by Low Kian Seong
    I have a server which is running a few discrete Python, Java application which most of the time imports data into a PostGreSQL database. I would like to know from people out there who have experience tuning enterprise grade servers how do i go about calculating in a holistic way the amount of tuning needed for my server for example vm.swappiness, vm.overcommit_ratio and other numerical tunings needed for my server. I tried to enable sar on my server to capture daily numbers but these are more along the lines of total numbers and I can't figure out how to allocate memory for my applications. Help would be appreciated. Thanks.

    Read the article

  • How can I see logs in a server after a kernel panic hang ?

    - by Low Kian Seong
    I am running a production gentoo Linux machine, and recently there was a situation where the server hung in my co-located premises and when I got there I noticed that the server was hung on what appeared to be a kernel panic hang. I rebooted the machine with a hard reboot and was disappointed to find out that I could not find a shred of evidence anywhere on why the machine hung. Is it true that when I do a hard reboot the messages itself will get lost or is there a setting I can do somewhere say in syslog-ng or maybe in sysctl to at least preserve the error log so that I can prevent such mishaps from happening in the future ? I am running a 2.6.x kernel by the way. Thanks in advance.

    Read the article

  • How can I see logs in a server after a kernel panic hang?

    - by Low Kian Seong
    I am running a production gentoo Linux machine, and recently there was a situation where the server hung in my co-located premises and when I got there I noticed that the server was hung on what appeared to be a kernel panic hang. I rebooted the machine with a hard reboot and was disappointed to find out that I could not find a shred of evidence anywhere on why the machine hung. Is it true that when I do a hard reboot the messages itself will get lost or is there a setting I can do somewhere say in syslog-ng or maybe in sysctl to at least preserve the error log so that I can prevent such mishaps from happening in the future ? I am running a 2.6.x kernel by the way. Thanks in advance.

    Read the article

  • What is the best log rotator for Python wsgi applications ?

    - by Low Kian Seong
    I am running a wsgi based application that has concurrent users accessing it. For my logs needs I tried logrotate but found that logrotate is not too friendly to Python applications, so I tried using RotatingFileHandler and even worse found my logs all chopped up and part of it went missing! I am considering ConcurrentRotatingFileHandler, my question is, has anyone out there experienced the same thing and better yet do you have any battle tested solution for Python wsgi, concurrently accessed applications?

    Read the article

  • What is the best way to handle the multitude of different logs created all around the place?

    - by Low Kian Seong
    I run a few applications which creates their own logs. Then I run cron scripts on the same server to do importing of data for my app. When these cron errors out, the default is it sends emails to the user that runs the cron job. There are just too many places that I need to check the logs and mails for stuff that might have potentially went wrong. My question is, what is the best way to do this or even better is like a log parser application which will go through all the system logs when something really goes wrong instead of me having to go through it daily?

    Read the article

  • Duplicate an AppEngine Query object to create variations of a filter without affecting the base quer

    - by Steve Mayne
    In my AppEngine project I have a need to use a certain filter as a base then apply various different extra filters to the end, retrieving the different result sets separately. e.g.: base_query = MyModel.all().filter('mainfilter', 123) Then I need to use the results of various sub queries separately: subquery1 = basequery.filter('subfilter1', 'xyz') #Do something with subquery1 results here subquery2 = basequery.filter('subfilter2', 'abc') #Do something with subquery2 results here Unfortunately 'filter()' affects the state of the basequery Query instance, rather than just returning a modified version. Is there any way to duplicate the Query object and use it as a base? Is there perhaps a standard Python way of duping an object that could be used? The extra filters are actually applied by the results of different forms dynamically within a wizard, and they use the 'running total' of the query in their branch to assess whether to ask further questions. Obviously I could pass around a rudimentary stack of filter criteria, but I'd rather use the Query itself if possible, as it adds simplicity and elegance to the solution.

    Read the article

  • How to set timeout for exclusive lock in PostgreSQL

    - by Low Kian Seong
    I have an import script that was failing because of the 'Exclusive nowait' option I set my script. This caused the script to error out the first time it could not get the exclusive lock on the table. My script did it this way: "LOCK TABLE %s IN EXCLUSIVE MODE NOWAIT" Now my script works it's just that I want to be able to set the timeout for PostgreSQL instead of having it wait for the maximum time which is 15mins. I prefer to set it in posgresql.conf. Is there a way to do this?

    Read the article

  • Migrating a blog from Orchard 0.5 to 0.9

    - by Bertrand Le Roy
    My personal blog still runs on Orchard 0.5, because the theme that I used to build it is not yet available for more recent versions, but it is still very important for me to know that I can migrate all my content and comments to a new version at any time. Fortunately, Nick Mayne has been consistently shipping a BlogML module a few days after each of the Orchard versions shipped. Because the module gallery for each version is behind a different URL and is kept alive even after a new one shipped, it is very easy to install the module for both versions. Step 0: Setting up the migration environment In order to do the migration, I made a local copy of the production site on my laptop (data included: I'm using SQL CE) and I also created a new local site with a fresh install of Orchard 0.9. Step 1: Enable the gallery feature on both versions From the admin UI, go to Features and locate the Gallery feature under "Packaging". Enable it. You may now click on "Browse Gallery" on the 0.5 instance and "Modules" under "Gallery" for 0.9: Step 2: Install the BlogML module on both versions From the gallery page, locate the BlogML module and install it. Do it on both versions. Then go to Features and enable BlogML under "Content Publishing". Do it on both versions. Step 3: Export from the 0.5 version Click on "Manage Blog" then on "Export using BlogML" from the 0.5 version. The module then informs you of the path of the saved file: Step 4: Import into the 0.9 version From the 0.9 version, click "Import under "Blogs". Click the button to browse to the file that you just saved from 0.5. Then click "Upload file and Import" Step 5: Copy the 0.5 media folder into 0.9 Copy the contents of the 0.5 version's media folder into the media folder of the 0.9 version. Once that is done, you can delete the "Default/Blog Exports" subfolder. Step 6: Configure the target blog Click "Manage Blog", then "Blog Properties" and restore any properties you had on the source blog. For me, it was the title and URL as well as to set the blog as the home page and show it on the main menu: Step 7: Republish the new site to the production server Once this is done and everything works locally, you are ready to publish to the production site. I use FTP. Note: this should work just as well for any couple of versions for which the BlogML module exists, and not just for 0.5 and 0.9.

    Read the article

  • creating objects in list

    - by prince23
    List myList = new List { new Users{ Name="Kumar", Gender="M", Age=75, Parent="All"}, new Users{ Name="Suresh",Gender="M", Age=50, Parent="Kumar"}, new Users{ Name="Bennette", Gender="F",Age=45, Parent="Kumar"}, new Users{ Name="kian", Gender="M",Age=20, Parent="Suresh"}, new Users{ Name="Nathani", Gender="M",Age=15, Parent="Suresh"}, new Users{ Name="Peter", Gender="M",Age=90, Parent="All"}, new Users{ Name="Mica", Age=56, Gender="M",Parent="Peter"}, new Users{ Name="Linderman", Gender="M",Age=51, Parent="Peter"}, new Users{ Name="john", Age=25, Gender="M",Parent="Mica"}, new Users{ Name="tom", Gender="M",Age=21, Parent="Mica"}, new Users{ Name="Ando", Age=64, Gender="M",Parent="All"}, new Users{ Name="Maya", Age=24, Gender="M",Parent="Ando"}, new Users{ Name="Niki Sanders", Gender="F",Age=2, Parent="Maya"}, new Users{ Name="Angela Patrelli", Gender="F",Age=3, Parent="Maya"}, }; now i need to format the data like here i need to check the parent based on the parent i will be creating objects under the parent objects now { Name="Kumar", Gender="M", Age=75, Parent="All" } this is the top level as a property Parent ="all" now under parent object kumar here we again create a new object to store these information under object(kumar who is the parent) new Users{ Name="Suresh",Gender="M", Age=50, Parent="Kumar"}, new Users{ Name="Bennette", Gender="F",Age=45, Parent="Kumar"}, what i need to do here is i need to check the parent based on the parent create further objects under it ex: i need to achive like this. looking for the syntax how i can do it. public class SampleProjectData { public static ObservableCollection<Product> GetSampleData() { DateTime dtS = DateTime.Now; ObservableCollection<Product> teams = new ObservableCollection<Product>(); teams.Add(new Product() { PDName = "Product1", OverallStartTime = dtS, OverallEndTime = dtS + TimeSpan.FromDays(3), }); Project emp = new Project() { PName = "Project1", OverallStartTime = dtS + TimeSpan.FromDays(1), OverallEndTime = dtS + TimeSpan.FromDays(6) }; emp.Tasks.Add(new Task() { StartTime = dtS, EndTime = dtS + TimeSpan.FromDays(2), TaskName = "John's Task 3" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(3), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "John's Task 2" }); teams[0].Projects.Add(emp); emp = new Project() { PName = "Project2", OverallStartTime = dtS + TimeSpan.FromDays(1.5), OverallEndTime = dtS + TimeSpan.FromDays(5.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Victor's Task" }); teams[0].Projects.Add(emp); emp = new Project() { PName = "Project3", OverallStartTime = dtS + TimeSpan.FromDays(2), OverallEndTime = dtS + TimeSpan.FromDays(5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Jason's Task 1" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(7), EndTime = dtS + TimeSpan.FromDays(9), TaskName = "Jason's Task 2" }); teams[0].Projects.Add(emp); teams.Add(new Product() { PDName = "Product2", OverallStartTime = dtS, OverallEndTime = dtS + TimeSpan.FromDays(3) }); emp = new Project() { PName = "Project4", OverallStartTime = dtS + TimeSpan.FromDays(0.5), OverallEndTime = dtS + TimeSpan.FromDays(3.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1.5), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Vicky's Task" }); teams[1].Projects.Add(emp); emp = new Project() { PName = "Project5", OverallStartTime = dtS + TimeSpan.FromDays(2), OverallEndTime = dtS + TimeSpan.FromDays(6) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(2.2), EndTime = dtS + TimeSpan.FromDays(3.8), TaskName = "Oleg's Task 1" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(5), EndTime = dtS + TimeSpan.FromDays(6), TaskName = "Oleg's Task 2" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(8), EndTime = dtS + TimeSpan.FromDays(9.6), TaskName = "Oleg's Task 3" }); teams[1].Projects.Add(emp); emp = new Project() { PName = "Project6", OverallStartTime = dtS + TimeSpan.FromDays(2.5), OverallEndTime = dtS + TimeSpan.FromDays(4.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(0.8), EndTime = dtS + TimeSpan.FromDays(2), TaskName = "Kim's Task" }); teams[1].Projects.Add(emp); teams.Add(new Product() { PDName = "Product3", OverallStartTime = dtS, OverallEndTime = dtS + TimeSpan.FromDays(3) }); emp = new Project() { PName = "Project7", OverallStartTime = dtS + TimeSpan.FromDays(5), OverallEndTime = dtS + TimeSpan.FromDays(7.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1.5), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Balaji's Task 1" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(5), EndTime = dtS + TimeSpan.FromDays(8), TaskName = "Balaji's Task 2" }); teams[2].Projects.Add(emp); emp = new Project() { PName = "Project8", OverallStartTime = dtS + TimeSpan.FromDays(3), OverallEndTime = dtS + TimeSpan.FromDays(6.3) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1.75), EndTime = dtS + TimeSpan.FromDays(2.25), TaskName = "Li's Task" }); teams[2].Projects.Add(emp); emp = new Project() { PName = "Project9", OverallStartTime = dtS + TimeSpan.FromDays(2), OverallEndTime = dtS + TimeSpan.FromDays(6) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(2), EndTime = dtS + TimeSpan.FromDays(3), TaskName = "Stacy's Task" }); teams[2].Projects.Add(emp); return teams; } } above is an sample data where i am grouping them with static data in the same way i need **to for teh data which is cmg from DB and i need to store them list** all these three data are comig from different services. and i am storing them in a list now i have three tables data Product , Project, Task. all the data are coming from webservies. i have created three list where i am storing the data in list. List<Project>objpro= new List<Project>(); List<Product>objproduct= new List<Product>(); LIst<Task>objTask= new List<Task>(); **now what i need to do is i need to do the mapping between these tables. if you see above. i have object of Product under Product i have added object of Project and then under project object i have added task object.** now from the above data which is stored in the list i need to do the same mapping between class. and group the data. public class Product : INotifyPropertyChanged { public Product() { this.Projects = new ObservableCollection<Project>(); } public string PDName { get; set; } public ObservableCollection<Project> Projects { get; set; } private DateTime _st; public DateTime OverallStartTime { get { return _st; } set { if (this._st != value) { TimeSpan dur = this._et - this._st; this._st = value; this.OnPropertyChanged("OverallStartTime"); this.OverallEndTime = value + dur; } } } private DateTime _et; public DateTime OverallEndTime { get { return _et; } set { if (this._et != value) { this._et = value; this.OnPropertyChanged("OverallEndTime"); } } } #region INotifyPropertyChanged Members protected void OnPropertyChanged(string name) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(name)); } public event PropertyChangedEventHandler PropertyChanged; #endregion } public class Project : INotifyPropertyChanged { public Project() { this.Tasks = new ObservableCollection<Task>(); } public string PName { get; set; } public ObservableCollection<Task> Tasks { get; set; } DateTime _st; public DateTime OverallStartTime { get { return _st; } set { if (this._st != value) { TimeSpan dur = this._et - this._st; this._st = value; this.OnPropertyChanged("OverallStartTime"); this.OverallEndTime = value + dur; } } } DateTime _et; public DateTime OverallEndTime { get { return _et; } set { if (this._et != value) { this._et = value; this.OnPropertyChanged("OverallEndTime"); } } } #region INotifyPropertyChanged Members protected void OnPropertyChanged(string name) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(name)); } public event PropertyChangedEventHandler PropertyChanged; #endregion } public class Task : INotifyPropertyChanged { public string TaskName { get; set; } DateTime _st; public DateTime StartTime { get { return _st; } set { if (this._st != value) { TimeSpan dur = this._et - this._st; this._st = value; this.OnPropertyChanged("StartTime"); this.EndTime = value + dur; } } } private DateTime _et; public DateTime EndTime { get { return _et; } set { if (this._et != value) { this._et = value; this.OnPropertyChanged("EndTime"); } } } #region INotifyPropertyChanged Members protected void OnPropertyChanged(string name) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(name)); } public event PropertyChangedEventHandler PropertyChanged; #endregion } hope my question is clear

    Read the article

1