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• In ADUC MMC, Advanced View, how to get Attribute Editor tab on the result of a Find?

  - by geoffc

  In Win2008 MS added a new Tab on objects in ADUC. Called Attribute Editor it is like Novell Console One's Other tab, or an arbitrary LDAP editor view, or an ADSI Edit style view. Basically it shows all allowed attributes for the object class, and allows you to edit according to your permissions. You need to enable Advanced Options in the View menu before it shows up. This is great, however it only shows up when you browse the directory tree and select an object. If you use the Find tool and open an object Attribute Editor is not shown. How annoying! Especially if your domain has more than 2000 users in a single container, then you almost must use Find to get to an object. Is there any way to make the Attribute Editor tab show up after using Find to open an object?

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• Part 8: How to name EBS Customizations

  - by volker.eckardt(at)oracle.com

  You might wonder why I am discussing this here. The reason is simple: nearly every project has a bit different naming conventions, which makes a the life always a bit complicated (for developers, but also setup responsible, and also for consultants).  Although we always create a document to describe the technical object naming conventions, I have rarely seen a dedicated document  with functional naming conventions. To be precisely, from my stand point, there should always be one global naming definition for an implementation! Let me discuss some related questions: What is the best convention for the customization reference? How to name database objects (tables, packages etc.)? How to name functional objects like Value Sets, Concurrent Programs, etc. How to separate customizations from standard objects best? What is the best convention for the customization reference? The customization reference is the key you use to reference your customization from other lists, from the project plan etc. Usually it is something like XXHU_CONV_22 (HU=customer abbreviation, CONV=Conversion object #22) or XXFA_DEPRN_RPT_02 (FA=Fixed Assets, DEPRN=Short object group, here depreciation, RPT=Report, 02=2nd report in this area) As this is just a reference (not an object name yet), I would prefer the second option. XX=Customization, FA=Main EBS Module linked (you may have sometimes more, but FA is the main) DEPRN_RPT=Short name to specify the customization 02=a unique number Important here is that the HU isn’t used, because XX is enough to mark a custom object, and the 3rd+4th char can be used by the EBS module short name. How to name database objects (tables, packages etc.)? I was leading different developer teams, and I know that one common way is it to take the Customization reference and add more chars behind to classify the object (like _V for view and _T1 for triggers etc.). The only concern I have with this approach is the reusability. If you name your view XXFA_DEPRN_RPT_02_V, no one will by choice reuse this nice view, as it seams to be specific for this CEMLI. My suggestion is rather to name the view XXFA_DEPRN_PERIODS_V and allow herewith reusability for other CEMLIs (although the view will be deployed primarily with CEMLI package XXFA_DEPRN_RPT_02). (check also one of the following Blogs where I will talk about deployment.) How to name Value Sets, Concurrent Programs, etc. For Value Sets I would go with the same convention as for database objects, starting with XX<Module> …. For Concurrent Programs the situation is a bit different. This “object” is seen and used by a lot of users, and they will search for. In many projects it is common to start again with the company short name, or with XX. My proposal would differ. If you have created your own report and you name it “XX: Invoice Report”, the user has to remember that this report does not start with “I”, it starts with X. Would you like typing an X if you are looking for an Invoice report? No, you wouldn’t! So my advise would be to name it:   “Invoice Report (XXAP)”. Still we know it is custom (because of the XXAP), but the end user will type the key “i” to get it (and will see similar reports starting also with “i”). I hope that the general schema behind has now become obvious. How to separate customizations from standard objects best? I would not have this section here if the naming would not play an important role. Unfortunately, we can not always link a custom application to our own object, therefore the naming is really important. In the file system structure we use our $XXyy_TOP, in JAVA_TOP it is perhaps also “xx” in front. But in the database itself? Although there are different concepts in place, still many implementations are using the standard “apps” approach, means custom objects are stored in the apps schema (which should not cause any trouble). Final advise: review the naming conventions regularly, once a month. You may have to add more! And, publish them! To summarize: Technical and functional customized objects should always follow a naming convention. This naming convention should be project wide, and only one place shall be used to maintain (like in a Wiki). If the name is for the end user, rather put a customization identifier at the end; if it is an internal name, start with XX…

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• What level of detail to use in an interface members descriptions?

  - by famousgarkin

  I am extracting interfaces from some classes in .NET, and I am not completely sure about what level of detail of description to use for some of the interface members (properties, methods). An example: interface ISomeInterface { /// <summary> /// Checks if the object is checked out. /// </summary> /// <returns> /// Returns true if the object is checked out, or if the object locking is not enabled, /// otherwise returns false. /// </returns> bool IsObjectCheckedOut(); } class SomeImplementation : ISomeInterface { public bool IsObjectCheckedOut() { // An implementation of the method that returns true if the object is checked out, // or if the object locking is not enabled } } The part in question is the <returns>...</returns> section of the IsObjectCheckedOut description in the interface. Is it ok to include such a detail about return value in the interface itself, as the code that will work with the interface should know exactly what that method will do? All the current implementations of the method will do just that. But is it ok to limit the possible other/future implementations by description this way? Or should this not be included in the interface description, as there is no way to actually ensure that other/future implementations will do exactly this? Is it better to be as general as possible regarding the interface in such circumstances? I am currently inclined to the latter option.

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• Should actors in a game be responsible for drawing themselves?

  - by alex

  I am very new to game development, but not to programming. I am (again) playing around with a Pong type game using JavaScript's canvas element. I have created a Paddle object which has the following properties... width height x y colour I also have a Pong object which has properties such as... width height backgroundColour draw(). The draw() method currently is resetting the canvas and that is where a question came up. Should the Paddle object have a draw() method responsible for its drawing, or should the draw() of the Pong object be responsible for drawing its actors (I assume that is the correct term, please correct me if I'm incorrect). I figured that it would be advantagous for the Paddle to draw itself, as I instantiate two objects, Player and Enemy. If it were not in the Pong's draw(), I'd need to write similar code twice. What is the best practice here? Thanks.

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• Oracle as a Service in the Cloud

  - by Jason Williamson

  This should really be a Tweet, but I guess I'm writing a bit more. In theme of data migration and legacy modernization, I am seeing more and more of a push to consolidate data sources, especially from non-oracle to oracle in an effort to save dollars. From a modernization perspective, this fits in quite well. We are able to migrate things like Terradata, Sybase and DB2 and put that all into an Oracle database and then provide that as a OaaS (Oracle as a Service) Cloud offering. This seems to be a growing trend, and not unlike the cool RDS Amazon Database cloud being built on Oracle as well. We again find ourselves back in the similar theme of migration, however. The target technology sounds like a winner (COBOL to Java/SOA...DB2/Datacom/Adabas to Oracle) but the age-old problem of how to get there still persists. It it not trivial to migrate large amounts of pre-relational or "devolved" relational data. To do this, we again must revert back to a tight roadmap to migration and leverage the growing tools and services that we have. I'm working on a couple of new sections and chapters for a book that Tom and Prakash and I are writing around Database Migration and Consolidation. I'll share some snipits shortly.

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• When should one use "out" parameters?

  - by qegal

  In Objective-C, there are several methods like initWithContentsOfFile:encoding:error: where one passes in a reference to an NSError object for the error: parameter. In this example, the value of the NSError object passed in can change based on what goes on at runtime when the method is being called and whether the body of the method was executed in a certain way successfully. In a way I think of this NSError object as sort of like a second return value from the method, and only differs from an object anObject in the statement return anObject; in that when this statement is called, execution leaves the method. So my question is, not only in the context of error handling in Objective-C, but in general, when should one use an "out" parameter in place of returning said value in a return statement?

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• Modelling Attributes using Value Objects

  Look beyond fundamental data types when modelling object attributes

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• Best practice for organizing/storing character/monster data in an RPG?

  - by eclecto

  Synopsis: Attempting to build a cross-platform RPG app in Adobe Flash Builder and am trying to figure out the best class hierarchy and the best way to store the static data used to build each of the individual "hero" and "monster" types. My programming experience, particularly in AS3, is embarrassingly small. My ultra-alpha method is to include a "_class" object in the constructor for each instance. The _class, in turn, is a static Object pulled from a class created specifically for that purpose, so things look something like this: // Character.as package { public class Character extends Sprite { public var _strength:int; // etc. public function Character(_class:Object) { _strength = _class._strength; // etc. } } } // MonsterClasses.as package { public final class MonsterClasses extends Object { public static const Monster1:Object={ _strength:50, // etc. } // etc. } } // Some other class in which characters/monsters are created. // Create a new instance of Character var myMonster = new Character(MonsterClasses.Monster1); Another option I've toyed with is the idea of making each character class/monster type its own subclass of Character, but I'm not sure if it would be efficient or even make sense considering that these classes would only be used to store variables and would add no new methods. On the other hand, it would make creating instances as simple as var myMonster = new Monster1; and potentially cut down on the overhead of having to read a class containing the data for, at a conservative preliminary estimate, over 150 monsters just to fish out the one monster I want (assuming, and I really have no idea, that such a thing might cause any kind of slowdown in execution). But long story short, I want a system that's both efficient at compile time and easy to work with during coding. Should I stick with what I've got or try a different method? As a subquestion, I'm also assuming here that the best way to store data that will be bundled with the final game and not read externally is simply to declare everything in AS3. Seems to me that if I used, say, XML or JSON I'd have to use the associated AS3 classes and methods to pull in the data, parse it, and convert it to AS3 object(s) anyway, so it would be inefficient. Right?

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• How to load Image in C# and set properties of the Picture Box

  - by SAMIR BHOGAYTA

  Create a C# application drag a picture Box, four buttons and open file dialog on the form. Write code on btn_browse Button click ----------------------------------------- private void btn_browse_Click(object sender, System.EventArgs e) { try { OpenFileDialog open = new OpenFileDialog(); open.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp"; if (open.ShowDialog()==DialogResult.OK) { pictureBox1.Image = new Bitmap(open.FileName); } } catch (Exception) { throw new ApplicationException("Failed loading image"); } } Write code on btn_StretchImage Button click ------------------------------------------------ private void btn_StretchImage_Click(object sender, System.EventArgs e) { pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage; } Write code on btn_AutoSize Button click ------------------------------------------------- private void btn_AutoSize_Click(object sender, System.EventArgs e) { pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.AutoSize; } Write code on btn_CenterImage Button click -------------------------------------------------- private void btn_CenterImage_Click(object sender, System.EventArgs e) { pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.CenterImage; }

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• Strategies for managing use of types in Python

  - by dave

  I'm a long time programmer in C# but have been coding in Python for the past year. One of the big hurdles for me was the lack of type definitions for variables and parameters. Whereas I totally get the idea of duck typing, I do find it frustrating that I can't tell the type of a variable just by looking at it. This is an issue when you look at someone else's code where they've used ambiguous names for method parameters (see edit below). In a few cases, I've added asserts to ensure parameters comply with an expected type but this goes against the whole duck typing thing. On some methods, I'll document the expected type of parameters (eg: list of user objects), but even this seems to go against the idea of just using an object and let the runtime deal with exceptions. What strategies do you use to avoid typing problems in Python? Edit: Example of the parameter naming issues: If our code base we have a task object (ORM object) and a task_obj object (higher level object that embeds a task). Needless to say, many methods accept a parameter named 'task'. The method might expect a task or a task_obj or some other construct such as a dictionary of task properties - it is not clear. It is them up to be to look at how that parameter is used in order to work out what the method expects.

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• Translate along local axis

  - by Aaron

  I have an object with a position matrix and a rotation matrix (derived from a quaternion, but I digress). I'm able to translate this object along world-relative vectors, but I'm trying to figure out how to translate it along local-relative vectors. So if the object is tilted 45 degrees around its Z-axis the vector (1, 0, 0) would make it move to the upper right. For world-space translations I simply turn the movement vector into a matrix and multiply it by the position matrix: position_mat = translation_mat * position_mat. For local-space translations I'd think I'd have to use the rotation matrix into that formula, but I see the object spin around instead when I apply a translation over time no matter where I multiply the rotation matrix.

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• concurrency::extent<N> from amp.h

  - by Daniel Moth

  Overview We saw in a previous post how index<N> represents a point in N-dimensional space and in this post we'll see how to define the N-dimensional space itself. With C++ AMP, an N-dimensional space can be specified with the template class extent<N> where you define the size of each dimension. From a look and feel perspective, you'd expect the programmatic interface of a point type and size type to be similar (even though the concepts are different). Indeed, exactly like index<N>, extent<N> is essentially a coordinate vector of N integers ordered from most- to least- significant, BUT each integer represents the size for that dimension (and hence cannot be negative). So, if you read the description of index, you won't be surprised with the below description of extent<N> There is the rank field returning the value of N you passed as the template parameter. You can construct one extent from another (via the copy constructor or the assignment operator), you can construct it by passing an integer array, or via convenience constructor overloads for 1- 2- and 3- dimension extents. Note that the parameterless constructor creates an extent of the specified rank with all bounds initialized to 0. You can access the components of the extent through the subscript operator (passing it an integer). You can perform some arithmetic operations between extent objects through operator overloading, i.e. ==, !=, +=, -=, +, -. There are operator overloads so that you can perform operations between an extent and an integer: -- (pre- and post- decrement), ++ (pre- and post- increment), %=, *=, /=, +=, –= and, finally, there are additional overloads for plus and minus (+,-) between extent<N> and index<N> objects, returning a new extent object as the result. In addition to the usual suspects, extent offers a contains function that tests if an index is within the bounds of the extent (assuming an origin of zero). It also has a size function that returns the total linear size of this extent<N> in units of elements. Example code extent<2> e(3, 4); _ASSERT(e.rank == 2); _ASSERT(e.size() == 3 * 4); e += 3; e[1] += 6; e = e + index<2>(3,-4); _ASSERT(e == extent<2>(9, 9)); _ASSERT( e.contains(index<2>(8, 8))); _ASSERT(!e.contains(index<2>(8, 9))); grid<N> Our upcoming pre-release bits also have a similar type to extent, grid<N>. The way you create a grid is by passing it an extent, e.g. extent<3> e(4,2,6); grid<3> g(e); I am not going to dive deeper into grid, suffice for now to think of grid<N> simply as an alias for the extent<N> object, that you create when you encounter a function that expects a grid object instead of an extent object. Usage The extent class on its own simply defines the size of the N-dimensional space. We'll see in future posts that when you create containers (arrays) and wrappers (array_views) for your data, it is an extent<N> object that you'll need to use to create those (and use an index<N> object to index into them). We'll also see that it is a grid<N> object that you pass to the new parallel_for_each function that I'll cover in the next post. Comments about this post by Daniel Moth welcome at the original blog.

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• Enabling and Disabling components in Unity

  - by Blue

  I'm trying to create an enable/ disable game objects in Unity. I used GameObject.SetActiveRecursively but it only works one-way. I used a collider in which when an object enters the collider. The game objects become enabled. When they leave or get to a certain point, they disable. How would I make this a two way system, making it able to be enabled while inside the collider and disabled when outside the collider? -- The collider is in the game object who is being disabled and enabled. According to this information from Unity Answers, the object becomes disabled. So how would I make the object enabled?

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• DataObjectBase

  DataObjectBase - the new Object class for data objects!

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• Use a SQL Database for a Desktop Game

  - by sharethis

  Developing a Game Engine I am planning a computer game and its engine. There will be a 3 dimensional world with first person view and it will be single player for now. The programming language is C++ and it uses OpenGL. Data Centered Design Decision My design decision is to use a data centered architecture where there is a global event manager and a global data manager. There are many components like physics, input, sound, renderer, ai, ... Each component can trigger and listen to events. Moreover, each component can read, edit, create and remove data. The question is about the data manager. Whether to Use a Relational Database Should I use a SQL Database, e.g. SQLite or MySQL, to store the game data? This contains virtually all game content like items, characters, inventories, ... Except of meshes and textures which are even more performance related, so I will keep them in memory. Is a SQL database fast enough to use it for realtime reading and writing game informations, like the position of a moving character? I also need to care about cross-platform compatibility. Aside from keeping everything in memory, what alternatives do I have? Advantages Would Be The advantages of using a relational database like MySQL would be the data orientated structure which allows fast computation. I would not need objects for representing entities. I could easily query data of objects near the player needed for rendering. And I don't have to take care about data of objects far away. Moreover there would be no need for savegames since the hole game state is saved in the database. Last but not least, expanding the game to an online game would be relative easy because there already is a place where the hole game state is stored.

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• Searching for context in Silverlight applications

  - by PeterTweed

  A common behavior in business applications that have developed through the ages is for a user to be able to get information or execute commands in relation to some information/function displayed by right clicking the object in question and popping up a context menu that offers relevant options to choose. The Silverlight Toolkit April 2010 release introduced the context menu object.  This can be added to other UI objects and display options for the user to choose.  The menu items can be enabled or disabled as per your application logic and icons can be added to the menu items to add visual effect.  This post will walk you through how to use the context menu object from the Silverlight Toolkit. Steps: 1. Create a new Silverlight 4 application 2. Copy the following namespace definition to the user control object of the MainPage.xaml file: xmlns:my="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Input.Toolkit"   3. Copy the following XAML into the LayoutRoot grid in MainPage.xaml:          <Border CornerRadius="15" Background="Blue" Width="400" Height="100">             <TextBlock Foreground="White" FontSize="20" Text="Context Menu In This Border...." HorizontalAlignment="Center" VerticalAlignment="Center" >             </TextBlock>             <my:ContextMenuService.ContextMenu>                 <my:ContextMenu >                     <my:MenuItem                 Header="Copy"                 Click="CopyMenuItem_Click" Name="copyMenuItem">                         <my:MenuItem.Icon>                             <Image Source="copy-icon-small.png"/>                         </my:MenuItem.Icon>                     </my:MenuItem>                     <my:Separator/>                     <my:MenuItem Name="pasteMenuItem"                 Header="Paste"                 Click="PasteMenuItem_Click">                         <my:MenuItem.Icon>                             <Image Source="paste-icon-small.png"/>                         </my:MenuItem.Icon>                     </my:MenuItem>                 </my:ContextMenu>             </my:ContextMenuService.ContextMenu>         </Border>   The above code associates a context menu with two menu items and a separator between them to the border object.  The menu items has icons associated with them to add visual appeal.  The menu items have click event handlers that will be added in the MainPage.xaml.cs code behind in a later step. 4. Add two icon sized images to the ClientBin directory of the web project hosting the Silverlight application, named copy-icon-small.png and paste-icon-small.jpg respectively.  I used copy and paste icons as the names suggest. 5. Add the following code to the class in MainPage.xaml.cs file:         private void CopyMenuItem_Click(object sender, RoutedEventArgs e)         {             MessageBox.Show("Copy selected");         }           private void PasteMenuItem_Click(object sender, RoutedEventArgs e)         {             MessageBox.Show("Paste selected");         }   This code adds the event handlers for the menu items defined in step 3. 6. Run the application, right click on the border and select a menu option and see the appropriate message box displayed. Congratulations it’s that easy!   Take the Slalom Challenge at www.slalomchallenge.com!

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• How to get Rosegarden to work with timidity?

  - by molybtek

  I'm having problems getting Rosegarden to play midi using Timidity on Ubuntu 11.10 amd64. I've tried mapping the MIDI playback device to one of the Timidity port that was automatically created on start up and that failed. I've also tried manually starting timidity using the -iA option, and mapping the Rosegarden's MIDI playback device to one of the new ports, and that still failed. When I close Rosegarden, I can hear one or two notes get played. Would anyone know how I can get Rosegarden to work again. Thanks.

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• How can I test linkable/executable files that require re-hosting or retargeting?

  - by hagubear

  Due to data protection, I cannot discuss fine details of the work itself so apologies PROBLEM CASE Sometimes my software projects require merging/integration with third party (customer or other suppliers) software. these software are often in linkable executables or object code (requires that my source code is retargeted and linked with it). When I get the executables or object code, I cannot validate its operation fully without integrating it with my system. My initial idea is that executables are not meant to be unit tested, they are meant to be linkable with other system, but what is the guarantee that post-linkage and integration behaviour will be okay? There is also no sufficient documentation available (from the customer) to indicate how to go about integrating the executables or object files. I know this is philosophical question, but apparently not enough research could be found at this moment to conclude to a solution. I was hoping that people could help me go to the right direction by suggesting approaches. To start, I have found out that Avionics OEM software is often rehosted and retargeted by third parties e.g. simulator makers. I wonder how they test them. Surely, the source code will not be supplied due to IPR rgulations. UPDATE I have received reasonable and very useful suggestions regarding this area. My current struggle has shifted into testing 3rd party OBJECT code that needs to be linked with my own source code (retargeted) on my host machine. How can I even test object code? Surely, I need to link them first to even think about doing anything. Is it the post-link behaviour that needs to be determined and scripted (using perl,Tcl, etc.) so that inputs and outputs could be verified? No clue!! :( thanks,

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• How to display consistent background image

  - by Tofu_Craving_Redish_BlueDragon

  Drawing a large background is relatively slow in PyGame. In order to avoid drawing BG every frame, you could draw it once, then do nothing. However, if something is overdrawn onto the surface and keeps moving, you will need to redraw the background in order to "erase" the color pixels left by moving object; otherwise, you will have "traces" of the moving object. I have a moving object in my PyGame. However, I do not want to "clear the color buffer" by redrawing the background image. Redrawing the background image every frame is slow. My solution : I will "clear" only required portions (where the "traces" of moving object are left) of the "buffer" by redrawing portions of background. Is there any other better way to have a consistent background?

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• More efficient in range checking

  - by Mob

  I am going to use a specific example in my question, but overall it is pretty general. I use java and libgdx. I have a ship that moves through space. In space there is debris that the ship can tractor beam in and and harvest. Debris is stored in a list, and the object contains it own x and y values. So currently there is no way to to find the debris's location without first looking at the debris object. Now at any given time there can be a huge (1000+) amount of debris in space, and I figure that calculating the distance between the ship and every single piece of debris and comparing it to maximum tractor beam length is rather inefficient. I have thought of dividing space into sectors, and have each sector contain a list of every object in it. This way I could only check nearby sectors. However this essentially doubles memory for the list. (I would reference the same object so it wouldn't double overall. I am not CS major, but I doubt this would be hugely significant.) This also means anytime an object moves it has to calculate which sector it is in, again not a huge problem. I also don't know if I can use some sort of 2D MAP that uses x and y values as keys. But since I am using float locations this sounds more trouble than its worth. I am kind of new to programming games, and I imagined there would be some eloquent solution to this issue.

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• How best to look up objects by label?

  - by dsollen

  I am writing the server backed by a pre-written API. I'm going to get a number of strings representing ports, signals, paths, etc etc etc. I need to look up the object associated with a given label, these objects are all in memory (no sql magic to do this for me). My question is, how best do I associate a given unique label with the mutable object it represents? I have enough objects that looking through every signal or every port to find the one that matches is possible, but may be slightly too slow. To be honest the direct 'look at every object' method is probably good enough for so small a body of objects and anything else is premature optimization, but I still am curious what the proper solution would be if I thought my signals were going to grow a bit larger. As I see it there are two options available. First would be to to create a 'store' that is a simple map between object and label. I could have it so that every time I call addObject the object is automatically saved into a hashmap or the like. This works, but relies on my properly adding and deleting each object so the map doesn't grow indefinitely. The biggest issue to me is that this involves having some hidden static map in my ModelObject class that just feels...wrong somehow. The other option is to have some method that can interpret the labels. All of these labels are derived from the underlying objects. So I can look at the signal label, for instance, and say "these 20 characters are the port" to figure out what port I need. This would allow me to quickly figure out what I need. However, if the label method is changed the translateLabelToObject method needs to be updated as well or everything breaks. Which solution is cleaner, or possibly a cleaner solution than either of above? For the record I'm working with sufficient number of variables to make direct comparison a little slow, but not enough to be concerned about memory overhead, written in java. All objects that have labels I need to look up extend the same parent class.

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• Generics Converter for Basic Types

  A generics method to convert an object to a basic type

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• Best Practice: What can be the hashCode() method implementation if custom field used in equals() method are null?

  - by goodspeed

  What is the best practice to return a value for hashCode() method if custom field used in equals are null ? I have a situation, where equals() override is implemented using custom fields. Usually it it is better to override hashCode() also using that custom fields used in equals(). But if all the custom fields used in equals() are null, then what would be the best implementation for hashCode()? Example: class Person { private String firstName; private String lastName; public String getFirstName() { return firstName; } public String getLastName() { return lastName; } @Override public boolean equals(Object object) { boolean result = false; if (object == null || object.getClass() != getClass()) { result = false; } else { Person person = (Person) object; if (this.firstName == person.getFirstName() && this.lastName == tiger.getLastName()) { result = true; } } return result; } @Override public int hashCode() { int hash = 3; if(this.firstName == null || this.lastName == null) { // <b>What is the best practice here, </b> // <b>is return super.hashCode() better ?</b> } hash = 7 * hash + this.firstName.hashCode(); hash = 7 * hash + this.lastName.hashCode(); return hash; } } is it required to check for null in hashCode() ? If yes, what should be returned if custom values are null ?

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• Accessing Hardware in Silverlight using COM

  An example of a COM object written in C# that allows access to hardware from Silverlight

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• How to ensure that a member variable is initialized before calling a class method

  - by Omkar Ekbote

  There's a class with a parametrized constructor that initializes a member variable. All public methods of the class then use this member variable to do something. I want to ensure that the caller always creates an object using the parametrized constructor (there is also a setter for this member variable) and then call that object's methods. In essence, it should be impossible for the caller to call any method without setting a value to the member variable (either by using the parametrized constructor or the setter). Currently, a caller can simply make an object using the default constructor and then call that object's method - I want to avoid checking whether or not the member variable is set in each and every one of the 20-odd methods of the class (and throw an exception if it is not). Though a runtime solution is acceptable (better than the one I mentioned above); a compile-time solution is preferable so that any developer will not be allowed to make that mistake and then waste hours debuggging it!

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