Search Results

Search found 40226 results on 1610 pages for 'object relational model'.

Page 388/1610 | < Previous Page | 384 385 386 387 388 389 390 391 392 393 394 395  | Next Page >

• XML Manipulation with Apache AXIOM

  Apache AXIOM (AXis2 Object Model) is a pull-based, XML Infoset-compliant object model that supports on-demand building of the object tree. Learn the basis of Axiom and how to use it.

  Read the article

• Pattern for Accessing MySQL connection

  - by Dipan Mehta

  We have an application which is C++ trying to access MySQL database. There are several (about 5 or so) threads in the application (with Boost library for threading) and in each thread has a few objects, each of which is trying to access Database for its' own purpose. It has a simple ORM kind of model but that really is not an important factor here. There are three potential access patterns i can think of: There could be single connection object per application or thread and is shared between all (or group). The object needs to be thread safe and there will be contentions but MySQL will not be fired with too many connections. Every object could initiate connection on its own. The database needs to take care of concurrency (which i think MySQL can) and the design could be much simpler. There could be two possibilities here. a. either object keeps a persistent connection for its life OR b. object initiate connection as and when needed. To simplify the contention as in case of 1 and not to create too many sockets as in case of 2, we can have group/set based connections. So there could be there could be more than one connection (say N), each of this connection could be shared connection across M objects. Naturally, each of the pattern has different resource cost and would work under different constraints and objectives. What criteria should i use to choose the pattern of this for my own application? What are some of the advantages and disadvantages of each of these pattern over the other? Are there any other pattern which is better? PS: I have been through these questions: mysql, one connection vs multiple and MySQL with mutiple threads and processes But they don't quite answer exactly what i am trying to ask.

  Read the article

• Render an image with separate layers for shadows/reflections in 3D Studio Max?

  - by Bernd Plontsch

  I have a scene with a simple object standing on a ground in the center. Caused by lights and the ground material there is some shadow and reflection on the ground surrounding the object. How can I render an image containing 3 separate layers for the object the ground the reflection / shadow on the ground Which format to use for this (it should include all 3 layers + I should be able to enable/disable them in Photoshop)? How do I define or prepare those layers for being rendering as image layers?

  Read the article

• WPF: Reloading app parts to handle persistence as well as memory management.

  - by Ingó Vals

  I created a app using Microsoft's WPF. It mostly handles data reading and input as well as associating relations between data within specific parameters. As a total beginner I made some bad design decision ( not so much decisions as using the first thing I got to work ) but now understanding WPF better I'm getting the urge to refactor my code with better design principles. I had several problems but I guess each deserves it's own question for clarity. Here I'm asking for proper ways to handle the data itself. In the original I wrapped each row in a object when fetched from database ( using LINQ to SQL ) somewhat like Active Record just not active or persistence (each app instance had it's own data handling part). The app has subunits handling different aspects. However as it was setup it loaded everything when started. This creates several problems, for example often it wouldn't be neccesary to load a part unless we were specifically going to work with that part so I wan't some form of lazy loading. Also there was problem with inner persistance because you might create a new object/row in one aspect and perhaps set relation between it and different object but the new object wouldn't appear until the program was restarted. Persistance between instances of the app won't be huge problem because of the small amount of people using the program. While I could solve this now using dirty tricks I would rather refactor the program and do it elegantly, Now the question is how. I know there are several ways and a few come to mind: 1) Each aspect of the program is it's own UserControl that get's reloaded/instanced everytime you navigate to it. This ensures you only load up the data you need and you get some persistancy. DB server located on same LAN and tables are small so that shouldn't be a big problem. Minor drawback is that you would have to remember the state of each aspect so you wouldn't always start at beginners square. 2) Having a ViewModel type object at the base level of the app with lazy loading and some kind of timeout. I would then propegate this object down the visual tree to ensure every aspect is getting it's data from the same instance 3) Semi active record data layer with static load methods. 4) Some other idea What in your opinion is the most practical way in WPF, what does MVVM assume?

  Read the article

• New SQL Azure Development Accelerator Core promotional offer announced

  - by Eric Nelson

  This is (almost) a straight copy and paste but represents an important announcement worthy of a little more “exposure” :-) Starting August 1, 2010, we will release a new SQL Azure Development Accelerator Core promotional offer.  This new offer will give you the flexibility to purchase commitment quantities of SQL Azure Business Edition databases independent of other Windows Azure platform services at a deeply discounted monthly price.  The offer is valid only for a six month term.  You may purchase in 10 GB increments the amount of our Business Edition relational database that you require (each Business Edition database is capable of storing up to 50 GB).  The offer price will be $74.95 per 10 GB per month.  This promotional offer represents 25% off of our normal consumption rates.  Monthly Business Edition relational database usage exceeding the purchased commitment amount and usage for other Windows Azure platform services for this offer will be charged at our normal consumption rates.  Please click here for full details of our new SQL Azure Development Accelerator Core offer.  Related Links: Details of 5GB and 50GB databases have been released http://ukazure.ning.com UK community site Getting started with the Windows Azure Platform

  Read the article

• Powershell variables to string

  - by Mike Koerner

  I'm new to powershell. I'm trying to write an error handler to wrap around my script.  Part of the error handler is dumping out some variable settings.  I spent a while trying to do this and couldn't google a complete solution so I thought I'd post something. I want to display the $myinvocation variable. In powershell you can do this PS C:\> $myInvocation for my purpose I want to create a stringbuilder object and append the $myinvocation info.  I tried this $sbOut = new-object System.Text.Stringbuilder $sbOut.appendLine($myinvocation) $sbOut.ToString() This produces                                    Capacity                                MaxCapacity                                     Length                                    --------                                -----------                                     ------                                          86                                 2147483647                                         45 System.Management.Automation.InvocationInfo This is not what I wanted so I tried $sbOut.appendLine(($myinvocation|format-list *)) This produced                                    Capacity                                MaxCapacity                                     Length                                    --------                                -----------                                     ------                                         606                                 2147483647                                        305 Microsoft.PowerShell.Commands.Internal.Format.FormatStartData Microsoft.PowerShell.Commands.Internal.Format.GroupStartData Micros oft.PowerShell.Commands.Internal.Format.FormatEntryData Microsoft.PowerShell.Commands.Internal.Format.GroupEndData Microsoft.Powe rShell.Commands.Internal.Format.FormatEndData Finally I figured out how to produce what I wanted: $sbOut = new-object System.Text.Stringbuilder [void]$sbOut.appendLine(($myinvocation|out-string)) $sbOut.ToString() MyCommand        : $sbOut = new-object System.Text.Stringbuilder                                    [void]$sbOut.appendLine(($myinvocation|out-string))                                      $sbOut.ToString()                    BoundParameters  : {} UnboundArguments : {} ScriptLineNumber : 0 OffsetInLine     : 0 HistoryId        : 13 ScriptName       : Line             : PositionMessage  : InvocationName   : PipelineLength   : 2 PipelinePosition : 1 ExpectingInput   : False CommandOrigin    : Runspace Note the [void] in front of the stringbuilder variable doesn't show the Capacity,MaxCapacity of the stringbuilder object.  The pipe to out-string makes the output a string. It's not pretty but it works.

  Read the article

• To access parentAM instance from within nestedAM JUnit test class

  - by Abhishek Dwivedi

  In normal model project, the way to access parent AM from within nested AM is simple - ParentAMImpl parentAM =  (ParentAMImpl)this.getRootApplicationModule(); However, the same approach doesn't help in JUnit model project. Use the following approach -  Inside setUp() method --  ParentAM parentAM =  (ParentAM)Configuration.createRootApplicationModule(ROOT_AM, ROOT_AM_CONFIG); Inside tearDown() method -- Configuration.releaseRootApplicationModule(parentAM, true);

  Read the article

• Green (Screen) Computing

  - by onefloridacoder

  I recently was given an assignment to create a UX where a user could use the up and down arrow keys, as well as the tab and enter keys to move through a Silverlight datagrid that is going be used as part of a high throughput data entry UI. And to be honest, I’ve not trapped key codes since I coded JavaScript a few years ago.  Although the frameworks I’m using made it easy, it wasn’t without some trial and error.    The other thing that bothered me was that the customer tossed this into the use case as they were delivering the use case.  Fine.  I’ll take a whack at anything and beat up myself and beg (I’m not beyond begging for help) the community for help to get something done if I have to. It wasn’t as bad as I thought and I thought I would hopefully save someone a few keystrokes if you wanted to build a green screen for your customer.   Here’s the ValueConverter to handle changing the strings to decimals and then back again.  The value is a nullable valuetype so there are few extra steps to take.  Usually the “ConvertBack()” method doesn’t get addressed but in this case we have two-way binding and the converter needs to ensure that if the user doesn’t enter a value it will remain null when the value is reapplied to the model object’s setter.  1: using System; 2: using System.Windows.Data; 3: using System.Globalization; 4:  5: public class NullableDecimalToStringConverter : IValueConverter 6: { 7: public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 8: { 9: if (!(((decimal?)value).HasValue)) 10: { 11: return (decimal?)null; 12: } 13: if (!(value is decimal)) 14: { 15: throw new ArgumentException("The value must be of type decimal"); 16: } 17:  18: NumberFormatInfo nfi = culture.NumberFormat; 19: nfi.NumberDecimalDigits = 4; 20:  21: return ((decimal)value).ToString("N", nfi); 22: } 23:  24: public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 25: { 26: decimal nullableDecimal; 27: decimal.TryParse(value.ToString(), out nullableDecimal); 28:  29: return nullableDecimal == 0 ? null : nullableDecimal.ToString(); 30: } 31: }            The ConvertBack() method uses TryParse to create a value from the incoming string so if the parse fails, we get a null value back, which is what we would expect.  But while I was testing I realized that if the user types something like “2..4” instead of “2.4”, TryParse will fail and still return a null.  The user is getting “puuu-lenty” of eye-candy to ensure they know how many values are affected in this particular view. Here’s the XAML code.   This is the simple part, we just have a DataGrid with one column here that’s bound to the the appropriate ViewModel property with the Converter referenced as well. 1: <data:DataGridTextColumn 2: Header="On-Hand" 3: Binding="{Binding Quantity, 4: Mode=TwoWay, 5: Converter={StaticResource DecimalToStringConverter}}" 6: IsReadOnly="False" /> Nothing too magical here.  Just some XAML to hook things up.   Here’s the code behind that’s handling the DataGridKeyup event.  These are wired to a local/private method but could be converted to something the ViewModel could use, but I just need to get this working for now. 1: // Wire up happens in the constructor 2: this.PicDataGrid.KeyUp += (s, e) => this.HandleKeyUp(e);   1: // DataGrid.BeginEdit fires when DataGrid.KeyUp fires. 2: private void HandleKeyUp(KeyEventArgs args) 3: { 4: if (args.Key == Key.Down || 5: args.Key == Key.Up || 6: args.Key == Key.Tab || 7: args.Key == Key.Enter ) 8: { 9: this.PicDataGrid.BeginEdit(); 10: } 11: }   And that’s it.  The ValueConverter was the biggest problem starting out because I was using an existing converter that didn’t take nullable value types into account.   Once the converter was passing back the appropriate value (null, “#.####”) the grid cell(s) and the model objects started working as I needed them to. HTH.

  Read the article

• How to port animation from one skeleton to another?

  - by shawn

  While I need to do this in a Blender3D modeler script, the math should be similar for other modelers or realtime engines. Blender3D specific terminology: Armature = skeleton EditBone = rest pose bone (stores the rest pose matrix) PoseBone = can store a different pose (animation matrix) for each frame of your animation I need to share animations (Blender Actions) between Armatures which have EditBones with same names and which have the same positions, but can have different (rest pose) angles and scales. Plus the Armatures might have different bone hierarchy (bone parenting/ no bone parenting). Why I need this: I've made an importer/exporter for a 3d format for a game. The format doesn't store enough info to connect/parent the bones, which makes posing/animating character models in a 3d modeller nearly impossible (original model files for the 3d modeler don't exist, this is for modding). As there are only 2 character skeleton types in the game, I decided to optionally allow to generate the bone from a hardcoded data in the model importer and undo that in the exporter. This allows to easily pose the model for checking weights, easily create weights, makes it easier for Blender to generate automatic weights and of course makes animating possible. This worked perfectly: the importer optionally generated the Armature itself and the exporter removed those changes, so the exported model works with existing animations in the game. But now I'm writing an importer and exporter for the game's animation format and here come the problems of: Trying to make original animations work in Blender with my "custom" (modified) Armature Trying to make animations created by using the "custom" (modified) Armature work with the original models in the game (and Blender). Constraints or bone snapping inside Blender won't work as they don't care that the bones have different angles in the rest pose, they will still face the same direction. It seems I just need to get the "difference" between the EditBone matrices of all EditBones for the two Armatures somehow and apply that difference to PoseBone matrices of all PoseBones, for all frames of my animation. I need to know how to get that difference and how to apply it. BTW, PoseBone matrices are relative to rest pose, they are by default [1.000000, 0.000000, 0.000000, 0.000000](matrix [row 0]) [0.000000, 1.000000, 0.000000, 0.000000](matrix [row 1]) [0.000000, 0.000000, 1.000000, 0.000000](matrix [row 2]) [0.000000, 0.000000, 0.000000, 1.000000](matrix [row 3]) So the question is: How to get the difference between two bone (EditBone) matrices to apply that difference to the animation matrices (PoseBone matrices)? Please be easy on the matrix math.

  Read the article

• Multithreading: Communication from Parent thread to child thread

  - by Dennis Nowland

  I have a List of threads normally 3 threads each of the threads reference a webbrowser control that communicates with the parent control to populate a datagridview. What I need to do is when the user clicks the button in a datagridviewButtonCell corresponding data will be sent back to the webbrowser control within the child thread that originally communicated with the main thread. but when I try to do this I receive the following error message 'COM object that has been separated from its underlying RCW cannot be used.' my problem is that I can not figure out how to reference the relevant webbrowser control. I would appreciate any help that anyone can give me. The language used is c# winforms .Net 4.0 targeted Code sample: The following code is executed when user click on the Start button in the main thread private void StartSubmit(object idx) { /* method used by the new thread to initialise a 'myBrowser' inherited from the webbrowser control each submitters object is an a custom Control called 'myBrowser' which holds detail about the function of the object eg: */ //index: is an integer value which represents the threads id int index = (int)idx; //submitters[index] is an instance of the 'myBrowser' control submitters[index] = new myBrowser(); //threads integer id submitters[index]._ThreadNum = index; // naming convention used 'browser' +the thread index submitters[index].Name = "browser" + index; //set list in 'myBrowser' class to hold a copy of the list found in the main thread submitters[index]._dirs = dirLists[index]; // suppress and javascript errors the may occur in the 'myBrowser' control submitters[index].ScriptErrorsSuppressed = true; //execute eventHandler submitters[index].DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(DocumentCompleted); //advance to the next un-opened address in datagridview the navigate the that address //in the 'myBrowser' control. SetNextDir(submitters[index]); } private void btnStart_Click(object sender, EventArgs e) { // used to fill list<string> for use in each thread. fillDirs(); //connections is the list<Thread> holding the thread that have been opened //1 to 10 maximum for (int n = 0; n < (connections.Length); n++) { //initialise new thread to the StartSubmit method passing parameters connections[n] = new Thread(new ParameterizedThreadStart(StartSubmit)); // naming convention used conn + the threadIndex ie: 'conn1' to 'conn10' connections[n].Name = "conn" + n.ToString(); // due to the webbrowser control needing to be ran in the single //apartment state connections[n].SetApartmentState(ApartmentState.STA); //start thread passing the threadIndex connections[n].Start(n); } } Once the 'myBrowser' control is fully loaded I am inserting form data into webforms found in webpages loaded via data enter into rows found in the datagridview. Once a user has entered the relevant details into the different areas in the row the can then clicking a DataGridViewButtonCell that has tha collects the data entered and then has to be send back to the corresponding 'myBrowser' object that is found on a child thread. Thank you

  Read the article

• Which approach would lead to an API that is easier to use?

  - by Clem

  I'm writing a JavaScript API and for a particular case, I'm wondering which approach is the sexiest. Let's take an example: writing a VideoPlayer, I add a getCurrentTime method which gives the elapsed time since the start. The first approach simply declares getCurrentTime as follows: getCurrentTime():number where number is the native number type. This approach includes a CURRENT_TIME_CHANGED event so that API users can add callbacks to be aware of time changes. Listening to this event would look like the following: myVideoPlayer.addEventListener(CURRENT_TIME_CHANGED, function(evt){ console.log ("current time = "+evt.getDispatcher().getCurrentTime()); }); The second approach declares getCurrentTime differently: getCurrentTime():CustomNumber where CustomNumber is a custom number object, not the native one. This custom object dispatches a VALUE_CHANGED event when its value changes, so there is no need for the CURRENT_TIME_CHANGED event! Just listen to the returned object for value changes! Listening to this event would look like the following: myVideoPlayer.getCurrentTime().addEventListener(VALUE_CHANGED, function(evt){ console.log ("current time = "+evt.getDispatcher().valueOf()); }); Note that CustomNumber has a valueOf method which returns a native number that lets the returned CustomNumber object being used as a number, so: var result = myVideoPlayer.getCurrentTime()+5; will work! So in the first approach, we listen to an object for a change in its property's value. In the second one we directly listen to the property for a change on its value. There are multiple pros and cons for each approach, I just want to know which one the developers would prefer to use!

  Read the article

• introducing pointers to a large software project

  - by stefan

  I have a fairly large software project written in c++. In there, there is a class foo which represents a structure (by which i don't mean the programmers struct) in which foo-objects can be part of a foo-object. Here's class foo in simplest form: class Foo { private: std::vector<unsigned int> indices; public: void addFooIndex(unsigned int); unsigned int getFooIndex(unsigned int); }; Every foo-object is currently stored in an object of class bar. class Bar { private: std::vector<Foo> foos; public: void addFoo(Foo); std::vector<Foo> getFoos(); } So if a foo-object should represent a structure with a "inner" foo-object, I currently do Foo foo; Foo innerFoo; foo.addFooIndex(bar.getFoos().size() - 1); bar.addFoo(innerFoo); And to get it, I obviously use: Foo foo; for ( unsigned int i = 0; i < foo.getFooIndices().size(); ++i ) { Foo inner_foo; assert( foo.getFooIndices().at(i) < bar.getFoos().size() ); inner_foo = bar.getFoos().at(foo.getFooIndices().at(i)); } So this is not a problem. It just works. But it's not the most elegant solution. I now want to make the inner foos to be "more connected" with the foo-object. It would be obviously to change class foo to: class Foo { private: std::vector<Foo*> foo_pointers; public: void addFooPointer(Foo*); std::vector<Foo*> getFooPointers(); }; So now, for my question: How to gently change this basic class without messing up the whole code? Is there a "clean way"?

  Read the article

• consume a .net webservice using jQuery

  - by Babunareshnarra

  Implementation shows the way to consume web service using jQuery. The client side AJAX with HTTP POST request is significant when it comes to loading speed and responsiveness.Following is the service created that return's string in JSON.[WebMethod][ScriptMethod(ResponseFormat = ResponseFormat.Json)]public string getData(string marks){    DataTable dt = retrieveDataTable("table", @"              SELECT * FROM TABLE WHERE MARKS='"+ marks.ToString() +"' ");    List<object> RowList = new List<object>();    foreach (DataRow dr in dt.Rows)    {        Dictionary<object, object> ColList = new Dictionary<object, object>();        foreach (DataColumn dc in dt.Columns)        {            ColList.Add(dc.ColumnName,            (string.Empty == dr[dc].ToString()) ? null : dr[dc]);        }        RowList.Add(ColList);    }    JavaScriptSerializer js = new JavaScriptSerializer();    string JSON = js.Serialize(RowList);    return JSON;}Consuming the webservice $.ajax({    type: "POST",    data: '{ "marks": "' + val + '"}', // This is required if we are using parameters    contentType: "application/json",    dataType: "json",    url: "/dataservice.asmx/getData",    success: function(response) {               RES = JSON.parse(response.d);        var obj = JSON.stringify(RES);     }     error: function (msg) {                    alert('failure');     }});Remember to reference jQuery library on the page.

  Read the article

• Looking to trade a 1U HP Proliant DL360 G5 in exchange for a small linux VPS

  - by user597875

  I have a 1U HP Proliant DL360 G5 that I have no place to rack and would like to trade it for a small linux VPS. If interested let me know... Here are the specs of the server: Model: Intel Xeon CPU 5150 @ 2.66GHz, 4MB L2 Cache Processor Speed: 2.7GHz Processor Sockets: 2 Processor Cores per Socket: 2 Logical Processors: 4 8GB of memory 4x72GB 10k SAS drives Manufacturer: HP Model: Proliant DL360 G5 BIOS Version: P58

  Read the article

• Having trouble compiling UnrealScript with defaultproperties

  - by Enchanter

  Have just started scripting in Unreal Script and am following the instructions of the opening chapter of a book on the subject. I have set the development tools up as described in the book such that it is now possible to compile the scripts for UDK before adding them to a level. My issue is: the very first script the book asks you to compile is the following: class AwesomeActor extends Actor placeable; defaultproperties { Begin Object Class=SpriteComponent Name = Sprite Sprite = Texture2D'EditorResources.S_NavP' End Object Components.Add(Sprite) } And when I hit F9 in the compiler I get the following error message: Error, BEGIN OBJECT: Must specify valid name for suboject/copmponent: Begin Object class=SpriteComponent name = Sprite My question: As far as I'm aware I've copied the code from the book veribatim including capital and smaller case letters but I'm getting this error and I was wondering if anyone knew why and if so how I would fix it?

  Read the article

• Updates about Multidimensional vs Tabular #ssas #msbi

  - by Marco Russo (SQLBI)

  I recently read the blog post from James Serra Tabular model: Not ready for prime time? (read also the comments because there are discussions about a few points raised by James) and the following post from Christian Wade Multidimensional or Tabular. In the last 2 years I worked with many companies adopting Tabular in different scenarios and I agree with some of the points expressed by James in his post (especially about missing features in Tabular if compared to Multidimensional), but I strongly disagree in others. In general, Tabular is a good choice for a new project when: the development team does not have a good knowledge of Multidimensional and MDX (DAX is faster to learn, not so easy as it is sold by MS, but definitely easier than MDX) you don’t need calculations based on hierarchies (common in certain financial applications, but not so common as it could seem) there are important calculations based on distinct count measures there are complex calculations based on many-to-many relationships Until now, I never suggested to migrate an existing Multidimensional model to a Tabular one. There should be very important reasons for that, such as performance issues in distinct count and many-to-many relationships that cannot be easily solved by optimizing the Multidimensional model, but I still never encountered this scenario. I would say that in 80% of the new projects, you might use either Multidimensional or Tabular and the real difference is the time-to-market depending on the skills of the development team. So it’s not strange that who is used to Multidimensional is not moving to Tabular, not getting a particular benefit from the new model unless specific requirements exist. The recent DAXMD feature that allows using SharePoint Power View on Multidimensional is a really important one, even if I’d like having also Excel Power View enabled for this scenario (this should be just a question of time). Another scenario in which I’m seeing a growing adoption of Tabular is in companies that creates models for their product/service and do that by using XMLA or Tabular AMO 2012. I am used to call them ISVs, even if those providing services cannot be really defined in this way. These companies are facing the multitenancy challenge with Tabular and even if this is a niche market, I see some potential here, because adopting Tabular seems a much more natural choice than Multidimensional in those scenario where an analytical engine has to be embedded to deliver one of the features of a larger product/service delivered to customers. I’d like to see other feedbacks in the comments: tell your story of choosing between Tabular and Multidimensional in a BI project you started with SQL Server 2012, thanks!

  Read the article

• What happens at control invoke function?

  - by user65909

  A question about form controls invoke function. Control1 is created on thread1. If you want to update something in Control1 from thread2 you must do something like: delegate void SetTextCallback(string txt); void setText(string txt) { if (this.textBox1.InvokeRequired) { SetTextCallback d = new SetTextCallback(setText); this.Invoke(d, new object[] { txt }); } else { // this will run on thread1 even when called from thread2 this.textBox1.AppendText(msg); } }` What happens behind the scenes here? This invoke behaves different from a normal object invoke. When you want to call a function in an object on a specific thread, then that thread must be waiting on some queue of delegates, and execute the incoming delegates. Is it correct that the windows forms control invoke function is completely different from the standard object invoke function?

  Read the article

• Getting an OBB out of another OBB?

  - by Milo

  I'm working on collision resolution for my game. I just need a good way to get an object out of another object if it gets stuck. In this case a car. Here is a typical scenario. The red car is in the green object. How do I correctly get it out so the car can slide along the edge of the object as it should. I tried: if(buildings.size() > 0) { Entity e = buildings.get(0); Vector2D vel = new Vector2D(); vel.x = vehicle.getVelocity().x; vel.y = vehicle.getVelocity().y; vel.normalize(); while(vehicle.getRect().overlaps(e.getRect())) { vehicle.setCenter(vehicle.getCenterX() - vel.x * 0.1f, vehicle.getCenterY() - vel.y * 0.1f); } colided = true; } But that does not work too well. Is there some sort of vector I could calculate to use as the vector to move the car away from the object? Thanks

  Read the article

• Is `break` and `continue` bad programming practice?

  - by Mikhail

  My boss keeps mentioning nonchalantly that bad programmers use break and continue in loops. I use them all the time because they make sense; let me show you the inspiration: function verify(object) { if (object->value < 0) return false; if (object->value > object->max_value) return false; if (object->name == "") return false; ... } The point here is that first the function checks that the conditions are correct, then executes the actual functionality. IMO same applies with loops: while (primary_condition) { if (loop_count > 1000) break; if (time_exect > 3600) break; if (this->data == "undefined") continue; if (this->skip == true) continue; ... } I think this makes it easier to read & debug; but I also don't see a downside. Please comment.

  Read the article

• What are good reasons to use explicit interface implementation for the sole purpose of hiding members?

  - by Nathanus

  During one of my studies into the intricacies of C#, I came across an interesting passage concerning explicit interface implementation. While this syntax is quite helpful when you need to resolve name clashes, you can use explicit interface implementation simply to hide more "advanced" members from the object level. The difference between allowing the use of object.method() or requiring the casting of ((Interface)object).method() seems like mean-spirited obfuscation to my inexperienced eyes. The text noted that this will hide the method from Intellisense at the object level, but why would you want to do that if it was not necessary to avoid name conflicts?

  Read the article

• Best Creational Pattern for loggers in a multi-threaded system?

  - by Dipan Mehta

  This is a follow up question on my past questions : Concurrency pattern of logger in multithreaded application As suggested by others, I am putting this question separately. As the learning from the last question. In a multi-threaded environment, the logger should be made thread safe and probably asynchronous (where in messages are queued while a background thread does writing releasing the requesting object thread). The logger could be signleton or it can be a per-group logger which is a generalization of the above. Now, the question that arise is how does logger should be assigned to the object? There are two options I can think of: 1. Object requesting for the logger: Should each of the object call some global API such as get_logger()? Such an API returns "the" singleton or the group logger. However, I feel this involves assumption about the Application environment to implement the logger -which I think is some kind of coupling. If the same object needs to be used by other application - this new application also need to implement such a method. 2. Assign logger through some known API The other alternative approach is to create a kind of virtual class which is implemented by application based on App's own structure and assign the object sometime in the constructor. This is more generalized method. Unfortunately, when there are so many objects - and rather a tree of objects passing on the logger objects to each level is quite messy. My question is there a better way to do this? If you need to pick any one of the above, which approach is would you pick and why? Other questions remain open about how to configure them: How do objects' names or ID are assigned so that will be used for printing on the log messages (as the module names) How do these objects find the appropriate properties (such as log levels, and other such parameters) In the first approach, the central API needs to deal with all this varieties. In the second approach - there needs to be additional work. Hence, I want to understand from the real experience of people, as to how to write logger effectively in such an environment.

  Read the article

• OTN's Virtual Developer Day: Deep dive on WebLogic and Java EE 6

  - by ruma.sanyal

  Come join us and learn how Oracle WebLogic Server enables a whole new level of productivity for enterprise developers. Also hear the latest on Java EE 6 and the programming tenets that have made it a true platform breakthrough, with new programming paradigms, persistence strategies, and more: Convention over configuration - minimal XML Leaner and meaner API - and one that is an open standard POJO model - managed beans for testable components Annotation-based programming model - decorate and inject Reduce or eliminate need for deployment descriptors Traditional API for advanced users How to participate: register online, and we'll email you the details.

  Read the article

• Better use on the name of variables

  - by Cuartico

  I have a method that looks like this: Public Function NormalizeStreetAddress(country As Namespace.Country, streetAddress As Namespace.StreetAddress) _ As Namespace.StreetAddress Dim _streetAddress As New Namespace.StreetAddress = streetAddress If My.Settings.Streeteable = True Then Dim _AddressCustom As New Namespace.AddressCustom _streetAddress = _AddressCustom.NormalizeStreetAddress(country, streetAddress) End If Return _streetAddress End Function I receive a streetAddress object, but inside the method I need to use another streetAddress object which I called _streetAddress — is that following the standard? A friend of mine told me that object names such as _yourNameObject are for global variables, but I can't find info about this and I want to make this method more readable.

  Read the article

• Strategies for managUse 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.

  Read the article

• Passing Strings by Ref

  - by SGWellens

  Humbled yet again…DOH! No matter how much experience you acquire, no matter how smart you may be, no matter how hard you study, it is impossible to keep fully up to date on all the nuances of the technology we are exposed to. There will always be gaps in our knowledge: Little 'dead zones' of uncertainty. For me, this time, it was about passing string parameters to functions. I thought I knew this stuff cold. First, a little review... Value Types and Ref Integers and structs are value types (as opposed to reference types). When declared locally, their memory storage is on the stack; not on the heap. When passed to a function, the function gets a copy of the data and works on the copy. If a function needs to change a value type, you need to use the ref keyword.  Here's an example:     // ---- declaration -----------------     public struct MyStruct    {        public string StrTag;    }     // ---- functions -----------------------     void SetMyStruct(MyStruct myStruct)     // pass by value    {        myStruct.StrTag = "BBB";    }     void SetMyStruct(ref MyStruct myStruct)  // pass by ref    {        myStruct.StrTag = "CCC";    }     // ---- Usage -----------------------     protected void Button1_Click(object sender, EventArgs e)    {        MyStruct Data;        Data.StrTag = "AAA";         SetMyStruct(Data);        // Data.StrTag is still "AAA"         SetMyStruct(ref Data);        // Data.StrTag is now "CCC"    } No surprises here. All value types like ints, floats, datetimes, enums, structs, etc. work the same way. And now on to... Class Types and Ref     // ---- Declaration -----------------------------     public class MyClass    {        public string StrTag;    }     // ---- Functions ----------------------------     void SetMyClass(MyClass myClass)  // pass by 'value'    {        myClass.StrTag = "BBB";    }     void SetMyClass(ref MyClass myClass)   // pass by ref    {        myClass.StrTag = "CCC";    }     // ---- Usage ---------------------------------------     protected void Button2_Click(object sender, EventArgs e)    {        MyClass Data = new MyClass();        Data.StrTag = "AAA";         SetMyClass(Data);          // Data.StrTag is now "BBB"         SetMyClass(ref Data);        // Data.StrTag is now "CCC"    }  No surprises here either. Since Classes are reference types, you do not need the ref keyword to modify an object. What may seem a little strange is that with or without the ref keyword, the results are the same: The compiler knows what to do. So, why would you need to use the ref keyword when passing an object to a function? Because then you can change the reference itself…ie you can make it refer to a completely different object. Inside the function you can do: myClass = new MyClass() and the old object will be garbage collected and the new object will be returned to the caller. That ends the review. Now let's look at passing strings as parameters. The String Type and Ref Strings are reference types. So when you pass a String to a function, you do not need the ref keyword to change the string. Right? Wrong. Wrong, wrong, wrong. When I saw this, I was so surprised that I fell out of my chair. Getting up, I bumped my head on my desk (which really hurt). My bumping the desk caused a large speaker to fall off of a bookshelf and land squarely on my big toe. I was screaming in pain and hopping on one foot when I lost my balance and fell. I struck my head on the side of the desk (once again) and knocked myself out cold. When I woke up, I was in the hospital where due to a database error (thanks Oracle) the doctors had put casts on both my hands. I'm typing this ever so slowly with just my ton..tong ..tongu…tongue. But I digress. Okay, the only true part of that story is that I was a bit surprised. Here is what happens passing a String to a function.     // ---- Functions ----------------------------     void SetMyString(String myString)   // pass by 'value'    {        myString = "BBB";    }     void SetMyString(ref String myString)  // pass by ref    {        myString = "CCC";    }     // ---- Usage ---------------------------------     protected void Button3_Click(object sender, EventArgs e)    {        String MyString = "AAA";         SetMyString(MyString);        // MyString is still "AAA"  What!!!!         SetMyString(ref MyString);        // MyString is now "CCC"    } What the heck. We should not have to use the ref keyword when passing a String because Strings are reference types. Why didn't the string change? What is going on?   I spent hours unssuccessfully researching this anomaly until finally, I had a Eureka moment: This code: String MyString = "AAA"; Is semantically equivalent to this code (note this code doesn't actually compile): String MyString = new String(); MyString = "AAA"; Key Point: In the function, the copy of the reference is pointed to a new object and THAT object is modified. The original reference and what it points to is unchanged. You can simulate this behavior by modifying the class example code to look like this:      void SetMyClass(MyClass myClass)  // call by 'value'    {        //myClass.StrTag = "BBB";        myClass = new MyClass();        myClass.StrTag = "BBB";    } Now when you call the SetMyClass function without using ref, the parameter is unchanged...just like the string example.  I hope someone finds this useful. Steve Wellens

  Read the article

< Previous Page | 384 385 386 387 388 389 390 391 392 393 394 395  | Next Page >