Search Results

Search found 37817 results on 1513 pages for 'function signatures'.

Page 697/1513 | < Previous Page | 693 694 695 696 697 698 699 700 701 702 703 704  | Next Page >

  • Drawing a texture at the end of a trace (crosshair?) UDK

    - by Dave Voyles
    I'm trying to draw a crosshair at the end of my trace. If my crosshair does not hit a pawn or static mesh (ex, just a skybox) then the crosshair stays locked on a certain point at that actor - I want to say its origin. Ex: Run across a pawn, then it turns yellow and stays on that pawn. If it runs across the skybox, then it stays at one point on the box. Weird? How can I get my crosshair to stay consistent? I've included two images for reference, to help illustrate. Note: The wrench is actually my crosshair. The "X" is just a debug crosshair. Ignore that. /// Image 1 /// /// Image 2 /// /*************************************************************************** * Draws the crosshair ***************************************************************************/ function bool CheckCrosshairOnFriendly() { local float CrosshairSize; local vector HitLocation, HitNormal, StartTrace, EndTrace, ScreenPos; local actor HitActor; local MyWeapon W; local Pawn MyPawnOwner; /** Sets the PawnOwner */ MyPawnOwner = Pawn(PlayerOwner.ViewTarget); /** Sets the Weapon */ W = MyWeapon(MyPawnOwner.Weapon); /** If we don't have an owner, then get out of the function */ if ( MyPawnOwner == None ) { return false; } /** If we have a weapon... */ if ( W != None) { /** Values for the trace */ StartTrace = W.InstantFireStartTrace(); EndTrace = StartTrace + W.MaxRange() * vector(PlayerOwner.Rotation); HitActor = MyPawnOwner.Trace(HitLocation, HitNormal, EndTrace, StartTrace, true, vect(0,0,0),, TRACEFLAG_Bullet); DrawDebugLine(StartTrace, EndTrace, 100,100,100,); /** Projection for the crosshair to convert 3d coords into 2d */ ScreenPos = Canvas.Project(HitLocation); /** If we haven't hit any actors... */ if ( Pawn(HitActor) == None ) { HitActor = (HitActor == None) ? None : Pawn(HitActor.Base); } } /** If our trace hits a pawn... */ if ((Pawn(HitActor) == None)) { /** Draws the crosshair for no one - Grey*/ CrosshairSize = 28 * (Canvas.ClipY / 768) * (Canvas.ClipX /1024); Canvas.SetDrawColor(100,100,128,255); Canvas.SetPos(ScreenPos.X - (CrosshairSize * 0.5f), ScreenPos.Y -(CrosshairSize * 0.5f)); Canvas.DrawTile(class'UTHUD'.default.AltHudTexture, CrosshairSize, CrosshairSize, 600, 262, 28, 27); return false; } /** Draws the crosshair for friendlies - Yellow */ CrosshairSize = 28 * (Canvas.ClipY / 768) * (Canvas.ClipX /1024); Canvas.SetDrawColor(255,255,128,255); Canvas.SetPos(ScreenPos.X - (CrosshairSize * 0.5f), ScreenPos.Y -(CrosshairSize * 0.5f)); Canvas.DrawTile(class'UTHUD'.default.AltHudTexture, CrosshairSize, CrosshairSize, 600, 262, 28, 27); return true; }

    Read the article

  • How To Use The Search Feature in Almost any App on Windows 8

    - by Taylor Gibb
    Searching in Windows 8 has changed significantly, in fact at first you might think that all most Metro apps “lack” a search function altogether. Read on to find out how you can use the search feature in almost any app in Windows 8. HTG Explains: How Windows Uses The Task Scheduler for System Tasks HTG Explains: Why Do Hard Drives Show the Wrong Capacity in Windows? Java is Insecure and Awful, It’s Time to Disable It, and Here’s How

    Read the article

  • LWJGL - Mixing 2D and 3D

    - by nathan
    I'm trying to mix 2D and 3D using LWJGL. I have wrote 2D little method that allow me to easily switch between 2D and 3D. protected static void make2D() { glEnable(GL_BLEND); GL11.glMatrixMode(GL11.GL_PROJECTION); GL11.glLoadIdentity(); glOrtho(0.0f, SCREEN_WIDTH, SCREEN_HEIGHT, 0.0f, 0.0f, 1.0f); GL11.glMatrixMode(GL11.GL_MODELVIEW); GL11.glLoadIdentity(); } protected static void make3D() { glDisable(GL_BLEND); GL11.glMatrixMode(GL11.GL_PROJECTION); GL11.glLoadIdentity(); // Reset The Projection Matrix GLU.gluPerspective(45.0f, ((float) SCREEN_WIDTH / (float) SCREEN_HEIGHT), 0.1f, 100.0f); // Calculate The Aspect Ratio Of The Window GL11.glMatrixMode(GL11.GL_MODELVIEW); glLoadIdentity(); } The in my rendering code i would do something like: make2D(); //draw 2D stuffs here make3D(); //draw 3D stuffs here What i'm trying to do is to draw a 3D shape (in my case a quad) and i 2D image. I found this example and i took the code from TextureLoader, Texture and Sprite to load and render a 2D image. Here is how i load the image. TextureLoader loader = new TextureLoader(); Sprite s = new Sprite(loader, "player.png") And how i render it: make2D(); s.draw(0, 0); It works great. Here is how i render my quad: glTranslatef(0.0f, 0.0f, 30.0f); glScalef(12.0f, 9.0f, 1.0f); DrawUtils.drawQuad(); Once again, no problem, the quad is properly rendered. DrawUtils is a simple class i wrote containing utility method to draw primitives shapes. Now my problem is when i want to mix both of the above, loading/rendering the 2D image, rendering the quad. When i try to load my 2D image with the following: s = new Sprite(loader, "player.png); My quad is not rendered anymore (i'm not even trying to render the 2D image at this point). Only the fact of creating the texture create the issue. After looking a bit at the code of Sprite and TextureLoader i found that the problem appears after the call of the glTexImage2d. In the TextureLoader class: glTexImage2D(target, 0, dstPixelFormat, get2Fold(bufferedImage.getWidth()), get2Fold(bufferedImage.getHeight()), 0, srcPixelFormat, GL_UNSIGNED_BYTE, textureBuffer); Commenting this like make the problem disappear. My question is then why? Is there anything special to do after calling this function to do 3D? Does this function alter the render part, the projection matrix?

    Read the article

  • design a model for a system of dependent variables

    - by dbaseman
    I'm dealing with a modeling system (financial) that has dozens of variables. Some of the variables are independent, and function as inputs to the system; most of them are calculated from other variables (independent and calculated) in the system. What I'm looking for is a clean, elegant way to: define the function of each dependent variable in the system trigger a re-calculation, whenever a variable changes, of the variables that depend on it A naive way to do this would be to write a single class that implements INotifyPropertyChanged, and uses a massive case statement that lists out all the variable names x1, x2, ... xn on which others depend, and, whenever a variable xi changes, triggers a recalculation of each of that variable's dependencies. I feel that this naive approach is flawed, and that there must be a cleaner way. I started down the path of defining a CalculationManager<TModel> class, which would be used (in a simple example) something like as follows: public class Model : INotifyPropertyChanged { private CalculationManager<Model> _calculationManager = new CalculationManager<Model>(); // each setter triggers a "PropertyChanged" event public double? Height { get; set; } public double? Weight { get; set; } public double? BMI { get; set; } public Model() { _calculationManager.DefineDependency<double?>( forProperty: model => model.BMI, usingCalculation: (height, weight) => weight / Math.Pow(height, 2), withInputs: model => model.Height, model.Weight); } // INotifyPropertyChanged implementation here } I won't reproduce CalculationManager<TModel> here, but the basic idea is that it sets up a dependency map, listens for PropertyChanged events, and updates dependent properties as needed. I still feel that I'm missing something major here, and that this isn't the right approach: the (mis)use of INotifyPropertyChanged seems to me like a code smell the withInputs parameter is defined as params Expression<Func<TModel, T>>[] args, which means that the argument list of usingCalculation is not checked at compile time the argument list (weight, height) is redundantly defined in both usingCalculation and withInputs I am sure that this kind of system of dependent variables must be common in computational mathematics, physics, finance, and other fields. Does someone know of an established set of ideas that deal with what I'm grasping at here? Would this be a suitable application for a functional language like F#? Edit More context: The model currently exists in an Excel spreadsheet, and is being migrated to a C# application. It is run on-demand, and the variables can be modified by the user from the application's UI. Its purpose is to retrieve variables that the business is interested in, given current inputs from the markets, and model parameters set by the business.

    Read the article

  • Thoughts on schemas and schema proliferation

    - by jamiet
    In SQL Server 2005 Microsoft introduced user-schema separation and since then I have seen the use of schemas increase; whereas before I would typically see databases where all objects were in the [dbo] schema I now see databases that have multiple schemas, a database I saw recently had 31 (thirty one) of them. I can’t help but wonder whether this is a good thing or not – clearly 31 is an extreme case but I question whether multiple schemas create more problems than they solve? I have been involved in many discussions that go something like this: Developer #1> “I have a new function to add to the database and I’m not sure which schema to put it in” Developer #2> “What does it do?” Developer #1> “It provides data to a report in Reporting Services” Developer #2> “Ok, so put it in the [reports] schema” Developer #1> “Well I could, but the data will only be used by our Financial reporting folks so shouldn’t I put it in the [financial] schema?” Developer #2> “Maybe, yes” Developer #1> “Mind you, the data is supposed to be used for regulatory reporting to the FSA, should I put it in [regulatory]?” Developer #2> “Err….” You get the idea!!! The more schemas that exist in your database then the more chance that their supposed usages will overlap. I’m left wondering whether the use of schemas is actually necessary. I don’t view really see them as an aid to security because I generally believe that principles should be assigned permissions on objects as-needed on a case-by-case basis (and I have a stock SQL query that deciphers them all for me) so why bother using them at all? I can envisage a use where a database is used to house objects pertaining to many different business functions (which, in itself, is an ambiguous term) and in that circumstance perhaps a schema per business function would be appropriate; hence of late I have been loosely following this edict: If some objects in a database could be moved en masse to another database without the need to remove any foreign key constraints then those objects could legitimately exist in a dedicated schema. I am interested to know what other people’s thoughts are on this. If you would like to share then please do so in the comments. @Jamiet

    Read the article

  • How to implement SHA-2 in SQL Server 2005 or 2008 with a CLR assembly

    SQL Server 2012 supports SHA-256 and SHA-512 through the HASHBYTES() function, but earlier versions of SQL Server do not. SHA-256, SHA-384 and SHA-512 can, however, be implemented in SQL Server 2005 or SQL Server 2008 with the CLR assembly described in this article. Optimize SQL Server performance“With SQL Monitor, we can be proactive in our optimization process, instead of waiting until a customer reports a problem,” John Trumbul, Sr. Software Engineer. Optimize your servers with a free trial.

    Read the article

  • Rounding functions in DAX

    - by Marco Russo (SQLBI)
    Today I prepared a table of the many rounding functions available in DAX (yes, it’s part of the book we’re writing), so that I have a complete schema of the better function to use, depending on the round operation I need to do. Here is the list of functions used and then the results shown for a relevant set of values. FLOOR = FLOOR( Tests[Value], 0.01 ) TRUNC = TRUNC( Tests[Value], 2 ) ROUNDDOWN = ROUNDDOWN( Tests[Value], 2 ) MROUND = MROUND( Tests[Value], 0.01 ) ROUND = ROUND( Tests[Value], 2 )...(read more)

    Read the article

  • Build a view frustum from angles

    - by MulletDevil
    I have 4 angles, left, right, top & bottom. These angles are in degrees. They define the angle between the forward vector and the corresponding side. I am trying to use these to calculate the required values for Perseective Off Centre function found here http://docs.unity3d.com/Documentation/ScriptReference/Camera-projectionMatrix.html I tried doing (near plane-far plane) * Tan(angle) But that didn't give the correct results.

    Read the article

  • What problems can arise from emulating concepts from another languages?

    - by Vandell
    I've read many times on the web that if your language doesn't support some concept, for example, object orientation, or maybe function calls, and it's considered a good practice in this other context, you should do it. The only problem I can see now is that other programmers may find your code too different than the usual, making it hard for them to program. What other problems do you think may arise from this?

    Read the article

  • Zooming in isometric engine using XNA

    - by Yheeky
    I´m currently working on an isometric game engine and right now I´m looking for help concerning my zoom function. On my tilemap there are several objects, some of them are selectable. When a house (texture size 128 x 256) is placed on the map I create an array containing all pixels (= 32768 pixels). Therefore each pixel has an alpha value I check if the value is bigger than 200 so it seems to be a pixel which belongs to the building. So if the mouse cursor is on this pixel the building will be selected - PixelCollision. Now I´ve already implemented my zooming function which works quite well. I use a scale variable which will change my calculation on drawing all map items. What I´m looking for right now is a precise way to find out if a zoomed out/in house is selected. My formula works for values like 0,5 (zoomed out) or 2 (zoomed in) but not for in between. Here is the code I use for the pixel index: var pixelIndex = (int)(((yPos / (Scale * Scale)) * width) + (xPos / Scale) + 1); Example: Let´s assume my mouse is over pixel coordinate 38/222 on the original house texture. Using the code above we get the following pixel index. var pixelIndex = ((222 / (1 * 1)) * 128) + (38 / 1) + 1; = (222 * 128) + 39 = 28416 + 39 = 28455 If we now zoom out to scale 0,5, the texture size will change to 64 x 128 and the amount of pixels will decrease from 32768 to 8192. Of course also our mouse point changes by the scale to 19/111. The formula makes it easy to calculate the original pixelIndex using our new coordinates: var pixelIndex = ((111 / (0.5 * 0.5)) * 64) + (19 / 0.5) + 1; = (444 * 64) + 39 = 28416 + 39 = 28455 But now comes the problem. If I zoom out just to scale 0.75 it does not work any more. The pixel amount changes from 32768 to 18432 pixels since texture size is 96 x 192. Mouse point is transformed to point 28/166. The formula gives me a wrong pixelIndex. var pixelIndex = ((166 / (0.75 * 0.75)) * 96) + (28 / 0.75) + 1; = (295.11 * 96) + 38.33 = 28330.66 + 38.33 = 28369 Does anyone have a clue what´s wrong in my code? Must be the first part (28330.66) which causes the calculation problem. Thanks! Yheeky

    Read the article

  • What are known approaches to graphing algebraic expressions?

    - by jeremynealbrown
    I am planning to build an expression parser that will be used to graph algebraic functions ( think TI-83 ) with JavaScript. Functions will take the form of f(x)= Aside from typical operators such as: + - * / ^ I'd also like to add support for inline functions such as: sin(), cos(), log() and random(). I have looked at implementing the Shunting Yard algorithm for parsing expressions, but it does not look like an efficient approach to evaluating a function with a hundreds or thousands of inputs. What other known algorithms exist for this task?

    Read the article

  • Create a kind of Interface c++ [migrated]

    - by Liuka
    I'm writing a little 2d rendering framework with managers for input and resources like textures and meshes (for 2d geometry models, like quads) and they are all contained in a class "engine" that interacts with them and with a directX class. So each class have some public methods like init or update. They are called by the engine class to render the resources, create them, but a lot of them should not be called by the user: //in pseudo c++ //the textures manager class class TManager { private: vector textures; .... public: init(); update(); renderTexture(); //called by the "engine class" loadtexture(); gettexture(); //called by the user } class Engine { private: Tmanager texManager; public: Init() { //initialize all the managers } Render(){...} Update(){...} Tmanager* GetTManager(){return &texManager;} //to get a pointer to the manager //if i want to create or get textures } In this way the user, calling Engine::GetTmanager will have access to all the public methods of Tmanager, including init update and rendertexture, that must be called only by Engine inside its init, render and update functions. So, is it a good idea to implement a user interface in the following way? //in pseudo c++ //the textures manager class class TManager { private: vector textures; .... public: init(); update(); renderTexture(); //called by the "engine class" friend class Tmanager_UserInterface; operator Tmanager_UserInterface*(){return reinterpret_cast<Tmanager_UserInterface*>(this)} } class Tmanager_UserInterface : private Tmanager { //delete constructor //in this class there will be only methods like: loadtexture(); gettexture(); } class Engine { private: Tmanager texManager; public: Init() Render() Update() Tmanager_UserInterface* GetTManager(){return texManager;} } //in main function //i need to load a texture //i always have access to Engine class engine-GetTmanger()-LoadTexture(...) //i can just access load and get texture; In this way i can implement several interface for each object, keeping visible only the functions i (and the user) will need. There are better ways to do the same?? Or is it just useless(i dont hide the "framework private functions" and the user will learn to dont call them)? Before i have used this method: class manager { public: //engine functions userfunction(); } class engine { private: manager m; public: init(){//call manager init function} manageruserfunciton() { //call manager::userfunction() } } in this way i have no access to the manager class but it's a bad way because if i add a new feature to the manager i need to add a new method in the engine class and it takes a lot of time. sorry for the bad english.

    Read the article

  • Should one comment differently in functional languages

    - by Tom Squires
    I'm just getting started with functional programming and I'm wondering the correct way to comment my code. It seems a little redundant to comment a short function as the names and signature already should tell you everything you need to know. Commenting larger functions also seems a little redundant since they are generally comprised of smaller self-descriptive functions. What is the correct way to comment a functional program? Should I use the same approach as in iterative programming?

    Read the article

  • Why is MaybeChannelBound callable?

    - by William Payne
    The Queue class in the python kombu library inherits from MaybeChannelBound, which in turn implements the call method (making it callable). The call() method itself is a thin wrapper around the bind() method. It is not clear why this was done, as calling the bind() method seems (to my simple mind, at least) to be clearer and more descriptive of the intent of the function. Why would somebody use the call() method in a situation like this?

    Read the article

  • How do I use D3DXVec3Unproject with D3D11?

    - by Miguel P
    I'm having a small issue with D3DXVec3Unproject. I'm currently using Direct3D 11 and not 10, and the signature for this function is: D3DXVECTOR3 *pOut, CONST D3DXVECTOR3 *pV, CONST D3D10_VIEWPORT *pViewport, CONST D3DXMATRIX *pProjection, CONST D3DXMATRIX *pView, CONST D3DXMATRIX *pWorld As you may have noticed, it requires a D3D10_VIEWPORT, and I'm using a Direct3D 11 viewport, D3D11_VIEWPORT. Do you have any ideas how I can use D3DXVec3Unproject with Direct3D 11?

    Read the article

  • Strange date relationships with #PowerPivot

    - by Marco Russo (SQLBI)
    A reader of my PowerPivot book highlighted a strange behavior of the relationship between a datetime column and a Calendar table. Long story short: it seems that PowerPivot automatically round the date to the “neareast day”, but instead of simply removing the time (truncating the decimal part of the decimal number internally used to represent a datetime value) a rounding function seems used, moving the date to the next day if the time part contain a PM time. As you can imagine, this becomes particularly...(read more)

    Read the article

  • What does 'Lock Version' do?

    - by richzilla
    Having installed an experimental version of dropbox and installed in manually, i dont want the deb in synaptic to download any updates (as theyll over write the changes ive done manually i assume). Ive found the lock version option in synaptic, im assuming this stops a particular deb from downloading any new versions of itself? Also can i just unlock it again when the version from the deb catches up with the experimental version that i have installed? Am i correct or does it serve another function?

    Read the article

  • Box2D relations

    - by Valentino Ru
    As far as I know, the unit in Box2D is meters. When I use Box2D in Processing with JBox2D, I set the "world size" as the window size specified in the setup(). Now I'm wondering if there is any function that scales down the world. For example, how can I simulate the throw of tennis ball within a room, without using a window of only 5 x 5 pixels? Additionally, is there any good documentation like the Java API?

    Read the article

  • Deciding between obj->func() and func(obj)

    - by GSto
    I was thinking about this when I was starting to set up some code for a new project: are there any rules of thumb for when a method should be part of an object, and when it should be a stand alone function that takes an object as a parameter? EDIT: as pointed out in a comment, this can depend on language. I was working in C++ when it came to mind, though I'm this is an issue across a number of languages (and would still love to see answers that pertain to them).

    Read the article

  • Why don't languages include implication as a logical operator?

    - by Maciej Piechotka
    It might be a strange question, but why there is no implication as a logical operator in many languages (Java, C, C++, Python Haskell - although as last one have user defined operators its trivial to add it)? I find logical implication much clearer to write (particularly in asserts or assert-like expressions) then negation with or: encrypt(buf, key, mode, iv = null) { assert (mode != ECB --> iv != null); assert (mode == ECB || iv != null); assert (implies(mode != ECB, iv != null)); // User-defined function }

    Read the article

  • Validate if aTextBox Value Start with a Specific Letter

    - by Vincent Maverick Durano
    In case you will be working on a page that needs to validate the first character of the TextBox entered by a user then here are two options that you can use: Option 1: Using an array   1: <asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server"> 2: <script type="text/javascript"> 3: function CheckFirstChar(o) { 4: var arr = ['A', 'B', 'C', 'D']; 5: if (o.value.length > 0) { 6: for (var i = 0; i < arr.length; i++) { 7: if (o.value.charAt(0) == arr[i]) { 8: alert('Valid'); 9: return true; 10: } 11: else { 12: alert('InValid'); 13: return false; 14: } 15: } 16: } 17: } 18: </script> 19: </asp:Content> 20: <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> 21: <asp:TextBox ID="TextBox1" runat="server" onblur="return CheckFirstChar(this);"></asp:TextBox> 22: </asp:Content>   The example above uses an array of string for storing the list of  characters that a TextBox value should start with. We then iterate to the array and compare the first character of TextBox value to see if it matches any characters from the array. Option 2: Using Regular Expression (Preferred way)   1: <asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server"> 2: <script type="text/javascript"> 3: function CheckFirstChar(o) { 4: pattern = /^(A|B|C|D)/; 5: if (!pattern.test(o.value)) { 6: alert('InValid'); 7: return false; 8: } else { 9: alert('Valid'); 10: return true; 11: } 12: } 13: </script> 14: </asp:Content> 15: <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> 16: <asp:TextBox ID="TextBox1" runat="server" onblur="return CheckFirstChar(this);"></asp:TextBox> 17: </asp:Content>   The example above uses regular expression with the pattern  /^(A|B|C|D)/. This will check if the TextBox value starts with A,B,C or D. Please note that it's case sensitive. If you want to allow lower case then you can alter the patter to this /^(A|B|C|D)/i. The i in the last part will cause a case-insensitive search.   That's it! I hope someone find this post useful!

    Read the article

  • Google analytics e-commerce tracking

    - by crayden
    Good morning or afternoon wherever you are, I am having issues with Google Analytics e-commerce tracking. On certain days it the e-commerce tracking is returning a value of $1.00 of revenue which is impossible because it is a hotel booking website. Im am so puzzled and not knowing where to go next with this. Any assistance is greatly appreciated. Thank you! Here is some code that might help, I received this from our contact who develops the booking engine. This is included on every page except the reservation confirmation page: <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-26956700-1']); _gaq.push(["_setDomainName", "none"]); _gaq.push(["_setAllowLinker", true]); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); </script> This is included only on the reservation confirmation page: (The "${res.xxx}" elements are replaced on the server side with reservation details.) <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(["_setAccount", "UA-26956700-1"]); _gaq.push(["_setDomainName", "none"]); _gaq.push(["_setAllowLinker", true]); _gaq.push(["_trackPageview"]); _gaq.push(["_addTrans", "${res.confirmationNumber}", "Sunshine", "${res.grandTotal}", "${res.totalPriceTax}", "", "", "", ""]); _gaq.push(["_addItem", "${res.confirmationNumber}", "${res.roomType}", "", "", "${res.totalPrice}", "1"]); _gaq.push(["_addItem", "${res.confirmationNumber}", "Options", "", "","${res.otherChargeChoices.totalCostExclTax}", "1"]); _gaq.push(["_trackTrans"]); (function(){ var ga = document.createElement("script"); ga.type = "text/javascript"; ga.async = true; ga.src = ("https:" == document.location.protocol ? "https://ssl" : "http://www") + ".google-analytics.com/ga.js"; var s = document.getElementsByTagName("script")[0]; s.parentNode.insertBefore(ga, s); })();

    Read the article

  • Understanding exceptional cases

    - by Justin
    I've been studying the use of exceptions in various php projects (such as Doctrine and Zend Framework). Exceptions seem to be thrown when unordinary input/state occurs. A perfect example is Doctrine throwing an exception when you try to use a invalid query string. I think the creators of the doctrine api understood that first, you can't query data by using an invalid DQL statement, and a developer should immediately be warned that an error has occurred, rather then letting execution continue with the possibility of an error code going un-checked. I also bet that this simplifies reading the code. I can't think of a situation where you would want to use an invalid DQL statement, except unit testing. Since this is true, it's better to avoid plaguing a bunch of code with null/error checks and use exceptions. I've read in books that exceptions shouldn't be thrown when validating dating user input. I've seen examples where of where the guideline is broken. One example is the Zend framework. If supplying an invalid controller or action name, an exception is thrown. Unlike doctrine, the user has more direct control over this sort of input. I know you can configure an error controller and set up a 404 message or what have you, but I'm curious why they have used an exception in this scenario? I guess you can argue the Zend Framework does not know how to continue processing the quest. One last example Is I wrote a function to return some html based on a given resource type. This resource type is hard-coded and sent when a user interacts with a web site (such as clicking a button to display the form to input data). I don't expect users to be mucking around with the request type. Under normal operating conditions, the resource type should be valid. To clean up some logic, I was going to throw an exception if a particular form wasn't found. This is mainly to find the correct form associated with a resource type so proper validation can occur. Does this sound like a valid use case for an exception? Right now it's pretty trivial, but I do plan to implement a restful consumer and re-using a function to map resources to their validation services would be very useful. I can then catch the exception and based on the consumer, return an error message suitable for the request type...

    Read the article

< Previous Page | 693 694 695 696 697 698 699 700 701 702 703 704  | Next Page >