Search Results

Search found 20733 results on 830 pages for 'ui design'.

Page 1/830 | 1 2 3 4 5 6 7 8 9 10 11 12 | Next Page >

What is difference between Interaction design, Visual Design, Web design, UX design, UI design, UI d

- by rajakvk

What is difference between Interaction design, Visual Design, Web design, UX design, UI design, UI development? BTB, link found below answered for UI Vs UX. http://stackoverflow.com/questions/1334496/difference-between-ui-and-ux

Read the article
Good design cannot be over-design

- by ??? Shengyuan Lu

Many engineers intend to design software to build "flexible" system in which many design patterns and interfaces there. Eventually too many interfaces and complex inheritances mess up the system. In most cases I think the improper design caused the mess, rather than not over-design. If design is reasonable, it's hard to be over. Alternatively, If we don't have enough skill to achieve flexible design, we choose to plain and practical design. What's your opinion about my understanding?

Read the article
design pattern advice: graph -> computation

- by csetzkorn

I have a domain model, persisted in a database, which represents a graph. A graph consists of nodes (e.g. NodeTypeA, NodeTypeB) which are connected via branches. The two generic elements (nodes and branches will have properties). A graph will be sent to a computation engine. To perform computations the engine has to be initialised like so (simplified pseudo code): Engine Engine = new Engine() ; Object ID1 = Engine.AddNodeTypeA(TypeA.Property1, TypeA.Property2, …, TypeA.Propertyn); Object ID2 = Engine.AddNodeTypeB(TypeB.Property1, TypeB.Property2, …, TypeB.Propertyn); Engine.AddBranch(ID1,ID2); Finally the computation is performed like this: Engine.DoSomeComputation(); I am just wondering, if there are any relevant design patterns out there, which help to achieve the above using good design principles. I hope this makes sense. Any feedback would be very much appreciated.

Read the article
Ubuntu 12.04 + Eclipse 64 bits key binding error

- by user110933

The text is quite extense so, this is just a part of it: !SESSION 2012-11-23 10:15:52.442 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 10:16:06.408 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 10:16:06.408 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.eclipse.ui.workbench 4 0 2012-11-23 10:16:10.409 !MESSAGE An unexpected exception was thrown. !STACK 0 java.lang.NullPointerException at org.eclipse.ui.internal.WorkbenchWindow.putToolbarLabel(WorkbenchWindow.java:1697) at org.eclipse.ui.internal.menus.MenuAdditionCacheEntry.createToolBarAdditionContribution(MenuAdditionCacheEntry.java:208) at org.eclipse.ui.internal.menus.MenuAdditionCacheEntry.createContributionItems(MenuAdditionCacheEntry.java:177) at org.eclipse.ui.internal.menus.TrimContributionManager.update(TrimContributionManager.java:224) at org.eclipse.ui.internal.WorkbenchWindow.updateLayoutDataForContents(WorkbenchWindow.java:3874) at org.eclipse.ui.internal.WorkbenchWindow.setCoolBarVisible(WorkbenchWindow.java:3675) at org.eclipse.ui.internal.ViewIntroAdapterPart.setBarVisibility(ViewIntroAdapterPart.java:203) at org.eclipse.ui.internal.ViewIntroAdapterPart.dispose(ViewIntroAdapterPart.java:106) at org.eclipse.ui.internal.WorkbenchPartReference.doDisposePart(WorkbenchPartReference.java:737) at org.eclipse.ui.internal.ViewReference.doDisposePart(ViewReference.java:107) at org.eclipse.ui.internal.WorkbenchPartReference.dispose(WorkbenchPartReference.java:684) at org.eclipse.ui.internal.WorkbenchPage.disposePart(WorkbenchPage.java:1801) at org.eclipse.ui.internal.WorkbenchPage.partRemoved(WorkbenchPage.java:1793) at org.eclipse.ui.internal.ViewFactory.releaseView(ViewFactory.java:257) at org.eclipse.ui.internal.Perspective.dispose(Perspective.java:292) at org.eclipse.ui.internal.WorkbenchPage.dispose(WorkbenchPage.java:1872) at org.eclipse.ui.internal.WorkbenchWindow.closeAllPages(WorkbenchWindow.java:894) at org.eclipse.ui.internal.WorkbenchWindow.hardClose(WorkbenchWindow.java:1729) at org.eclipse.ui.internal.WorkbenchWindow.busyClose(WorkbenchWindow.java:730) at org.eclipse.ui.internal.WorkbenchWindow.access$0(WorkbenchWindow.java:715) at org.eclipse.ui.internal.WorkbenchWindow$6.run(WorkbenchWindow.java:867) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.ui.internal.WorkbenchWindow.close(WorkbenchWindow.java:865) at org.eclipse.jface.window.WindowManager.close(WindowManager.java:109) at org.eclipse.ui.internal.Workbench$18.run(Workbench.java:1114) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.ui.internal.Workbench.busyClose(Workbench.java:1111) at org.eclipse.ui.internal.Workbench.access$15(Workbench.java:1040) at org.eclipse.ui.internal.Workbench$25.run(Workbench.java:1284) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.ui.internal.Workbench.close(Workbench.java:1282) at org.eclipse.ui.internal.Workbench.close(Workbench.java:1254) at org.eclipse.ui.internal.WorkbenchWindow.busyClose(WorkbenchWindow.java:727) at org.eclipse.ui.internal.WorkbenchWindow.access$0(WorkbenchWindow.java:715) at org.eclipse.ui.internal.WorkbenchWindow$6.run(WorkbenchWindow.java:867) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.ui.internal.WorkbenchWindow.close(WorkbenchWindow.java:865) at org.eclipse.jface.window.Window.handleShellCloseEvent(Window.java:741) at org.eclipse.jface.window.Window$3.shellClosed(Window.java:687) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:98) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1276) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1300) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1285) at org.eclipse.swt.widgets.Shell.closeWidget(Shell.java:617) at org.eclipse.swt.widgets.Shell.gtk_delete_event(Shell.java:1191) at org.eclipse.swt.widgets.Widget.windowProc(Widget.java:1750) at org.eclipse.swt.widgets.Control.windowProc(Control.java:5116) at org.eclipse.swt.widgets.Display.windowProc(Display.java:4369) at org.eclipse.swt.internal.gtk.OS._gtk_main_do_event(Native Method) at org.eclipse.swt.internal.gtk.OS.gtk_main_do_event(OS.java:8295) at org.eclipse.swt.widgets.Display.eventProc(Display.java:1192) at org.eclipse.swt.internal.gtk.OS._g_main_context_iteration(Native Method) at org.eclipse.swt.internal.gtk.OS.g_main_context_iteration(OS.java:2332) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3177) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665) at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499) at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584) at org.eclipse.equinox.launcher.Main.run(Main.java:1438) at org.eclipse.equinox.launcher.Main.main(Main.java:1414) !SESSION 2012-11-23 10:36:07.863 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 10:36:13.181 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 10:36:13.181 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.eclipse.osgi 2 1 2012-11-23 10:39:04.681 !MESSAGE NLS unused message: CacheManager_CannotLoadNonUrlLocation in: org.eclipse.equinox.internal.p2.repository.messages !SESSION 2012-11-23 15:14:12.933 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 15:14:23.380 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:14:23.380 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.springframework.ide.eclipse.uaa 4 2 2012-11-23 15:14:32.800 !MESSAGE Problems occurred when invoking code from plug-in: "org.springframework.ide.eclipse.uaa". !STACK 0 java.lang.NullPointerException at org.springframework.ide.eclipse.internal.uaa.monitor.CommandUsageMonitor.startMonitoring(CommandUsageMonitor.java:61) at org.springframework.ide.eclipse.uaa.UaaPlugin$1$1.run(UaaPlugin.java:91) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.springframework.ide.eclipse.uaa.UaaPlugin$1.run(UaaPlugin.java:85) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54) !SESSION 2012-11-23 15:15:21.833 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 15:15:27.283 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:15:27.283 !MESSAGE A conflict occurred for ALT+SHIFT+R: Binding(ALT+SHIFT+R, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) Binding(ALT+SHIFT+R, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.defaultAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,system) !ENTRY org.eclipse.jface 2 0 2012-11-23 15:18:41.265 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:18:41.265 !MESSAGE A conflict occurred for ALT+SHIFT+E: Binding(ALT+SHIFT+E, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.wst.jsdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.wst.jsdt.ui.category.refactoring,Refactor - JavaScript,JavaScript Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) !SESSION 2012-11-23 15:18:56.267 ----------------------------------------------- eclipse.buildId=I20120608-1200 java.version=1.7.0_09 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US Command-line arguments: -os linux -ws gtk -arch x86_64 !ENTRY org.eclipse.jface 2 0 2012-11-23 15:19:01.605 !MESSAGE Keybinding conflicts occurred. They may interfere with normal accelerator operation. !SUBENTRY 1 org.eclipse.jface 2 0 2012-11-23 15:19:01.605 !MESSAGE A conflict occurred for ALT+SHIFT+E: Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.wst.jsdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.wst.jsdt.ui.category.refactoring,Refactor - JavaScript,JavaScript Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(org.eclipse.jdt.ui.edit.text.java.rename.element,Rename - Refactoring , Rename the selected element, Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), , ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user) Binding(ALT+SHIFT+E, ParameterizedCommand(Command(oracle.eclipse.tools.common.services.ui.refactor.rename.command,Rename, Rename the selected text., Category(org.eclipse.jdt.ui.category.refactoring,Refactor - Java,Java Refactoring Actions,true), oracle.eclipse.tools.common.services.ui.refactor.internal.ArtifactRefactoringCommandHandler, ,,true),null), org.eclipse.ui.emacsAcceleratorConfiguration, org.eclipse.ui.contexts.window,,,user)

Read the article
Recommendations for books and training resources covering for Design for Programmers

- by Jon Hopkins

Off the back of one of the answers to this question (currently the second highest scoring), it made me think, what's the best way to get developers up to speed on good basic design principals. I'm not talking about making them into graphic designers but some developers almost take pride in ugly UIs, seeing them as unimportant next to the functionality. What primarily interested in are the graphic design elements rather than the usability aspects which is pretty well covered by books such as Don't Make Me Think. Use of white space, emphasis, font selection and a million other things I'm probably not even aware of. I know people are often seen as artistic or not artistic but surely the basics can be taught and someone has written a book covering this?

Read the article
How should I design a correct OO design in case of a Business-logic wide operation

- by Mithir

EDIT: Maybe I should ask the question in a different way. in light of ammoQ's comment, I realize that I've done something like suggested which is kind of a fix and it is fine by me. But I still want to learn for the future, so that if I develop new code for operations similar to this, I can design it correctly from the start. So, if I got the following characteristics: The relevant input is composed from data which is connected to several different business objects All the input data is validated and cross-checked Attempts are made in order to insert the data to the DB All this is just a single operation from Business side prospective, meaning all of the cross checking and validations are just side effects. I can't think of any other way but some sort of Operator/Coordinator kind of Object which activates the entire procedure, but then I fall into a Functional-Decomposition kind of code. so is there a better way in doing this? Original Question In our system we have many complex operations which involve many validations and DB activities. One of the main Business functionality could have been designed better. In short, there were no separation of layers, and the code would only work from the scenario in which it was first designed at, and now there were more scenarios (like requests from an API or from other devices) So I had to redesign. I found myself moving all the DB code to objects which acts like Business to DB objects, and I've put all the business logic in an Operator kind of a class, which I've implemented like this: First, I created an object which will hold all the information needed for the operation let's call it InformationObject. Then I created an OperatorObject which will take the InformationObject as a parameter and act on it. The OperatorObject should activate different objects and validate or check for existence or any scenario in which the business logic is compromised and then make the operation according to the information on the InformationObject. So my question is - Is this kind of implementation correct? PS, this Operator only works on a single Business-wise Operation.

Read the article
Loose Coupling in Object Oriented Design

- by m3th0dman

I am trying to learn GRASP and I found this explained (here on page 3) about Low Coupling and I was very surprised when I found this: Consider the method addTrack for an Album class, two possible methods are: addTrack( Track t ) and addTrack( int no, String title, double duration ) Which method reduces coupling? The second one does, since the class using the Album class does not have to know a Track class. In general, parameters to methods should use base types (int, char ...) and classes from the java.* packages. I tend to diasgree with this; I believe addTrack(Track t) is better than addTrack(int no, String title, double duration) due to various reasons: It is always better for a method to as fewer parameters as possible (according to Uncle Bob's Clean Code none or one preferably, 2 in some cases and 3 in special cases; more than 3 needs refactoring - these are of course recommendations not holly rules). If addTrack is a method of an interface, and the requirements need that a Track should have more information (say year or genre) then the interface needs to be changed and so that the method should supports another parameter. Encapsulation is broke; if addTrack is in an interface, then it should not know the internals of the Track. It is actually more coupled in the second way, with many parameters. Suppose the no parameter needs to be changed from int to long because there are more than MAX_INT tracks (or for whatever reason); then both the Track and the method need to be changed while if the method would be addTrack(Track track) only the Track would be changed. All the 4 arguments are actually connected with each other, and some of them are consequences from others. Which approach is better?

Read the article
Design suggestions needed to create a MathBuilder framework

- by Darf Zon

Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

Read the article
Starting to create a MathBuilder framework, help to start creating the design

- by Darf Zon

Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

Read the article
jQuery UI Accordion CSS

- by ScG

I am planning to use the jQuery UI Accordion and also the default theme provided I see that the jQuery UI Accordion uses the following classes from this url link text <div class="ui-accordion ui-widget ui-helper-reset"> <h3 class="ui-accordion-header ui-helper-reset ui-state-active ui-corner-top"> <span class="ui-icon ui-icon-triangle-1-s"/> <a href="#">Section 1</a> </h3> <div class="ui-accordion-content ui-helper-reset ui-widget-content ui-corner-bottom ui-accordion-content-active"> Section 1 content </div> <h3 class="ui-accordion-header ui-helper-reset ui-state-default ui-corner-all"> <span class="ui-icon ui-icon-triangle-1-e"/> <a href="#">Section 2</a> </h3> <div class="ui-accordion-content ui-helper-reset ui-widget-content ui-corner-bottom"> Section 2 content </div> <h3 class="ui-accordion-header ui-helper-reset ui-state-default ui-corner-all"> <span class="ui-icon ui-icon-triangle-1-e"/> <a href="#">Section 3</a> </h3> <div class="ui-accordion-content ui-helper-reset ui-widget-content ui-corner-bottom"> Section 3 content </div> </div> I do not want to use the entire CSS from the theme file, just the ones required for the UI Accordion. However I am not able to create the same effect. Anyone can help?

Read the article
Duplication in parallel inheritance hierarchies

- by flamingpenguin

Using an OO language with static typing (like Java), what are good ways to represent the following model invariant without large amounts of duplication. I have two (actually multiple) flavours of the same structure. Each flavour requires its own (unique to that flavour data) on each of the objects within that structure as well as some shared data. But within each instance of the aggregation only objects of one (the same) flavour are allowed. FooContainer can contain FooSources and FooDestinations and associations between the "Foo" objects BarContainer can contain BarSources and BarDestinations and associations between the "Bar" objects interface Container() { List<? extends Source> sources(); List<? extends Destination> destinations(); List<? extends Associations> associations(); } interface FooContainer() extends Container { List<? extends FooSource> sources(); List<? extends FooDestination> destinations(); List<? extends FooAssociations> associations(); } interface BarContainer() extends Container { List<? extends BarSource> sources(); List<? extends BarDestination> destinations(); List<? extends BarAssociations> associations(); } interface Source { String getSourceDetail1(); } interface FooSource extends Source { String getSourceDetail2(); } interface BarSource extends Source { String getSourceDetail3(); } interface Destination { String getDestinationDetail1(); } interface FooDestination extends Destination { String getDestinationDetail2(); } interface BarDestination extends Destination { String getDestinationDetail3(); } interface Association { Source getSource(); Destination getDestination(); } interface FooAssociation extends Association { FooSource getSource(); FooDestination getDestination(); String getFooAssociationDetail(); } interface BarAssociation extends Association { BarSource getSource(); BarDestination getDestination(); String getBarAssociationDetail(); }

Read the article
Design patterns and multiple programming language

- by Eduard Florinescu

I am referring here to the design patterns found in the GOF book. First how I see it, there are a few peculiarities to design pattern and knowing multiple language knowledge, for example in Java you really need a singleton but in Python you can do without it you write a module, I saw somewhere a wiki trying to write all GOF patterns for JavaScript and the entries where empty, I guess because it might be a daunting task. If there is someone who is using design patterns and is programming in multiple programming languages supporting the OOP paradigm and can give me a hint on how should I approach design patterns that might help me in all languages I use(Java, JavaScript, Python, Ruby): Can I write good application without knowing exactly the GOF design patterns or I might need some of them which might be crucial and if yes which one, are they alternatives to GOF for specific languages, and should a programmer or a team make its own design patterns set?

Read the article
Design patterns and multiple programming languages

- by Eduard Florinescu

I am referring here to the design patterns found in the GOF book. First, how I see it, there are a few peculiarities to design pattern and knowing multiple languages, for example in Java you really need a singleton but in Python you can do without it you write a module, I saw somewhere a wiki trying to write all GOF patterns for JavaScript and all the entries were empty, I guess because it might be a daunting task to do that adaptation. If there is someone who is using design patterns and is programming multiple languages supporting the OOP paradigm and can give me a hint on how should I approach design patterns. An approach that might help me in all languages I use(Java, JavaScript, Python, Ruby): Can I write good application without knowing exactly the GOF design patterns or I might need just some of them which might be crucial and if yes which one, are there alternatives to GOF for specific languages, and should a programmer or a team make their own design patterns set?

Read the article
Is the design notion of layers contrived?

- by Bruce

Hi all I'm reading through Eric Evans' awesome work, Domain-Driven Design. However, I can't help feeling that the 'layers' model is contrived. To expand on that statement, it seems as if it tries to shoe-horn various concepts into a specific, neat model, that of layers talking to each other. It seems to me that the layers model is too simplified to actually capture the way that (good) software works. To expand further: Evans says: "Partition a complex program into layers. Develop a design within each layer that is cohesive and that depends only on the layers below. Follow standard architectural patterns to provide loose coupling to the layers above." Maybe I'm misunderstanding what 'depends' means, but as far as I can see, it can either mean a) Class X (in the UI for example) has a reference to a concrete class Y (in the main application) or b) Class X has a reference to a class Y-ish object providing class Y-ish services (ie a reference held as an interface). If it means (a), then this is clearly a bad thing, since it defeats re-using the UI as a front-end to some other application that provides Y-ish functionality. But if it means (b), then how is the UI any more dependent on the application, than the application is dependent on the UI? Both are decoupled from each other as much as they can be while still talking to each other. Evans' layer model of dependencies going one way seems too neat. First, isn't it more accurate to say that each area of the design provides a module that is pretty much an island to itself, and that ideally all communication is through interfaces, in a contract-driven/responsibility-driven paradigm? (ie, the 'dependency only on lower layers' is contrived). Likewise with the domain layer talking to the database - the domain layer is as decoupled (through DAO etc) from the database as the database is from the domain layer. Neither is dependent on the other, both can be swapped out. Second, the idea of a conceptual straight line (as in from one layer to the next) is artificial - isn't there more a network of intercommunicating but separate modules, including external services, utility services and so on, branching off at different angles? Thanks all - hoping that your responses can clarify my understanding on this..

Read the article
jQuery UI Tabs Plugin Broke

- by Warren J Thompson

We are using the jquery ui tabs arrow plugin from this fiddle: http://jsfiddle.net/dECtZ/282/, but like many plugins, it breaks with the latest version of jQuery. We were able to get the csscur to work, but still get the following error in the jquery core (line 353): Uncaught TypeError: Cannot assign to read only property 'length' of function (e,t){if(!this._createWidget)return new o(e,t);arguments.length&&this._createWidget(e,t)} Code is as follows: (function($, undefined) { if (!$.xui) { $.xui = {}; } var tabs = $.extend({}, $.ui.tabs.prototype), _super = { _create: tabs._create, _destroy: tabs._destroy, _update: tabs._update }; $.xui.tabs = $.extend(tabs, { options: $.extend({}, tabs.options, { scrollable: false, changeOnScroll: false, closable: false, resizable: false, resizeHandles: "e,s,se" }), _create: function() { var self = this, o = self.options; _super._create.apply(self); if (o.scrollable) { self.element.addClass("ui-tabs-scrollable"); var scrollContainer = $('<div class="ui-tabs-scroll-container"></div>').prependTo(this.element); self.header = $('<div class="ui-tabs-nav-scrollable ui-widget-header ui-corner-all"></div>').prependTo(scrollContainer); var nav = self.element.find(".ui-tabs-nav:first").removeClass("ui-widget-header ui-corner-all").appendTo(this.header); var arrowsNav = $('<ol class="ui-helper-reset ui-helper-clearfix ui-tabs-nav-arrows"></ol>').prependTo(self.element); var navPrev = $('<li class="ui-tabs-arrow-previous ui-state-default ui-corner-bl ui-corner-tl" title="Previous"><a href="#"><span class="ui-icon ui-icon-carat-1-w">Previous tab</span></a></li>').prependTo(arrowsNav).hide(), navNext = $('<li class="ui-tabs-arrow-next ui-state-default ui-corner-tr ui-corner-br" title="Next"><a href="#"><span class="ui-icon ui-icon-carat-1-e">Next tab</span></a></li>').appendTo(arrowsNav).hide(); var scrollTo = function(to, delay) { var navWidth = 0, arrowWidth = navPrev.outerWidth(), marginLeft = -(parseInt(nav.css("marginLeft"), 10)), hwidth = self.header.width(), newMargin = 0; nav.find("li").each(function() { navWidth += $(this).outerWidth(true); }); if (to instanceof $.Event) { } else { newMargin = marginLeft+to; if (newMargin > (navWidth-hwidth)) { newMargin = (navWidth-hwidth); } else if (newMargin < 0) { newMargin = 0; } nav.stop(true).animate({ marginLeft: -(newMargin) }, delay, function(){ $(window).trigger("resize.tabs"); }); } } var holdTimer = false; navPrev.add(navNext).bind({ "click": function(e) { var isNext = this === navNext[0]; e.preventDefault(); if (o.changeOnScroll) { self.select(self.options.selected + (isNext ? 1 : -1)); } else { if (!holdTimer) scrollTo(isNext ? 150 : -150, 250); } }, "mousedown": function(e){ if (!o.changeOnScroll) { var isNext = this === navNext[0], duration = 10, pos = 15, timer; if (holdTimer) clearTimeout(holdTimer); holdTimer = setTimeout(timer = function(){ scrollTo(isNext ? pos : -(pos), duration); holdTimer = setTimeout(arguments.callee, duration); }, 150); } }, "mouseup mouseout": function(e){ if (!o.changeOnScroll) { clearTimeout(holdTimer); holdTimer = false; nav.stop(); } } }); self.header.bind('mousewheel', function(e, d, dX, dY) { e.preventDefault(); if (d === -1) { navNext.click(); } else if (d === 1) { navPrev.click(); } }); $(window).bind("resize.tabs", function(e) { var navWidth = 0; var arrowWidth = navPrev.outerWidth(); nav.find("li").each(function() { navWidth += $(this).outerWidth(true); }); var marginLeft = -(parseInt(nav.css("marginLeft"), 10)), hwidth = self.header.width(); if (navWidth > (hwidth+marginLeft)) { self.header.addClass("ui-tabs-arrow-r"); navNext.show("fade"); if (marginLeft > 0) { self.header.addClass("ui-tabs-arrow-l"); navPrev.show("fade"); } else { self.header.removeClass("ui-tabs-arrow-l"); navPrev.hide("fade"); } } else { self.header.removeClass("ui-tabs-arrows ui-tabs-arrow-l"); navNext.hide("fade"); if (marginLeft > 0) { self.header.addClass("ui-tabs-arrow-l"); navPrev.show("fade"); } else { self.header.removeClass("ui-tabs-arrow-l"); navPrev.hide("fade"); } } }).trigger("resize.tabs"); arrowsNav.find("li").bind({ "mouseenter focus": function(e) { $(this).addClass("ui-state-hover"); }, "mouseleave blur": function(e) { $(this).removeClass("ui-state-hover"); } }); this.anchors.bind("click.tabs", function(){ var li = $(this).parent(), arrowWidth = navPrev.outerWidth(), width = li.outerWidth(true), hwidth = self.header.width(), pos = li.position().left, marginLeft = -(parseInt(nav.stop(true,true).css("marginLeft"),10)), newMargin = -1; if (li.index() === 0) { newMargin = 0; } else if ((pos+width) >= (hwidth+marginLeft)) { newMargin = pos-hwidth+width; if ((li.index()+1) < nav.find("li").length) { newMargin += arrowWidth; } } else if (pos < marginLeft) { newMargin = pos-arrowWidth; } if (newMargin > -1) { nav.animate({ marginLeft: -(newMargin) }, 250, function(){ $(window).trigger("resize.tabs"); }); } }); } return self; }, _update: function(){ console.log(arguments); _super._update.apply(this); } }); $.widget("xui.tabs", $.xui.tabs); })(jQuery); $(function() { $("#tabs").tabs({ scrollable: true, changeOnScroll: false, closable: true }); $("#switcher").themeswitcher(); });

Read the article
How to conciliate OOAD and Database Design?

- by user1620696

Recently I've studied about object oriented analysis and design and I liked a lot about it. In every place I've read people say that the idea is to start with the minimum set of requirements and go improving along the way, revisiting this each iteration and making it better as we contiuously develop and contact the customer interested in the software. In particular, one course from Lynda.com said a lot of that: we don't want to spend a lot of time planing everything upfront, we just want to have the minimum to get started and then improve this each iteration. Now, I've also seem a course from the same guy about database design, and there he says differently. He says that although when working with object orientation he likes the agile iterative approach, for database design we should really spend a lot of time planing things upfront instead of just going along the way with the minimum. But this confuses me a little. Indeed, the database will persist important data from our domain model and perhaps configurations of the software and so on. Now, if I'm going to continuously revist the analysis and design of the model, it seems the database design should change also. In the same way, if we plan all the database upfront it seems we are also planing all the model upfront, so the two ideas seems to be incompatible. I really like agile iterative approach, but I'm also looking at getting better design for the database also, so when working with agile iterative approach, how should we deal with the database design?

Read the article
software architecture (OO design) refresher course

- by PeterT

I am lead developer and team lead in a small RAD team. Deadlines are tight and we have to release often, which we do, and this is what keep the business happy. While we (the development team) are trying to maintain the quality of the code (clean and short methods), I can't help but notice that the overall quality of the OO design&architecture is getting worse over the time - the library we are working on is gradually reducing itself to a "bag of functions". Well, we try to use the design patterns, but since we don't really have much time for a design as such we are mostly using the creational ones. I have read Code Complete / Design Patterns (GOF & enterprise) / Progmatic Programmer / and many books from Effective XXX series. Should I re-read them again as I have read them a long time ago and forgotten quite a lot, or there are other / better OO design / software architeture books been published since then which I should definitely read? Any ideas, recommendations on how can I get the situation under control and start improving the architecture. The way I see it - I will start improving the architectural / design quality of software components I am working on and then will start helping other team members once I find what is working for me.

Read the article
Who benefits from the use of Design Patterns?

Who benefits from the use of design patterns is like asking who benefits from clean air or a good education. All of the stakeholders of a project benefit from the use of design patterns. Project Sponsor Project sponsors benefit from the use of design patterns because they promote reduced development time which translates in to shorter project timelines and greater return on investment compared to other projects that do not make use of design patterns. Project Manager Project managers benefit from the use of design patterns because they reduce the amount of time needed to design a system, and typically the sub components of the system already have a proven track record. System Architect/Engineer System architects/engineers benefit from the use of design patterns because reduce the amount of time needed to design the core a system. The additional time is used to alter the design pattern through the use of innovative design and common design principles to adhere to the project’s requirements. Programmer Programmers benefit from the use of design patterns because they can reuse existing code already established by the design pattern and only have to integrate the changes outlined by the system architects/engineers. Tester Testers benefit from the use of design patterns because they can alter the existing test established for the design pattern to take in to account the changes made by the system architects/engineers. User Users benefit from the use of design patterns because the software is typically delivered sooner than projects that do not incorporate the use of design patterns, and they are assumed that the system will work as designed because it was based on a system that was already proven to work properly.

Read the article
The Incremental Architect’s Napkin - #5 - Design functions for extensibility and readability

- by Ralf Westphal

Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/24/the-incremental-architectrsquos-napkin---5---design-functions-for.aspx The functionality of programs is entered via Entry Points. So what we´re talking about when designing software is a bunch of functions handling the requests represented by and flowing in through those Entry Points. Designing software thus consists of at least three phases: Analyzing the requirements to find the Entry Points and their signatures Designing the functionality to be executed when those Entry Points get triggered Implementing the functionality according to the design aka coding I presume, you´re familiar with phase 1 in some way. And I guess you´re proficient in implementing functionality in some programming language. But in my experience developers in general are not experienced in going through an explicit phase 2. “Designing functionality? What´s that supposed to mean?” you might already have thought. Here´s my definition: To design functionality (or functional design for short) means thinking about… well, functions. You find a solution for what´s supposed to happen when an Entry Point gets triggered in terms of functions. A conceptual solution that is, because those functions only exist in your head (or on paper) during this phase. But you may have guess that, because it´s “design” not “coding”. And here is, what functional design is not: It´s not about logic. Logic is expressions (e.g. +, -, && etc.) and control statements (e.g. if, switch, for, while etc.). Also I consider calling external APIs as logic. It´s equally basic. It´s what code needs to do in order to deliver some functionality or quality. Logic is what´s doing that needs to be done by software. Transformations are either done through expressions or API-calls. And then there is alternative control flow depending on the result of some expression. Basically it´s just jumps in Assembler, sometimes to go forward (if, switch), sometimes to go backward (for, while, do). But calling your own function is not logic. It´s not necessary to produce any outcome. Functionality is not enhanced by adding functions (subroutine calls) to your code. Nor is quality increased by adding functions. No performance gain, no higher scalability etc. through functions. Functions are not relevant to functionality. Strange, isn´t it. What they are important for is security of investment. By introducing functions into our code we can become more productive (re-use) and can increase evolvability (higher unterstandability, easier to keep code consistent). That´s no small feat, however. Evolvable code can hardly be overestimated. That´s why to me functional design is so important. It´s at the core of software development. To sum this up: Functional design is on a level of abstraction above (!) logical design or algorithmic design. Functional design is only done until you get to a point where each function is so simple you are very confident you can easily code it. Functional design an logical design (which mostly is coding, but can also be done using pseudo code or flow charts) are complementary. Software needs both. If you start coding right away you end up in a tangled mess very quickly. Then you need back out through refactoring. Functional design on the other hand is bloodless without actual code. It´s just a theory with no experiments to prove it. But how to do functional design? An example of functional design Let´s assume a program to de-duplicate strings. The user enters a number of strings separated by commas, e.g. a, b, a, c, d, b, e, c, a. And the program is supposed to clear this list of all doubles, e.g. a, b, c, d, e. There is only one Entry Point to this program: the user triggers the de-duplication by starting the program with the string list on the command line C:\>deduplicate "a, b, a, c, d, b, e, c, a" a, b, c, d, e …or by clicking on a GUI button. This leads to the Entry Point function to get called. It´s the program´s main function in case of the batch version or a button click event handler in the GUI version. That´s the physical Entry Point so to speak. It´s inevitable. What then happens is a three step process: Transform the input data from the user into a request. Call the request handler. Transform the output of the request handler into a tangible result for the user. Or to phrase it a bit more generally: Accept input. Transform input into output. Present output. This does not mean any of these steps requires a lot of effort. Maybe it´s just one line of code to accomplish it. Nevertheless it´s a distinct step in doing the processing behind an Entry Point. Call it an aspect or a responsibility - and you will realize it most likely deserves a function of its own to satisfy the Single Responsibility Principle (SRP). Interestingly the above list of steps is already functional design. There is no logic, but nevertheless the solution is described - albeit on a higher level of abstraction than you might have done yourself. But it´s still on a meta-level. The application to the domain at hand is easy, though: Accept string list from command line De-duplicate Present de-duplicated strings on standard output And this concrete list of processing steps can easily be transformed into code:static void Main(string[] args) { var input = Accept_string_list(args); var output = Deduplicate(input); Present_deduplicated_string_list(output); } Instead of a big problem there are three much smaller problems now. If you think each of those is trivial to implement, then go for it. You can stop the functional design at this point. But maybe, just maybe, you´re not so sure how to go about with the de-duplication for example. Then just implement what´s easy right now, e.g.private static string Accept_string_list(string[] args) { return args[0]; } private static void Present_deduplicated_string_list( string[] output) { var line = string.Join(", ", output); Console.WriteLine(line); } Accept_string_list() contains logic in the form of an API-call. Present_deduplicated_string_list() contains logic in the form of an expression and an API-call. And then repeat the functional design for the remaining processing step. What´s left is the domain logic: de-duplicating a list of strings. How should that be done? Without any logic at our disposal during functional design you´re left with just functions. So which functions could make up the de-duplication? Here´s a suggestion: De-duplicate Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Processing step 2 obviously was the core of the solution. That´s where real creativity was needed. That´s the core of the domain. But now after this refinement the implementation of each step is easy again:private static string[] Parse_string_list(string input) { return input.Split(',') .Select(s => s.Trim()) .ToArray(); } private static Dictionary<string,object> Compile_unique_strings(string[] strings) { return strings.Aggregate( new Dictionary<string, object>(), (agg, s) => { agg[s] = null; return agg; }); } private static string[] Serialize_unique_strings( Dictionary<string,object> dict) { return dict.Keys.ToArray(); } With these three additional functions Main() now looks like this:static void Main(string[] args) { var input = Accept_string_list(args); var strings = Parse_string_list(input); var dict = Compile_unique_strings(strings); var output = Serialize_unique_strings(dict); Present_deduplicated_string_list(output); } I think that´s very understandable code: just read it from top to bottom and you know how the solution to the problem works. It´s a mirror image of the initial design: Accept string list from command line Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Present de-duplicated strings on standard output You can even re-generate the design by just looking at the code. Code and functional design thus are always in sync - if you follow some simple rules. But about that later. And as a bonus: all the functions making up the process are small - which means easy to understand, too. So much for an initial concrete example. Now it´s time for some theory. Because there is method to this madness ;-) The above has only scratched the surface. Introducing Flow Design Functional design starts with a given function, the Entry Point. Its goal is to describe the behavior of the program when the Entry Point is triggered using a process, not an algorithm. An algorithm consists of logic, a process on the other hand consists just of steps or stages. Each processing step transforms input into output or a side effect. Also it might access resources, e.g. a printer, a database, or just memory. Processing steps thus can rely on state of some sort. This is different from Functional Programming, where functions are supposed to not be stateful and not cause side effects.[1] In its simplest form a process can be written as a bullet point list of steps, e.g. Get data from user Output result to user Transform data Parse data Map result for output Such a compilation of steps - possibly on different levels of abstraction - often is the first artifact of functional design. It can be generated by a team in an initial design brainstorming. Next comes ordering the steps. What should happen first, what next etc.? Get data from user Parse data Transform data Map result for output Output result to user That´s great for a start into functional design. It´s better than starting to code right away on a given function using TDD. Please get me right: TDD is a valuable practice. But it can be unnecessarily hard if the scope of a functionn is too large. But how do you know beforehand without investing some thinking? And how to do this thinking in a systematic fashion? My recommendation: For any given function you´re supposed to implement first do a functional design. Then, once you´re confident you know the processing steps - which are pretty small - refine and code them using TDD. You´ll see that´s much, much easier - and leads to cleaner code right away. For more information on this approach I call “Informed TDD” read my book of the same title. Thinking before coding is smart. And writing down the solution as a bunch of functions possibly is the simplest thing you can do, I´d say. It´s more according to the KISS (Keep It Simple, Stupid) principle than returning constants or other trivial stuff TDD development often is started with. So far so good. A simple ordered list of processing steps will do to start with functional design. As shown in the above example such steps can easily be translated into functions. Moving from design to coding thus is simple. However, such a list does not scale. Processing is not always that simple to be captured in a list. And then the list is just text. Again. Like code. That means the design is lacking visuality. Textual representations need more parsing by your brain than visual representations. Plus they are limited in their “dimensionality”: text just has one dimension, it´s sequential. Alternatives and parallelism are hard to encode in text. In addition the functional design using numbered lists lacks data. It´s not visible what´s the input, output, and state of the processing steps. That´s why functional design should be done using a lightweight visual notation. No tool is necessary to draw such designs. Use pen and paper; a flipchart, a whiteboard, or even a napkin is sufficient. Visualizing processes The building block of the functional design notation is a functional unit. I mostly draw it like this: Something is done, it´s clear what goes in, it´s clear what comes out, and it´s clear what the processing step requires in terms of state or hardware. Whenever input flows into a functional unit it gets processed and output is produced and/or a side effect occurs. Flowing data is the driver of something happening. That´s why I call this approach to functional design Flow Design. It´s about data flow instead of control flow. Control flow like in algorithms is of no concern to functional design. Thinking about control flow simply is too low level. Once you start with control flow you easily get bogged down by tons of details. That´s what you want to avoid during design. Design is supposed to be quick, broad brush, abstract. It should give overview. But what about all the details? As Robert C. Martin rightly said: “Programming is abot detail”. Detail is a matter of code. Once you start coding the processing steps you designed you can worry about all the detail you want. Functional design does not eliminate all the nitty gritty. It just postpones tackling them. To me that´s also an example of the SRP. Function design has the responsibility to come up with a solution to a problem posed by a single function (Entry Point). And later coding has the responsibility to implement the solution down to the last detail (i.e. statement, API-call). TDD unfortunately mixes both responsibilities. It´s just coding - and thereby trying to find detailed implementations (green phase) plus getting the design right (refactoring). To me that´s one reason why TDD has failed to deliver on its promise for many developers. Using functional units as building blocks of functional design processes can be depicted very easily. Here´s the initial process for the example problem: For each processing step draw a functional unit and label it. Choose a verb or an “action phrase” as a label, not a noun. Functional design is about activities, not state or structure. Then make the output of an upstream step the input of a downstream step. Finally think about the data that should flow between the functional units. Write the data above the arrows connecting the functional units in the direction of the data flow. Enclose the data description in brackets. That way you can clearly see if all flows have already been specified. Empty brackets mean “no data is flowing”, but nevertheless a signal is sent. A name like “list” or “strings” in brackets describes the data content. Use lower case labels for that purpose. A name starting with an upper case letter like “String” or “Customer” on the other hand signifies a data type. If you like, you also can combine descriptions with data types by separating them with a colon, e.g. (list:string) or (strings:string[]). But these are just suggestions from my practice with Flow Design. You can do it differently, if you like. Just be sure to be consistent. Flows wired-up in this manner I call one-dimensional (1D). Each functional unit just has one input and/or one output. A functional unit without an output is possible. It´s like a black hole sucking up input without producing any output. Instead it produces side effects. A functional unit without an input, though, does make much sense. When should it start to work? What´s the trigger? That´s why in the above process even the first processing step has an input. If you like, view such 1D-flows as pipelines. Data is flowing through them from left to right. But as you can see, it´s not always the same data. It get´s transformed along its passage: (args) becomes a (list) which is turned into (strings). The Principle of Mutual Oblivion A very characteristic trait of flows put together from function units is: no functional units knows another one. They are all completely independent of each other. Functional units don´t know where their input is coming from (or even when it´s gonna arrive). They just specify a range of values they can process. And they promise a certain behavior upon input arriving. Also they don´t know where their output is going. They just produce it in their own time independent of other functional units. That means at least conceptually all functional units work in parallel. Functional units don´t know their “deployment context”. They now nothing about the overall flow they are place in. They are just consuming input from some upstream, and producing output for some downstream. That makes functional units very easy to test. At least as long as they don´t depend on state or resources. I call this the Principle of Mutual Oblivion (PoMO). Functional units are oblivious of others as well as an overall context/purpose. They are just parts of a whole focused on a single responsibility. How the whole is built, how a larger goal is achieved, is of no concern to the single functional units. By building software in such a manner, functional design interestingly follows nature. Nature´s building blocks for organisms also follow the PoMO. The cells forming your body do not know each other. Take a nerve cell “controlling” a muscle cell for example:[2] The nerve cell does not know anything about muscle cells, let alone the specific muscel cell it is “attached to”. Likewise the muscle cell does not know anything about nerve cells, let a lone a specific nerve cell “attached to” it. Saying “the nerve cell is controlling the muscle cell” thus only makes sense when viewing both from the outside. “Control” is a concept of the whole, not of its parts. Control is created by wiring-up parts in a certain way. Both cells are mutually oblivious. Both just follow a contract. One produces Acetylcholine (ACh) as output, the other consumes ACh as input. Where the ACh is going, where it´s coming from neither cell cares about. Million years of evolution have led to this kind of division of labor. And million years of evolution have produced organism designs (DNA) which lead to the production of these different cell types (and many others) and also to their co-location. The result: the overall behavior of an organism. How and why this happened in nature is a mystery. For our software, though, it´s clear: functional and quality requirements needs to be fulfilled. So we as developers have to become “intelligent designers” of “software cells” which we put together to form a “software organism” which responds in satisfying ways to triggers from it´s environment. My bet is: If nature gets complex organisms working by following the PoMO, who are we to not apply this recipe for success to our much simpler “machines”? So my rule is: Wherever there is functionality to be delivered, because there is a clear Entry Point into software, design the functionality like nature would do it. Build it from mutually oblivious functional units. That´s what Flow Design is about. In that way it´s even universal, I´d say. Its notation can also be applied to biology: Never mind labeling the functional units with nouns. That´s ok in Flow Design. You´ll do that occassionally for functional units on a higher level of abstraction or when their purpose is close to hardware. Getting a cockroach to roam your bedroom takes 1,000,000 nerve cells (neurons). Getting the de-duplication program to do its job just takes 5 “software cells” (functional units). Both, though, follow the same basic principle. Translating functional units into code Moving from functional design to code is no rocket science. In fact it´s straightforward. There are two simple rules: Translate an input port to a function. Translate an output port either to a return statement in that function or to a function pointer visible to that function. The simplest translation of a functional unit is a function. That´s what you saw in the above example. Functions are mutually oblivious. That why Functional Programming likes them so much. It makes them composable. Which is the reason, nature works according to the PoMO. Let´s be clear about one thing: There is no dependency injection in nature. For all of an organism´s complexity no DI container is used. Behavior is the result of smooth cooperation between mutually oblivious building blocks. Functions will often be the adequate translation for the functional units in your designs. But not always. Take for example the case, where a processing step should not always produce an output. Maybe the purpose is to filter input. Here the functional unit consumes words and produces words. But it does not pass along every word flowing in. Some words are swallowed. Think of a spell checker. It probably should not check acronyms for correctness. There are too many of them. Or words with no more than two letters. Such words are called “stop words”. In the above picture the optionality of the output is signified by the astrisk outside the brackets. It means: Any number of (word) data items can flow from the functional unit for each input data item. It might be none or one or even more. This I call a stream of data. Such behavior cannot be translated into a function where output is generated with return. Because a function always needs to return a value. So the output port is translated into a function pointer or continuation which gets passed to the subroutine when called:[3]void filter_stop_words( string word, Action<string> onNoStopWord) { if (...check if not a stop word...) onNoStopWord(word); } If you want to be nitpicky you might call such a function pointer parameter an injection. And technically you´re right. Conceptually, though, it´s not an injection. Because the subroutine is not functionally dependent on the continuation. Firstly continuations are procedures, i.e. subroutines without a return type. Remember: Flow Design is about unidirectional data flow. Secondly the name of the formal parameter is chosen in a way as to not assume anything about downstream processing steps. onNoStopWord describes a situation (or event) within the functional unit only. Translating output ports into function pointers helps keeping functional units mutually oblivious in cases where output is optional or produced asynchronically. Either pass the function pointer to the function upon call. Or make it global by putting it on the encompassing class. Then it´s called an event. In C# that´s even an explicit feature.class Filter { public void filter_stop_words( string word) { if (...check if not a stop word...) onNoStopWord(word); } public event Action<string> onNoStopWord; } When to use a continuation and when to use an event dependens on how a functional unit is used in flows and how it´s packed together with others into classes. You´ll see examples further down the Flow Design road. Another example of 1D functional design Let´s see Flow Design once more in action using the visual notation. How about the famous word wrap kata? Robert C. Martin has posted a much cited solution including an extensive reasoning behind his TDD approach. So maybe you want to compare it to Flow Design. The function signature given is:string WordWrap(string text, int maxLineLength) {...} That´s not an Entry Point since we don´t see an application with an environment and users. Nevertheless it´s a function which is supposed to provide a certain functionality. The text passed in has to be reformatted. The input is a single line of arbitrary length consisting of words separated by spaces. The output should consist of one or more lines of a maximum length specified. If a word is longer than a the maximum line length it can be split in multiple parts each fitting in a line. Flow Design Let´s start by brainstorming the process to accomplish the feat of reformatting the text. What´s needed? Words need to be assembled into lines Words need to be extracted from the input text The resulting lines need to be assembled into the output text Words too long to fit in a line need to be split Does sound about right? I guess so. And it shows a kind of priority. Long words are a special case. So maybe there is a hint for an incremental design here. First let´s tackle “average words” (words not longer than a line). Here´s the Flow Design for this increment: The the first three bullet points turned into functional units with explicit data added. As the signature requires a text is transformed into another text. See the input of the first functional unit and the output of the last functional unit. In between no text flows, but words and lines. That´s good to see because thereby the domain is clearly represented in the design. The requirements are talking about words and lines and here they are. But note the asterisk! It´s not outside the brackets but inside. That means it´s not a stream of words or lines, but lists or sequences. For each text a sequence of words is output. For each sequence of words a sequence of lines is produced. The asterisk is used to abstract from the concrete implementation. Like with streams. Whether the list of words gets implemented as an array or an IEnumerable is not important during design. It´s an implementation detail. Does any processing step require further refinement? I don´t think so. They all look pretty “atomic” to me. And if not… I can always backtrack and refine a process step using functional design later once I´ve gained more insight into a sub-problem. Implementation The implementation is straightforward as you can imagine. The processing steps can all be translated into functions. Each can be tested easily and separately. Each has a focused responsibility. And the process flow becomes just a sequence of function calls: Easy to understand. It clearly states how word wrapping works - on a high level of abstraction. And it´s easy to evolve as you´ll see. Flow Design - Increment 2 So far only texts consisting of “average words” are wrapped correctly. Words not fitting in a line will result in lines too long. Wrapping long words is a feature of the requested functionality. Whether it´s there or not makes a difference to the user. To quickly get feedback I decided to first implement a solution without this feature. But now it´s time to add it to deliver the full scope. Fortunately Flow Design automatically leads to code following the Open Closed Principle (OCP). It´s easy to extend it - instead of changing well tested code. How´s that possible? Flow Design allows for extension of functionality by inserting functional units into the flow. That way existing functional units need not be changed. The data flow arrow between functional units is a natural extension point. No need to resort to the Strategy Pattern. No need to think ahead where extions might need to be made in the future. I just “phase in” the remaining processing step: Since neither Extract words nor Reformat know of their environment neither needs to be touched due to the “detour”. The new processing step accepts the output of the existing upstream step and produces data compatible with the existing downstream step. Implementation - Increment 2 A trivial implementation checking the assumption if this works does not do anything to split long words. The input is just passed on: Note how clean WordWrap() stays. The solution is easy to understand. A developer looking at this code sometime in the future, when a new feature needs to be build in, quickly sees how long words are dealt with. Compare this to Robert C. Martin´s solution:[4] How does this solution handle long words? Long words are not even part of the domain language present in the code. At least I need considerable time to understand the approach. Admittedly the Flow Design solution with the full implementation of long word splitting is longer than Robert C. Martin´s. At least it seems. Because his solution does not cover all the “word wrap situations” the Flow Design solution handles. Some lines would need to be added to be on par, I guess. But even then… Is a difference in LOC that important as long as it´s in the same ball park? I value understandability and openness for extension higher than saving on the last line of code. Simplicity is not just less code, it´s also clarity in design. But don´t take my word for it. Try Flow Design on larger problems and compare for yourself. What´s the easier, more straightforward way to clean code? And keep in mind: You ain´t seen all yet ;-) There´s more to Flow Design than described in this chapter. In closing I hope I was able to give you a impression of functional design that makes you hungry for more. To me it´s an inevitable step in software development. Jumping from requirements to code does not scale. And it leads to dirty code all to quickly. Some thought should be invested first. Where there is a clear Entry Point visible, it´s functionality should be designed using data flows. Because with data flows abstraction is possible. For more background on why that´s necessary read my blog article here. For now let me point out to you - if you haven´t already noticed - that Flow Design is a general purpose declarative language. It´s “programming by intention” (Shalloway et al.). Just write down how you think the solution should work on a high level of abstraction. This breaks down a large problem in smaller problems. And by following the PoMO the solutions to those smaller problems are independent of each other. So they are easy to test. Or you could even think about getting them implemented in parallel by different team members. Flow Design not only increases evolvability, but also helps becoming more productive. All team members can participate in functional design. This goes beyon collective code ownership. We´re talking collective design/architecture ownership. Because with Flow Design there is a common visual language to talk about functional design - which is the foundation for all other design activities. PS: If you like what you read, consider getting my ebook “The Incremental Architekt´s Napkin”. It´s where I compile all the articles in this series for easier reading. I like the strictness of Function Programming - but I also find it quite hard to live by. And it certainly is not what millions of programmers are used to. Also to me it seems, the real world is full of state and side effects. So why give them such a bad image? That´s why functional design takes a more pragmatic approach. State and side effects are ok for processing steps - but be sure to follow the SRP. Don´t put too much of it into a single processing step. ? Image taken from www.physioweb.org ? My code samples are written in C#. C# sports typed function pointers called delegates. Action is such a function pointer type matching functions with signature void someName(T t). Other languages provide similar ways to work with functions as first class citizens - even Java now in version 8. I trust you find a way to map this detail of my translation to your favorite programming language. I know it works for Java, C++, Ruby, JavaScript, Python, Go. And if you´re using a Functional Programming language it´s of course a no brainer. ? Taken from his blog post “The Craftsman 62, The Dark Path”. ?

Read the article
Web workflow solution - how should I approach the design?

- by Tom Pickles

We've been tasked with creating a web based workflow tool to track change management. It has a single workflow with multiple synchronous tasks for the most part, but branch out at a point to tasks running in parallel which meet up later on. There will be all sorts of people using the application, and all of them will need to see their outstanding tasks for each change, but only theirs, not others. There will also be a high level group of people who oversee all changes, so need to see everything. They will need to see tasks which have not been done in the specified time, who's responsible etc. The data will be persisted to a SQL database. It'll all be put together using .Net. I've been trying to learn and implement OOP into my designs of late, but I'm wondering if this is moot in this instance as it may be better to have the business logic for this in stored procedures in the DB. I could use POCO's, a front end layer and a data access layer for the web application and just use it as a mechanism for CRUD actions on the DB, then use SP's fired in the DB to apply the business rules. On the other hand, I could use an object oriented design within the web app, but as the data in the app is state-less, is this a bad idea? I could try and model out the whole application into a class structure, implementing interfaces, base classes and all that good stuff. So I would create a change class, which contained a list of task classes/types, which defined each task, and implement an ITask interface etc. Put end-user types into the tasks to identify who should be doing what task. Then apply all the business logic in the respective class methods etc. What approach do you guys think I should be using for this solution?

Read the article
Design review , class design

- by user3651810

I have class design for storing patient information could you please review the design and let me know anything wrong or not corrent I have designed three interfaces IPatient IPatientHistory IPrescription IPatient Id Firstname LastName DOB BloogGroup Mobile List<IPatientHistory> ----------------------- GetPatientById() GetPatientHistory() IPatientHistory HistoryId PatientId DateOfVisit cause List<IPrescription> ----------------------- GetPrescription() IPrescription PrescriptionId PatientHistoryId MedicineName totalQty MorningQty NoonQty NightQTy

Read the article
how to improve design ability

- by Cong Hui

I recently went on a couple of interviews and all of them asked a one or two design questions, like how you would design a chess, monopoly, and so on. I didn't do good on those since I am a college student and lack of the experience of implementing big and complex systems. I figure the only way to improve my design capability is to read lots of others' code and try to implement myself. Therefore, for those companies that ask these questions, what are their real goals in this? I figure most of college grads start off working in a team guided by a senior leader in their first jobs. They might not have lots of design experience fresh out of colleges. Anyone could give pointers about how to practice those skills? Thank you very much

Read the article
jquery.ui.draggable.js and jquery.ui.widget.js conflict

- by Daniel S

hello I had a working application, which uses a jquery ui dialog. I wanted to make the dialog draggable. As far as I know the only thing needed is the jquery.ui.draggable.js script. So I added it to the scripts I am using, but know I get the following error (as shown in the firebug console): base is not a constructor The relevante line in jquery.ui.widget.js is: var basePrototype = new base(); This is how I am adding all the scripts: <script type="text/javascript" src="/media/development-bundle/jquery-1.4.2.js"></script> <script type="text/javascript" src="/media/development-bundle/ui/jquery.ui.core.js"></script> <script type="text/javascript" src="/media/development-bundle/ui/jquery.ui.widget.js"></script> <script type="text/javascript" src="/media/development-bundle/ui/jquery.ui.draggable.js"></script> <script type="text/javascript" src="/media/development-bundle/ui/jquery.ui.position.js"></script> <script type="text/javascript" src="/media/development-bundle/ui/jquery.ui.autocomplete.js"></script> <script type="text/javascript" src="/media/development-bundle/ui/jquery.ui.dialog.js"></script> Am I doing something wrong? or is this a problem with jquery? Thanks in advance for any help

Read the article
Multithreaded UI desktop application issues

- by igor

I am involved into development a rich UI project: desktop windows application. Application uses asynchronous invocations and in its turn it should be ready to process external messages (events). The problem is clear: at first time it was built as a simple prototype and it was not stress tested and all was fine. Then application was grown: the number of calls to server and number of events from server are high and performance is low. What is more users noticed that sometimes performance is extremal low. Asynchronous invocations based on thread pool (BeginInvoke, EndInvoke), external events are going from WCF service (.NET 3.5). My goal is synchronization of all tasks and putting priorities to every executions in desktop application. My question is: is there any practice how to reach my goal: patterns, task priority list, others? What should I do at first, second and next times? Thanks

Read the article
Multithreded UI desktop application issues

- by igor

I am involved into development a rich UI project: desktop windows application. Application uses asynchronous invocations and in its turn it should be ready to process external messages (events). The problem is clear: at first time it was built as a simple prototype and it was not stress tested and all was fine. Then application was grown: the number of calls to server and number of events from server are high and performance is low. What is more users noticed that sometimes performance is extremal low. Asynchronous invocations based on thread pool (BeginInvoke, EndInvoke), external events are going from WCF service (.NET 3.5). My goal is synchronization of all tasks and putting priorities to every executions in desktop application. My question is: is there any practice how to reach my goal: patterns, task priority list, others? What should I do at first, second and next times? Thanks

Read the article

Search Results

Search found 20733 results on 830 pages for 'ui design'.

Page 1/830 | 1 2 3 4 5 6 7 8 9 10 11 12 | Next Page >

- by rajakvk

- by ??? Shengyuan Lu

- by csetzkorn

- by user110933

- by Jon Hopkins

- by Mithir

- by m3th0dman

- by Darf Zon

- by Darf Zon

- by ScG

- by flamingpenguin

- by Eduard Florinescu

- by Eduard Florinescu

- by Bruce

- by Warren J Thompson

- by user1620696

- by PeterT

- by Ralf Westphal

- by Tom Pickles

- by user3651810

- by Cong Hui

- by Daniel S

- by igor

- by igor

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