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  • Can't run init script on boot after another init script

    - by Colin McQueen
    I have three init scripts and the Broker init script runs fine, but when I try to run the Consumer init script and then the Data Collector init script, the only process that is running is the Broker. I added the symbolic links to the run levels using update-rc.d for each script and I also changed the number prefixes in the symbolic links to try and run the scripts in the proper order but that did not work. I am able to run the scripts from the terminal and they work fine but they need to all be started on boot. Any ideas as to why my other scripts are not running? Also inside my Consumer and Data Collector I am running: su user1 -c 'java -jar foo.jar' to start the services. Also the Consumer Java class sits and waits for a message from the queue, so the Java code does not stop until I specify the stop argument for the init script. The Broker has to start first, then the Consumer, then the Data Collector. Adding the symbolic links for the runlevels: sudo update-rc.d Broker defaults 10 90 sudo update-rc.d Consumer defaults 15 85 sudo update-rc.d DataCollector defaults 20 80

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  • VSNewFile: A Visual Studio Addin to More Easily Add New Items to a Project

    - by InfinitiesLoop
    My first Visual Studio Add-in! Creating add-ins is pretty simple, once you get used to the CommandBar model it is using, which is apparently a general Office suite extensibility mechanism. Anyway, let me first explain my motivation for this. It started out as an academic exercise, as I have always wanted to dip my feet in a little VS extensibility. But I thought of a legitimate need for an add-in, at least in my personal experience, so it took on new life. But I figured I can’t be the only one who has felt this way, so I decided to publish the add-in, and host it on GitHub (VSNewFile on GitHub) hoping to spur contributions. Adding Files the Built-in Way Here’s the problem I wanted to solve. You’re working on a project, and it’s time to add a new file to the project. Whatever it is – a class, script, html page, aspx page, or what-have-you, you go through a menu or keyboard shortcut to get to the “Add New Item” dialog. Typically, you do it by right-clicking the location where you want the file (the project or a folder of it): This brings up a dialog the contains, well, every conceivable type of item you might want to add. It’s all the available item templates, which can result in anywhere from a ton to a veritable sea of choices. To be fair, this dialog has been revamped in Visual Studio 2010, which organizes it a little better than Visual Studio 2008, and adds a search box. It also loads noticeably faster.   To me, this dialog is just getting in my way. If I want to add a JavaScript script to my project, I don’t want to have to hunt for the script template item in this dialog. Yes, it is categorized, and yes, it now has a search box. But still, all this UI to swim through when all I need is a new file in the project. I will name it. I will provide the content, I don’t even need a ‘template’. VS kind of realizes this. In the add menu in a class library project, for example, there is a “Add Class…” choice. But all this really does is select that project item from the dialog by default. You still must wait for the dialog, see it, and type in a name for the file. How is that really any different than hitting F2 on an existing item? It isn’t. Adding Files the Hack Way What I often find myself doing, just to avoid going through this dialog, is to copy and paste an existing file, rename it, then “CTRL-A, DEL” the content. In a few short keystrokes I’ve got my new file. Even if the original file wasn’t the right type, it doesn’t matter – I will rename it anyway, including the extension. It works well enough if the place I am adding the file to doesn’t have much in it already. But if there are a lot of files at that level, it sucks, because the new file will have the name “Copy of xyz”, causing it to be moved into the ‘C’ section of the alphabetically sorted items, which might be far, far away from the original file (and so I tend to try and copy a file that starts with ‘C’ *evil grin*). Using ‘Export Template’ To be completely fair I should at least mention this feature. I’m not even sure if this is new in VS 2010 or not (I think so). But it allows you to export a project item or items, including potential project references required by it. Then it becomes a new item in the available ‘installed templates’. No doubt this is useful to help bootstrap new projects. But that still requires you to go through the ‘New Item’ dialog. Adding Files with VSNewFile So hopefully I have sufficiently defined the problem and got a few of you to think, “Yeah, me too!”… What VSNewFile does is let you skip the dialog entirely by adding project items directly to the context menu. But it does a bit more than that, so do read on. For example, to add a new class, you can right-click the location and pick that option. A new .cs file is instantly added to the project, and the new item is selected and put into the ‘rename’ mode immediately. The default items available are shown here. But you can customize them. You can also customize the content of each template. To do so, you create a directory in your documents folder, ‘VSNewFile Templates’. In there, you drop the templates you want to use, but you name them in a particular way. For example, here’s a template that will add a new item named “Add TITLE”. It will add a project item named “SOMEFILE.foo” (or ‘SOMEFILE1.foo’ if that exists, etc). The format of the file name is: <ORDER>_<KEY>_<BASE FILENAME>_<ICON ID>_<TITLE>.<EXTENTION> Where: <ORDER> is a number that lets you determine the order of the items in the menu (relative to each other). <KEY> is a case sensitive identifier different for each template item. More on that later. <BASE FILENAME> is the default name of the file, which doesn’t matter that much, since they will be renaming it anyway. <ICON ID> is a number the dictates the icon used for the menu item. There are a huge number of built-in choices. More on that later. <TITLE> is the string that will appear in the menu. And, the contents of the file are the default content for the item (the ‘template’). The content of the file can contain anything you want, of course. But it also supports two tokens: %NAMESPACE% and %FILENAME%, which will be replaced with the corresponding values. Here is the content of this sample: testing Namespace = %NAMESPACE% Filename = %FILENAME% I kind went back and forth on this. I could have made it so there’d be an XML or JSON file that defines the templates, instead of cramming all this data into the filename itself. I like the simplicity of this better. It makes it easy to customize since you can literally just throw these files around, copy them from someone else, etc, without worrying about merge data into a central description file, in whatever format. Here’s our new item showing up: Practical Use One immediate thing I am using this for is to make it easier to add very commonly used scripts to my web projects. For example, uh, say, jQuery? :) All I need to do is drop jQuery-1.4.2.js and jQuery-1.4.2.min.js into the templates folder, provide the order, title, etc, and then instantly, I can now add jQuery to any project I have without even thinking about “where is jQuery? Can I copy it from that other project?”   Using the KEY There are two reasons for the ‘key’ portion of the item. First, it allows you to turn off the built-in, default templates, which are: FILE = Add File (generic, empty file) VB = Add VB Class CS = Add C# Class (includes some basic usings) HTML = Add HTML page (includes basic structure, doctype, etc) JS = Add Script (includes an immediately-invoking function closure) To turn one off, just include a file with the name “_<KEY>”. For example, to turn off all the items except our custom one, you do this: The other reason for the key is that there are new Visual Studio Commands created for each one. This makes it possible to bind a keyboard shortcut to one of them. So you could, for example, have a keyboard combination that adds a new web page to your website, or a new CS class to your class library, etc. Here is our sample item showing up in the keyboard bindings option. Even though the contents of the template directory may change from one launch of Visual Studio to the next, the bindings will remain attached to any item with a particular key, thanks to it taking care not to lose keyboard bindings even though the commands are completely recreated each time. The Icon Face ID Visual Studio uses a Microsoft Office style add-in mechanism, I gather. There are a predetermined set of built-in icons available. You can use your own icons when developing add-ins, of course, but I’m no designer. I just wanted to find appropriate-ish icons for the built-in templates, and allow you to choose from an existing built-in icon for your own. Unfortunately, there isn’t a lot out there on the interwebs that helps you figure out what the built-in types are. There’s an MSDN article that describes at length a way to create a program that lists all the icons. But I don’t want to write a program to figure them out! Just show them to me! Sheesh :) Thankfully, someone out there felt the same way, and uses a novel hack to get the icons to show up in an outlook toolbar. He then painstakingly took screenshots of them, one group at a time. It isn’t complete though – there are tens of thousands of icons. But it’s good enough. If anyone has an exhaustive list, please let me, and the rest of the add-in community know. Icon Face ID Reference Installing the Add-in It will work with Visual Studio 2008 and Visual Studio 2010. Just unzip the release into your Documents\Visual Studio 20xx\Addins folder. It contains the binary and the Visual Studio “.addin” file. For example, the path to mine is: C:\Users\InfinitiesLoop\Documents\Visual Studio 2010\Addins Conclusion So that’s it! I hope you find it as useful as I have. It’s on GitHub, so if you’re into this kind of thing, please do fork it and improve it! Reference: VSNewFile on GitHub VSNewFile release on GitHub Icon Face ID Reference

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  • Integrating NetBeans for Raspberry Pi Java Development

    - by speakjava
    Raspberry Pi IDE Java Development The Raspberry Pi is an incredible device for building embedded Java applications but, despite being able to run an IDE on the Pi it really pushes things to the limit.  It's much better to use a PC or laptop to develop the code and then deploy and test on the Pi.  What I thought I'd do in this blog entry was to run through the steps necessary to set up NetBeans on a PC for Java code development, with automatic deployment to the Raspberry Pi as part of the build process. I will assume that your starting point is a Raspberry Pi with an SD card that has one of the latest Raspbian images on it.  This is good because this now includes the JDK 7 as part of the distro, so no need to download and install a separate JDK.  I will also assume that you have installed the JDK and NetBeans on your PC.  These can be downloaded here. There are numerous approaches you can take to this including mounting the file system from the Raspberry Pi remotely on your development machine.  I tried this and I found that NetBeans got rather upset if the file system disappeared either through network interruption or the Raspberry Pi being turned off.  The following method uses copying over SSH, which will fail more gracefully if the Pi is not responding. Step 1: Enable SSH on the Raspberry Pi To run the Java applications you create you will need to start Java on the Raspberry Pi with the appropriate class name, classpath and parameters.  For non-JavaFX applications you can either do this from the Raspberry Pi desktop or, if you do not have a monitor connected through a remote command line.  To execute the remote command line you need to enable SSH (a secure shell login over the network) and connect using an application like PuTTY. You can enable SSH when you first boot the Raspberry Pi, as the raspi-config program runs automatically.  You can also run it at any time afterwards by running the command: sudo raspi-config This will bring up a menu of options.  Select '8 Advanced Options' and on the next screen select 'A$ SSH'.  Select 'Enable' and the task is complete. Step 2: Configure Raspberry Pi Networking By default, the Raspbian distribution configures the ethernet connection to use DHCP rather than a static IP address.  You can continue to use DHCP if you want, but to avoid having to potentially change settings whenever you reboot the Pi using a static IP address is simpler. To configure this on the Pi you need to edit the /etc/network/interfaces file.  You will need to do this as root using the sudo command, so something like sudo vi /etc/network/interfaces.  In this file you will see this line: iface eth0 inet dhcp This needs to be changed to the following: iface eth0 inet static     address 10.0.0.2     gateway 10.0.0.254     netmask 255.255.255.0 You will need to change the values in red to an appropriate IP address and to match the address of your gateway. Step 3: Create a Public-Private Key Pair On Your Development Machine How you do this will depend on which Operating system you are using: Mac OSX or Linux Run the command: ssh-keygen -t rsa Press ENTER/RETURN to accept the default destination for saving the key.  We do not need a passphrase so simply press ENTER/RETURN for an empty one and once more to confirm. The key will be created in the file .ssh/id_rsa.pub in your home directory.  Display the contents of this file using the cat command: cat ~/.ssh/id_rsa.pub Open a window, SSH to the Raspberry Pi and login.  Change directory to .ssh and edit the authorized_keys file (don't worry if the file does not exist).  Copy and paste the contents of the id_rsa.pub file to the authorized_keys file and save it. Windows Since Windows is not a UNIX derivative operating system it does not include the necessary key generating software by default.  To generate the key I used puttygen.exe which is available from the same site that provides the PuTTY application, here. Download this and run it on your Windows machine.  Follow the instructions to generate a key.  I remove the key comment, but you can leave that if you want. Click "Save private key", confirm that you don't want to use a passphrase and select a filename and location for the key. Copy the public key from the part of the window marked, "Public key for pasting into OpenSSH authorized_keys file".  Use PuTTY to connect to the Raspberry Pi and login.  Change directory to .ssh and edit the authorized_keys file (don't worry if this does not exist).  Paste the key information at the end of this file and save it. Logout and then start PuTTY again.  This time we need to create a saved session using the private key.  Type in the IP address of the Raspberry Pi in the "Hostname (or IP address)" field and expand "SSH" under the "Connection" category.  Select "Auth" (see the screen shot below). Click the "Browse" button under "Private key file for authentication" and select the file you saved from puttygen. Go back to the "Session" category and enter a short name in the saved sessions field, as shown below.  Click "Save" to save the session. Step 4: Test The Configuration You should now have the ability to use scp (Mac/Linux) or pscp.exe (Windows) to copy files from your development machine to the Raspberry Pi without needing to authenticate by typing in a password (so we can automate the process in NetBeans).  It's a good idea to test this using something like: scp /tmp/foo [email protected]:/tmp on Linux or Mac or pscp.exe foo pi@raspi:/tmp on Windows (Note that we use the saved configuration name instead of the IP address or hostname so the public key is picked up). pscp.exe is another tool available from the creators of PuTTY. Step 5: Configure the NetBeans Build Script Start NetBeans and create a new project (or open an existing one that you want to deploy automatically to the Raspberry Pi). Select the Files tab in the explorer window and expand your project.  You will see a build.xml file.  Double click this to edit it. This file will mostly be comments.  At the end (but within the </project> tag) add the XML for <target name="-post-jar">, shown below Here's the code again in case you want to use cut-and-paste: <target name="-post-jar">   <echo level="info" message="Copying dist directory to remote Pi"/>   <exec executable="scp" dir="${basedir}">     <arg line="-r"/>     <arg value="dist"/>     <arg value="[email protected]:NetBeans/CopyTest"/>   </exec>  </target> For Windows it will be slightly different: <target name="-post-jar">   <echo level="info" message="Copying dist directory to remote Pi"/>   <exec executable="C:\pi\putty\pscp.exe" dir="${basedir}">     <arg line="-r"/>     <arg value="dist"/>     <arg value="pi@raspi:NetBeans/CopyTest"/>   </exec> </target> You will also need to ensure that pscp.exe is in your PATH (or specify a fully qualified pathname). From now on when you clean and build the project the dist directory will automatically be copied to the Raspberry Pi ready for testing.

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  • JavaScript local alias pattern

    - by Bertrand Le Roy
    Here’s a little pattern that is fairly common from JavaScript developers but that is not very well known from C# developers or people doing only occasional JavaScript development. In C#, you can use a “using” directive to create aliases of namespaces or bring them to the global scope: namespace Fluent.IO { using System; using System.Collections; using SystemIO = System.IO; In JavaScript, the only scoping construct there is is the function, but it can also be used as a local aliasing device, just like the above using directive: (function($, dv) { $("#foo").doSomething(); var a = new dv("#bar"); })(jQuery, Sys.UI.DataView); This piece of code is making the jQuery object accessible using the $ alias throughout the code that lives inside of the function, without polluting the global scope with another variable. The benefit is even bigger for the dv alias which stands here for Sys.UI.DataView: think of the reduction in file size if you use that one a lot or about how much less you’ll have to type… I’ve taken the habit of putting almost all of my code, even page-specific code, inside one of those closures, not just because it keeps the global scope clean but mostly because of that handy aliasing capability.

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  • What groupware/project-management apps (preferably self-hosted webapp) do you recommend for a small dev shop?

    - by HedgeMage
    I run a small Drupal consulting shop and we've been trying different groupware solutions for what seems like ages, yet nothing we've found seems to be a good fit. We don't need CRM-overkill such as SugarCRM offers -- it's just too much for our small size. We do need git integration (at a minimum, an easy way to associate commits with issues) Time tracking on configurable or 15m increments per-project issue tracking billing (incl. recurring billing for support contracts, etc) some sort of per-project notes/wiki for things like login credentials, client contact info, etc. Contact logging (Client foo called at 2:20pm and asked to add bar to the spec, signed addendum with pricing due to client NLT CoB today, to be returned by CoB tomorrow) Open source solutions are greatly preferred to closed ones Most of all, it should be very efficient to use. Several solutions just fell out of use here because they required too many clicks for simple, frequent tasks like logging time spent on an issue or noting a call from a client. It shouldn't take 20 minutes to make a note. Edit: I almost forgot to mention: we're a mixed Linux/Mac shop with no Windows users.

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  • Building Simple Workflows in Oozie

    - by dan.mcclary
    Introduction More often than not, data doesn't come packaged exactly as we'd like it for analysis. Transformation, match-merge operations, and a host of data munging tasks are usually needed before we can extract insights from our Big Data sources. Few people find data munging exciting, but it has to be done. Once we've suffered that boredom, we should take steps to automate the process. We want codify our work into repeatable units and create workflows which we can leverage over and over again without having to write new code. In this article, we'll look at how to use Oozie to create a workflow for the parallel machine learning task I described on Cloudera's site. Hive Actions: Prepping for Pig In my parallel machine learning article, I use data from the National Climatic Data Center to build weather models on a state-by-state basis. NCDC makes the data freely available as gzipped files of day-over-day observations stretching from the 1930s to today. In reading that post, one might get the impression that the data came in a handy, ready-to-model files with convenient delimiters. The truth of it is that I need to perform some parsing and projection on the dataset before it can be modeled. If I get more observations, I'll want to retrain and test those models, which will require more parsing and projection. This is a good opportunity to start building up a workflow with Oozie. I store the data from the NCDC in HDFS and create an external Hive table partitioned by year. This gives me flexibility of Hive's query language when I want it, but let's me put the dataset in a directory of my choosing in case I want to treat the same data with Pig or MapReduce code. CREATE EXTERNAL TABLE IF NOT EXISTS historic_weather(column 1, column2) PARTITIONED BY (yr string) STORED AS ... LOCATION '/user/oracle/weather/historic'; As new weather data comes in from NCDC, I'll need to add partitions to my table. That's an action I should put in the workflow. Similarly, the weather data requires parsing in order to be useful as a set of columns. Because of their long history, the weather data is broken up into fields of specific byte lengths: x bytes for the station ID, y bytes for the dew point, and so on. The delimiting is consistent from year to year, so writing SerDe or a parser for transformation is simple. Once that's done, I want to select columns on which to train, classify certain features, and place the training data in an HDFS directory for my Pig script to access. ALTER TABLE historic_weather ADD IF NOT EXISTS PARTITION (yr='2010') LOCATION '/user/oracle/weather/historic/yr=2011'; INSERT OVERWRITE DIRECTORY '/user/oracle/weather/cleaned_history' SELECT w.stn, w.wban, w.weather_year, w.weather_month, w.weather_day, w.temp, w.dewp, w.weather FROM ( FROM historic_weather SELECT TRANSFORM(...) USING '/path/to/hive/filters/ncdc_parser.py' as stn, wban, weather_year, weather_month, weather_day, temp, dewp, weather ) w; Since I'm going to prepare training directories with at least the same frequency that I add partitions, I should also add that to my workflow. Oozie is going to invoke these Hive actions using what's somewhat obviously referred to as a Hive action. Hive actions amount to Oozie running a script file containing our query language statements, so we can place them in a file called weather_train.hql. Starting Our Workflow Oozie offers two types of jobs: workflows and coordinator jobs. Workflows are straightforward: they define a set of actions to perform as a sequence or directed acyclic graph. Coordinator jobs can take all the same actions of Workflow jobs, but they can be automatically started either periodically or when new data arrives in a specified location. To keep things simple we'll make a workflow job; coordinator jobs simply require another XML file for scheduling. The bare minimum for workflow XML defines a name, a starting point, and an end point: <workflow-app name="WeatherMan" xmlns="uri:oozie:workflow:0.1"> <start to="ParseNCDCData"/> <end name="end"/> </workflow-app> To this we need to add an action, and within that we'll specify the hive parameters Also, keep in mind that actions require <ok> and <error> tags to direct the next action on success or failure. <action name="ParseNCDCData"> <hive xmlns="uri:oozie:hive-action:0.2"> <job-tracker>localhost:8021</job-tracker> <name-node>localhost:8020</name-node> <configuration> <property> <name>oozie.hive.defaults</name> <value>/user/oracle/weather_ooze/hive-default.xml</value> </property> </configuration> <script>ncdc_parse.hql</script> </hive> <ok to="WeatherMan"/> <error to="end"/> </action> There are a couple of things to note here: I have to give the FQDN (or IP) and port of my JobTracker and NameNode. I have to include a hive-default.xml file. I have to include a script file. The hive-default.xml and script file must be stored in HDFS That last point is particularly important. Oozie doesn't make assumptions about where a given workflow is being run. You might submit workflows against different clusters, or have different hive-defaults.xml on different clusters (e.g. MySQL or Postgres-backed metastores). A quick way to ensure that all the assets end up in the right place in HDFS is just to make a working directory locally, build your workflow.xml in it, and copy the assets you'll need to it as you add actions to workflow.xml. At this point, our local directory should contain: workflow.xml hive-defaults.xml (make sure this file contains your metastore connection data) ncdc_parse.hql Adding Pig to the Ooze Adding our Pig script as an action is slightly simpler from an XML standpoint. All we do is add an action to workflow.xml as follows: <action name="WeatherMan"> <pig> <job-tracker>localhost:8021</job-tracker> <name-node>localhost:8020</name-node> <script>weather_train.pig</script> </pig> <ok to="end"/> <error to="end"/> </action> Once we've done this, we'll copy weather_train.pig to our working directory. However, there's a bit of a "gotcha" here. My pig script registers the Weka Jar and a chunk of jython. If those aren't also in HDFS, our action will fail from the outset -- but where do we put them? The Jython script goes into the working directory at the same level as the pig script, because pig attempts to load Jython files in the directory from which the script executes. However, that's not where our Weka jar goes. While Oozie doesn't assume much, it does make an assumption about the Pig classpath. Anything under working_directory/lib gets automatically added to the Pig classpath and no longer requires a REGISTER statement in the script. Anything that uses a REGISTER statement cannot be in the working_directory/lib directory. Instead, it needs to be in a different HDFS directory and attached to the pig action with an <archive> tag. Yes, that's as confusing as you think it is. You can get the exact rules for adding Jars to the distributed cache from Oozie's Pig Cookbook. Making the Workflow Work We've got a workflow defined and have collected all the components we'll need to run. But we can't run anything yet, because we still have to define some properties about the job and submit it to Oozie. We need to start with the job properties, as this is essentially the "request" we'll submit to the Oozie server. In the same working directory, we'll make a file called job.properties as follows: nameNode=hdfs://localhost:8020 jobTracker=localhost:8021 queueName=default weatherRoot=weather_ooze mapreduce.jobtracker.kerberos.principal=foo dfs.namenode.kerberos.principal=foo oozie.libpath=${nameNode}/user/oozie/share/lib oozie.wf.application.path=${nameNode}/user/${user.name}/${weatherRoot} outputDir=weather-ooze While some of the pieces of the properties file are familiar (e.g., JobTracker address), others take a bit of explaining. The first is weatherRoot: this is essentially an environment variable for the script (as are jobTracker and queueName). We're simply using them to simplify the directives for the Oozie job. The oozie.libpath pieces is extremely important. This is a directory in HDFS which holds Oozie's shared libraries: a collection of Jars necessary for invoking Hive, Pig, and other actions. It's a good idea to make sure this has been installed and copied up to HDFS. The last two lines are straightforward: run the application defined by workflow.xml at the application path listed and write the output to the output directory. We're finally ready to submit our job! After all that work we only need to do a few more things: Validate our workflow.xml Copy our working directory to HDFS Submit our job to the Oozie server Run our workflow Let's do them in order. First validate the workflow: oozie validate workflow.xml Next, copy the working directory up to HDFS: hadoop fs -put working_dir /user/oracle/working_dir Now we submit the job to the Oozie server. We need to ensure that we've got the correct URL for the Oozie server, and we need to specify our job.properties file as an argument. oozie job -oozie http://url.to.oozie.server:port_number/ -config /path/to/working_dir/job.properties -submit We've submitted the job, but we don't see any activity on the JobTracker? All I got was this funny bit of output: 14-20120525161321-oozie-oracle This is because submitting a job to Oozie creates an entry for the job and places it in PREP status. What we got back, in essence, is a ticket for our workflow to ride the Oozie train. We're responsible for redeeming our ticket and running the job. oozie -oozie http://url.to.oozie.server:port_number/ -start 14-20120525161321-oozie-oracle Of course, if we really want to run the job from the outset, we can change the "-submit" argument above to "-run." This will prep and run the workflow immediately. Takeaway So, there you have it: the somewhat laborious process of building an Oozie workflow. It's a bit tedious the first time out, but it does present a pair of real benefits to those of us who spend a great deal of time data munging. First, when new data arrives that requires the same processing, we already have the workflow defined and ready to run. Second, as we build up a set of useful action definitions over time, creating new workflows becomes quicker and quicker.

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  • Evil DRY

    - by StefanSteinegger
    DRY (Don't Repeat Yourself) is a basic software design and coding principle. But there is just no silver bullet. While DRY should increase maintainability by avoiding common design mistakes, it could lead to huge maintenance problems when misunderstood. The root of the problem is most probably that many developers believe that DRY means that any piece of code that is written more then once should be made reusable. But the principle is stated as "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system." So the important thing here is "knowledge". Nobody ever said "every piece of code". I try to give some examples of misusing the DRY principle. Code Repetitions by Coincidence There is code that is repeated by pure coincidence. It is not the same code because it is based on the same piece of knowledge, it is just the same by coincidence. It's hard to give an example of such a case. Just think about some lines of code the developer thinks "I already wrote something similar". Then he takes the original code, puts it into a public method, even worse into a base class where none had been there before, puts some weird arguments and some if or switch statements into it to support all special cases and calls this "increasing maintainability based on the DRY principle". The resulting "reusable method" is usually something the developer not even can give a meaningful name, because its contents isn't anything specific, it is just a bunch of code. For the same reason, nobody will really understand this piece of code. Typically this method only makes sense to call after some other method had been called. All the symptoms of really bad design is evident. Fact is, writing this kind of "reusable methods" is worse then copy pasting! Believe me. What will happen when you change this weird piece of code? You can't say what'll happen, because you can't understand what the code is actually doing. So better don't touch it anymore. Maintainability just died. Of course this problem is with any badly designed code. But because the developer tried to make this method as reusable as possible, large parts of the system get dependent on it. Completely independent parts get tightly coupled by this common piece of code. Changing on the single common place will have effects anywhere in the system, a typical symptom of too tight coupling. Without trying to dogmatically (and wrongly) apply the DRY principle, you just had a system with a weak design. Now you get a system which just can't be maintained anymore. So what can you do against it? When making code reusable, always identify the generally reusable parts of it. Find the reason why the code is repeated, find the common "piece of knowledge". If you have to search too far, it's probably not really there. Explain it to a colleague, if you can't explain or the explanation is to complicated, it's probably not worth to reuse. If you identify the piece of knowledge, don't forget to carefully find the place where it should be implemented. Reusing code is never worth giving up a clean design. Methods always need to do something specific. If you can't give it a simple and explanatory name, you did probably something weird. If you can't find the common piece of knowledge, try to make the code simpler. For instance, if you have some complicated string or collection operations within this code, write some general-purpose operations into a helper class. If your code gets simple enough, its not so bad if it can't be reused. If you are not able to find anything simple and reasonable, copy paste it. Put a comment into the code to reference the other copies. You may find a solution later. Requirements Repetitions by Coincidence Let's assume that you need to implement complex tax calculations for many countries. It's possible that some countries have very similar tax rules. These rules are still completely independent from each other, since every country can change it of its own. (Assumed that this similarity is actually by coincidence and not by political membership. There might be basic rules applying to all European countries. etc.) Let's assume that there are similarities between an Asian country and an African country. Moving the common part to a central place will cause problems. What happens if one of the countries changes its rules? Or - more likely - what happens if users of one country complain about an error in the calculation? If there is shared code, it is very risky to change it, even for a bugfix. It is hard to find requirements to be repeated by coincidence. Then there is not much you can do against the repetition of the code. What you really should consider is to make coding of the rules as simple as possible. So this independent knowledge "Tax Rules in Timbuktu" or wherever should be as pure as possible, without much overhead and stuff that does not belong to it. So you can write every independent requirement short and clean. DRYing try-catch and using Blocks This is a technical issue. Blocks like try-catch or using (e.g. in C#) are very hard to DRY. Imagine a complex exception handling, including several catch blocks. When the contents of the try block as well as the contents of the individual catch block are trivial, but the whole structure is repeated on many places in the code, there is almost no reasonable way to DRY it. try { // trivial code here using (Thingy thing = new thingy) { //trivial, but always different line of code } } catch(FooException foo) { // trivial foo handling } catch (BarException bar) { // trivial bar handling } catch { // trivial common handling } finally { // trivial finally block } The key here is that every block is trivial, so there is nothing to just move into a separate method. The only part that differs from case to case is the line of code in the body of the using block (or any other block). The situation is especially interesting if the many occurrences of this structure are completely independent: they appear in classes with no common base class, they don't aggregate each other and so on. Let's assume that this is a common pattern in service methods within the whole system. Examples of Evil DRYing in this situation: Put a if or switch statement into the method to choose the line of code to execute. There are several reasons why this is not a good idea: The close coupling of the formerly independent implementation is the strongest. Also the readability of the code and the use of a parameter to control the logic. Put everything into a method which takes a delegate as argument to call. The caller just passes his "specific line of code" to this method. The code will be very unreadable. The same maintainability problems apply as for any "Code Repetition by Coincidence" situations. Enforce a base class to all the classes where this pattern appears and use the template method pattern. It's the same readability and maintainability problem as above, but additionally complex and tightly coupled because of the base class. I would call this "Inheritance by Coincidence" which will not lead to great software design. What can you do against it: Ideally, the individual line of code is a call to a class or interface, which could be made individual by inheritance. If this would be the case, it wouldn't be a problem at all. I assume that it is no such a trivial case. Consider to refactor the error concept to make error handling easier. The last but not worst option is to keep the replications. Some pattern of code must be maintained in consistency, there is nothing we can do against it. And no reason to make it unreadable. Conclusion The DRY-principle is an important and basic principle every software developer should master. The key is to identify the "pieces of knowledge". There is code which can't be reused easily because of technical reasons. This requires quite a bit flexibility and creativity to make code simple and maintainable. It's not the problem of the principle, it is the problem of blindly applying a principle without understanding the problem it should solve. The result is mostly much worse then ignoring the principle.

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  • Web API, JavaScript, Chrome &amp; Cross-Origin Resource Sharing

    - by Brian Lanham
    The team spent much of the week working through this issues related to Chrome running on Windows 8 consuming cross-origin resources using Web API.  We thought it was resolved on day 2 but it resurfaced the next day.  We definitely resolved it today though.  I believe I do not fully understand the situation but I am going to explain what I know in an effort to help you avoid and/or resolve a similar issue. References We referenced many sources during our trial-and-error troubleshooting.  These are the links we reference in order of applicability to the solution: Zoiner Tejada JavaScript and other material from -> http://www.devproconnections.com/content1/topic/microsoft-azure-cors-141869/catpath/windows-azure-platform2/page/3 WebDAV Where I learned about “Accept” –>  http://www-jo.se/f.pfleger/cors-and-iis? IT Hit Tells about NOT using ‘*’ –> http://www.webdavsystem.com/ajax/programming/cross_origin_requests Carlos Figueira Sample back-end code (newer) –> http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d (older version) –> http://code.msdn.microsoft.com/CORS-support-in-ASPNET-Web-01e9980a   Background As a measure of protection, Web designers (W3C) and implementers (Google, Microsoft, Mozilla) made it so that a request, especially a JSON request (but really any URL), sent from one domain to another will only work if the requestee “knows” about the requester and allows requests from it. So, for example, if you write a ASP.NET MVC Web API service and try to consume it from multiple apps, the browsers used may (will?) indicate that you are not allowed by showing an “Access-Control-Allow-Origin” error indicating the requester is not allowed to make requests. Internet Explorer (big surprise) is the odd-hair-colored step-child in this mix. It seems that running locally at least IE allows this for development purposes.  Chrome and Firefox do not.  In fact, Chrome is quite restrictive.  Notice the images below. IE shows data (a tabular view with one row for each day of a week) while Chrome does not (trust me, neither does Firefox).  Further, the Chrome developer console shows an XmlHttpRequest (XHR) error. Screen captures from IE (left) and Chrome (right). Note that Chrome does not display data and the console shows an XHR error. Why does this happen? The Web browser submits these requests and processes the responses and each browser is different. Okay, so, IE is probably the only one that’s truly different.  However, Chrome has a specific process of performing a “pre-flight” check to make sure the service can respond to an “Access-Control-Allow-Origin” or Cross-Origin Resource Sharing (CORS) request.  So basically, the sequence is, if I understand correctly:  1)Page Loads –> 2)JavaScript Request Processed by Browser –> 3)Browsers Prepares to Submit Request –> 4)[Chrome] Browser Submits Pre-Flight Request –> 5)Server Responds with HTTP 200 –> 6)Browser Submits Request –> 7)Server Responds with Data –> 8)Page Shows Data This situation occurs for both GET and POST methods.  Typically, GET methods are called with query string parameters so there is no data posted.  Instead, the requesting domain needs to be permitted to request data but generally nothing more is required.  POSTs on the other hand send form data.  Therefore, more configuration is required (you’ll see the configuration below).  AJAX requests are not friendly with this (POSTs) either because they don’t post in a form. How to fix it. The team went through many iterations of self-hair removal and we think we finally have a working solution.  The trial-and-error approach eventually worked and we referenced many sources for the information.  I indicate those references above.  There are basically three (3) tasks needed to make this work. Assumptions: You are using Visual Studio, Web API, JavaScript, and have Cross-Origin Resource Sharing, and several browsers. 1. Configure the client Joel Cochran centralized our “cors-oriented” JavaScript (from here). There are two calls including one for GET and one for POST function(url, data, callback) {             console.log(data);             $.support.cors = true;             var jqxhr = $.post(url, data, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("post", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send(data);                     } else {                         console.log(">" + jqXhHR.status);                         alert("corsAjax.post error: " + status + ", " + errorThrown);                     }                 });         }; The GET CORS JavaScript function (credit to Zoiner Tejada) function(url, callback) {             $.support.cors = true;             var jqxhr = $.get(url, null, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("get", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send();                     } else {                         alert("CORS is not supported in this browser or from this origin.");                     }                 });         }; The POST CORS JavaScript function (credit to Zoiner Tejada) Now you need to call these functions to get and post your data (instead of, say, using $.Ajax). Here is a GET example: corsAjax.get(url, function(data) { if (data !== null && data.length !== undefined) { // do something with data } }); And here is a POST example: corsAjax.post(url, item); Simple…except…you’re not done yet. 2. Change Web API Controllers to Allow CORS There are actually two steps here.  Do you remember above when we mentioned the “pre-flight” check?  Chrome actually asks the server if it is allowed to ask it for cross-origin resource sharing access.  So you need to let the server know it’s okay.  This is a two-part activity.  a) Add the appropriate response header Access-Control-Allow-Origin, and b) permit the API functions to respond to various methods including GET, POST, and OPTIONS.  OPTIONS is the method that Chrome and other browsers use to ask the server if it can ask about permissions.  Here is an example of a Web API controller thus decorated: NOTE: You’ll see a lot of references to using “*” in the header value.  For security reasons, Chrome does NOT recognize this is valid. [HttpHeader("Access-Control-Allow-Origin", "http://localhost:51234")] [HttpHeader("Access-Control-Allow-Credentials", "true")] [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPATCH, COPY, MOVE, DELETE, MKCOL, LOCK, UNLOCK, PUT, GETLIB, VERSION-CONTROL, CHECKIN, CHECKOUT, UNCHECKOUT, REPORT, UPDATE, CANCELUPLOAD, HEAD, OPTIONS, GET, POST")] [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destination, Content-Type, Depth, User-Agent, X-File-Size, X-Requested-With, If-Modified-Since, X-File-Name, Cache-Control")] [HttpHeader("Access-Control-Max-Age", "3600")] public abstract class BaseApiController : ApiController {     [HttpGet]     [HttpOptions]     public IEnumerable<foo> GetFooItems(int id)     {         return foo.AsEnumerable();     }     [HttpPost]     [HttpOptions]     public void UpdateFooItem(FooItem fooItem)     {         // NOTE: The fooItem object may or may not         // (probably NOT) be set with actual data.         // If not, you need to extract the data from         // the posted form manually.         if (fooItem.Id == 0) // However you check for default...         {             // We use NewtonSoft.Json.             string jsonString = context.Request.Form.GetValues(0)[0].ToString();             Newtonsoft.Json.JsonSerializer js = new Newtonsoft.Json.JsonSerializer();             fooItem = js.Deserialize<FooItem>(new Newtonsoft.Json.JsonTextReader(new System.IO.StringReader(jsonString)));         }         // Update the set fooItem object.     } } Please note a few specific additions here: * The header attributes at the class level are required.  Note all of those methods and headers need to be specified but we find it works this way so we aren’t touching it. * Web API will actually deserialize the posted data into the object parameter of the called method on occasion but so far we don’t know why it does and doesn’t. * [HttpOptions] is, again, required for the pre-flight check. * The “Access-Control-Allow-Origin” response header should NOT NOT NOT contain an ‘*’. 3. Headers and Methods and Such We had most of this code in place but found that Chrome and Firefox still did not render the data.  Interestingly enough, Fiddler showed that the GET calls succeeded and the JSON data is returned properly.  We learned that among the headers set at the class level, we needed to add “ACCEPT”.  Note that I accidentally added it to methods and to headers.  Adding it to methods worked but I don’t know why.  We added it to headers also for good measure. [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPA... [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destin... Next Steps That should do it.  If it doesn’t let us know.  What to do next?  * Don’t hardcode the allowed domains.  Note that port numbers and other domain name specifics will cause problems and must be specified.  If this changes do you really want to deploy updated software?  Consider Miguel Figueira’s approach in the following link to writing a custom HttpHeaderAttribute class that allows you to specify the domain names and then you can do it dynamically.  There are, of course, other ways to do it dynamically but this is a clean approach. http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d

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  • Naming conventions: camelCase versus underscore_case ? what are your thoughts about it? [closed]

    - by poelinca
    I've been using underscore_case for about 2 years and I recently switched to camelCase because of the new job (been using the later one for about 2 months and I still think underscore_case is better suited for large projects where there are alot of programmers involved, mainly because the code is easier to read). Now everybody at work uses camelCase because (so they say) the code looks more elegant . What are you're thoughts about camelCase or underscore_case p.s. please excuse my bad english Edit Some update first: platform used is PHP (but I'm not expecting strict PHP platform related answers , anybody can share their thoughts on which would be the best to use , that's why I came here in the first place) I use camelCase just as everibody else in the team (just as most of you recomend) we use Zend Framework which also recommends camelCase Some examples (related to PHP) : Codeigniter framework recommends underscore_case , and honestly the code is easier to read . ZF recomends camelCase and I'm not the only one who thinks ZF code is a tad harder to follow through. So my question would be rephrased: Let's take a case where you have the platform Foo which doesn't recommend any naming conventions and it's the team leader's choice to pick one. You are that team leader, why would you pick camelCase or why underscore_case? p.s. thanks everybody for the prompt answers so far

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  • Highly scalable and dynamic "rule-based" applications?

    - by Prof Plum
    For a large enterprise app, everyone knows that being able to adjust to change is one of the most important aspects of design. I use a rule-based approach a lot of the time to deal with changing business logic, with each rule being stored in a DB. This allows for easy changes to be made without diving into nasty details. Now since C# cannot Eval("foo(bar);") this is accomplished by using formatted strings stored in rows that are then processed in JavaScript at runtime. This works fine, however, it is less than elegant, and would not be the most enjoyable for anyone else to pick up on once it becomes legacy. Is there a more elegant solution to this? When you get into thousands of rules that change fairly frequently it becomes a real bear, but this cannot be that uncommon of a problem that someone has not thought of a better way to do this. Any suggestions? Is this current method defensible? What are the alternatives? Edit: Just to clarify, this is a large enterprise app, so no matter which solution works, there will be plenty of people constantly maintaining its rules and data (around 10). Also, The data changes frequently enough to say that some sort of centralized server system is basically a must.

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  • What to choose for a multilingual site with support for Markdown and commenting

    - by Kent
    I want to publish articles at a multilingual site. I want to be able to write an article in two languages and have them available on separate URLs: thesite.foo/english-breakfast thesite.com/engelsk-frukost If the users web browser is set to English I'd like to show a small notice at the top of the Swedish version with a link to the English one. The link should have an appropriate rel attribute for a translation (search for hreflang at http://diveintohtml5.org/semantics.html). There should be a way to list all articles belonging to these sets: Swedish only, English only, Swedish versions + English only, English versions + Swedish only. I'd like to publish these as four RSS-feeds. And I would like to have two versions of the main site, one in Swedish (showing Swedish versions + English only) and one in English (showing English versions). I shall be able to write the articles using Markdown, as that is the formatting language I find most convenient. There should be a way for users to comment. And some kind of way for me to protect myself against comment spam. I am leaning towards learning Drupal. I suspect I'll have to code this behavior myself as a module. To be frank I'd rather work with Java. Is Drupal the way to go? Or is there something more suitable for this project?

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  • Adventures in MVVM &ndash; My ViewModel Base &ndash; Silverlight Support!

    - by Brian Genisio's House Of Bilz
    More Adventures in MVVM In my last post, I outlined the powerful features that are available in the ViewModelSupport.  It takes advantage of the dynamic features of C# 4.0 (as well as some 3.0 goodies) to help eliminate the plumbing that often comes with writing ViewModels.  If you are interested in learning about the capabilities, please take a look at that post and look at the code on CodePlex.  When I wrote about the ViewModel base class, I complained that the features did not work in Silverlight because as of 4.0, it does not support binding to dynamic properties.  Although I still think this is a bummer, I am happy to say that I have come up with a workaround.  In the Silverlight version of my base class, I include a PropertyCollectionConverter that lets you bind to dynamic properties in the ViewModelBase, especially the convention-based commands that the base class supports. To take advantage of any properties that are not statically defined, you can bind to the Properties property of the ViewModel and pass in a converter parameter for the name of the property you want to bind. For example, a ViewModel that looks like this: public class ExampleViewModel : ViewModelBase { public void Execute_MyCommand() { Set("Text", "Foo"); } } Can bind to the dynamic property and the convention-based command with the following XAML. <TextBlock Text="{Binding Properties, Converter={StaticResource PropertiesConverter}, ConverterParameter=Text}" Margin="5" /> <Button Content="Execute MyCommand" Command="{Binding Properties, Converter={StaticResource PropertiesConverter}, ConverterParameter=MyCommand}" Margin="5" /> Of course, it is not as pretty as binding to Text and MyCommand like you can in WPF.  But, it is better than having a failed feature.  This allows you to share your ViewModels between WPF and Silverlight very easily.  <BeatDeadHorse>Hopefully, in Silverlight 5.0, we will see binding to dynamic properties more directly????</BeatDeadHorse>

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  • Purpose of "new" keyword

    - by Channel72
    The new keyword in languages like Java, Javascript, and C# creates a new instance of a class. This syntax seems to have been inherited from C++, where new is used specifically to allocate a new instance of a class on the heap, and return a pointer to the new instance. In C++, this is not the only way to construct an object. You can also construct an object on the stack, without using new - and in fact, this way of constructing objects is much more common in C++. So, coming from a C++ background, the new keyword in languages like Java, Javascript, and C# seemed natural and obvious to me. Then I started to learn Python, which doesn't have the new keyword. In Python, an instance is constructed simply by calling the constructor, like: f = Foo() At first, this seemed a bit off to me, until it occurred to me that there's no reason for Python to have new, because everything is an object so there's no need to disambiguate between various constructor syntaxes. But then I thought - what's really the point of new in Java? Why should we say Object o = new Object();? Why not just Object o = Object();? In C++ there's definitely a need for new, since we need to distinguish between allocating on the heap and allocating on the stack, but in Java all objects are constructed on the heap, so why even have the new keyword? The same question could be asked for Javascript. In C#, which I'm much less familiar with, I think new may have some purpose in terms of distinguishing between object types and value types, but I'm not sure. Regardless, it seems to me that many languages which came after C++ simply "inherited" the new keyword - without really needing it. It's almost like a vestigial keyword. We don't seem to need it for any reason, and yet it's there. Question: Am I correct about this? Or is there some compelling reason that new needs to be in C++-inspired memory-managed languages like Java, Javascript and C#?

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  • How to Implement Complex Form Data?

    - by SoulBeaver
    I'm supposed to implement a relatively complex form that looks like follows, but has at least four more pages requiring the user to fill in all necessary information for the tracks: This data will need to be sent to the server, which is implemented using Dropwizard. I'm looking for best practices on how to upload and send such a complex form with potentially dozens of songs to the server. The simplest available solution I have seen is a simple multipart/form-data request with the following form schema (Source): Client <html> <body> <h1>File Upload with Jersey</h1> <form action="rest/file/upload" method="post" enctype="multipart/form-data"> <p> Select a file : <input type="file" name="file" size="45" /> </p> <input type="submit" value="Upload It" /> </form> </body> </html> Server @POST @Path("/upload") @Consumes(MediaType.MULTIPART_FORM_DATA) public Response uploadTrack(final FormDataMultiPart multiPart) { List<FormDataBodyPart> artists = multiPart.getFields("artist"); StringBuffer output = new StringBuffer(); for (FormDataBodyPart artist : artists) output.append(artist.getValueAs(String.class)); List<FormDataBodyPart> tracks = multiPart.getFields("track"); for (FormDataBodyPart track : tracks) writeToFile(track.getValueAs(InputStream.class), "Foo"); return Response.status(200).entity(output.toString()).build(); } Then I have also read about file uploads via Ajax or Formdata (Mozilla HttpRequest) which allows for Posts in the formats application/x-www-form-urlencoded, multipart/form-data, or text/plain. I don't know which approach, if any, is best. An ideal solution would be to utilize Jackson to convert a json string into my data objects, but I don't get the impression that this is possible with binary data.

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  • CodePlex Daily Summary for Monday, May 28, 2012

    CodePlex Daily Summary for Monday, May 28, 2012Popular ReleasesScreenShot: InstallScreenShot: This is the current stable release..Net Code Samples: Code Samples: Code samples (SLNs).LINQ_Koans: LinqKoans v.02: Cleaned up a bitKeelKit: KeelKit 3.0.7600.638: ?、??MySQL?Model?? Mysql ????? ? http://dev.mysql.com/downloads/connector/net/ ??? mysql-connector-net-6.5.4.msi ???, VS???KeelKit ???????MySQL , ????????? ?? DemoMySQL.rar ???, ???????????MySqL??Model. ?????? C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\machine.config ??? ??????。 <system.data> <DbProviderFactories> <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlC...TwitterOAuth: TwitterOauth 0.25.16.0116: Beta releasetesttom05242012git02: d1: d1testdd05242012git001: zxczxc: zxczxczxcCODE Framework: 4.0.20524.0: This release has quite a few enhancements for WPF applications and SOA features. See change logs for more details.CommonLibrary.NET: CommonLibrary.NET 0.9.8 - Final Release: A collection of very reusable code and components in C# 4.0 ranging from ActiveRecord, Csv, Command Line Parsing, Configuration, Holiday Calendars, Logging, Authentication, and much more. FluentscriptCommonLibrary.NET 0.9.8 contains a scripting language called FluentScript. Application: FluentScript Version: 0.9.8 Build: 0.9.8.4 Changeset: 75050 ( CommonLibrary.NET ) Release date: May 24, 2012 Binaries: CommonLibrary.dll Namespace: ComLib.Lang Project site: http://fluentscript.codeplex.com...System Center Orchestrator Integration Packs: Active Directory 3.2: An integration pack enabling AD Automation 3.2 Updates LDAP Pathing updated to support cross forest scenarios Get Object Property Value Filtering efficiency enhancementsBunch of Small Tools: Mélangeur de vocabulaire japonais: Permet de générer des exercices de vocabulaire aléatoire à partir de listes de vocabulaire japonais. 22 listes sont fournies avec le programme.Expression Tree Visualizer for VS 2010: Expression Tree Visualizer Beta: This is a beta release, in this release some expression types are not handled and use a default visualization behavior. The first release will be published soon. Wait for it...Ulfi: Ulfi source: Build with Visual Studio 2010 Express C# or betterJayData - The cross-platform HTML5 data-management library for JavaScript: JayData 1.0 RC1 Refresh 2: JayData is a unified data access library for JavaScript developers to query and update data from different sources like webSQL, indexedDB, OData, Facebook or YQL. See it in action in this 6 minutes video: http://www.youtube.com/watch?v=LlJHgj1y0CU RC1 R2 Release highlights Knockout.js integrationUsing the Knockout.js module, your UI can be automatically refreshed when the data model changes, so you can develop the front-end of your data manager app even faster. Querying 1:N relations in W...Christoc's DotNetNuke Module Development Template: 00.00.08 for DNN6: BEFORE USE YOU need to install the MSBuild Community Tasks available from http://msbuildtasks.tigris.org For best results you should configure your development environment as described in this blog post Then read this latest blog post about customizing and using these custom templates. Installation is simple To use this template place the ZIP (not extracted) file in your My Documents\Visual Studio 2010\Templates\ProjectTemplates\Visual C#\Web OR for VB My Documents\Visual Studio 2010\Te...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.53: fix issue #18106, where member operators on numeric literals caused the member part to be duplicated when not minifying numeric literals ADD NEW FEATURE: ability to create source map files! The first mapfile format to be supported is the Script# format. Use the new -map filename switch to create map files when building your sources.CreditAnalytics: CreditAnalytics Release 1.5: 22 May 2012 (v1.5) (Build 449) Regressor Framework: Implementation of the regressor set, tolerance check, curve scenario regressors, regression framework suite, and the eventual regression output. Discount Curve Regression: Regressing Base Curve Creation, scenario Curve creation, and calculation of spot/effective implied rates and discount factors. Credit Curve Regression: Regressing Base Curve Creation, scenario Curve creation, and calculation of spot/effective implied hazard rates, reco...BlackJumboDog: Ver5.6.3: 2012.05.22 Ver5.6.3  (1) HTTP????????、ftp://??????????????????????LogicCircuit: LogicCircuit 2.12.5.22: Logic Circuit - is educational software for designing and simulating logic circuits. Intuitive graphical user interface, allows you to create unrestricted circuit hierarchy with multi bit buses, debug circuits behavior with oscilloscope, and navigate running circuits hierarchy. Changes of this versionThis release is fixing start up issue.Orchard Project: Orchard 1.4.2: This is a service release to address 1.4 and 1.4.1 bugs. Please read our release notes for Orchard 1.4.2: http://docs.orchardproject.net/Documentation/Orchard-1-4-Release-NotesNew Projects.Net Code Samples: Various .Net code samples. AFSAspnetPusherV1: my new wns project lolAFSAspnetPusherV2: renewed version ofAFSAspnetPusherV4: renewed one v4AgileDesign Utilities Library: This library provides common functionality usable for most software projects: Logger - Asynchronous logging on top of new Microsoft logging class TraceSource with simplified API NameOf - Avoid using string names using static reflection Various reflection helpersAssociate Many to Many Relationship Entities Tool for Dynamics CRM 2011: Associate Many to many relationship tool is used for Dynamics CRM 2011 to associate or disassociate N:N relationship entities. This tool is dynamics crm 2011 solution, which consist of one entity and one plugin. Entity "Many to Many Relationship" record is used by Many to many relationship plugin to associate or disassociate entities. If many to many relationship entity record is created then plugin associate/disassociate entities from record data.Boxhead Multiplayer Server: A PHP dedicated server for my multiplayer version of Boxhead.CodedUITraceFiletoCSV: Console Application to parse the result file generated by Coded UI Test execution ".trx" into a comma separated file for more readable and detailed result.FlipExt: FlipExt is an easy to use image converter. It converts any image to .png .bmp .jpg .gif .tif .jpeg .tiff .ico. More extensions will be added soon.Foo Values Maker: Foo creates values for your test class variables so that you can write tests faster.FoodFree: Projeto de monitoramento de enchentesHouodeProject: ????ITLand of Dreams, Codename: Waterloo: We want to create a classical Live-MMORPG you can play on your smartphone (in the first step only “Windows Phone” will be supported) with the basic idea of Ultima Online or similiar games in our mind. You can create one or more characters, choose some name, gender, basic attributes (skin and hair color, …) a race (e.g. ‘Human’) and a profession (e.g. ‘fighter’ or ‘craftsman’). Now he can freely travel through the whole world, meeting other players, fighting monsters, absolving quests, tra...Makecert UI: Makecert UI is a shell layer application on top of the Microsoft makecert.exe utility. Makecert UI makes it easy for you to create self signed certificates, even from your own CA.MS CRM Rich Text box: Rich text box plug-in for MS CRM 2011. Hope it will be helpful for many of you. Thank you for using it and let me know if any further help needed.Nivo Slider Web Part SharePoint 2010: SharePoint 2010 implementation of Nivo Slider. Easy way to put Nivo slider on any page!!Office365 Weather WebPart: Office 365 WebPart that displays a 5 day weather forecast for a given location. The weather data is retrieved from the Met Office feed hosted on the Windows Azure Data Market. This is a free data feed that provides weather data for the UK only.Private Cloud Solution Design: This project is named “Training Cloud”. It provides an appropriate solution which can be used for technical audiences self learning with a hands-on-lab experience using Microsoft technology hosted in a virtualized environment built on System Center 2012. Since it depends on hardware, such as RAM, Sotrage, Network , etc. At last, the end user could have all labs ready which deloyed on private cloud. And it can be easily matain , setup labs with cloud’s function. pyUpdater: pyupdater provides a platform for updating python based applications.SharePoint Document Navigator: SP Document Navigator is a front-end solution for navigating a document library using jQuery and jQuery Mobile Trimetable: Train schedule for WP7Upload Master Pages & Page Layouts to Master Page Gallery using PowerShell: This document details the steps to upload Master pages and Page Layouts to Master Page Gallery using the “Upload Master Pages” Utility. 1- Download the .zip file 2- Edit the “UploadMasterPages.bat” file and Change the <<site collection url>> in the text below with respect to the environment. e.g. http://sitecollectionurl 3- Save the “UploadMasterPages.bat” file and close it. 4- Put all of your master pages and page layouts to Doc folder. 5- Run “UploadMasterPages.bat” file as Administrat...vivo: vivo Vietnamese Voice Vietnamese Voice recognition project thaihung.bkhn@gmail.com http://eking.vnvnv: VNV Vietnamese Voice Vietnamese Voice recognition project thaihung.bkhn@gmail.com http://eking.vnWindows Phone 7 User Guide Page: Take your app's users through a guided tour! Make your app's hidden gems shine, make users understand your app's logic and UX better.WP-FTS: This plugin for Wordpress replaces the default search engine, implemented using a simple "LIKE" operator, with the usage of the more powerful Full-Text Engine that comes with SQL Server.

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  • Drupal 7 Advice Needed: "Portal" Creation

    - by WernerCD
    Question: What is the best game plan for building what I want. I'm rebuilding the company intranet and am trying to get our "Portals" system re-created in Drupal. I'm trying to learn Panels, because thats what I think would do this, but I just can't seem to get it working. Menu at top, drop down lists for various webpages, tools, internal applications... and Department Portals. When you click on a department portal, you get the same menu at top... and on the main part of the page you have a menu on the left, with content on the right. Menu stays on the left, content loads next to it. Each Portal has its own menu and content (least of which is "Home"). Ultimately, I'd like to be able to say - users with role "Foo" can add/edit/delete Portal Bar. - Each Portal starts with a "Home" - Each Portal has its own Menu tree's. (Picture 2 above has a < ul for video tutorials that would be a second level menu. So more than one deep.) - Content on the right side of the portal should be flexible (Video, PDF via fileviewer, etc) - Portal Bar should have its own Folder to contain it's content. I'm trying to do this in Panels, but I can't seem to put the pieces together in my mind and in practice. I hope I'm making sense, because the dizzying array of stuff is killing me lol.

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  • ASMLib

    - by wcoekaer
    Oracle ASMlib on Linux has been a topic of discussion a number of times since it was released way back when in 2004. There is a lot of confusion around it and certainly a lot of misinformation out there for no good reason. Let me try to give a bit of history around Oracle ASMLib. Oracle ASMLib was introduced at the time Oracle released Oracle Database 10g R1. 10gR1 introduced a very cool important new features called Oracle ASM (Automatic Storage Management). A very simplistic description would be that this is a very sophisticated volume manager for Oracle data. Give your devices directly to the ASM instance and we manage the storage for you, clustered, highly available, redundant, performance, etc, etc... We recommend using Oracle ASM for all database deployments, single instance or clustered (RAC). The ASM instance manages the storage and every Oracle server process opens and operates on the storage devices like it would open and operate on regular datafiles or raw devices. So by default since 10gR1 up to today, we do not interact differently with ASM managed block devices than we did before with a datafile being mapped to a raw device. All of this is without ASMLib, so ignore that one for now. Standard Oracle on any platform that we support (Linux, Windows, Solaris, AIX, ...) does it the exact same way. You start an ASM instance, it handles storage management, all the database instances use and open that storage and read/write from/to it. There are no extra pieces of software needed, including on Linux. ASM is fully functional and selfcontained without any other components. In order for the admin to provide a raw device to ASM or to the database, it has to have persistent device naming. If you booted up a server where a raw disk was named /dev/sdf and you give it to ASM (or even just creating a tablespace without asm on that device with datafile '/dev/sdf') and next time you boot up and that device is now /dev/sdg, you end up with an error. Just like you can't just change datafile names, you can't change device filenames without telling the database, or ASM. persistent device naming on Linux, especially back in those days ways to say it bluntly, a nightmare. In fact there were a number of issues (dating back to 2004) : Linux async IO wasn't pretty persistent device naming including permissions (had to be owned by oracle and the dba group) was very, very difficult to manage system resource usage in terms of open file descriptors So given the above, we tried to find a way to make this easier on the admins, in many ways, similar to why we started working on OCFS a few years earlier - how can we make life easier for the admins on Linux. A feature of Oracle ASM is the ability for third parties to write an extension using what's called ASMLib. It is possible for any third party OS or storage vendor to write a library using a specific Oracle defined interface that gets used by the ASM instance and by the database instance when available. This interface offered 2 components : Define an IO interface - allow any IO to the devices to go through ASMLib Define device discovery - implement an external way of discovering, labeling devices to provide to ASM and the Oracle database instance This is similar to a library that a number of companies have implemented over many years called libODM (Oracle Disk Manager). ODM was specified many years before we introduced ASM and allowed third party vendors to implement their own IO routines so that the database would use this library if installed and make use of the library open/read/write/close,.. routines instead of the standard OS interfaces. PolyServe back in the day used this to optimize their storage solution, Veritas used (and I believe still uses) this for their filesystem. It basically allowed, in particular, filesystem vendors to write libraries that could optimize access to their storage or filesystem.. so ASMLib was not something new, it was basically based on the same model. You have libodm for just database access, you have libasm for asm/database access. Since this library interface existed, we decided to do a reference implementation on Linux. We wrote an ASMLib for Linux that could be used on any Linux platform and other vendors could see how this worked and potentially implement their own solution. As I mentioned earlier, ASMLib and ODMLib are libraries for third party extensions. ASMLib for Linux, since it was a reference implementation implemented both interfaces, the storage discovery part and the IO part. There are 2 components : Oracle ASMLib - the userspace library with config tools (a shared object and some scripts) oracleasm.ko - a kernel module that implements the asm device for /dev/oracleasm/* The userspace library is a binary-only module since it links with and contains Oracle header files but is generic, we only have one asm library for the various Linux platforms. This library is opened by Oracle ASM and by Oracle database processes and this library interacts with the OS through the asm device (/dev/asm). It can install on Oracle Linux, on SuSE SLES, on Red Hat RHEL,.. The library itself doesn't actually care much about the OS version, the kernel module and device cares. The support tools are simple scripts that allow the admin to label devices and scan for disks and devices. This way you can say create an ASM disk label foo on, currently /dev/sdf... So if /dev/sdf disappears and next time is /dev/sdg, we just scan for the label foo and we discover it as /dev/sdg and life goes on without any worry. Also, when the database needs access to the device, we don't have to worry about file permissions or anything it will be taken care of. So it's a convenience thing. The kernel module oracleasm.ko is a Linux kernel module/device driver. It implements a device /dev/oracleasm/* and any and all IO goes through ASMLib - /dev/oracleasm. This kernel module is obviously a very specific Oracle related device driver but it was released under the GPL v2 so anyone could easily build it for their Linux distribution kernels. Advantages for using ASMLib : A good async IO interface for the database, the entire IO interface is based on an optimal ASYNC model for performance A single file descriptor per Oracle process, not one per device or datafile per process reducing # of open filehandles overhead Device scanning and labeling built-in so you do not have to worry about messing with udev or devlabel, permissions or the likes which can be very complex and error prone. Just like with OCFS and OCFS2, each kernel version (major or minor) has to get a new version of the device drivers. We started out building the oracleasm kernel module rpms for many distributions, SLES (in fact in the early days still even for this thing called United Linux) and RHEL. The driver didn't make sense to get pushed into upstream Linux because it's unique and specific to the Oracle database. As it takes a huge effort in terms of build infrastructure and QA and release management to build kernel modules for every architecture, every linux distribution and every major and minor version we worked with the vendors to get them to add this tiny kernel module to their infrastructure. (60k source code file). The folks at SuSE understood this was good for them and their customers and us and added it to SLES. So every build coming from SuSE for SLES contains the oracleasm.ko module. We weren't as successful with other vendors so for quite some time we continued to build it for RHEL and of course as we introduced Oracle Linux end of 2006 also for Oracle Linux. With Oracle Linux it became easy for us because we just added the code to our build system and as we churned out Oracle Linux kernels whether it was for a public release or for customers that needed a one off fix where they also used asmlib, we didn't have to do any extra work it was just all nicely integrated. With the introduction of Oracle Linux's Unbreakable Enterprise Kernel and our interest in being able to exploit ASMLib more, we started working on a very exciting project called Data Integrity. Oracle (Martin Petersen in particular) worked for many years with the T10 standards committee and storage vendors and implemented Linux kernel support for DIF/DIX, data protection in the Linux kernel, note to those that wonder, yes it's all in mainline Linux and under the GPL. This basically gave us all the features in the Linux kernel to checksum a data block, send it to the storage adapter, which can then validate that block and checksum in firmware before it sends it over the wire to the storage array, which can then do another checksum and to the actual DISK which does a final validation before writing the block to the physical media. So what was missing was the ability for a userspace application (read: Oracle RDBMS) to write a block which then has a checksum and validation all the way down to the disk. application to disk. Because we have ASMLib we had an entry into the Linux kernel and Martin added support in ASMLib (kernel driver + userspace) for this functionality. Now, this is all based on relatively current Linux kernels, the oracleasm kernel module depends on the main kernel to have support for it so we can make use of it. Thanks to UEK and us having the ability to ship a more modern, current version of the Linux kernel we were able to introduce this feature into ASMLib for Linux from Oracle. This combined with the fact that we build the asm kernel module when we build every single UEK kernel allowed us to continue improving ASMLib and provide it to our customers. So today, we (Oracle) provide Oracle ASMLib for Oracle Linux and in particular on the Unbreakable Enterprise Kernel. We did the build/testing/delivery of ASMLib for RHEL until RHEL5 but since RHEL6 decided that it was too much effort for us to also maintain all the build and test environments for RHEL and we did not have the ability to use the latest kernel features to introduce the Data Integrity features and we didn't want to end up with multiple versions of asmlib as maintained by us. SuSE SLES still builds and comes with the oracleasm module and they do all the work and RHAT it certainly welcome to do the same. They don't have to rebuild the userspace library, it's really about the kernel module. And finally to re-iterate a few important things : Oracle ASM does not in any way require ASMLib to function completely. ASMlib is a small set of extensions, in particular to make device management easier but there are no extra features exposed through Oracle ASM with ASMLib enabled or disabled. Often customers confuse ASMLib with ASM. again, ASM exists on every Oracle supported OS and on every supported Linux OS, SLES, RHEL, OL withoutASMLib Oracle ASMLib userspace is available for OTN and the kernel module is shipped along with OL/UEK for every build and by SuSE for SLES for every of their builds ASMLib kernel module was built by us for RHEL4 and RHEL5 but we do not build it for RHEL6, nor for the OL6 RHCK kernel. Only for UEK ASMLib for Linux is/was a reference implementation for any third party vendor to be able to offer, if they want to, their own version for their own OS or storage ASMLib as provided by Oracle for Linux continues to be enhanced and evolve and for the kernel module we use UEK as the base OS kernel hope this helps.

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  • What to choose for a multilingual site with support for Markdown and commenting

    - by Kent
    I want to publish articles at a multilingual site. I want to be able to write an article in two languages and have them available on separate URLs: thesite.foo/english-breakfast thesite.com/engelsk-frukost If the users web browser is set to English I'd like to show a small notice at the top of the Swedish version with a link to the English one. The link should have an appropriate rel attribute for a translation (search for hreflang at http://diveintohtml5.org/semantics.html). There should be a way to list all articles belonging to these sets: Swedish only, English only, Swedish versions + English only, English versions + Swedish only. I'd like to publish these as four RSS-feeds. And I would like to have two versions of the main site, one in Swedish (showing Swedish versions + English only) and one in English (showing English versions). I shall be able to write the articles using Markdown, as that is the formatting language I find most convenient. There should be a way for users to comment. And some kind of way for me to protect myself against comment spam. I am leaning towards learning Drupal. I suspect I'll have to code this behavior myself as a module. To be frank I'd rather work with Java. Is Drupal the way to go? Or is there something more suitable for this project?

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  • Is it OK to use dynamic typing to reduce the amount of variables in scope?

    - by missingno
    Often, when I am initializing something I have to use a temporary variable, for example: file_str = "path/to/file" file_file = open(file) or regexp_parts = ['foo', 'bar'] regexp = new RegExp( regexp_parts.join('|') ) However, I like to reduce the scope my variables to the smallest scope possible so there is less places where they can be (mis-)used. For example, I try to use for(var i ...) in C++ so the loop variable is confined to the loop body. In these initialization cases, if I am using a dynamic language, I am then often tempted to reuse the same variable in order to prevent the initial (and now useless) value from being used latter in the function. file = "path/to/file" file = open(file) regexp = ['...', '...'] regexp = new RegExp( regexp.join('|') ) The idea is that by reducing the number of variables in scope I reduce the chances to misuse them. However this sometimes makes the variable names look a little weird, as in the first example, where "file" refers to a "filename". I think perhaps this would be a non issue if I could use non-nested scopes begin scope1 filename = ... begin scope2 file = open(filename) end scope1 //use file here //can't use filename on accident end scope2 but I can't think of any programming language that supports this. What rules of thumb should I use in this situation? When is it best to reuse the variable? When is it best to create an extra variable? What other ways do we solve this scope problem?

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  • Unrealscript splitting a string

    - by burntsugar
    Note, this is repost from stackoverflow - I have only just discovered this site :) I need to split a string in Unrealscript, in the same way that Java's split function works. For instance - return the string "foo" as an array of char. I have tried to use the SplitString function: array SplitString( string Source, optional string Delimiter=",", optional bool bCullEmpty ) Wrapper for splitting a string into an array of strings using a single expression. as found at http://udn.epicgames.com/Three/UnrealScriptFunctions.html but it returns the entire String. simulated function wordDraw() { local String inputString; inputString = "trolls"; local string whatwillitbe; local int b; local int x; local array<String> letterArray; letterArray = SplitString(inputString,, false); for (x = 0; x < letterArray.Length; x++) { whatwillitbe = letterArray[x]; `log('it will be '@whatwillitbe); b = letterarray.Length; `log('letterarray length is '@b); `log('letter number '@x); } } Output is: b returns: 1 whatwillitbe returns: trolls However I would like b to return 6 and whatwillitbe to return each character individually. I have had a few answers proposed, however, I would still like to properly understand how the SplitString function works. For instance, if the Delimiter parameter is optional, what does the function use as a delimiter by default?

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  • Why do memory-managed languages retain the `new` keyword?

    - by Channel72
    The new keyword in languages like Java, Javascript, and C# creates a new instance of a class. This syntax seems to have been inherited from C++, where new is used specifically to allocate a new instance of a class on the heap, and return a pointer to the new instance. In C++, this is not the only way to construct an object. You can also construct an object on the stack, without using new - and in fact, this way of constructing objects is much more common in C++. So, coming from a C++ background, the new keyword in languages like Java, Javascript, and C# seemed natural and obvious to me. Then I started to learn Python, which doesn't have the new keyword. In Python, an instance is constructed simply by calling the constructor, like: f = Foo() At first, this seemed a bit off to me, until it occurred to me that there's no reason for Python to have new, because everything is an object so there's no need to disambiguate between various constructor syntaxes. But then I thought - what's really the point of new in Java? Why should we say Object o = new Object();? Why not just Object o = Object();? In C++ there's definitely a need for new, since we need to distinguish between allocating on the heap and allocating on the stack, but in Java all objects are constructed on the heap, so why even have the new keyword? The same question could be asked for Javascript. In C#, which I'm much less familiar with, I think new may have some purpose in terms of distinguishing between object types and value types, but I'm not sure. Regardless, it seems to me that many languages which came after C++ simply "inherited" the new keyword - without really needing it. It's almost like a vestigial keyword. We don't seem to need it for any reason, and yet it's there. Question: Am I correct about this? Or is there some compelling reason that new needs to be in C++-inspired memory-managed languages like Java, Javascript and C#?

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  • I don't understand the definition of side effects

    - by Chris Okyen
    I don't understand the wikipedia article on Side Effects: In computer science, a function or expression is said to have a side effect if, in addition to returning a value, it also 1.) Modifies some state or 2.) Has an observable interaction with calling functions or the outside world. I know an example of the first thing that causes a function or expression to have side effects - modifying a state Function and Expression modifying a state : 1.) foo(int X) { return x = x % x; } a = a + 1; What does 2.) - Has an observable interaction with calling functions or the outside world," mean? - Please give an example. The article continues on to say, "For example, a function might modify a global or static variable, modify one of its arguments, raise an exception, write data to a display or file, read data, or call other side-effecting functions...." Are all these examples, examples of 1.) - Modifiying some state , or are they also part of 2.) - Has an observable interaction with calling functions or the outside world?

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  • Which is a better practice - helper methods as instance or static?

    - by Ilian Pinzon
    This question is subjective but I was just curious how most programmers approach this. The sample below is in pseudo-C# but this should apply to Java, C++, and other OOP languages as well. Anyway, when writing helper methods in my classes, I tend to declare them as static and just pass the fields if the helper method needs them. For example, given the code below, I prefer to use Method Call #2. class Foo { Bar _bar; public void DoSomethingWithBar() { // Method Call #1. DoSomethingWithBarImpl(); // Method Call #2. DoSomethingWithBarImpl(_bar); } private void DoSomethingWithBarImpl() { _bar.DoSomething(); } private static void DoSomethingWithBarImpl(Bar bar) { bar.DoSomething(); } } My reason for doing this is that it makes it clear (to my eyes at least) that the helper method has a possible side-effect on other objects - even without reading its implementation. I find that I can quickly grok methods that use this practice and thus help me in debugging things. Which do you prefer to do in your own code and what are your reasons for doing so?

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  • What conventions or frameworks exist for MVVM in Perl?

    - by Will Sheppard
    We're using Catalyst to render lots of webforms in what will become a large application. I don't like the way all the form data is confusingly into a big hash in the Controller, before being passed to the template. It seems jumbled up and messy for the template. I'm sure there are real disadvantages that I haven't described properly... Are there? One solution is to just decide on a convention for the hash, e.g.: { defaults => { type => ['a', 'b', 'c'] }, input => { type => 'a' }, output => { message => "2 widgets found of type a", widgets => [ 'foo', 'bar' ] } } Another way is to store the page/form data as attributes in a class (a ViewModel?), and pass a whole object to the template, which it could use like this: <p class="message">[% model.message %]<p> [% FOREACH widget IN model.widgets %] Which way is more flexible for large applications? Are there any other solutions or existing Catalyst-compatible frameworks?

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  • which style of member-access is preferable

    - by itwasntpete
    the purpose of oop using classes is to encapsulate members from the outer space. i always read that accessing members should be done by methods. for example: template<typename T> class foo_1 { T state_; public: // following below }; the most common doing that by my professor was to have a get and set method. // variant 1 T const& getState() { return state_; } void setState(T const& v) { state_ = v; } or like this: // variant 2 // in my opinion it is easier to read T const& state() { return state_; } void state(T const& v) { state_ = v; } assume the state_ is a variable, which is checked periodically and there is no need to ensure the value (state) is consistent. Is there any disadvantage of accessing the state by reference? for example: // variant 3 // do it by reference T& state() { return state_; } or even directly, if I declare the variable as public. template<typename T> class foo { public: // variant 4 T state; }; In variant 4 I could even ensure consistence by using c++11 atomic. So my question is, which one should I prefer?, Is there any coding standard which would decline one of these pattern? for some code see here

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