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  • OWB 11gR2 &ndash; OMB and File Editing

    - by David Allan
    Here we will see how we can use the IDE for editing OMB scripts. The 11gR2 release is based on the common Oracle platform IDE used also by JDeveloper. It comes with a bunch of standard behavior for editing and rendering code. One of the lesser known things is that if you drop a text file into OWB you can edit it. So you can drop your tcl scripts right into OWB and edit in-place, and don’t need another IDE like Eclipse just for this task. Cool, so you have the file here. There may be no line numbers, you can toggle line numbers on by right clicking in the gutter. If we edit the file within the OWB IDE, the save is a little different from normal. OWB doesn’t normally manipulate files so things like ctrl-s to save, saves the OWB objects, but if you edit a file the closing of the file will ask if you want to save it – check it out. Now we enter the realm of ‘he who dares’…. Note the IDE doesn’t know about tcl files out of the box, so you see above there is no syntax highlighting. The code is identified by the extension… .java is java, .html is HTML etc. With OWB, the OMB scripts are tcl, we usually have .tcl extension on these files. One of the things we can do to trick up the syntax highlighting is to simply rename the file to have a .java suffix, then all of a sudden we get syntax highlighting, see the illustration here where side by side we see a the file with a .java extension and a .tcl extension. Not ideal pretending to be .java but gets us a way to having something more useful than notepad. We can then change the syntax highlighting such that we get Eclipse like highlighting within the IDE from the Tools Preferences option; You then get the Eclipse like rendering albeit using a little tweak on the file names… Might be useful if you are doing any kind of heavy duty OMB script development and just want a single IDE. The OMBPlus panel is then at hand for executing and testing it out.

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  • Shelving &ndash; What is it &ndash; and more importantly, can it help me?

    - by Chris Skardon
    Since we shifted to TFS we’ve had the ability to perform what is known as ‘shelving’. Shelving (whilst not a wholly new topic in the world of SCC) is new to us, and didn’t exist in our previous SCC solution – SVN. Soo… what is it? What? Shelving is a way to check-in but not check-in your code. By shelving you submit a copy of your ‘pending changes’ to the SCC server, (which maintains a list of the shelvesets) and once that is done you can either continue working, or undo your changes, safe in the knowledge that a backup copy exists on the server. You can unshelve your code at any time and get back to the state you were when you shelved. Yer, that is great but why not just check it in?? Shelvesets don’t have to build. The shelveset you put in there could be entirely broken, or it might solve every bug in the system – shelves aren’t continuously integrated so you can shelve anything. Hmmmm… What else? Shelving allows us to do some pretty cool stuff that beforehand was quite frankly a pain. For instance – Gated Check-ins are implemented via the shelving mechanism, when code is checked-in, what you’re actually doing is shelving it, the Build Controller will build the shelveset with the original code and if it succeeds, the code will be committed, if it fails – well – it’s only you that has to fix the code :) Other nice features are things like the ability to share code you are working on… For example, if I was having trouble with a particular piece of code, I could shelve it, and then you (yes you) could then get that shelveset and check out the problem for yourself, and if you fix it?? Well – you could check-it in! Nice, but day-to-day shizzle? Let’s say you’ve been working on your project and your project manager comes over to you and says: “Hey, errr, bad times, there is an urgent bug we need you to fix, it needs to go out now!” (also for this to play out – we’ll need to assume you’re currently working in the 'release’ branch for another bug fix (maybe))… You could undo all your current changes (obviously you’ll probably backup your code using zip or something I imagine) fix the bug, then re-copy your backup over the top, or you could shelve and unshelve. Perhaps some other uses will awaken the shelver in you… :) Before each checkin – if you shelve, you no longer need to worry (if indeed you do) about resolving conflicts and mysteriously losing your code… Going home at night? Not checking in straight away? Why not shelve, this way – should the worst come to the worst and your local pc gives up, you can just get the shelveset onto another machine and be up and running in literally seconds minutes…

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  • Robust line of sight test on the inside of a polygon with tolerance

    - by David Gouveia
    Foreword This is a followup to this question and the main problem I'm trying to solve. My current solution is an hack which involves inflating the polygon, and doing most calculations on the inflated polygon instead. My goal is to remove this step completely, and correctly solve the problem with calculations only. Problem Given a concave polygon and treating all of its edges as if they were walls in a level, determine whether two points A and B are in line of sight of each other, while accounting for some degree of floating point errors. I'm currently basing my solution on a series of line-segment interection tests. In other words: If any of the end points are outside the polygon, they are not in line of sight. If both end points are inside the polygon, and the line segment from A to B crosses any of the edges from the polygon, then they are not in line of sight. If both end points are inside the polygon, and the line segment from A to B does not cross any of the edges from the polygon, then they are in line of sight. But the problem is dealing correctly with all the edge cases. In particular, it must be able to deal with all the situations depicted below, where red lines are examples that should be rejected, and green lines are examples that should be accepted. I probably missed a few other situations, such as when the line segment from A to B is colinear with an edge, but one of the end points is outside the polygon. One point of particular interest is the difference between 1 and 9. In both cases, both end points are vertices of the polygon, and there are no edges being intersected, but 1 should be rejected while 9 should be accepted. How to distinguish these two? I could check some middle point within the segment to see if it falls inside or not, but it's easy to come up with situations in which it would fail. Point 7 was also pretty tricky and I had to to treat it as a special case, which checks if two points are adjacent vertices of the polygon directly. But there are also other chances of line segments being col linear with the edges of the polygon, and I'm still not entirely sure how I should handle those cases. Is there any well known solution to this problem?

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  • RIM's current BB7 developer toolset is a joke

    - by mbrit
    tl;dr - RIM's current developer toolset is not fit for purpose.Background to this is that I'm currently working on a PhoneGap/Cordova project for a client that has to run on BlackBerry. The tooling is so ridiculous to use that even though I had a gentle dig at them in a Guardian piece it's worth having a more full-on attack.At the moment, RIM's pitch is that apps are built for the current BBOS7 devices using WebWorks. This is an HTML-based toolset. Essentially a browser is spun up in a native app container and your app is powered by JavaScript. Specific JavaScript libraries exist that thunk down to native capabilities no the device. I happen to use PhoneCap/Cordova in combination with this.The tooling is non-existent. I'm using TextMate, Ant, and Terminal to develop the app. There's no "console.log" output, and no debugging. The only way to instrument the app is to put "alert" calls in your code.Apart from the fact that that's *not* fine in 2012, how about this… every time you deploy a new app to the device, the device has to reboot. This process takes six minutes on a relatively modern BlackBerry device. How about this as well - in order to get a file into the package it has to be signed. My small app over here has 100 different files (75 or so generated). Signing doesn't happen locally, it happens on RIM's servers in Waterloo. Thus whenever you deploy the app you have this utility have to call RIM's servers 100 times. More to the point, sometimes during the day these servers have "micro-downtime" moments where they're unreachable for five or ten minutes, normally two or three times a day. Oh yes, you'll also get an email sent to you per signing on success or failure. 100 inbound emails, per deployment.(I started this post at the beginning of one of these cycles, by the way. That's how long it takes to build and deploy *once*. By the way, the change I made didn't work.)To clarify:* Change the script,* Build it using Ant,* Ant will spin up a Java app that talks to RIM's servers to sign it.* Receive 100 emails, assuming the server is up.* App deployed - takes about 30 seconds.* BlackBerry device restarts - takes about six minutes.* Find and open the app. Go through security prompts.* Test the app, with no "console.log" output and no debugger."Why not use the simulator?" I hear you ask. Well, apart from the fact that the simulator refused to reach any network service over HTTPS that I happen to own? (Some people suggest changing DNS settings for this known issue.) Admittedly, the simulator does show you console.log, but you still have the "six minute" restart issue on the simulator.Developers will understand this problem. Breaking concentration for six-plus minutes every time you want to deploy an app turns developing into a nightmare. Combining that with no worthy debugging tools turns the toolset into a joke.

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  • Commerce, Anyway You Want It

    - by David Dorf
    I believe our industry is finally starting to realize the importance of letting consumers determine how, when, and where to interact with retailers.  Over the last few months I've seen several articles discussing the importance of removing the barriers between existing channels. Paula Rosenblum of RSR first brought the term omni-channel to my attention back in September. She stated, "omni-channel retail isn’t the merging of channels – rather, it’s the use of all possible channels (present and future) to enhance the customer experience in a profitable way." I added to her thoughts in this blog posting in which I said, "For retailers to provide an omni-channel experience, there needs to be one logical representation of products, prices, promotions, and customers across all channels. The only thing that varies is the presentation of the content based on the delivery mechanism (e.g. shelf labels, mobile phone, web site, print, etc.) and often these mechanisms can be combined in various ways." More recently Brian Walker of Gartner suggested we stop using the term multi-channel and begin thinking more about consumer touch-points. "It is time for organizations to leave their channel-oriented ways behind, and enter the era of agile commerce--optimizing their people, processes and technology to serve today's empowered, ever-connected customers across this rapidly evolving set of customer touch points." Now Jason Goldberg, better known as RetailGeek, says we should start breaking down the channel silos by re-casting the VP of E-Commerce as the VP of Digital Marketing, and change his/her focus to driving sales across all channels using digital media. This logic is based on the fact that consumers switch between channels, or touch-points as Brian prefers, as part of their larger buying process. Today's smart consumer leverages the Web, mobile, and stores to provide the best shopping experience, so retailers need to make this easier. Regardless of what we call it, the key take-away is that "multi-channel" is not only an antiquated term but also an idea who's time has passed.  Today, retailers must look at e-commerce, m-commerce, f-commerce, catalogs, and traditional store sales collectively and through the consumers' eyes.  The goal is not to drive sales through each channel but rather to just drive sales -- using whatever method the customer prefers.  There really should be just one cart.

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  • VS2010 Launch Presentations

    Last week I was in Vegas to present at the DevConnections / VS2010 Launch event.  The show was well-attended and everybody I spoke to agreed it was educational and enjoyable.  My three talks were all on Wednesday, 14 April 2010, including one at 8am for which I was impressed to see a large turnout in attendance.   Pragmatic ASP.NET Tips, Tricks, and Tools My first session was on tips, tricks, and tools for ASP.NET developers.  This is a talk Ive given in past years, but which I refine every time.  I usually like to have a full session to devote to tools, and a separate talk just for Tips and Tricks, but for this show I was only given the one 75-minute slot, so I had to cut some materials to make things fit.  The talk went well, all the demos work, and the attendees seemed to enjoy it, and I like giving it, so hopefully I can continue to present on this topic in future DevConnections shows. Download the ASP.NET Tips, Tricks, and Tools slides and demos.   Whats New in ASP.NET MVC 2 My second talk of the day followed immediately after the Tips and Tricks talk, and was a brand new talk for me.  I have to throw out a thank-you to Phil for letting me see his MIX slide deck before he gave his talk, as that was a big help.  The official whats new document online is also worth checking out if youre interested in this subject.  Download the Whats New in ASP.NET MVC 2 slides and demos.   SOLIDify Your ASP.NET MVC 2 Application Just because youre using a ASP.NET MVC doesnt mean your code cant still end up being a big ball of mud.  This session describes a number of principles of software design that can help ensure applications remain loosely-coupled and malleable even as they age and increase in features and complexity.  This was my last talk of the day and did have one minor demo failure involving a database constraint.  Ive given this talk many times before, and in this case I had to fit it into a 60-minute timeslot, so Im not sure I had quite enough time to drive home all of the concepts to everyone in the audience.  That said, I did hear a number of positive comments on how the talk went, so thats encouraging. Download the SOLIDify Your ASP.NET MVC 2 Application slides and demos.   In my sessions, I promised to have these posted by the end of the weekend theyre going up at 10pm Sunday night (my time) 2 hours to spare!  Enjoy! Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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

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

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  • Partners, Start your Engines

    - by Kristin Rose
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Hello speed racer - OPN here to inform you that in case you missed it, our ISV Focused PartnerCast took place last week in Oracle’s Redwood Shores studio. Without a roadblock in site, Oracle’s key drivers discussed topics like Optimized and Oracle’s Cloud offerings; even OPN partner MSC took it to the next level by stopping by to share with us their first hand experience with the Oracle Exastack Optimized program. By stepping into Oracle’s ”Motor Speedway”, better known as the Exastack lab, MSC was able to fine tune, test and optimize their application on Oracle Exadata, as well as gain outstanding expertise on several technical areas such as optimizing multithreaded applications and database tuning. By optimizing their solution, MSC has “decreased their deployment time and saw a 30 percent performance improvement in database.” Sounds like someone’s gearing up for an “Oracle Indy 500.” By achieving Oracle Exadata Optimized status, MSC is putting performance in the driver’s seat, and their customers at the front of the race by delivering a solution that is tuned for performance, scalability and reliability. So go ahead and let the Oracle Exastack Optimized pit crew take you to the finish line. Learn how to go from 0-60 by watching MSC’s segment of the ISV Focused PartnerCast below. Ready… Set… Optimize! The OPN Communications Team

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  • It's Here! Visual Studio 2010 and ASP.NET 4.0 Ship

    Today Microsoft released Visual Studio 2010 and ASP.NET 4.0. I've been using the RC version of Visual Studio 2010 quite a bit for the past couple of months and have really grown to like it. It has a host of features and enhancements that improve developer productivity, from improved IntelliSense to better multiple monitor support. Plus there's something about the user experience that, to me, makes it feel better than Visual Studio 2008. I don't know if it's the new blue color motif or what, but the IDE seems more modern looking and more responsive to my mouse movements and other input. Anyway, if you've not yet downloaded Visual Studio 2010 and ASP.NET 4.0, why not? As with previous versions of Visual Studio there's a free Express Edition and VS2010 and ASP.NET 4.0 runs side-by-side with earlier versions of Visual Studio and ASP.NET. And with Visual Studio 2010's multi-targeting you can even use VS2010 as your development editor for ASP.NET 2.0 and ASP.NET 3.5 web applications. (Although be forewarned if you have multiple developers working on the application that the project files in VS2010 and earlier versions of Visual Studio differ.) This week's article on 4Guys explores my favorite new features of Visual Studio 2010. Here's an excerpt: The Visual Studio 2010 user experience is noticeably different than with previous versions. Some of the changes are cosmetic - gone is the decades-old red and orange color scheme, having been replaced with blues and purples - while others are more substantial. For instance, the Visual Studio 2010 shell was rewritten from the ground up to use Microsoft's Windows Presentation Foundation (WPF). In addition to an updated user experience, Visual Studio introduces an array of new features designed to improve developer productivity. There are new tools for searching for files, types, and class members; it's now easier than ever to use IntelliSense; the Toolbox can be searched using the keyboard; and you can use a single editor - Visual Studio 2010 - to work on. This article explores some of the new features in Visual Studio 2010. It is not meant to be an exhaustive list, but rather highlights those features that I, as an ASP.NET developer, find most useful in my line of work. Read on to learn more! And, in closing, here are some helpful VS2010 and ASP.NET 4.0 links: One click installation for ASP.NET 4.0, Visual Web Developer 2010, .NET Framework 4.0, and ASP.NET MVC 2 Eight Quick Hit videos showing some of the cool new VS2010 features VS2010 and ASP.NET 4.0 Release Announcement with some great info/links from none other than Scott Guthrie Happy Programming!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Maximum Availability with Oracle GoldenGate

    - by Irem Radzik
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Oracle Database offers a variety of built-in and optional products for maximum availability, and it is well known for its robust high availability and disaster recovery solutions. With its heterogeneous, real-time, transactional data movement capabilities, Oracle GoldenGate is a key part of the Maximum Availability Architecture for Oracle Database. This week on Thursday Dec. 13th we will be presenting in a live webcast how Oracle GoldenGate fits into Oracle Database Maximum Availability Architecture (MAA). Joe Meeks from the Oracle Database High Availability team will discuss how Oracle GoldenGate complements other key products within MAA such as Active Data Guard. Nick Wagner from GoldenGate PM team will present how to upgrade to latest Oracle Database release without any downtime. Nick will also cover 2 new features of  Oracle GoldenGate 11gR2:  Integrated Capture for Oracle Database and Automated Conflict Detection and Resolution. Nick will provide in depth review of these new features with examples. Oracle GoldenGate also offers maximum availability for non-Oracle databases, such as HP NonStop, SQL Server, DB2 (LUW, iSeries, or zSeries) and more. The same robust, reliable real-time, bidirectional data movement capabilities apply to all supported databases.  I'd like to invite you to join us on Thursday Dec. 13th 10am PT/1pm ET to hear from the product experts on how to use GoldenGate for maximizing database availability and to ask your questions. You can find the registration link below. Webcast: Maximum Availability with Oracle GoldenGate Thursday Dec. 13th 10am PT/1pm ET Look forward to another great webcast with lots of interaction with the audience. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

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  • Configuring keyboard input to eliminate unused diacritics

    - by David Cesarino
    I'd like to change the way diacritics work under Xubuntu. My problem My native language is pt-BR and my notebook has an american keyboard. Thus, I use ' and " followed by keys like u and c to achieve things like ú, ç and ü. It all works well. However, in the case of apostrophes and quotes, that creates a problem when I use ' followed by: letters that won't accept the acute accent ( ´ , ACUTE ACCENT -- 0x00B4) at all, like t; and letters that won't accept the acute in pt-BR, like r. In 1, ' with t does absolutely nothing. In 2, ' with r creates r (LATIN SMALL LETTER R WITH ACUTE -- 0x0155), which is used, afaik, for some eastern european languages like slovak. It isn't used in portuguese, just like ?, s, z, ?, ?, ?, n and all consonants (portuguese do not take diacritics in consonants). Question That said, is there a way to better support the portuguese-brazilian language using an american keyboard? It is very common here --- I actually prefer the american keyboard to our own, known as “ABNT”. Desired solution I'd like to deactivate unused diacritics, so case 2 would behave just like case 1. Additionally, if possible, I'd like case 1 to behave like it does under Windows. As an example, typing ' followed by t should write 't (acute followed by T) instead of doing nothing. About 2, in my humble opinion, doing nothing is counterproductive. I realize the behavior is reasonable according to logic ("there isn't t-acute, so please tell the computer to typeset apostrophe --- ', SPACE --- instead of acute). But from a human, practical point of view, I think it makes more sense (to me, at least). Additional comments I believe this also applies to spanish, french, italian and other western european latin languages. On the console (Ctrl+Alt+F?), case 1 is not a problem. I don't need to press space as apostrophes are automatically added. However, there, I'm unable to access cedilla (ç). Two completely different behaviors. If it's just a matter of customizing text config files (possibly creating a custom layout or whatever), I'd be glad to share my efforts. I just need guide on the "howto" part. Somehow Google only points me to the "enough" people (those who cope with the situation and think that it works "well enough"). And since I have definitely migrated to Linux/Xubuntu after years, I'd like to leave just as I like it (and I'm sure others as well). For example, if there is some kind of scripting or definition to tell the computer to do what I described, so be it.

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  • Issue 56 - Super Stylesheets Skinning in DotNetNuke 5

    May 2010 Welcome to Issue 56 of DNN Creative Magazine In this issue we show you how to use the powerful new Super Stylesheets skinning feature in DotNetNuke 5. Super Stylesheets are ideal for both beginner and experienced skin designers, they provide skin layouts using CSS. The advantage of Super Stylesheets is that you can easily create a skin layout which works in all browsers without the need to learn complex CSS techniques. They are also very quick to build and you can change a skin layout in a matter of minutes rather than hours. We show you how to build a skin from the very beginning using Super Stylesheets, we show you how to create various skin layouts, as well as multi-layouts. We also show you how to style the skin, how to add tokens such as the logo, menu, login links etc. and walk you through how to create a fully working skin from scratch. Following this we continue the Open Web Studio tutorials, this month we demonstrate how to create an installable DotNetNuke PA module using OWS. This is an essential technique which allows you to package up the OWS applications that you have created and build them into an installable zip package. The zip file is then installable as a standard DotNetNuke module which means you can easily install your OWS applications on other DotNetNuke installations by simply installing them as a standard DotNetNuke module. To finish, we have part six of the "How to Build a News Application with DotNetMushroom Rapid Application Developer (RAD)" article, where we demonstrate how to create a News Carousel using RAD, JQuery and the JCarousel plugin. This issue comes complete with 15 videos. Skinning: Super Stylesheets Skinning in DotNetNuke 5 - DNN Layouts (12 videos - 98mins) Module Development Series: How to Create an Installable DotNetNuke PA Module Using OWS (3 videos - 23mins) How to Implement a News Carousel Using DotNetMushroom RAD and JQuery View issue 56 to download all of the videos in one zip file DNN Creative Magazine for DotNetNuke Web Designers Covering DotNetNuke module video reviews, video tutorials, mp3 interviews, resources and web design tips for working with DotNetNuke. In 56 issues we have created 578 videos!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • C# Dev - I've tried Lisps, but I don't get it.

    - by Jonathan Mitchem
    After a few months of learning about and playing with lisps, both CL and a bit of Clojure, I'm still not seeing a compelling reason to write anything in it instead of C#. I would really like some compelling reasons, or for someone to point out that I'm missing something really big. The strengths of a Lisp (per my research): Compact, expressive notation - More so than C#, yes... but I seem to be able to express those ideas in C# too. Implicit support for functional programming - C# with LINQ extension methods: mapcar = .Select( lambda ) mapcan = .Select( lambda ).Aggregate( (a,b) = a.Union(b) ) car/first = .First() cdr/rest = .Skip(1) .... etc. Lambda and higher-order function support - C# has this, and the syntax is arguably simpler: "(lambda (x) ( body ))" versus "x = ( body )" "#(" with "%", "%1", "%2" is nice in Clojure Method dispatch separated from the objects - C# has this through extension methods Multimethod dispatch - C# does not have this natively, but I could implement it as a function call in a few hours Code is Data (and Macros) - Maybe I haven't "gotten" macros, but I haven't seen a single example where the idea of a macro couldn't be implemented as a function; it doesn't change the "language", but I'm not sure that's a strength DSLs - Can only do it through function composition... but it works Untyped "exploratory" programming - for structs/classes, C#'s autoproperties and "object" work quite well, and you can easily escalate into stronger typing as you go along Runs on non-Windows hardware - Yeah, so? Outside of college, I've only known one person who doesn't run Windows at home, or at least a VM of Windows on *nix/Mac. (Then again, maybe this is more important than I thought and I've just been brainwashed...) The REPL for bottom-up design - Ok, I admit this is really really nice, and I miss it in C#. Things I'm missing in a Lisp (due to a mix of C#, .NET, Visual Studio, Resharper): Namespaces. Even with static methods, I like to tie them to a "class" to categorize their context (Clojure seems to have this, CL doesn't seem to.) Great compile and design-time support the type system allows me to determine "correctness" of the datastructures I pass around anything misspelled is underlined realtime; I don't have to wait until runtime to know code improvements (such as using an FP approach instead of an imperative one) are autosuggested GUI development tools: WinForms and WPF (I know Clojure has access to the Java GUI libraries, but they're entirely foreign to me.) GUI Debugging tools: breakpoints, step-in, step-over, value inspectors (text, xml, custom), watches, debug-by-thread, conditional breakpoints, call-stack window with the ability to jump to the code at any level in the stack (To be fair, my stint with Emacs+Slime seemed to provide some of this, but I'm partial to the VS GUI-driven approach) I really like the hype surrounding Lisps and I gave it a chance. But is there anything I can do in a Lisp that I can't do as well in C#? It might be a bit more verbose in C#, but I also have autocomplete. What am I missing? Why should I use Clojure/CL?

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  • Wired and Wireless Network Issues with PPPoE

    - by user9054
    down vote favorite Hi Friends, I have got this issue with Ubuntu 10.10. I have been with ubuntu 8.04 and then decided to try out ubuntu 10.10 . I booted with a LiveCD and was able to configure the wireless network painlessly using the livecd. So happily i installed ubuntu 10.10. As soon as ubuntu came up it detected the wireless network and i was able to assign a static IP to eth1 (i dont use DHCP option on my ADSL router) and enter a wap key and use pppoeconf to configure the dialer. The net was on and i was able to surf the net. All hunky dory so far. However on the next boot the fun started. It did not detect the wireless network. I could not see the network manager icon in the systray. I used ifconfig and saw that the entry for eth1 was missing. I used ifup eth1 and it said that eth1 was already up . Then i installed wifi-radar. Wifi-Radar detected the wireless network. I configured wifi-radar for the detected wireless network , set the wap driver as wext and used the manual IP settings. However on clicking connect wifi-radar started looking for a DHCP IP , needless to say it failed. For the love of god i cannot understand why wifi-radar is using DHCP when i have specified manual settings . Next i decided to use the wired network to surf the net looking for a solution . So i plugged in the network cable from my modem , it detected the plugged in connection , i configured eth0 , used pppoeconf and connected to the net. Then i foolishly decided to reboot my PC. And wonders of wonders , the same problem appeared. I cannot see eth0 in my ifconfig anymore. I used pon to start the dsl-provider connection and it said something about network error or something . Now my ifconfig shows only lo , both eth0 and eth1 have disappeared. Can anybody help me on this ? Is it a problem with ipv6 , if so how do you disable ipv6 on ubuntu 10.10 ? OR is this is a known issue with ubuntu 10.10 ? PS : 1) i tried linux mint 10 and had the same issue. On rebooting wireless network was not getting detected . 2) i have made myself the administrator so that there is no issue of rights or anything. Any help is appreciated.

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  • C++11 Tidbits: Decltype (Part 2, trailing return type)

    - by Paolo Carlini
    Following on from last tidbit showing how the decltype operator essentially queries the type of an expression, the second part of this overview discusses how decltype can be syntactically combined with auto (itself the subject of the March 2010 tidbit). This combination can be used to specify trailing return types, also known informally as "late specified return types". Leaving aside the technical jargon, a simple example from section 8.3.5 of the C++11 standard usefully introduces this month's topic. Let's consider a template function like: template <class T, class U> ??? foo(T t, U u) { return t + u; } The question is: what should replace the question marks? The problem is that we are dealing with a template, thus we don't know at the outset the types of T and U. Even if they were restricted to be arithmetic builtin types, non-trivial rules in C++ relate the type of the sum to the types of T and U. In the past - in the GNU C++ runtime library too - programmers used to address these situations by way of rather ugly tricks involving __typeof__ which now, with decltype, could be rewritten as: template <class T, class U> decltype((*(T*)0) + (*(U*)0)) foo(T t, U u) { return t + u; } Of course the latter is guaranteed to work only for builtin arithmetic types, eg, '0' must make sense. In short: it's a hack. On the other hand, in C++11 you can use auto: template <class T, class U> auto foo(T t, U u) -> decltype(t + u) { return t + u; } This is much better. It's generic and a construct fully supported by the language. Finally, let's see a real-life example directly taken from the C++11 runtime library as implemented in GCC: template<typename _IteratorL, typename _IteratorR> inline auto operator-(const reverse_iterator<_IteratorL>& __x, const reverse_iterator<_IteratorR>& __y) -> decltype(__y.base() - __x.base()) { return __y.base() - __x.base(); } By now it should appear be completely straightforward. The availability of trailing return types in C++11 allowed fixing a real bug in the C++98 implementation of this operator (and many similar ones). In GCC, C++98 mode, this operator is: template<typename _IteratorL, typename _IteratorR> inline typename reverse_iterator<_IteratorL>::difference_type operator-(const reverse_iterator<_IteratorL>& __x, const reverse_iterator<_IteratorR>& __y) { return __y.base() - __x.base(); } This was guaranteed to work well with heterogeneous reverse_iterator types only if difference_type was the same for both types.

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  • Wesquare (NL) helps major CG customer integrating Oracle Service Cloud (RightNow) with JDEdwards

    - by Richard Lefebvre
    Normal 0 false false false EN-US X-NONE X-NONE When this well known, Italy based, CG player claimed that they needed a new CRM tool, Oracle partner WeSquare had a precise idea of what would be required, knowing that the customer was using JDEdwards as an ERP: they immediately thoughts about a solution that would help synchronizing the customer’s back-end system with the new CRM interface. The customer asked for presentations from three companies, including Oracle, and eventually selected Oracle Service Cloud (RightNow) with Alfa Sistemi (Oracle Platinum Partner) as a System Integrator supported by Wesquare (Oracle Gold partner specialized in RightNow). Synchronizing an On Premises ERP with a new SaaS based CRM platform could be seen as an uphill task, but WeSquare was determined, during the presales cycle, to prove that they had the skills and the attitude to make the difference. So, they rolled up their sleeves and got to it: five days of relentless work, missed lunches, and hours of brainstorming showed its result in the form of a new interface that works fabulously well with the JDEdwards ERP back-end and was successfully pitched by Oracle to the end-customer to win the deal! WeSquare took the occasion to learn that they can integrate Oracle Service Cloud (RightNow) with practically every other solution that a customer may run. As part of the project, WeSquare was also involved in different add-on’s development with the aim of enriching Oracle Service Cloud’s functionality. WeSquare is based in The Netherlands with an in-shore practice supported by off-shore teams in India. WeSquare can integrate and synchronize any application with RightNow. For more information, visit www.wesquare.nl or contact Wiebe Blankenberg (Managing Director) at +31 (0) 6 3632 1104 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • How to discriminate from two nodes with identical frequencies in a Huffman's tree?

    - by Omega
    Still on my quest to compress/decompress files with a Java implementation of Huffman's coding (http://en.wikipedia.org/wiki/Huffman_coding) for a school assignment. From the Wikipedia page, I quote: Create a leaf node for each symbol and add it to the priority queue. While there is more than one node in the queue: Remove the two nodes of highest priority (lowest probability) from the queue Create a new internal node with these two nodes as children and with probability equal to the sum of the two nodes' probabilities. Add the new node to the queue. The remaining node is the root node and the tree is complete. Now, emphasis: Remove the two nodes of highest priority (lowest probability) from the queue Create a new internal node with these two nodes as children and with probability equal to the sum of the two nodes' probabilities. So I have to take two nodes with the lowest frequency. What if there are multiple nodes with the same low frequency? How do I discriminate which one to use? The reason I ask this is because Wikipedia has this image: And I wanted to see if my Huffman's tree was the same. I created a file with the following content: aaaaeeee nnttmmiihhssfffouxprl And this was the result: Doesn't look so bad. But there clearly are some differences when multiple nodes have the same frequency. My questions are the following: What is Wikipedia's image doing to discriminate the nodes with the same frequency? Is my tree wrong? (Is Wikipedia's image method the one and only answer?) I guess there is one specific and strict way to do this, because for our school assignment, files that have been compressed by my program should be able to be decompressed by other classmate's programs - so there must be a "standard" or "unique" way to do it. But I'm a bit lost with that. My code is rather straightforward. It literally just follows Wikipedia's listed steps. The way my code extracts the two nodes with the lowest frequency from the queue is to iterate all nodes and if the current node has a lower frequency than any of the two "smallest" known nodes so far, then it replaces the highest one. Just like that.

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  • Size doesn't matter

    - by ssoolsma
    Whenever I start a new project I *always* break up my code in different projects. Also known as n-tier solution. The scale of  the project doesn't matter, but make sure that each project is responsible for himself (or herself if you prefer). I make sure that i ....At least thought about how the project should work on the toilet or in a project team meeting.Have a solution directory and create my projects within. I like to name my project (and it's folders by the namespaces). For instance: When i'm creating a piece of (web)software called: ChuckNorris, i always include the software name in my projects. Start off with designing the DataAccess project. I name it: ChuckNorris.DataAccess which lets me easily identify the project incase the project scales alot.Build the classes which represent the database structure. Don't stop working on a class untill it's finished for now. Also, don't over-do the methods. Build stuff only when it's needed, and not think: "Hm, that would be cool to have". Cause most of the time you end up with unused code, and we don't want that.Build a unittest project and make sure you create the folder inside the project that it's testing. So, create the ChuckNorris.DataAccess.UnitTest project inside the folder of the dataaccess project. I would suggest using the nUnit testframework.Incase you though, hm i skip unittest: Don't! Just build it - it will safe you alot of time later onNow, read 5 again. Build that bloody unittest. Don't skip. (i cant emphasize this enough)Now, every class in the dataaccess project is responsible for itself. They don't rely on each other. This is where we use the BusinessLogic project for. Start creating the ChuckNorris.BusinessLogic project. (not inside the data-access project ofcourse, but withing the ChuckNorris folder.Combine stuff from data-access. This usual involves alot of copying the data-access classes and feels silly at first. (we'll get to that later on)Now you come up to a point of creating a service project. You might not always see why to use it, but see it as a way to expose your businesslogic to any application (including your own). Sometimes i use it as a so-called "Factory". Every call goes through this factory, so that's the only thing i'm exposing to any program, and make sure that those methods are the only ones that I allow you to invoke.Build any UI (website, phoneapp, forms application, silverlight, wpf or whatever) and reference it to you service project. Fall in love (cough) with this approach.It's possible that it doesn't seem to make much sense, and very incomplete. Well, that last part is correct. Next post will go in to detail of setting up your Data-Access project and use the entity framework.

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  • Oracle At QCon SF 2012

    - by Cassandra Clark - OTN
    Oracle Technology Network is a Platinum sponsor at QCon San Francisco.  (qconsf.com).  Don’t miss these great developer focused sessions: Shay ShmeltzerHow we simplified Web, Mobile and Cloud development for our own developers? - the Oracle StoryOver the past several years, Oracle has beendeveloping a new set of enterprise applications in what is probably one of thelargest Java based development project in the world. How do you take 3000 developers and make them productive? How do you insure the delivery of cutting edge UIs for both Mobile and Web channels? How do you enable Cloud baseddevelopment and deployment?  Come and learn how we did it at Oracle, and see how the same technologies and methodologies can apply to your development efforts. Dan SmithProject Lambda in Java 8Java SE 8 will include major enhancements to the Java Programming Language and its core libraries.  This suite of new features, known as Project Lambda in the OpenJDK community, includes lambda expressions, default methods, and parallel collections (and much more!).  The result will be a next-generation Java programming experience with more flexibility and better abstractions.   This talk will introduce the new Java features and offer a behind-the-scenes view of how they evolved and why they work the way that they do. Arun GuptaJSR 356: Building HTML5 WebSocket Applications in JavaThe family of HTML5 technologies has pushed the pendulum away from rich client technologies and toward ever-more-capable Web clients running on today’s browsers. In particular, WebSocket brings new opportunities for efficient peer-to-peer communication, providing the basis for a new generation of interactive and “live” Web applications. This session examines the efforts under way to support WebSocket in the Java programming model, from its base-level integration in the Java Servlet and Java EE containers to a new, easy-to-use API and toolset that are destined to become part of the standard Java platform. The full conference schedule is here: http://qconsf.com/sf2012/schedule/wednesday.jsp But wait, there’s more!  At the Oracle booth, we’ll also be covering: ·         Oracle ADF Mobile·         Oracle Developer Cloud Service·         Oracle ADF Essentials·         NetBeans Project Easel Lastly we’ll share the results of a short cloud survey at QConSF ater this week.  If you attended this year's Oracle OpenWorld and JavaOne conferences, it would be hard not to notice that Oracle is clearly "all-in" when it comes to the Cloud.  With Cloud computing being such a hot topic on many OTN members' minds, we'd like to know what you're doing in the cloud and invite you to take this short cloud survey.

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  • Legality of similar games

    - by Jamie Taylor
    This is my first question on GD.SE, and I hope it's in the right place. A little background: I'm an amateur (read: not explicitly employed to develop games, but am employed as a software developer) game developer and took a ComSci with Games Development degree. My Question: What is the legal situation/standpoint of creating a copycat title? I know that there are only N number of ways of solving a problem, and N number of ways to design a piece of software. Say that an independent developer designed a copycat game (a Tetris clone in this example) for instance, and decided to use that game to generate income for themselves as well as interest for their other products. Say the developer adds a disclaimer into the software along the lines of "based on , originally released c. by ." Are there any legal problems/grey areas with the developer in this example releasing this game, commercially? Would they run into legal problems? Should the developer in this example expect cease and desist orders or law suit claims from original publishers? Have original publishers been known to, effectively, kill independent projects because they are a little too close to older titles? I know that there was, at least, one attempt by a group of independent developers to remake Sonic the Hedgehog 2 and Sega shut them down. I also know of Sega shutting down development of the independent Streets of Rage Remake. I know that "but it's an old game, your honour," isn't a great legal standpoint when it comes to defending yourself. But, could an independent developer have a law suit filed against them for re-implementing an older title in a new way? I know that there are a lot of copycat versions of the older titles like Tetris available on app stores (and similar services), and that it would be very difficult for a major publisher to shut them all down. Regardless of this, is making a Tetris (or other game) copycat/clone illegal? We were taught lots of different things at University, but we never covered copyright law. I'm presuming that their thought behind it was "IF these students get jobs in games development, they wont need to know anything about the legal side of it, because their employers will have legal departments... presumably" tl;dr Is it illegal to create a clone or copycat of an old title, and make money from it?

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  • best way to "introduce" OOP/OOD to team of experienced C++ engineers

    - by DXM
    I am looking for an efficient way, that also doesn't come off as an insult, to introduce OOP concepts to existing team members? My teammates are not new to OO languages. We've been doing C++/C# for a long time so technology itself is familiar. However, I look around and without major infusion of effort (mostly in the form of code reviews), it seems what we are producing is C code that happens to be inside classes. There's almost no use of single responsibility principle, abstractions or attempts to minimize coupling, just to name a few. I've seen classes that don't have a constructor but get memset to 0 every time they are instantiated. But every time I bring up OOP, everyone always nods and makes it seem like they know exactly what I'm talking about. Knowing the concepts is good, but we (some more than others) seem to have very hard time applying them when it comes to delivering actual work. Code reviews have been very helpful but the problem with code reviews is that they only occur after the fact so to some it seems we end up rewriting (it's mostly refactoring, but still takes lots of time) code that was just written. Also code reviews only give feedback to an individual engineer, not the entire team. I am toying with the idea of doing a presentation (or a series) and try to bring up OOP again along with some examples of existing code that could've been written better and could be refactored. I could use some really old projects that no one owns anymore so at least that part shouldn't be a sensitive issue. However, will this work? As I said most people have done C++ for a long time so my guess is that a) they'll sit there thinking why I'm telling them stuff they already know or b) they might actually take it as an insult because I'm telling them they don't know how to do the job they've been doing for years if not decades. Is there another approach which would reach broader audience than a code review would, but at the same time wouldn't feel like a punishment lecture? I'm not a fresh kid out of college who has utopian ideals of perfectly designed code and I don't expect that from anyone. The reason I'm writing this is because I just did a review of a person who actually had decent high-level design on paper. However if you picture classes: A - B - C - D, in the code B, C and D all implement almost the same public interface and B/C have one liner functions so that top-most class A is doing absolutely all the work (down to memory management, string parsing, setup negotiations...) primarily in 4 mongo methods and, for all intents and purposes, calls almost directly into D. Update: I'm a tech lead(6 months in this role) and do have full support of the group manager. We are working on a very mature product and maintenance costs are definitely letting themselves be known.

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  • Will Online Learning Save Higher Education (and does it need saving)?

    - by user739873
    A lot (an awful lot) of education industry rag real estate has been devoted to the topics of online learning, MOOC’s, Udacity, edX, etc., etc. and to the uninitiated you’d think that the education equivalent of the cure for cancer had been discovered. There are certainly skeptics (whose voice is usually swiftly trampled upon by the masses) who feel we could over steer and damage or destroy something vital to teaching and learning (i.e. the classroom experience and direct interaction with human beings known as instructors), but for the most part prevailing opinion seems to be that online learning will take over the world and that higher education will never be the same. Now I’m sure that since you all know I work for a technology company you think I’m going to come down hard on the side of online learning proselytizers. Yes, I do believe that this revolution can and will provide access to massive numbers of individuals that either couldn’t afford (from a fiscal or time perspective) a traditional education, and that in some cases the online modality will actually be an improvement over certain traditional forms (such as courses taught by an adjunct or teaching assistant that has no business being a teacher). But I think several things need immediate attention or we’re likely to get so caught up in the delivery that we miss some of the real issues (and opportunities) around online learning. First and foremost, we’ve got to give some thought to how traditional information systems are going to accommodate thousands (possibly hundreds of thousands) of individual students each taking courses from many, many different “deliverers” with an expectation that successful completion of these courses will result in credit at many or most institutions. There’s also a huge opportunity to refine the delivery platform (no, LMS is not a commodity when you are talking about online delivery being your sole mode of operation) as well as the course itself by mining all kinds of data from the interactions that the students have with the material each time they take it. Social data analytics tools will be key in achieving this goal. What about accreditation (badging or competencies vs. traditional degrees)? And again, will the information systems in place today adapt to changes in this area fast enough? The type of scale that this shift in learning could drive has the potential to abruptly overwhelm just about every system in place today in higher education. I would like to (with a not so gentle reminder) refer you back to a blog entry I wrote when I first stepped into my current role at Oracle in which I talked about how higher ed needs an “Oracle” more than at any other time in it’s evolution (despite the somewhat mercantilist reputation it has in some circles). There just aren’t that many organizations that can deliver the kinds of solutions “at scale” that this brave new world of online education will demand. The future may be closer than we think. Cole

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  • Design pattern to handle queries using multiple models

    - by coderkane
    I am presented with a dilemma while trying to re-designing the class structure for my PHP/MySQL application to make it more elegant and conform it to the SOLID principle. The problem goes like this: Let as assume, there is an abstract class called person which has certain properties to define a generic person, such as name, age, date of birth etc. There are two classes, student, and teacher, that implements this abstract class. They add their own unique properties to it. I have designed all the three classes to include all the operational logic (details of which are not relevant in context of the question). Now, I need to create views/reports/data grids which contain details from multiple classes, for example, say, a list of all students doing projects in Chemistry mentored by a teacher whose name is the parameter to the query. This is just one example of a view, there are many different views in the application, which uses data from 3-4 tables, and each of them have multiple input parameters to generate them. Considering this particular example, I have written the relevant query using JOIN and the results are as expected and proper, now here is the dilemma: Keeping in mind the single responsibility principle, where should I keep this query? It does not belong to either Student class, or Teacher class or any other classes currently present. a) Should I create a new class, say dataView class, and design it as a MVC pattern and keep the query there? What about the other views? how do they fit in this architecture? b) Should I not keep the query in code at all, and make it DB View ? c) Am I completely wrong in the approach? If so what is the right approach? My considerations are as follows: a) should be easy to add new views later on if requirement comes, without having to copy-paste-modify code b) would like to make it as loosely coupled as possible so that if minor db structure changes happen, it does not break I did google searches on report design and OOP report generators, but all the result seem to focus on the visual design of the report rather than fetching the data. I have already taken care of the visual aspect of the report using MVC with html templates. I am sure this is a very fundamental problem with known solution, but I am somehow not able to find it (maybe searching with wrong keyword). Edit1: Modified the title to make it more relevant Edit2: The accepted answer got me thinking in the right direction and identify my design flaws, which eventually led me to find this question and the solution in Stack Overflow which gave me the detailed answer to clear the confusion.

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  • Ideas for time-keeping in a webbased RPG?

    - by ashy_32bit
    I'm assigned a task of doing the preliminary research stuff for a web-based MMO RPG. Now my buggiest problem here is "web based" vs "MMO RPG". I did some research about time keeping systems and I'm totally confused as how exactly something as real-time as an MMO-RPG can work on some pull-only (unidirectional) platform like HTTP. I know there is also a turn-based alternative to time keeping but can it work in an MMO setting ? EDIT: Take a battle for example, player A (human) wants to attack Player B (also human) in the open. How does it work when when player A issues the "attack" command on player B ? how do I inform player B that he is being attacked ? and then how exactly the battle goes on between the two in an HTTP based communication channel? To my knowledge this is impossible unless you resort to another technology (HTML is 1-way, that is you can just ask server and get response, server can't update you unless being asked to. this is very well-known and simply explained). So I though maybe I can somehow change the whole timekeeping model from real-time to a more non-real-time model (towards a turn based RPG for example) and somehow work around the whole problem of "interactivity". EDIT2: It is not that I don't wanna use any server side technologies. For sure it is not gonna work client-side-only even for the most trivial of the multi-player games, let alone an RPG. So sure there would be a (probably complex) server side component to it (the so called Game Engine I suppose). The problem is not the technology that implements the logic (game mechanics) bits but the communication technology and how it limits the game mechanics abilities (like how real-time or turn based it is gonna be). HTTP is a request-response protocol meaning you get served only if you ask for it (explicitly send a GET or POST request to the server). HTTP server can not inform you if anything of interest happens in the game world unless you refresh the page (as some suggested) or you use some bi-directional tech (totally different animals) like Flash, WebSock, HTML5 etc etc. So maybe the question is: Is it possible to implement a MMORPG using only HTML5/PHP and no periodic page refreshes? if so what would be rules to make it an MMO-RPG? Can't explain it any clearer. Sorry :D

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  • How granular should a command be in a CQ[R]S model?

    - by Aaronaught
    I'm considering a project to migrate part of our WCF-based SOA over to a service bus model (probably nServiceBus) and using some basic pub-sub to achieve Command-Query Separation. I'm not new to SOA, or even to service bus models, but I confess that until recently my concept of "separation" was limited to run-of-the-mill database mirroring and replication. Still, I'm attracted to the idea because it seems to provide all the benefits of an eventually-consistent system while sidestepping many of the obvious drawbacks (most notably the lack of proper transactional support). I've read a lot on the subject from Udi Dahan who is basically the guru on ESB architectures (at least in the Microsoft world), but one thing he says really puzzles me: As we get larger entities with more fields on them, we also get more actors working with those same entities, and the higher the likelihood that something will touch some attribute of them at any given time, increasing the number of concurrency conflicts. [...] A core element of CQRS is rethinking the design of the user interface to enable us to capture our users’ intent such that making a customer preferred is a different unit of work for the user than indicating that the customer has moved or that they’ve gotten married. Using an Excel-like UI for data changes doesn’t capture intent, as we saw above. -- Udi Dahan, Clarified CQRS From the perspective described in the quotation, it's hard to argue with that logic. But it seems to go against the grain with respect to SOAs. An SOA (and really services in general) are supposed to deal with coarse-grained messages so as to minimize network chatter - among many other benefits. I realize that network chatter is less of an issue when you've got highly-distributed systems with good message queuing and none of the baggage of RPC, but it doesn't seem wise to dismiss the issue entirely. Udi almost seems to be saying that every attribute change (i.e. field update) ought to be its own command, which is hard to imagine in the context of one user potentially updating hundreds or thousands of combined entities and attributes as it often is with a traditional web service. One batch update in SQL Server may take a fraction of a second given a good highly-parameterized query, table-valued parameter or bulk insert to a staging table; processing all of these updates one at a time is slow, slow, slow, and OLTP database hardware is the most expensive of all to scale up/out. Is there some way to reconcile these competing concerns? Am I thinking about it the wrong way? Does this problem have a well-known solution in the CQS/ESB world? If not, then how does one decide what the "right level" of granularity in a Command should be? Is there some "standard" one can use as a starting point - sort of like 3NF in databases - and only deviate when careful profiling suggests a potentially significant performance benefit? Or is this possibly one of those things that, despite several strong opinions being expressed by various experts, is really just a matter of opinion?

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