Search Results

Search found 105127 results on 4206 pages for 'know why'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 42/4206 | < Previous Page | 38 39 40 41 42 43 44 45 46 47 48 49  | Next Page >

  • Display x if x display y if y (bad title I know)

    - by user1914940
    Ok so after reading the title you are most likely like...what? Ok, so I have a jquery code that displays input box if an item with prefix Blue from dropdown menu is selected. Code: $(function() { $('#text1').hide(); $('#select2').on('change', function(event) { var opt = this.options[ this.selectedIndex ]; var picked_blue = $(opt).text().match(/Blue/i); if(picked_blue) { $('#text1').show(); } else { $('#text1').hide(); } }); }); But what I also need to add is to display something else if any other item from dropdown menu is selected.

    Read the article

  • How to know the order of component rendering in Flex

    - by Tam
    I have a component that has a sub-component they both use a shared variable from the model. The shared variable needs to be set by the parent component before it can be used by the child component. I did like this in the parent component: <mx:Canvas xmlns:mx="library://ns.adobe.com/flex/mx" ... creationComplete="group1_completeHandler(event)" > .... protected function group1_activateHandler(event:Event):void { model.myVariable = something; } .... <components:myCustomComponent> ... <components:myCustomComponent> ... </mx:Canvas> But for some reason when the code inside myCustomComponent tries to use myVariable for the first time I get a "null" object error. This means I guess that the child component gets rendered before the group1_activateHandler gets called and consequently myVariable gets set. What should I do to ensure that the parent container initializes the variable before the child component gets created?

    Read the article

  • Dont know how to select a few records from a table as utf8

    - by kwokwai
    Hi all, I don't have phpMyAdmin installed in my web site. Sometimes I was doing some select SQL command at the backend, but when I typed in this command to show all records from table Users: select * from Users; The records were printed as ???? | ??? ??? ??? |. I don't want to make any permanent changes to the charset in the database, so, how is it possible to temporarily displayed a few records as utf8 when needed?

    Read the article

  • A way to use Python which I don't know

    - by Konie
    In this quicksort function: def qsort2(list): if list == []: return [] else: pivot = list[0] # can't understand the following line lesser, equal, greater = partition(list[1:], [], [pivot], []) return qsort2(lesser) + equal + qsort2(greater) def partition(list, l, e, g): if list == []: return (l, e, g) else: head = list[0] if head < e[0]: return partition(list[1:], l + [head], e, g) elif head > e[0]: return partition(list[1:], l, e, g + [head]) else: return partition(list[1:], l, e + [head], g) I don't understand the sentence below the comment. Can someone tell me what is the meaning of this sentence here?

    Read the article

  • 5 reason why you should upgrade to new iPad (3rd generation)

    - by Gopinath
    Apple released the new iPad, 3rd generation, couple of days ago and they will be available in stores from March 16 onwards.  It’s the best tablet available in the market and for first time buyers it’s a no brainer to choose it. What about the iPad owners? Should they upgrade their iPad 2 to the new iPad? This is the question on the lips of most of the iPad owners. In this post we will provide you 5 reasons why you should upgrade your iPad, if more than two reasons are convincing then you should upgrade to the new iPad. Retina display – The best display ever made for mobile device, a game changer The new iPad comes with Retina display with screen resolution of 2048 x 1536, which is twice the resolution of iPad 2. Undoubtedly the iPad 3’s display is the best display ever made for a mobile device and it’s a game changer. With better resolution on iPad 3 eBook reading is going to be a pleasure with clear and crisp text Watching HD movies on iPad is going to be unbelievably good The new Games targeted for Retina display are going to be more realistic and needless to explain the pleasure of playing such games Graphic artists and photo editors get a professional on screen rendering support to create beautiful graphics 2x Faster & 2x Memory – Better Games and powerful Apps The new iPad is more powerful with 2x faster graphics and 2x more memory. Apple claims that the A5x processor of new iPad is 2x faster than iPad 2 and 4x faster than the best graphic chips available from other vendors. The RAM of  new iPad  is upgraded to 1 GB compared from 512 MB of iPad 2. With the fast processor and more memory, Apps and games are going to be blazing fast. 4G Internet – Browse the web at the speeds of 42 MB/sec Half of the iPad owners are frequent commuters who access internet over cellular networks, the new iPad’s 4G LTE is going to be a big boom for their  high data access needs. With the new iPad’s 4G LTE connectivity you can browse the web at 42 MB/sec and it mean you can watch a HD video without buffering issues. iPad 2 comes with 3G network support and it’s browsing speeds are way less than the new iPad. 5MP Camera – HD Movie Recording & gorgeous Photography iPad 2 has a 0.7 mega pixel camera and the new iPad comes with 5 megapixels camera. That is a huge boost for hobbyist  photographers and videographers. With the new iPad you can shoot gorgeous photos and 1080p HD video. The iSight camera of new iPad uses advanced optics with features like auto exposure, auto focus and face detection up to 10 faces. Amazon Pays up to $300 for old iPad 2 16 GB Wifi and more for other models Do you know that you can trade in your iPad 2 16 GB Wifi for upto $300? Amazon has an excellent trade in program for selling your used iPad 2s. Depending on the condition of the iPad 2  Amazon offers $234, $270, $300.00 for 16 GB Wifi versions that in Acceptable, Good and Like New conditions respectively.  The higher models of iPad 2s fetch you more money. With this great deal from Amazon the amount of extra money you need to spend for new iPad is almost half of their price. Visit Amazon Trade In’s website or read Amazon’s brilliant plan to pay you crazy money for your iPad 2 for more details. Related: New IPad Vs. IPad 2–Side By Side Comparison Of Hardware Specification [Infographic]

    Read the article

  • Why is IaaS important in Azure&hellip;

    - by Steve Loethen
    Three weeks ago, Microsoft released the next phase of Azure.  I have had several clients waiting on this release.  The fact that they have been waiting and are now more receptive to looking at the cloud.  Customers expressed fear of the unknown.  And a fear of lack of control, even when that lack of control also means a huge degree of flexibility to innovate with concerns about the underlying infrastructure.  I think IaaS will be that “gateway drug” to get customers who have been hesitant to take another look at the cloud.  The dialog can change from the cloud being this big scary unknown to a resource for workloads.  The conversations should have always been, and can know be even stronger, geared toward the following points: 1) The cloud is not unicorns and glitter, the cloud is resources.  Compute, storage, db’s, services bus, cache…..  Like many of the resources we have on-premise.  Not magic, just another resource with advantages and obstacles like any other resource. 2) The cloud should be part of the conversation for any new project.  All of the same criteria should be applied, on-premise or off.  Cost, security, reliability, scalability, speed to deploy, cost of licenses, need to customize image, complex workloads.  We have been having these discussions for years when we talk about on-premise projects.  We make decisions on OS’s, Databases, ESB’s, configuration and products based on a myriad of factors.  We use the same factors but now we have a additional set of resources to consider in our process. 3) The cloud is a great solution looking for some interesting problems.  It is our job to recognize the right problems that fit into the cloud, weigh the factors and decide what to do. IaaS makes this discussion easier, offers more choices, and often choices that many enterprises will find more better than PaaS.  Looking forward to helping clients realize the power of the cloud.

    Read the article

  • Why Haven’t NFC Payments Taken Off?

    - by David Dorf
    With the EMV 2015 milestone approaching rapidly, there’s been renewed interest in smartcards, those credit cards with an embedded computer chip.  Back in 1996 I was working for a vendor helping Visa introduce a stored-value smartcard to the US.  Visa Cash was debuted at the 1996 Olympics in Atlanta, and I firmly believed it was the beginning of a cashless society.  (I later worked on MasterCard’s system called Mondex, from the UK, which debuted the following year in Manhattan). But since you don’t have a Visa Cash card in your wallet, it’s obvious the project never took off.  It was convenient for consumers, faster for merchants, and more cost-effective for banks, so why did it fail?  All emerging payment systems suffer from the chicken-and-egg dilemma.  Consumers won’t carry the cards if few merchants accept them, and merchants won’t install the terminals if few consumers have cards. Today’s emerging payment providers are in a similar pickle.  There has to be enough value for all three constituents – consumers, merchants, banks – to change the status quo.  And it’s not enough to exceed the value, it’s got to be a leap in value, because people generally resist change.  ATMs and transit cards are great examples of this, and airline kiosks and self-checkout systems are to a lesser extent. Although Google Wallet and ISIS, the two leading NFC payment platforms in the US, have shown strong commitment, there’s been very little traction.  Yes, I can load my credit card number into my phone then tap to pay, but what was the incremental value over swiping my old card?  For it to be a leap in value, it has to offer more than just payment, which I can do very easily today.  The other two ingredients are thought to be loyalty programs and digital coupons, but neither Google nor ISIS really did them well. Of course a large portion of the mobile phone market doesn’t even support NFC thanks to Apple, and since it’s not in their best interest that situation is unlikely to change.  Another issue is getting access to the “secure element,” the chip inside the phone where accounts numbers can be held securely.  Telco providers and handset manufacturers own that area, and they’re not willing to share with banks.  (Host Card Emulation, which has been endorsed by MasterCard and Visa, might be a solution.) Square recently gave up on its wallet, and MCX (the group of retailers trying to create a mobile payment platform) is very slow out of the gate.  That leaves PayPal and a slew of smaller companies trying to introduce easier ways to pay. But is it really so cumbersome to carry and swipe (soon to insert) a credit card?  Aren’t there more important problems to solve in the retail customer experience?  Maybe Apple will come up with some novel way to use iBeacons and fingerprint identification to make payments, but for now I think we need to focus on upgrading to Chip-and-PIN and tightening security.  In the meantime, NFC payments will continue to struggle.

    Read the article

  • Why Cornell University Chose Oracle Data Masking

    - by Troy Kitch
    One of the eight Ivy League schools, Cornell University found itself in the unfortunate position of having to inform over 45,000 University community members that their personal information had been breached when a laptop was stolen. To ensure this wouldn’t happen again, Cornell took steps to ensure that data used for non-production purposes is de-identified with Oracle Data Masking. A recent podcast highlights why organizations like Cornell are choosing Oracle Data Masking to irreversibly de-identify production data for use in non-production environments. Organizations often copy production data, that contains sensitive information, into non-production environments so they can test applications and systems using “real world” information. Data in non-production has increasingly become a target of cyber criminals and can be lost or stolen due to weak security controls and unmonitored access. Similar to production environments, data breaches in non-production environments can cost millions of dollars to remediate and cause irreparable harm to reputation and brand. Cornell’s applications and databases help carry out the administrative and academic mission of the university. They are running Oracle PeopleSoft Campus Solutions that include highly sensitive faculty, student, alumni, and prospective student data. This data is supported and accessed by a diverse set of developers and functional staff distributed across the university. Several years ago, Cornell experienced a data breach when an employee’s laptop was stolen.  Centrally stored backup information indicated there was sensitive data on the laptop. With no way of knowing what the criminal intended, the university had to spend significant resources reviewing data, setting up service centers to handle constituent concerns, and provide free credit checks and identity theft protection services—all of which cost money and took time away from other projects. To avoid this issue in the future Cornell came up with several options; one of which was to sanitize the testing and training environments. “The project management team was brought in and they developed a project plan and implementation schedule; part of which was to evaluate competing products in the market-space and figure out which one would work best for us.  In the end we chose Oracle’s solution based on its architecture and its functionality.” – Tony Damiani, Database Administration and Business Intelligence, Cornell University The key goals of the project were to mask the elements that were identifiable as sensitive in a consistent and efficient manner, but still support all the previous activities in the non-production environments. Tony concludes,  “What we saw was a very minimal impact on performance. The masking process added an additional three hours to our refresh window, but it was well worth that time to secure the environment and remove the sensitive data. I think some other key points you can keep in mind here is that there was zero impact on the production environment. Oracle Data Masking works in non-production environments only. Additionally, the risk of exposure has been significantly reduced and the impact to business was minimal.” With Oracle Data Masking organizations like Cornell can: Make application data securely available in non-production environments Prevent application developers and testers from seeing production data Use an extensible template library and policies for data masking automation Gain the benefits of referential integrity so that applications continue to work Listen to the podcast to hear the complete interview.  Learn more about Oracle Data Masking by registering to watch this SANS Institute Webcast and view this short demo.

    Read the article

  • My Doors - Why Standards Matter to Business

    - by Brian Dayton
    "Standards save money." "Standards accelerate projects." "Standards make better solutions."   What do these statements mean to you? You buy technology solutions like Oracle Applications but you're a business person--trying to close the quarter, get performance reviews processed, negotiate a new sourcing contract, etc.   When "standards" come up in presentations and discussions do you: -          Nod your head politely -          Tune out and check your smart phone -          Turn to your IT counterpart and say "Bob's all over this standards thing, right Bob?"   Here's why standards matter. My wife wants new external doors downstairs, ones that would get more light into the rooms. Am I OK with that? "Uhh, sure...it's a little dark in the kitchen."   -          24 hours ago - wife calls to tell me that she's going to the hardware store and may look at doors -          20 hours ago - wife pulls into driveway, informs me that two doors are in the back of her station wagon, ready for me to carry -          19 hours ago - I re-discovered the fact that it's not fun to carry a solid wood door by myself -          5 hours ago - Local handyman, who was at our house anyway, tells me that the doors we bought will likely cost 2-3x the material cost in installation time and labor...the doors are standard but our doorways aren't   We could have done more research. I could be more handy. Sure. But the fact is, my 1951 house wasn't built with me in mind. They built what worked and called it a day.   The same holds true with a lot of business applications. They were designed and architected for one-time use with one use-case in mind. Today's business climate is different. If you're going to use your processes and technology to differentiate your business you should have at least a working knowledge of: -          How standards can benefit your business -          Your IT organization's philosophy around standards -          Your vendor's track-record around standards...and watch for those who pay lip-service to standards but don't follow through   The rallying cry in most IT organizations today is "learn more about the business, drop the acronyms." I'm not advocating that you go out and learn how to code in Java. But I do believe it will help your business and your decision-making process if you meet IT ½...even ¼ of the way there.   Epilogue: The door project has been put on hold and yours truly has to return the doors to the hardware store tomorrow.

    Read the article

  • Why Ultra-Low Power Computing Will Change Everything

    - by Tori Wieldt
    The ARM TechCon keynote "Why Ultra-Low Power Computing Will Change Everything" was anything but low-powered. The speaker, Dr. Johnathan Koomey, knows his subject: he is a Consulting Professor at Stanford University, worked for more than two decades at Lawrence Berkeley National Laboratory, and has been a visiting professor at Stanford University, Yale University, and UC Berkeley's Energy and Resources Group. His current focus is creating a standard (computations per kilowatt hour) and measuring computer energy consumption over time. The trends are impressive: energy consumption has halved every 1.5 years for the last 60 years. Battery life has made roughly a 10x improvement each decade since 1960. It's these improvements that have made laptops and cell phones possible. What does the future hold? Dr. Koomey said that in the past, the race by chip manufacturers was to create the fastest computer, but the priorities have now changed. New computers are tiny, smart, connected and cheap. "You can't underestimate the importance of a shift in industry focus from raw performance to power efficiency for mobile devices," he said. There is also a confluence of trends in computing, communications, sensors, and controls. The challenge is how to reduce the power requirements for these tiny devices. Alternate sources of power that are being explored are light, heat, motion, and even blood sugar. The University of Michigan has produced a miniature sensor that harnesses solar energy and could last for years without needing to be replaced. Also, the University of Washington has created a sensor that scavenges power from existing radio and TV signals.Specific devices designed for a purpose are much more efficient than general purpose computers. With all these sensors, instead of big data, developers should focus on nano-data, personalized information that will adjust the lights in a room, a machine, a variable sign, etc.Dr. Koomey showed some examples:The Proteus Digital Health Feedback System, an ingestible sensor that transmits when a patient has taken their medicine and is powered by their stomach juices. (Gives "powered by you" a whole new meaning!) Streetline Parking Systems, that provide real-time data about available parking spaces. The information can be sent to your phone or update parking signs around the city to point to areas with available spaces. Less driving around looking for parking spaces!The BigBelly trash system that uses solar power, compacts trash, and sends a text message when it is full. This dramatically reduces the number of times a truck has to come to pick up trash, freeing up resources and slashing fuel costs. This is a classic example of the efficiency of moving "bits not atoms." But researchers are approaching the physical limits of sensors, Dr. Kommey explained. With the current rate of technology improvement, they'll reach the three-atom transistor by 2041. Once they hit that wall, it will force a revolution they way we do computing. But wait, researchers at Purdue University and the University of New South Wales are both working on a reliable one-atom transistors! Other researchers are working on "approximate computing" that will reduce computing requirements drastically. So it's unclear where the wall actually is. In the meantime, as Dr. Koomey promised, ultra-low power computing will change everything.

    Read the article

  • Why doesn't Bumblebee work with Nvidia GT640M?

    - by Dickson Wong
    I've done a clean install of Ubuntu 12.04 from a liveCD on a Samsung Series 7 Chronos with a 3rd Gen i7 and the Nvidia GeForce GT 640M. I've followed this: (https://wiki.ubuntu.com/Bumblebee#Installation) to install bumblebee so I can switch to my discrete GPU. I have not used ironhide, or preivous bumblee since it's a clean install. When I use optirun, optirun says it can't initialize the GPU: [ERROR]Cannot access secondary GPU - error: [XORG] (EE) NVIDIA(0): Failed to initialize the NVIDIA GPU at PCI:1:0:0. Please [ERROR]Aborting because fallback start is disabled. I've looked at the troubleshooting page for bumblebee and I have the correct driver and do not think I have aspci disabled. Also, my keyboard becomes very unresponsive and my mouse skips and isn't smooth after optirun crashes. The only thing to fix this is a reboot. Here's my lspci | grep VGA output: 00:02.0 VGA compatible controller: Intel Corporation Ivy Bridge Graphics Controller (rev 09) 01:00.0 VGA compatible controller: NVIDIA Corporation Device 0fd2 (rev ff) It seems Ubuntu can see my graphics card. I don't really know what's going on.

    Read the article

  • Why is my Ubuntu 10.10 CD not booting?

    - by Tom Brito
    I have downloaded Ubuntu 10.10 and burned the ISO but it will not boot. I discarded problems with the ISO, as I've downloaded from the official website with no errors, and burned it with no errors. I discarded problems with the burning, as looks like it was recorded with no errors here and later in another computer. I discarded problems with my DVD reader as other cds boots fine. I'm currently using Ubuntu 9.10, I know I can upgrade via internet, but I have this same problem with my Windows XP cd, so I really would like to discover what's going on here.. My Ubuntu 9.10 cd boots just right, but the new one not. What else can be? Or what more precise tests can I make to discover where's the problem? --More info What happens when I try to boot with the Ubuntu 10.10 cd is that it behavior like there's no bootable cd in the drive. It just don't find the boot on the cd, and start the HD system. My notebook is an Amazon PC Intel Celeron 1.5 with 2Gb memory, a DVD-RW driver, HD samsung with 260GB.

    Read the article

  • Why is Ubuntu's clock getting slower or faster?

    - by ændrük
    Ubuntu's clock is off by about a half hour: Where do I even start troubleshooting this? It's allegedly being set "automatically from the Internet". How can I verify that "the Internet" knows what time it is? Details Ubuntu has had plenty of time to communicate with the Internet: $ date; uptime Fri May 18 05:56:00 PDT 2012 05:56:00 up 12 days, 10:48, 2 users, load average: 0.61, 0.96, 1.15 This time server I found via a web search does appear to know the correct time: $ date; ntpdate -q north-america.pool.ntp.org Fri May 18 05:56:09 PDT 2012 server 208.38.65.37, stratum 2, offset 1752.625337, delay 0.10558 server 46.166.138.172, stratum 2, offset 1752.648597, delay 0.10629 server 205.189.158.228, stratum 3, offset 1752.672466, delay 0.11829 18 May 05:56:18 ntpdate[29752]: step time server 208.38.65.37 offset 1752.625337 sec There aren't any reported errors related to NTP: $ grep -ic ntp /var/log/syslog 0 After rebooting, the time was automatically corrected and the following appeared in /var/log/syslog: May 18 17:58:12 aux ntpdate[1891]: step time server 91.189.94.4 offset 1838.497277 sec A log of the offset reported by ntpdate reveals that the clock is drifting by about 9 seconds every hour: $ while true; do ntpdate-debian -q | tail -n 1 >> 'drift.log'; sleep 16m; done ^C $ r -e ' attach(read.table("drift.log", header=FALSE)) clock <- as.POSIXct(paste(V1, V2, V3), format="%d %b %H:%M:%S") fit <- lm(V10~clock) png("drift.png") plot(clock, V10, xlab="Clock time", ylab="Time server offset (s)") abline(fit) mtext(sprintf("Drift rate: %.2f s/hr", fit$coefficients[[2]]*3600)) '

    Read the article

  • Why unhandled exceptions are useful

    - by Simon Cooper
    It’s the bane of most programmers’ lives – an unhandled exception causes your application or webapp to crash, an ugly dialog gets displayed to the user, and they come complaining to you. Then, somehow, you need to figure out what went wrong. Hopefully, you’ve got a log file, or some other way of reporting unhandled exceptions (obligatory employer plug: SmartAssembly reports an application’s unhandled exceptions straight to you, along with the entire state of the stack and variables at that point). If not, you have to try and replicate it yourself, or do some psychic debugging to try and figure out what’s wrong. However, it’s good that the program crashed. Or, more precisely, it is correct behaviour. An unhandled exception in your application means that, somewhere in your code, there is an assumption that you made that is actually invalid. Coding assumptions Let me explain a bit more. Every method, every line of code you write, depends on implicit assumptions that you have made. Take this following simple method, that copies a collection to an array and includes an item if it isn’t in the collection already, using a supplied IEqualityComparer: public static T[] ToArrayWithItem( ICollection<T> coll, T obj, IEqualityComparer<T> comparer) { // check if the object is in collection already // using the supplied comparer foreach (var item in coll) { if (comparer.Equals(item, obj)) { // it's in the collection already // simply copy the collection to an array // and return it T[] array = new T[coll.Count]; coll.CopyTo(array, 0); return array; } } // not in the collection // copy coll to an array, and add obj to it // then return it T[] array = new T[coll.Count+1]; coll.CopyTo(array, 0); array[array.Length-1] = obj; return array; } What’s all the assumptions made by this fairly simple bit of code? coll is never null comparer is never null coll.CopyTo(array, 0) will copy all the items in the collection into the array, in the order defined for the collection, starting at the first item in the array. The enumerator for coll returns all the items in the collection, in the order defined for the collection comparer.Equals returns true if the items are equal (for whatever definition of ‘equal’ the comparer uses), false otherwise comparer.Equals, coll.CopyTo, and the coll enumerator will never throw an exception or hang for any possible input and any possible values of T coll will have less than 4 billion items in it (this is a built-in limit of the CLR) array won’t be more than 2GB, both on 32 and 64-bit systems, for any possible values of T (again, a limit of the CLR) There are no threads that will modify coll while this method is running and, more esoterically: The C# compiler will compile this code to IL according to the C# specification The CLR and JIT compiler will produce machine code to execute the IL on the user’s computer The computer will execute the machine code correctly That’s a lot of assumptions. Now, it could be that all these assumptions are valid for the situations this method is called. But if this does crash out with an exception, or crash later on, then that shows one of the assumptions has been invalidated somehow. An unhandled exception shows that your code is running in a situation which you did not anticipate, and there is something about how your code runs that you do not understand. Debugging the problem is the process of learning more about the new situation and how your code interacts with it. When you understand the problem, the solution is (usually) obvious. The solution may be a one-line fix, the rewrite of a method or class, or a large-scale refactoring of the codebase, but whatever it is, the fix for the crash will incorporate the new information you’ve gained about your own code, along with the modified assumptions. When code is running with an assumption or invariant it depended on broken, then the result is ‘undefined behaviour’. Anything can happen, up to and including formatting the entire disk or making the user’s computer sentient and start doing a good impression of Skynet. You might think that those can’t happen, but at Halting problem levels of generality, as soon as an assumption the code depended on is broken, the program can do anything. That is why it’s important to fail-fast and stop the program as soon as an invariant is broken, to minimise the damage that is done. What does this mean in practice? To start with, document and check your assumptions. As with most things, there is a level of judgement required. How you check and document your assumptions depends on how the code is used (that’s some more assumptions you’ve made), how likely it is a method will be passed invalid arguments or called in an invalid state, how likely it is the assumptions will be broken, how expensive it is to check the assumptions, and how bad things are likely to get if the assumptions are broken. Now, some assumptions you can assume unless proven otherwise. You can safely assume the C# compiler, CLR, and computer all run the method correctly, unless you have evidence of a compiler, CLR or processor bug. You can also assume that interface implementations work the way you expect them to; implementing an interface is more than simply declaring methods with certain signatures in your type. The behaviour of those methods, and how they work, is part of the interface contract as well. For example, for members of a public API, it is very important to document your assumptions and check your state before running the bulk of the method, throwing ArgumentException, ArgumentNullException, InvalidOperationException, or another exception type as appropriate if the input or state is wrong. For internal and private methods, it is less important. If a private method expects collection items in a certain order, then you don’t necessarily need to explicitly check it in code, but you can add comments or documentation specifying what state you expect the collection to be in at a certain point. That way, anyone debugging your code can immediately see what’s wrong if this does ever become an issue. You can also use DEBUG preprocessor blocks and Debug.Assert to document and check your assumptions without incurring a performance hit in release builds. On my coding soapbox… A few pet peeves of mine around assumptions. Firstly, catch-all try blocks: try { ... } catch { } A catch-all hides exceptions generated by broken assumptions, and lets the program carry on in an unknown state. Later, an exception is likely to be generated due to further broken assumptions due to the unknown state, causing difficulties when debugging as the catch-all has hidden the original problem. It’s much better to let the program crash straight away, so you know where the problem is. You should only use a catch-all if you are sure that any exception generated in the try block is safe to ignore. That’s a pretty big ask! Secondly, using as when you should be casting. Doing this: (obj as IFoo).Method(); or this: IFoo foo = obj as IFoo; ... foo.Method(); when you should be doing this: ((IFoo)obj).Method(); or this: IFoo foo = (IFoo)obj; ... foo.Method(); There’s an assumption here that obj will always implement IFoo. If it doesn’t, then by using as instead of a cast you’ve turned an obvious InvalidCastException at the point of the cast that will probably tell you what type obj actually is, into a non-obvious NullReferenceException at some later point that gives you no information at all. If you believe obj is always an IFoo, then say so in code! Let it fail-fast if not, then it’s far easier to figure out what’s wrong. Thirdly, document your assumptions. If an algorithm depends on a non-trivial relationship between several objects or variables, then say so. A single-line comment will do. Don’t leave it up to whoever’s debugging your code after you to figure it out. Conclusion It’s better to crash out and fail-fast when an assumption is broken. If it doesn’t, then there’s likely to be further crashes along the way that hide the original problem. Or, even worse, your program will be running in an undefined state, where anything can happen. Unhandled exceptions aren’t good per-se, but they give you some very useful information about your code that you didn’t know before. And that can only be a good thing.

    Read the article

  • Why is there no service-oriented language?

    - by Wolfgang
    Edit: To avoid further confusion: I am not talking about web services and such. I am talking about structuring applications internally, it's not about how computers communicate. It's about programming languages, compilers and how the imperative programming paradigm is extended. Original: In the imperative programming field, we saw two paradigms in the past 20 years (or more): object-oriented (OO), and service-oriented (SO) aka. component-based (CB). Both paradigms extend the imperative programming paradigm by introducing their own notion of modules. OO calls them objects (and classes) and lets them encapsulates both data (fields) and procedures (methods) together. SO, in contrast, separates data (records, beans, ...) from code (components, services). However, only OO has programming languages which natively support its paradigm: Smalltalk, C++, Java and all other JVM-compatibles, C# and all other .NET-compatibles, Python etc. SO has no such native language. It only comes into existence on top of procedural languages or OO languages: COM/DCOM (binary, C, C++), CORBA, EJB, Spring, Guice (all Java), ... These SO frameworks clearly suffer from the missing native language support of their concepts. They start using OO classes to represent services and records. This leads to designs where there is a clear distinction between classes that have methods only (services) and those that have fields only (records). Inheritance between services or records is then simulated by inheritance of classes. Technically, its not kept so strictly but in general programmers are adviced to make classes to play only one of the two roles. They use additional, external languages to represent the missing parts: IDL's, XML configurations, Annotations in Java code, or even embedded DSL like in Guice. This is especially needed, but not limited to, since the composition of services is not part of the service code itself. In OO, objects create other objects so there is no need for such facilities but for SO there is because services don't instantiate or configure other services. They establish an inner-platform effect on top of OO (early EJB, CORBA) where the programmer has to write all the code that is needed to "drive" SO. Classes represent only a part of the nature of a service and lots of classes have to be written to form a service together. All that boiler plate is necessary because there is no SO compiler which would do it for the programmer. This is just like some people did it in C for OO when there was no C++. You just pass the record which holds the data of the object as a first parameter to the procedure which is the method. In a OO language this parameter is implicit and the compiler produces all the code that we need for virtual functions etc. For SO, this is clearly missing. Especially the newer frameworks extensively use AOP or introspection to add the missing parts to a OO language. This doesn't bring the necessary language expressiveness but avoids the boiler platform code described in the previous point. Some frameworks use code generation to produce the boiler plate code. Configuration files in XML or annotations in OO code is the source of information for this. Not all of the phenomena that I mentioned above can be attributed to SO but I hope it clearly shows that there is a need for a SO language. Since this paradigm is so popular: why isn't there one? Or maybe there are some academic ones but at least the industry doesn't use one.

    Read the article

  • Googlebot visit but no cache update - why?

    - by Mick
    I have made a new plain vanilla HTML website. I have been making regular modifications to it on an almost daily basis. The site is hosted by hostmonster and as part of their service they offer "awstats" to let you know assorted details of visitors to the site. One thing is puzzling me. According to awstats, a "robot/spider" calling itself "Googlebot" visited my site as recently as today (28th June 2011), but when I find my site on google (e.g. by searching for "full reserve banking") the cache is dated only the 5th June. I always thought that a visit from the google robot was synonymous with a cache update. Am I wrong? Or have I accidentally put something in the site telling google that nothing has been updated? EDIT: It seems a moderator has removed the name of my website, so there is now no chance that anyone could check out if I had made some error on my site :-( ... but anyway, in answer to paulmorriss' question, here is what aw stats was telling me:

    Read the article

  • Why is wireless slow with Atheros AR9285?

    - by Luke
    I know there are many posts like this, however none of the fixes I have found have worked. I had the issue on 11.04, and after having no luck fixing it decided to try 12.04 however this has not fixed the problem. I'm using a Lenovo IdeaPad, the network card is a Atheros Communications AR9285. edit add outputs: sudo iwconfig lo no wireless extensions. wlan0 IEEE 802.11bgn ESSID:"NETGEAR-PLOW" Mode:Managed Frequency:2.437 GHz Access Point: E0:91:F5:7D:1B:BA Bit Rate=65 Mb/s Tx-Power=15 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:on Link Quality=66/70 Signal level=-44 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:77 Invalid misc:63 Missed beacon:0 eth0 no wireless extensions. lspci -nnk | grep -iA2 net 06:00.0 Network controller [0280]: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) [168c:002b] (rev 01) Subsystem: Lenovo Device [17aa:30a1] Kernel driver in use: ath9k -- 07:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 02) Subsystem: Lenovo Device [17aa:392e] Kernel driver in use: r8169 Thanks

    Read the article

  • What is Devops and Why You Should Care?

    - by Tanu Sood
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* 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;} According to Wikipedia, DevOps (a portmanteau of development and operations) is a software development method that stresses communication, collaboration and integration between software developers and information technology (IT) professionals. DevOps is a response to the interdependence of software development and IT operations. It aims to help an organization rapidly produce software products and services. That definition of DevOps is the – what. The “why” is even easier. Standardized development methodology, clear communication and documented processes supported by a standards-based, proven middleware platform improves application development and management cycles, brings agility and provides greater availability and security to your IT infrastructure. Clearly, DevOps is about connecting people, products and processes. Ultimately, DevOps is about connecting IT to business. If you haven’t already seen it, do check out Bob Rhubart’s feature on DevOps in the latest issue of Oracle Magazine. And for more information on how Oracle Fusion Middleware, the #1 application infrastructure foundation, visit us on oracle.com Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* 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;}

    Read the article

  • Why I switch from Asana.com

    - by Anirudha
    Originally posted on: http://geekswithblogs.net/anirugu/archive/2013/10/24/why-i-switch-from-asana.com.aspxI used Asana.com from 1-2 years. have nice experience to use it. it’s not so easy. When I started using it it’s make many confusion. Now I switch from it.   When I first time see I really didn’t understand how to make a private list. There is a icon on top click on it and make it private. After doing that I still not sure if this is working. There is a lot of confusion made that time. I discuss too much to figure out small small things. The UI is interesting but so hard to understand.  What I am looking for is just a list that I can hold private. I would like to share it only if I put them shared and put email address of person to hold them same list. Few days ago I see that My Win8 phone have a app that call Microsoft OneNote. The good thing of this MS app is that I can record my voice in the app. If someone want to make a list for future then he just need to say and this can be recorded.  This is awesome when you feel that Mobile keypad is just not so fast as a normal regular keyboard.   Google docs are another good option to handle this thing. Just make a word file and use it. share it with friend with many option. One best thing is this app have very simply UI then any other apps.   One more alternative is https://trello.com which you hear from joel on their blog http://www.joelonsoftware.com/items/2011/09/13.html There are many html5 and browser based, mobile based app. Many of them support multi platform feature. this means you can have them from PC to your Pocket. One good thing we all wanted is offline. if you are not online thing will be saved and push back to server when you will be online.   The biggest problem with some apps are they are attractive easy but hard to learn. Their one feature are not clearly defined what he does. This make frustration and confusion to user. When app are not simple to use people start stop trying to learn it. That’s all the problem I have with asana.com If you don’t want to try anything then what about Sticky Notes that is part of Windows 7. This app are still usable since you can store the text on it. If you know any good app to make a task list that provide access from tablet/mobile then put comment here. In the whole world of app there is a lot of app for doing this same thing differently. I mention few of them here. I hope this is nice to describe it.   Thanks for read my post.

    Read the article

  • I don't understand why one of my vbo is overwritten by another

    - by Alays
    to create a vbo I use this function: public void loadVBO(){ vboID = GL15.glGenBuffers(); GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboID); GL15.glBufferData(GL15.GL_ARRAY_BUFFER, buf, GL15.GL_STATIC_DRAW); // Put the position coordinates in attribute list 0 GL20.glVertexAttribPointer(0, 4, GL11.GL_FLOAT, false,4*4+4*4+4*4+2*4 , 0); // Put the color components in attribute list 1 GL20.glVertexAttribPointer(1, 4, GL11.GL_FLOAT, false,4*4+4*4+4*4+2*4 , 4*4); GL20.glVertexAttribPointer(2, 4, GL11.GL_FLOAT, false,4*4+4*4+4*4+2*4 , 4*4+4*4); // Put the texture coordinates in attribute list 2 GL20.glVertexAttribPointer(3, 4, GL11.GL_FLOAT, false,4*4+4*4+4*4+2*4 , 4*4+4*4+4*4); GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0); } to display a vbo I use this function: public void displayVBO(){ GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, vboID); GL20.glEnableVertexAttribArray(0); GL20.glEnableVertexAttribArray(1); GL20.glEnableVertexAttribArray(2); GL20.glEnableVertexAttribArray(3); GL11.glDrawArrays(GL_TRIANGLES, 0, buf.capacity()); GL20.glDisableVertexAttribArray(0); GL20.glDisableVertexAttribArray(1); GL20.glDisableVertexAttribArray(2); GL20.glDisableVertexAttribArray(3); GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0); } So when I call map.loadVBO() and then ocean.loadVBO(), I think the second call overwrite the first vbo I don't know how ... When I call map.display() and ocean.display(), I have the ocean draw 2 times .... Thanks.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 38 39 40 41 42 43 44 45 46 47 48 49  | Next Page >