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  • Silverlight 4 caching issue?

    - by DavidS
    I am currently experiencing a weird caching problem it would seem. When I load my data intially, I return all the data within given dates and my graph looks as follows: Then I filter the data to return a subset of the original data for the same date range (not that it matters) and I get the following view of my data: However, I intermittently get the following when I refresh the same filterd view of the data: One can see that not all the data gets cached but only some of it i.e. for 12 Dec 2010 and 5 dec 2010(not shown here). I've looked at my queries and the correct data is getting pulled out. It is only on the presentation layer i.e. on Mainpage.xaml.cs that this erroneous data seems to exist. I've stepped through the code and the data is corect through all the layers except on the presentation layer. Has anyone experienced this before? Is there some sort of caching going in the background that is keeping that data in the background as I've got browser caching off? I am using the LoadOperation in the callback method within the Load method of the DomainContext if that helps...

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  • Creation of model in core data on the fly

    - by user1740045
    How can we create a model in core data on the fly? I.e getting the schema of database from somewhere and then creating a Core Data Object graph? *QuesTion:* Yes thats fine, agreed with all the advantages. But, can anybody can tell practically, what is the benefit of integrating Core Data into project instead of using SQL directly. 1.No need to write SQL boiler plate code [but need to learn Core Data Model (steep curve)] 2.WE can undo and redo changes [but practically who needs it] 3.we can migrate to another schema [that can be done by SQLite as well jus need to add another field into table] 4.For say aggregation on some field in table,in Core Data we need to loop through Core Data Objects whereas in SQLite we need to first write SQLite Boiler Plate Code and then the basic aggregation SQL query,which is easy to write,only length of code will increase...But in case of Core Data (need to learn a lot). So apart from reducing the length of Code,does it actually adds value to project? or in terms of Memory Efficiency,Performance,etc.. PS: If anybody has actualy worked on Core Data(Model Creation On the Fly) , if possible share and gve pointers..thanks!

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  • git contributors not showing up properly in github/etc.

    - by RobH
    I'm working in a team on a big project, but when I'm doing the merges I'd like the developers name to appear in github as the author -- currently, I'm the only one showing up since I'm merging. Context: There are 4 developers, and we're using the "integration manager" workflow using GitHub. Our "blessed" repo is under the organization, and each developer manages their pub/private repo. I've been tasked with being the integration manager, so I'm doing the merges, etc. Where I could be messing up is that I'm basically working out of my rob/project.git instead of the org/project.git -- so when I do local merges I operate on my repo then I push to both my public and the org public. (Make sense?) When I push to the blessed repo nobody else shows up as an author, since all commits are coming from me -- how can I get around this? -- Also, we all forked org/project.git, yet in the network graph nobody is showing up -- did we mess this up too? I'm used to working with git solo and don't have too much experience with handling a team of devs. Merging seems like the right thing to do, but I'm being thrown off since GitHub is kind of ignoring the other contributors. If this makes no sense at all, how do you use GitHub to manage a single project across 4 developers? (preferably the integration mgr workflow, branching i think would solve the problem) Thanks for any help

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  • How To: Custom HTML / CSS Text Button for "Facebook like" & "Twitter Follow"

    - by 1Line
    So i have had a little hunt online about creating custom Facebook like buttons and custom twitter follow button but not really found a solution so thought i would ask here and see if anyone knows of a solution for this (currently i have coded some jQuery to get Facebook and Twitter counts using JSON which works but want some custom buttons as per below) I have the count working all ok, just need to tackle the like and follow buttons - it is done in jquery at the moment so would like to continue to use that if this has to be done via that. at the moment i use the API for each to get the count, if i can integrate into the current js i have to get the calls / functions i require would be good: // grab from facebook var facebook = $.getJSON('https://graph.facebook.com/'+f_page+'?callback=?', function(data) { fb_count = data['likes'].toString(); fb_count_gt = data['likes'].toString(); fb_count = add_commas(fb_count); $('#fb_count').html(fb_count); }); // grab from twitter var twitter = $.getJSON("https://twitter.com/users/"+t_page+".json?callback=?",function(data) { twit_count = data['followers_count'].toString(); twit_count_gt = data['followers_count'].toString(); twit_count = add_commas(twit_count); $('#twitter_count').html(twit_count); }); Thanks in advance!

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  • How do I grab hold of a pop-up that is opened from a frame?

    - by KLA
    I am testing a website using WatiN. On one of the pages I get a "report" in an Iframe, within this I frame there is a link to download and save the report. But since the only way to get to the link is to use frame.Link(...) the pop-up closes immediately after opening; Code snippet below //Click the create graph button ie.Button(Find.ById("ctl00_ctl00_ContentPlaceHolder1_TopBoxContentPlaceHolder_btnCreateGraph")).Click(); //Lets export the data ie.Div(Find.ById("colorbox")); ie.Div(Find.ById("cboxContent")); ie.Div(Find.ById("cboxLoadedContent")); Thread.Sleep(1000);//Used to cover performance issues Frame frame = ie.Frame(Find.ByName(frameNameRegex)); for (int Count = 0; Count < 10000000; Count++) {double nothing = (Count/12); }//Do nothing I just need a short pause //SelectList waits for a postback which does not occur. try { frame.SelectList(Find.ById("rvReport_ctl01_ctl05_ctl00")).SelectByValue("Excel"); } catch (Exception) { //Do nothing } //Now click export frame.Link(Find.ById("rvReport_ctl01_ctl05_ctl01")).ClickNoWait(); IE ieNewBrowserWindow = IE.AttachTo<IE>(Find.ByUrl(urlRegex)); fileDownloadHandler.WaitUntilFileDownloadDialogIsHandled(150); fileDownloadHandler.WaitUntilDownloadCompleted(200); I have tried using ie instead of frame which is why all those ie.Div's are present. if I use frame the pop-up window opens and closes instantly. If I use ie I get a link not found error. If I click on the link manually, while the test is "trying to find the link" the file will download correctly.

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  • AutoMapper strings to enum descriptions

    - by 6footunder
    Given the requirement: Take an object graph, set all enum type properties based on the processed value of a second string property. Convention dictates that the name of the source string property will be that of the enum property with a postfix of "Raw". By processed we mean we'll need to strip specified characters e.t.c. I've looked at custom formatters, value resolvers and type converters, none of which seems like a solution for this? We want to use AutoMapper as opposed to our own reflection routine for two reasons, a) it's used extensively throughout the rest of the project and b) it gives you recursive traversal ootb. -- Example -- Given the (simple) structure below, and this: var tmp = new SimpleClass { CountryRaw = "United States", Person = new Person { GenderRaw="Male" } }; var tmp2 = new SimpleClass(); Mapper.Map(tmp, tmp2); we'd expect tmp2's MappedCountry enum to be Country.UnitedStates and the Person property to have a gender of Gender.Male. public class SimpleClass1 { public string CountryRaw {get;set;} public Country MappedCountry {get;set;} public Person Person {get;set;} } public class Person { public string GenderRaw {get;set;} public Gender Gender {get;set;} public string Surname {get;set;} } public enum Country { UnitedStates = 1, NewZealand = 2 } public enum Gender { Male, Female, Unknown } Thanks

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  • How do I improve this linear regression function?

    - by user558383
    I have the following PHP function that I'm using to draw a trend line. However, it sometimes plots the line below all the points in the scatter graph. Is there an error in my function or is there a better way to do it. I think it might be something to do with that with the line it produces, it treats all the residuals (the distances from the scatter points to the line) as positive regardless of them being above or below the line. function linear_regression($x, $y) { $n = count($x); $x_sum = array_sum($x); $y_sum = array_sum($y); $xx_sum = 0; $xy_sum = 0; for($i = 0; $i < $n; $i++) { $xy_sum+=($x[$i]*$y[$i]); $xx_sum+=($x[$i]*$x[$i]); } $m = (($n * $xy_sum) - ($x_sum * $y_sum)) / (($n * $xx_sum) - ($x_sum * $x_sum)); $b = ($y_sum - ($m * $x_sum)) / $n; return array("m"=>$m, "b"=>$b); }

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  • Tigther code - javascript object array

    - by Scott Silvi
    Inside the callback of a $.getJSON call, I have the code outlined below. The first for block aggregates 'total' & assigns values to sov[i]. The map function calculates the percentage of total. I then instantiate a variable called sovData. With the jQuery Flot graph, any objects that are empty aren't added to the pie chart, so this works for up to 7 different slices/datasets. What I'd like to do is only initialize the ones I need (e.g. sovData would have up to 'howMany - 1' (kws.length -1 ) objects inside of it, likely via something similar to dashboards[i] & sov[i]. How would I do this? Code: var sov = [], howMany = kws.length, total = 0, i = 0; for ( i; i < howMany; i++) { total += sov[ i ] = +parseInt(data.sov['sov' + ( i+1 ) ],10) || 0; } var dashboards = data.dashboards; sov = $.map( sov, function(v) { var s = Math.round( ( (v / total) * 10e3 ) / 100); return s < 1 ? 1 : s; }); var sovData = [{ label : dashboards[0], data : sov[0] }, { label : dashboards[1], data : sov[1] }, { label : dashboards[2], data : sov[2] }, { label : dashboards[3], data : sov[3] }, { label : dashboards[4], data : sov[4] }, { label : dashboards[5], data : sov[5] }, { label : dashboards[6], data : sov[6] } ]

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  • Agile Development

    - by James Oloo Onyango
    Alot of literature has and is being written about agile developement and its surrounding philosophies. In my quest to find the best way to express the importance of agile methodologies, i have found Robert C. Martin's "A Satire Of Two Companies" to be both the most concise and thorough! Enjoy the read! Rufus Inc Project Kick Off Your name is Bob. The date is January 3, 2001, and your head still aches from the recent millennial revelry. You are sitting in a conference room with several managers and a group of your peers. You are a project team leader. Your boss is there, and he has brought along all of his team leaders. His boss called the meeting. "We have a new project to develop," says your boss's boss. Call him BB. The points in his hair are so long that they scrape the ceiling. Your boss's points are just starting to grow, but he eagerly awaits the day when he can leave Brylcream stains on the acoustic tiles. BB describes the essence of the new market they have identified and the product they want to develop to exploit this market. "We must have this new project up and working by fourth quarter October 1," BB demands. "Nothing is of higher priority, so we are cancelling your current project." The reaction in the room is stunned silence. Months of work are simply going to be thrown away. Slowly, a murmur of objection begins to circulate around the conference table.   His points give off an evil green glow as BB meets the eyes of everyone in the room. One by one, that insidious stare reduces each attendee to quivering lumps of protoplasm. It is clear that he will brook no discussion on this matter. Once silence has been restored, BB says, "We need to begin immediately. How long will it take you to do the analysis?" You raise your hand. Your boss tries to stop you, but his spitwad misses you and you are unaware of his efforts.   "Sir, we can't tell you how long the analysis will take until we have some requirements." "The requirements document won't be ready for 3 or 4 weeks," BB says, his points vibrating with frustration. "So, pretend that you have the requirements in front of you now. How long will you require for analysis?" No one breathes. Everyone looks around to see whether anyone has some idea. "If analysis goes beyond April 1, we have a problem. Can you finish the analysis by then?" Your boss visibly gathers his courage: "We'll find a way, sir!" His points grow 3 mm, and your headache increases by two Tylenol. "Good." BB smiles. "Now, how long will it take to do the design?" "Sir," you say. Your boss visibly pales. He is clearly worried that his 3 mms are at risk. "Without an analysis, it will not be possible to tell you how long design will take." BB's expression shifts beyond austere.   "PRETEND you have the analysis already!" he says, while fixing you with his vacant, beady little eyes. "How long will it take you to do the design?" Two Tylenol are not going to cut it. Your boss, in a desperate attempt to save his new growth, babbles: "Well, sir, with only six months left to complete the project, design had better take no longer than 3 months."   "I'm glad you agree, Smithers!" BB says, beaming. Your boss relaxes. He knows his points are secure. After a while, he starts lightly humming the Brylcream jingle. BB continues, "So, analysis will be complete by April 1, design will be complete by July 1, and that gives you 3 months to implement the project. This meeting is an example of how well our new consensus and empowerment policies are working. Now, get out there and start working. I'll expect to see TQM plans and QIT assignments on my desk by next week. Oh, and don't forget that your crossfunctional team meetings and reports will be needed for next month's quality audit." "Forget the Tylenol," you think to yourself as you return to your cubicle. "I need bourbon."   Visibly excited, your boss comes over to you and says, "Gosh, what a great meeting. I think we're really going to do some world shaking with this project." You nod in agreement, too disgusted to do anything else. "Oh," your boss continues, "I almost forgot." He hands you a 30-page document. "Remember that the SEI is coming to do an evaluation next week. This is the evaluation guide. You need to read through it, memorize it, and then shred it. It tells you how to answer any questions that the SEI auditors ask you. It also tells you what parts of the building you are allowed to take them to and what parts to avoid. We are determined to be a CMM level 3 organization by June!"   You and your peers start working on the analysis of the new project. This is difficult because you have no requirements. But from the 10-minute introduction given by BB on that fateful morning, you have some idea of what the product is supposed to do.   Corporate process demands that you begin by creating a use case document. You and your team begin enumerating use cases and drawing oval and stick diagrams. Philosophical debates break out among the team members. There is disagreement as to whether certain use cases should be connected with <<extends>> or <<includes>> relationships. Competing models are created, but nobody knows how to evaluate them. The debate continues, effectively paralyzing progress.   After a week, somebody finds the iceberg.com Web site, which recommends disposing entirely of <<extends>> and <<includes>> and replacing them with <<precedes>> and <<uses>>. The documents on this Web site, authored by Don Sengroiux, describes a method known as stalwart-analysis, which claims to be a step-by-step method for translating use cases into design diagrams. More competing use case models are created using this new scheme, but again, people can't agree on how to evaluate them. The thrashing continues. More and more, the use case meetings are driven by emotion rather than by reason. If it weren't for the fact that you don't have requirements, you'd be pretty upset by the lack of progress you are making. The requirements document arrives on February 15. And then again on February 20, 25, and every week thereafter. Each new version contradicts the previous one. Clearly, the marketing folks who are writing the requirements, empowered though they might be, are not finding consensus.   At the same time, several new competing use case templates have been proposed by the various team members. Each template presents its own particularly creative way of delaying progress. The debates rage on. On March 1, Prudence Putrigence, the process proctor, succeeds in integrating all the competing use case forms and templates into a single, all-encompassing form. Just the blank form is 15 pages long. She has managed to include every field that appeared on all the competing templates. She also presents a 159- page document describing how to fill out the use case form. All current use cases must be rewritten according to the new standard.   You marvel to yourself that it now requires 15 pages of fill-in-the-blank and essay questions to answer the question: What should the system do when the user presses Return? The corporate process (authored by L. E. Ott, famed author of "Holistic Analysis: A Progressive Dialectic for Software Engineers") insists that you discover all primary use cases, 87 percent of all secondary use cases, and 36.274 percent of all tertiary use cases before you can complete analysis and enter the design phase. You have no idea what a tertiary use case is. So in an attempt to meet this requirement, you try to get your use case document reviewed by the marketing department, which you hope will know what a tertiary use case is.   Unfortunately, the marketing folks are too busy with sales support to talk to you. Indeed, since the project started, you have not been able to get a single meeting with marketing, which has provided a never-ending stream of changing and contradictory requirements documents.   While one team has been spinning endlessly on the use case document, another team has been working out the domain model. Endless variations of UML documents are pouring out of this team. Every week, the model is reworked.   The team members can't decide whether to use <<interfaces>> or <<types>> in the model. A huge disagreement has been raging on the proper syntax and application of OCL. Others on the team just got back from a 5-day class on catabolism, and have been producing incredibly detailed and arcane diagrams that nobody else can fathom.   On March 27, with one week to go before analysis is to be complete, you have produced a sea of documents and diagrams but are no closer to a cogent analysis of the problem than you were on January 3. **** And then, a miracle happens.   **** On Saturday, April 1, you check your e-mail from home. You see a memo from your boss to BB. It states unequivocally that you are done with the analysis! You phone your boss and complain. "How could you have told BB that we were done with the analysis?" "Have you looked at a calendar lately?" he responds. "It's April 1!" The irony of that date does not escape you. "But we have so much more to think about. So much more to analyze! We haven't even decided whether to use <<extends>> or <<precedes>>!" "Where is your evidence that you are not done?" inquires your boss, impatiently. "Whaaa . . . ." But he cuts you off. "Analysis can go on forever; it has to be stopped at some point. And since this is the date it was scheduled to stop, it has been stopped. Now, on Monday, I want you to gather up all existing analysis materials and put them into a public folder. Release that folder to Prudence so that she can log it in the CM system by Monday afternoon. Then get busy and start designing."   As you hang up the phone, you begin to consider the benefits of keeping a bottle of bourbon in your bottom desk drawer. They threw a party to celebrate the on-time completion of the analysis phase. BB gave a colon-stirring speech on empowerment. And your boss, another 3 mm taller, congratulated his team on the incredible show of unity and teamwork. Finally, the CIO takes the stage to tell everyone that the SEI audit went very well and to thank everyone for studying and shredding the evaluation guides that were passed out. Level 3 now seems assured and will be awarded by June. (Scuttlebutt has it that managers at the level of BB and above are to receive significant bonuses once the SEI awards level 3.)   As the weeks flow by, you and your team work on the design of the system. Of course, you find that the analysis that the design is supposedly based on is flawedno, useless; no, worse than useless. But when you tell your boss that you need to go back and work some more on the analysis to shore up its weaker sections, he simply states, "The analysis phase is over. The only allowable activity is design. Now get back to it."   So, you and your team hack the design as best you can, unsure of whether the requirements have been properly analyzed. Of course, it really doesn't matter much, since the requirements document is still thrashing with weekly revisions, and the marketing department still refuses to meet with you.     The design is a nightmare. Your boss recently misread a book named The Finish Line in which the author, Mark DeThomaso, blithely suggested that design documents should be taken down to code-level detail. "If we are going to be working at that level of detail," you ask, "why don't we simply write the code instead?" "Because then you wouldn't be designing, of course. And the only allowable activity in the design phase is design!" "Besides," he continues, "we have just purchased a companywide license for Dandelion! This tool enables 'Round the Horn Engineering!' You are to transfer all design diagrams into this tool. It will automatically generate our code for us! It will also keep the design diagrams in sync with the code!" Your boss hands you a brightly colored shrinkwrapped box containing the Dandelion distribution. You accept it numbly and shuffle off to your cubicle. Twelve hours, eight crashes, one disk reformatting, and eight shots of 151 later, you finally have the tool installed on your server. You consider the week your team will lose while attending Dandelion training. Then you smile and think, "Any week I'm not here is a good week." Design diagram after design diagram is created by your team. Dandelion makes it very difficult to draw these diagrams. There are dozens and dozens of deeply nested dialog boxes with funny text fields and check boxes that must all be filled in correctly. And then there's the problem of moving classes between packages. At first, these diagram are driven from the use cases. But the requirements are changing so often that the use cases rapidly become meaningless. Debates rage about whether VISITOR or DECORATOR design patterns should be used. One developer refuses to use VISITOR in any form, claiming that it's not a properly object-oriented construct. Someone refuses to use multiple inheritance, since it is the spawn of the devil. Review meetings rapidly degenerate into debates about the meaning of object orientation, the definition of analysis versus design, or when to use aggregation versus association. Midway through the design cycle, the marketing folks announce that they have rethought the focus of the system. Their new requirements document is completely restructured. They have eliminated several major feature areas and replaced them with feature areas that they anticipate customer surveys will show to be more appropriate. You tell your boss that these changes mean that you need to reanalyze and redesign much of the system. But he says, "The analysis phase is system. But he says, "The analysis phase is over. The only allowable activity is design. Now get back to it."   You suggest that it might be better to create a simple prototype to show to the marketing folks and even some potential customers. But your boss says, "The analysis phase is over. The only allowable activity is design. Now get back to it." Hack, hack, hack, hack. You try to create some kind of a design document that might reflect the new requirements documents. However, the revolution of the requirements has not caused them to stop thrashing. Indeed, if anything, the wild oscillations of the requirements document have only increased in frequency and amplitude.   You slog your way through them.   On June 15, the Dandelion database gets corrupted. Apparently, the corruption has been progressive. Small errors in the DB accumulated over the months into bigger and bigger errors. Eventually, the CASE tool just stopped working. Of course, the slowly encroaching corruption is present on all the backups. Calls to the Dandelion technical support line go unanswered for several days. Finally, you receive a brief e-mail from Dandelion, informing you that this is a known problem and that the solution is to purchase the new version, which they promise will be ready some time next quarter, and then reenter all the diagrams by hand.   ****   Then, on July 1 another miracle happens! You are done with the design!   Rather than go to your boss and complain, you stock your middle desk drawer with some vodka.   **** They threw a party to celebrate the on-time completion of the design phase and their graduation to CMM level 3. This time, you find BB's speech so stirring that you have to use the restroom before it begins. New banners and plaques are all over your workplace. They show pictures of eagles and mountain climbers, and they talk about teamwork and empowerment. They read better after a few scotches. That reminds you that you need to clear out your file cabinet to make room for the brandy. You and your team begin to code. But you rapidly discover that the design is lacking in some significant areas. Actually, it's lacking any significance at all. You convene a design session in one of the conference rooms to try to work through some of the nastier problems. But your boss catches you at it and disbands the meeting, saying, "The design phase is over. The only allowable activity is coding. Now get back to it."   ****   The code generated by Dandelion is really hideous. It turns out that you and your team were using association and aggregation the wrong way, after all. All the generated code has to be edited to correct these flaws. Editing this code is extremely difficult because it has been instrumented with ugly comment blocks that have special syntax that Dandelion needs in order to keep the diagrams in sync with the code. If you accidentally alter one of these comments, the diagrams will be regenerated incorrectly. It turns out that "Round the Horn Engineering" requires an awful lot of effort. The more you try to keep the code compatible with Dandelion, the more errors Dandelion generates. In the end, you give up and decide to keep the diagrams up to date manually. A second later, you decide that there's no point in keeping the diagrams up to date at all. Besides, who has time?   Your boss hires a consultant to build tools to count the number of lines of code that are being produced. He puts a big thermometer graph on the wall with the number 1,000,000 on the top. Every day, he extends the red line to show how many lines have been added. Three days after the thermometer appears on the wall, your boss stops you in the hall. "That graph isn't growing quickly enough. We need to have a million lines done by October 1." "We aren't even sh-sh-sure that the proshect will require a m-million linezh," you blather. "We have to have a million lines done by October 1," your boss reiterates. His points have grown again, and the Grecian formula he uses on them creates an aura of authority and competence. "Are you sure your comment blocks are big enough?" Then, in a flash of managerial insight, he says, "I have it! I want you to institute a new policy among the engineers. No line of code is to be longer than 20 characters. Any such line must be split into two or more preferably more. All existing code needs to be reworked to this standard. That'll get our line count up!"   You decide not to tell him that this will require two unscheduled work months. You decide not to tell him anything at all. You decide that intravenous injections of pure ethanol are the only solution. You make the appropriate arrangements. Hack, hack, hack, and hack. You and your team madly code away. By August 1, your boss, frowning at the thermometer on the wall, institutes a mandatory 50-hour workweek.   Hack, hack, hack, and hack. By September 1st, the thermometer is at 1.2 million lines and your boss asks you to write a report describing why you exceeded the coding budget by 20 percent. He institutes mandatory Saturdays and demands that the project be brought back down to a million lines. You start a campaign of remerging lines. Hack, hack, hack, and hack. Tempers are flaring; people are quitting; QA is raining trouble reports down on you. Customers are demanding installation and user manuals; salespeople are demanding advance demonstrations for special customers; the requirements document is still thrashing, the marketing folks are complaining that the product isn't anything like they specified, and the liquor store won't accept your credit card anymore. Something has to give.    On September 15, BB calls a meeting. As he enters the room, his points are emitting clouds of steam. When he speaks, the bass overtones of his carefully manicured voice cause the pit of your stomach to roll over. "The QA manager has told me that this project has less than 50 percent of the required features implemented. He has also informed me that the system crashes all the time, yields wrong results, and is hideously slow. He has also complained that he cannot keep up with the continuous train of daily releases, each more buggy than the last!" He stops for a few seconds, visibly trying to compose himself. "The QA manager estimates that, at this rate of development, we won't be able to ship the product until December!" Actually, you think it's more like March, but you don't say anything. "December!" BB roars with such derision that people duck their heads as though he were pointing an assault rifle at them. "December is absolutely out of the question. Team leaders, I want new estimates on my desk in the morning. I am hereby mandating 65-hour work weeks until this project is complete. And it better be complete by November 1."   As he leaves the conference room, he is heard to mutter: "Empowermentbah!" * * * Your boss is bald; his points are mounted on BB's wall. The fluorescent lights reflecting off his pate momentarily dazzle you. "Do you have anything to drink?" he asks. Having just finished your last bottle of Boone's Farm, you pull a bottle of Thunderbird from your bookshelf and pour it into his coffee mug. "What's it going to take to get this project done? " he asks. "We need to freeze the requirements, analyze them, design them, and then implement them," you say callously. "By November 1?" your boss exclaims incredulously. "No way! Just get back to coding the damned thing." He storms out, scratching his vacant head.   A few days later, you find that your boss has been transferred to the corporate research division. Turnover has skyrocketed. Customers, informed at the last minute that their orders cannot be fulfilled on time, have begun to cancel their orders. Marketing is re-evaluating whether this product aligns with the overall goals of the company. Memos fly, heads roll, policies change, and things are, overall, pretty grim. Finally, by March, after far too many sixty-five hour weeks, a very shaky version of the software is ready. In the field, bug-discovery rates are high, and the technical support staff are at their wits' end, trying to cope with the complaints and demands of the irate customers. Nobody is happy.   In April, BB decides to buy his way out of the problem by licensing a product produced by Rupert Industries and redistributing it. The customers are mollified, the marketing folks are smug, and you are laid off.     Rupert Industries: Project Alpha   Your name is Robert. The date is January 3, 2001. The quiet hours spent with your family this holiday have left you refreshed and ready for work. You are sitting in a conference room with your team of professionals. The manager of the division called the meeting. "We have some ideas for a new project," says the division manager. Call him Russ. He is a high-strung British chap with more energy than a fusion reactor. He is ambitious and driven but understands the value of a team. Russ describes the essence of the new market opportunity the company has identified and introduces you to Jane, the marketing manager, who is responsible for defining the products that will address it. Addressing you, Jane says, "We'd like to start defining our first product offering as soon as possible. When can you and your team meet with me?" You reply, "We'll be done with the current iteration of our project this Friday. We can spare a few hours for you between now and then. After that, we'll take a few people from the team and dedicate them to you. We'll begin hiring their replacements and the new people for your team immediately." "Great," says Russ, "but I want you to understand that it is critical that we have something to exhibit at the trade show coming up this July. If we can't be there with something significant, we'll lose the opportunity."   "I understand," you reply. "I don't yet know what it is that you have in mind, but I'm sure we can have something by July. I just can't tell you what that something will be right now. In any case, you and Jane are going to have complete control over what we developers do, so you can rest assured that by July, you'll have the most important things that can be accomplished in that time ready to exhibit."   Russ nods in satisfaction. He knows how this works. Your team has always kept him advised and allowed him to steer their development. He has the utmost confidence that your team will work on the most important things first and will produce a high-quality product.   * * *   "So, Robert," says Jane at their first meeting, "How does your team feel about being split up?" "We'll miss working with each other," you answer, "but some of us were getting pretty tired of that last project and are looking forward to a change. So, what are you people cooking up?" Jane beams. "You know how much trouble our customers currently have . . ." And she spends a half hour or so describing the problem and possible solution. "OK, wait a second" you respond. "I need to be clear about this." And so you and Jane talk about how this system might work. Some of her ideas aren't fully formed. You suggest possible solutions. She likes some of them. You continue discussing.   During the discussion, as each new topic is addressed, Jane writes user story cards. Each card represents something that the new system has to do. The cards accumulate on the table and are spread out in front of you. Both you and Jane point at them, pick them up, and make notes on them as you discuss the stories. The cards are powerful mnemonic devices that you can use to represent complex ideas that are barely formed.   At the end of the meeting, you say, "OK, I've got a general idea of what you want. I'm going to talk to the team about it. I imagine they'll want to run some experiments with various database structures and presentation formats. Next time we meet, it'll be as a group, and we'll start identifying the most important features of the system."   A week later, your nascent team meets with Jane. They spread the existing user story cards out on the table and begin to get into some of the details of the system. The meeting is very dynamic. Jane presents the stories in the order of their importance. There is much discussion about each one. The developers are concerned about keeping the stories small enough to estimate and test. So they continually ask Jane to split one story into several smaller stories. Jane is concerned that each story have a clear business value and priority, so as she splits them, she makes sure that this stays true.   The stories accumulate on the table. Jane writes them, but the developers make notes on them as needed. Nobody tries to capture everything that is said; the cards are not meant to capture everything but are simply reminders of the conversation.   As the developers become more comfortable with the stories, they begin writing estimates on them. These estimates are crude and budgetary, but they give Jane an idea of what the story will cost.   At the end of the meeting, it is clear that many more stories could be discussed. It is also clear that the most important stories have been addressed and that they represent several months worth of work. Jane closes the meeting by taking the cards with her and promising to have a proposal for the first release in the morning.   * * *   The next morning, you reconvene the meeting. Jane chooses five cards and places them on the table. "According to your estimates, these cards represent about one perfect team-week's worth of work. The last iteration of the previous project managed to get one perfect team-week done in 3 real weeks. If we can get these five stories done in 3 weeks, we'll be able to demonstrate them to Russ. That will make him feel very comfortable about our progress." Jane is pushing it. The sheepish look on her face lets you know that she knows it too. You reply, "Jane, this is a new team, working on a new project. It's a bit presumptuous to expect that our velocity will be the same as the previous team's. However, I met with the team yesterday afternoon, and we all agreed that our initial velocity should, in fact, be set to one perfectweek for every 3 real-weeks. So you've lucked out on this one." "Just remember," you continue, "that the story estimates and the story velocity are very tentative at this point. We'll learn more when we plan the iteration and even more when we implement it."   Jane looks over her glasses at you as if to say "Who's the boss around here, anyway?" and then smiles and says, "Yeah, don't worry. I know the drill by now."Jane then puts 15 more cards on the table. She says, "If we can get all these cards done by the end of March, we can turn the system over to our beta test customers. And we'll get good feedback from them."   You reply, "OK, so we've got our first iteration defined, and we have the stories for the next three iterations after that. These four iterations will make our first release."   "So," says Jane, can you really do these five stories in the next 3 weeks?" "I don't know for sure, Jane," you reply. "Let's break them down into tasks and see what we get."   So Jane, you, and your team spend the next several hours taking each of the five stories that Jane chose for the first iteration and breaking them down into small tasks. The developers quickly realize that some of the tasks can be shared between stories and that other tasks have commonalities that can probably be taken advantage of. It is clear that potential designs are popping into the developers' heads. From time to time, they form little discussion knots and scribble UML diagrams on some cards.   Soon, the whiteboard is filled with the tasks that, once completed, will implement the five stories for this iteration. You start the sign-up process by saying, "OK, let's sign up for these tasks." "I'll take the initial database generation." Says Pete. "That's what I did on the last project, and this doesn't look very different. I estimate it at two of my perfect workdays." "OK, well, then, I'll take the login screen," says Joe. "Aw, darn," says Elaine, the junior member of the team, "I've never done a GUI, and kinda wanted to try that one."   "Ah, the impatience of youth," Joe says sagely, with a wink in your direction. "You can assist me with it, young Jedi." To Jane: "I think it'll take me about three of my perfect workdays."   One by one, the developers sign up for tasks and estimate them in terms of their own perfect workdays. Both you and Jane know that it is best to let the developers volunteer for tasks than to assign the tasks to them. You also know full well that you daren't challenge any of the developers' estimates. You know these people, and you trust them. You know that they are going to do the very best they can.   The developers know that they can't sign up for more perfect workdays than they finished in the last iteration they worked on. Once each developer has filled his or her schedule for the iteration, they stop signing up for tasks.   Eventually, all the developers have stopped signing up for tasks. But, of course, tasks are still left on the board.   "I was worried that that might happen," you say, "OK, there's only one thing to do, Jane. We've got too much to do in this iteration. What stories or tasks can we remove?" Jane sighs. She knows that this is the only option. Working overtime at the beginning of a project is insane, and projects where she's tried it have not fared well.   So Jane starts to remove the least-important functionality. "Well, we really don't need the login screen just yet. We can simply start the system in the logged-in state." "Rats!" cries Elaine. "I really wanted to do that." "Patience, grasshopper." says Joe. "Those who wait for the bees to leave the hive will not have lips too swollen to relish the honey." Elaine looks confused. Everyone looks confused. "So . . .," Jane continues, "I think we can also do away with . . ." And so, bit by bit, the list of tasks shrinks. Developers who lose a task sign up for one of the remaining ones.   The negotiation is not painless. Several times, Jane exhibits obvious frustration and impatience. Once, when tensions are especially high, Elaine volunteers, "I'll work extra hard to make up some of the missing time." You are about to correct her when, fortunately, Joe looks her in the eye and says, "When once you proceed down the dark path, forever will it dominate your destiny."   In the end, an iteration acceptable to Jane is reached. It's not what Jane wanted. Indeed, it is significantly less. But it's something the team feels that can be achieved in the next 3 weeks.   And, after all, it still addresses the most important things that Jane wanted in the iteration. "So, Jane," you say when things had quieted down a bit, "when can we expect acceptance tests from you?" Jane sighs. This is the other side of the coin. For every story the development team implements,   Jane must supply a suite of acceptance tests that prove that it works. And the team needs these long before the end of the iteration, since they will certainly point out differences in the way Jane and the developers imagine the system's behaviour.   "I'll get you some example test scripts today," Jane promises. "I'll add to them every day after that. You'll have the entire suite by the middle of the iteration."   * * *   The iteration begins on Monday morning with a flurry of Class, Responsibilities, Collaborators sessions. By midmorning, all the developers have assembled into pairs and are rapidly coding away. "And now, my young apprentice," Joe says to Elaine, "you shall learn the mysteries of test-first design!"   "Wow, that sounds pretty rad," Elaine replies. "How do you do it?" Joe beams. It's clear that he has been anticipating this moment. "OK, what does the code do right now?" "Huh?" replied Elaine, "It doesn't do anything at all; there is no code."   "So, consider our task; can you think of something the code should do?" "Sure," Elaine said with youthful assurance, "First, it should connect to the database." "And thereupon, what must needs be required to connecteth the database?" "You sure talk weird," laughed Elaine. "I think we'd have to get the database object from some registry and call the Connect() method. "Ah, astute young wizard. Thou perceives correctly that we requireth an object within which we can cacheth the database object." "Is 'cacheth' really a word?" "It is when I say it! So, what test can we write that we know the database registry should pass?" Elaine sighs. She knows she'll just have to play along. "We should be able to create a database object and pass it to the registry in a Store() method. And then we should be able to pull it out of the registry with a Get() method and make sure it's the same object." "Oh, well said, my prepubescent sprite!" "Hay!" "So, now, let's write a test function that proves your case." "But shouldn't we write the database object and registry object first?" "Ah, you've much to learn, my young impatient one. Just write the test first." "But it won't even compile!" "Are you sure? What if it did?" "Uh . . ." "Just write the test, Elaine. Trust me." And so Joe, Elaine, and all the other developers began to code their tasks, one test case at a time. The room in which they worked was abuzz with the conversations between the pairs. The murmur was punctuated by an occasional high five when a pair managed to finish a task or a difficult test case.   As development proceeded, the developers changed partners once or twice a day. Each developer got to see what all the others were doing, and so knowledge of the code spread generally throughout the team.   Whenever a pair finished something significant whether a whole task or simply an important part of a task they integrated what they had with the rest of the system. Thus, the code base grew daily, and integration difficulties were minimized.   The developers communicated with Jane on a daily basis. They'd go to her whenever they had a question about the functionality of the system or the interpretation of an acceptance test case.   Jane, good as her word, supplied the team with a steady stream of acceptance test scripts. The team read these carefully and thereby gained a much better understanding of what Jane expected the system to do. By the beginning of the second week, there was enough functionality to demonstrate to Jane. She watched eagerly as the demonstration passed test case after test case. "This is really cool," Jane said as the demonstration finally ended. "But this doesn't seem like one-third of the tasks. Is your velocity slower than anticipated?"   You grimace. You'd been waiting for a good time to mention this to Jane but now she was forcing the issue. "Yes, unfortunately, we are going more slowly than we had expected. The new application server we are using is turning out to be a pain to configure. Also, it takes forever to reboot, and we have to reboot it whenever we make even the slightest change to its configuration."   Jane eyes you with suspicion. The stress of last Monday's negotiations had still not entirely dissipated. She says, "And what does this mean to our schedule? We can't slip it again, we just can't. Russ will have a fit! He'll haul us all into the woodshed and ream us some new ones."   You look Jane right in the eyes. There's no pleasant way to give someone news like this. So you just blurt out, "Look, if things keep going like they're going, we're not going to be done with everything by next Friday. Now it's possible that we'll figure out a way to go faster. But, frankly, I wouldn't depend on that. You should start thinking about one or two tasks that could be removed from the iteration without ruining the demonstration for Russ. Come hell or high water, we are going to give that demonstration on Friday, and I don't think you want us to choose which tasks to omit."   "Aw forchrisakes!" Jane barely manages to stifle yelling that last word as she stalks away, shaking her head. Not for the first time, you say to yourself, "Nobody ever promised me project management would be easy." You are pretty sure it won't be the last time, either.   Actually, things went a bit better than you had hoped. The team did, in fact, have to drop one task from the iteration, but Jane had chosen wisely, and the demonstration for Russ went without a hitch. Russ was not impressed with the progress, but neither was he dismayed. He simply said, "This is pretty good. But remember, we have to be able to demonstrate this system at the trade show in July, and at this rate, it doesn't look like you'll have all that much to show." Jane, whose attitude had improved dramatically with the completion of the iteration, responded to Russ by saying, "Russ, this team is working hard, and well. When July comes around, I am confident that we'll have something significant to demonstrate. It won't be everything, and some of it may be smoke and mirrors, but we'll have something."   Painful though the last iteration was, it had calibrated your velocity numbers. The next iteration went much better. Not because your team got more done than in the last iteration but simply because the team didn't have to remove any tasks or stories in the middle of the iteration.   By the start of the fourth iteration, a natural rhythm has been established. Jane, you, and the team know exactly what to expect from one another. The team is running hard, but the pace is sustainable. You are confident that the team can keep up this pace for a year or more.   The number of surprises in the schedule diminishes to near zero; however, the number of surprises in the requirements does not. Jane and Russ frequently look over the growing system and make recommendations or changes to the existing functionality. But all parties realize that these changes take time and must be scheduled. So the changes do not cause anyone's expectations to be violated. In March, there is a major demonstration of the system to the board of directors. The system is very limited and is not yet in a form good enough to take to the trade show, but progress is steady, and the board is reasonably impressed.   The second release goes even more smoothly than the first. By now, the team has figured out a way to automate Jane's acceptance test scripts. The team has also refactored the design of the system to the point that it is really easy to add new features and change old ones. The second release was done by the end of June and was taken to the trade show. It had less in it than Jane and Russ would have liked, but it did demonstrate the most important features of the system. Although customers at the trade show noticed that certain features were missing, they were very impressed overall. You, Russ, and Jane all returned from the trade show with smiles on your faces. You all felt as though this project was a winner.   Indeed, many months later, you are contacted by Rufus Inc. That company had been working on a system like this for its internal operations. Rufus has canceled the development of that system after a death-march project and is negotiating to license your technology for its environment.   Indeed, things are looking up!

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  • value types in the vm

    - by john.rose
    value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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  • Firefox 3.5.6 causes entire computer to freeze

    - by Anthony Aziz
    Here's the situation: Environment: Just installed a fresh copy of Win7 Pro 32-bit to NTFS partition on 750GB SATA drive Hardware: E8400 3GHz ASUS P5QL Pro 4GB DDR2 1066 RAM EVGA 9800 GTX+ Plenty of cooling, no problems with hardware before Data is stored on a separate partition, including My Documents No security software is yet installed No extensions installed yet Problem: While using Firefox, sometimes the entire computer will freeze/hang. I get no mouse or keyboard input, can't CTRL+ALT+DEL, no "not responding" indication, just a static image on my display. My drivers are all up to date as far as I'm aware (I just installed this copy of Windows last week). I first noticed this when trying to install Xmarks. I went to the Xmarks site and tried to install and it would freeze. I managed to get it installed (Safe mode and the Mozilla addon site worked), but when I go to configure it (log in, etc), the computer freezes. I don't think it's a matter of usage time or memory issues, because while testing, I browsed wallpaper galleries for about 30 minutes, sometimes as many as 12-15 tabs open at a time, without issue. Sometimes I won't even try to install Xmarks at it will hang. I can install (some) other extensions, the only one I've tried is download status bar (which works). What I've done to try to fix: Restarted (duh) Windows safe mode Completely remove Firefox and install it to a new directory, according to Mozilla's KB (I haven't tried the profile manager, though I assume this does the same thing, except perhaps more thoroughly) Some BIOS changes, including Power options, disabling oveclocking (it was a modest overclock on the CPU, which has run Win7 beta and RC for almost a year now) Memtest Used another Windows user profile, same tragic results I'm STUCK now, with no idea what to do. I'm using Chrome as my main browser at the moment, but that's not something I want to be stuck with. I like Firefox and want to use it. I'm going to try creating a new profile first. One thing I did notice: I started leaving task manager and performance monitor open when anticipating (but dreading) a freeze. firefox.exe had low CPU and low memory, but it looked like overall disk usage was seeing some spikes on the small graph Performance Monitor gives you. I saw on one blog post a fellow using XP moved his Local Settings directory from a separate drive to his main drive, and that solved it, but I don't think my AppData directory is on my D: drive, and that's on the same physical device anyways. Still, something that might be worth trying. I'd extremely appreciate any help. Thanks very much. I really don't want to reinstall Windows from scratch again :( Anthony Aziz

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  • Reusing XSL template to be invoked with different relative XPaths

    - by meomaxy
    Here is my contrived example that illustrates what I am attempting to accomplish. I have an input XML file that I wish to flatten for further processing. Input file: <BICYCLES> <BICYCLE> <COLOR>BLUE</COLOR> <WHEELS> <WHEEL> <WHEEL_TYPE>FRONT</WHEEL_TYPE> <FLAT>NO</FLAT> <REFLECTORS> <REFLECTOR> <REFLECTOR_NUM>1</REFLECTOR_NUM> <COLOR>RED</COLOR> <SHAPE>SQUARE</SHAPE> </REFLECTOR> <REFLECTOR> <REFLECTOR_NUM>2</REFLECTOR_NUM> <COLOR>WHITE</COLOR> <SHAPE>ROUND</SHAPE> </REFLECTOR> </REFLECTORS> </WHEEL> <WHEEL> <WHEEL_TYPE>REAR</WHEEL_TYPE> <FLAT>NO</FLAT> </WHEEL> </WHEELS> </BICYCLE> </BICYCLES> The input is a list of <BICYCLE> nodes. Each <BICYCLE> has a <COLOR> and optionally has <WHEELS>. <WHEELS> is a list of <WHEEL> nodes, each of which has a few attributes, and optionally has <REFLECTORS>. <REFLECTORS> is a list of <REFLECTOR> nodes, each of which has a few attributes. The goal is to flatten this XML. This is the XSL I'm using: <xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:fn="http://www.w3.org/2005/xpath-functions"> <xsl:output method="xml" encoding="UTF-8" indent="yes" omit-xml-declaration="yes" xml:space="preserve"/> <xsl:template match="/"> <BICYCLES> <xsl:apply-templates/> </BICYCLES> </xsl:template> <xsl:template match="BICYCLE"> <xsl:choose> <xsl:when test="WHEELS"> <xsl:apply-templates select="WHEELS"/> </xsl:when> <xsl:otherwise> <BICYCLE> <COLOR><xsl:value-of select="COLOR"/></COLOR> <WHEEL_TYPE/> <FLAT/> <REFLECTOR_NUM/> <COLOR/> <SHAPE/> </BICYCLE> </xsl:otherwise> </xsl:choose> </xsl:template> <xsl:template match="WHEELS"> <xsl:apply-templates select="WHEEL"/> </xsl:template> <xsl:template match="WHEEL"> <xsl:choose> <xsl:when test="REFLECTORS"> <xsl:apply-templates select="REFLECTORS"/> </xsl:when> <xsl:otherwise> <BICYCLE> <COLOR><xsl:value-of select="../../COLOR"/></COLOR> <WHEEL_TYPE><xsl:value-of select="WHEEL_TYPE"/></WHEEL_TYPE> <FLAT><xsl:value-of select="FLAT"/></FLAT> <REFLECTOR_NUM/> <COLOR/> <SHAPE/> </BICYCLE> </xsl:otherwise> </xsl:choose> </xsl:template> <xsl:template match="REFLECTORS"> <xsl:apply-templates select="REFLECTOR"/> </xsl:template> <xsl:template match="REFLECTOR"> <BICYCLE> <COLOR><xsl:value-of select="../../../../COLOR"/></COLOR> <WHEEL_TYPE><xsl:value-of select="../../WHEEL_TYPE"/></WHEEL_TYPE> <FLAT><xsl:value-of select="../../FLAT"/></FLAT> <REFLECTOR_NUM><xsl:value-of select="REFLECTOR_NUM"/></REFLECTOR_NUM> <COLOR><xsl:value-of select="COLOR"/></COLOR> <SHAPE><xsl:value-of select="SHAPE"/></SHAPE> </BICYCLE> </xsl:template> </xsl:stylesheet> The output is: <BICYCLES xmlns:fn="http://www.w3.org/2005/xpath-functions" xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:xs="http://www.w3.org/2001/XMLSchema"> <BICYCLE> <COLOR>BLUE</COLOR> <WHEEL_TYPE>FRONT</WHEEL_TYPE> <FLAT>NO</FLAT> <REFLECTOR_NUM>1</REFLECTOR_NUM> <COLOR>RED</COLOR> <SHAPE>SQUARE</SHAPE> </BICYCLE> <BICYCLE> <COLOR>BLUE</COLOR> <WHEEL_TYPE>FRONT</WHEEL_TYPE> <FLAT>NO</FLAT> <REFLECTOR_NUM>2</REFLECTOR_NUM> <COLOR>WHITE</COLOR> <SHAPE>ROUND</SHAPE> </BICYCLE> <BICYCLE> <COLOR>BLUE</COLOR> <WHEEL_TYPE>REAR</WHEEL_TYPE> <FLAT>NO</FLAT> <REFLECTOR_NUM/> <COLOR/> <SHAPE/> </BICYCLE> </BICYCLES> What I don't like about this is that I'm outputting the color attribute in several forms: <COLOR><xsl:value-of select="../../../../COLOR"/></COLOR> <COLOR><xsl:value-of select="../../COLOR"/></COLOR> <COLOR><xsl:value-of select="COLOR"/></COLOR> <COLOR/> It seems like there ought to be a way to make a named template and invoke it from the various places where it is needed and pass some parameter that represents the path back to the <BICYCLE> node to which it refers. Is there a way to clean this up, say with a named template for bicycle fields, for wheel fields and for reflector fields? In the real world example this is based on, there are many more attributes to a "bicycle" than just color, and I want to make this XSL easy to change to include or exclude fields without having to change the XSL in multiple places.

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  • Problems using HibernateTemplate: java.lang.NoSuchMethodError: org.hibernate.SessionFactory.openSession()Lorg/hibernate/classic/Session;

    - by user2104160
    I am quite new in Spring world and I am going crazy trying to integrate Hibernate in Spring application using HibernateTemplate abstract support class I have the following class to persist on database table: package org.andrea.myexample.HibernateOnSpring.entity; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name="person") public class Person { @Id @GeneratedValue(strategy=GenerationType.AUTO) private int pid; private String firstname; private String lastname; public int getPid() { return pid; } public void setPid(int pid) { this.pid = pid; } public String getFirstname() { return firstname; } public void setFirstname(String firstname) { this.firstname = firstname; } public String getLastname() { return lastname; } public void setLastname(String lastname) { this.lastname = lastname; } } Next to it I have create an interface named PersonDAO in wich I only define my CRUD method. So I have implement this interface by a class named PersonDAOImpl that also extend the Spring abstract class HibernateTemplate: package org.andrea.myexample.HibernateOnSpring.dao; import java.util.List; import org.andrea.myexample.HibernateOnSpring.entity.Person; import org.springframework.orm.hibernate3.support.HibernateDaoSupport; public class PersonDAOImpl extends HibernateDaoSupport implements PersonDAO{ public void addPerson(Person p) { getHibernateTemplate().saveOrUpdate(p); } public Person getById(int id) { // TODO Auto-generated method stub return null; } public List<Person> getPersonsList() { // TODO Auto-generated method stub return null; } public void delete(int id) { // TODO Auto-generated method stub } public void update(Person person) { // TODO Auto-generated method stub } } (at the moment I am trying to implement only the addPerson() method) Then I have create a main class to test the operation of insert a new object into the database table: package org.andrea.myexample.HibernateOnSpring; import org.andrea.myexample.HibernateOnSpring.dao.PersonDAO; import org.andrea.myexample.HibernateOnSpring.entity.Person; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class MainApp { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); System.out.println("Contesto recuperato: " + context); Person persona1 = new Person(); persona1.setFirstname("Pippo"); persona1.setLastname("Blabla"); System.out.println("Creato persona1: " + persona1); PersonDAO dao = (PersonDAO) context.getBean("personDAOImpl"); System.out.println("Creato dao object: " + dao); dao.addPerson(persona1); System.out.println("persona1 salvata nel database"); } } As you can see the PersonDAOImpl class extends HibernateTemplate so I think that it have to contain the operation of setting of the sessionFactory... The problem is that when I try to run this MainApp class I obtain the following exception: Exception in thread "main" java.lang.NoSuchMethodError: org.hibernate.SessionFactory.openSession()Lorg/hibernate/classic/Session; at org.springframework.orm.hibernate3.SessionFactoryUtils.doGetSession(SessionFactoryUtils.java:323) at org.springframework.orm.hibernate3.SessionFactoryUtils.getSession(SessionFactoryUtils.java:235) at org.springframework.orm.hibernate3.HibernateTemplate.getSession(HibernateTemplate.java:457) at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:392) at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374) at org.springframework.orm.hibernate3.HibernateTemplate.saveOrUpdate(HibernateTemplate.java:737) at org.andrea.myexample.HibernateOnSpring.dao.PersonDAOImpl.addPerson(PersonDAOImpl.java:12) at org.andrea.myexample.HibernateOnSpring.MainApp.main(MainApp.java:26) Why I have this problem? how can I solve it? To be complete I also insert my pom.xml containing my dependencies list: <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>org.andrea.myexample</groupId> <artifactId>HibernateOnSpring</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>HibernateOnSpring</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <!-- Dipendenze di Spring Framework --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.2.1.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>3.2.1.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>3.2.1.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>3.2.1.RELEASE</version> </dependency> <dependency> <!-- Usata da Hibernate 4 per LocalSessionFactoryBean --> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>3.2.0.RELEASE</version> </dependency> <!-- Dipendenze per AOP --> <dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> <version>2.2.2</version> </dependency> <!-- Dipendenze per Persistence Managment --> <dependency> <!-- Apache BasicDataSource --> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.4</version> </dependency> <dependency> <!-- MySQL database driver --> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.23</version> </dependency> <dependency> <!-- Hibernate --> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>4.1.9.Final</version> </dependency> </dependencies> </project>

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  • Generic Aggregation of C++ Objects by Attribute When Attribute Name is Unknown at Runtime

    - by stretch
    I'm currently implementing a system with a number of class's representing objects such as client, business, product etc. Standard business logic. As one might expect each class has a number of standard attributes. I have a long list of essentially identical requirements such as: the ability to retrieve all business' whose industry is manufacturing. the ability to retrieve all clients based in London Class business has attribute sector and client has attribute location. Clearly this a relational problem and in pseudo SQL would look something like: SELECT ALL business in business' WHERE sector == manufacturing Unfortunately plugging into a DB is not an option. What I want to do is have a single generic aggregation function whose signature would take the form: vector<generic> genericAggregation(class, attribute, value); Where class is the class of object I want to aggregate, attribute and value being the class attribute and value of interest. In my example I've put vector as return type, but this wouldn't work. Probably better to declare a vector of relevant class type and pass it as an argument. But this isn't the main problem. How can I accept arguments in string form for class, attribute and value and then map these in a generic object aggregation function? Since it's rude not to post code, below is a dummy program which creates a bunch of objects of imaginatively named classes. Included is a specific aggregation function which returns a vector of B objects whose A object is equal to an id specified at the command line e.g. .. $ ./aggregations 5 which returns all B's whose A objects 'i' attribute is equal to 5. See below: #include <iostream> #include <cstring> #include <sstream> #include <vector> using namespace std; //First imaginativly names dummy class class A { private: int i; double d; string s; public: A(){} A(int i, double d, string s) { this->i = i; this->d = d; this->s = s; } ~A(){} int getInt() {return i;} double getDouble() {return d;} string getString() {return s;} }; //second imaginativly named dummy class class B { private: int i; double d; string s; A *a; public: B(int i, double d, string s, A *a) { this->i = i; this->d = d; this->s = s; this->a = a; } ~B(){} int getInt() {return i;} double getDouble() {return d;} string getString() {return s;} A* getA() {return a;} }; //Containers for dummy class objects vector<A> a_vec (10); vector<B> b_vec;//100 //Util function, not important.. string int2string(int number) { stringstream ss; ss << number; return ss.str(); } //Example function that returns a new vector containing on B objects //whose A object i attribute is equal to 'id' vector<B> getBbyA(int id) { vector<B> result; for(int i = 0; i < b_vec.size(); i++) { if(b_vec.at(i).getA()->getInt() == id) { result.push_back(b_vec.at(i)); } } return result; } int main(int argc, char** argv) { //Create some A's and B's, each B has an A... //Each of the 10 A's are associated with 10 B's. for(int i = 0; i < 10; ++i) { A a(i, (double)i, int2string(i)); a_vec.at(i) = a; for(int j = 0; j < 10; j++) { B b((i * 10) + j, (double)j, int2string(i), &a_vec.at(i)); b_vec.push_back(b); } } //Got some objects so lets do some aggregation //Call example aggregation function to return all B objects //whose A object has i attribute equal to argv[1] vector<B> result = getBbyA(atoi(argv[1])); //If some B's were found print them, else don't... if(result.size() != 0) { for(int i = 0; i < result.size(); i++) { cout << result.at(i).getInt() << " " << result.at(i).getA()->getInt() << endl; } } else { cout << "No B's had A's with attribute i equal to " << argv[1] << endl; } return 0; } Compile with: g++ -o aggregations aggregations.cpp If you wish :) Instead of implementing a separate aggregation function (i.e. getBbyA() in the example) I'd like to have a single generic aggregation function which accounts for all possible class attribute pairs such that all aggregation requirements are met.. and in the event additional attributes are added later, or additional aggregation requirements, these will automatically be accounted for. So there's a few issues here but the main one I'm seeking insight into is how to map a runtime argument to a class attribute. I hope I've provided enough detail to adequately describe what I'm trying to do...

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  • Monitoring tools that can take high rate and high volume?

    - by Jon Watte
    We're using Cacti with RRDTool to monitor and graph about 100,000 counters spread across about 1,000 Linux-based nodes. However, our current setup generally only gives us 5-minute graphs (with some data being minute-based); we often make changes where seeing feedback in "near real time" would be of value. I'd like approximately a week of 5- or 10-second data, a year of 1-minute data, and 5 years of 10-minute data. I have SSD disks and a dual-hexa-core server to spare. I tried setting up a Graphite/carbon/whisper server, and had about 15 nodes pipe to it, but it only has "average" for the retention function when promoting to older buckets. This is almost useless -- I'd like min, max, average, standard deviation, and perhaps "total sum" and "number of samples" or perhaps "95th percentile" available. The developer claims there's a new back-end "in beta" that allows you to write your own function, but this appears to still only do 1:1 retention (when saving older data, you really want the statistics calculated into many streams from a single input. Also, "in beta" seems a little risky for this installation. If I'm wrong about this assumption, I'd be happy to be shown my error! I've heard Zabbix recommended, but it puts data into MySQL or some other SQL database. 100,000 counters on a 5 second interval means 20,000 tps, and while I have an SSD, I don't have an 8-way RAID-6 with battery backup cache, which I think I'd need for that to work out :-) Again, if that's actually something that's not a problem, I'd be happy to be shown the error of my ways. Also, can Zabbix do the single data stream - promote with statistics thing? Finally, Munin claims to have a new 2.0 coming out "in beta" right now, and it boasts custom retention plans. However, again, it's that "in beta" part -- has anyone used that for real, and at scale? How did it perform, if so? I'm almost thinking about using a graphing front-end (such as Graphite) and rolling my own retention backend with a simple layer on top of mmap() and some stats. That wouldn't be particularly hard, and would probably perform very well, letting the kernel figure out the balance between frequency of flushing to disk and process operations. Any other suggestions I should look into? Note: it has to have shown itself able to sustain the kinds of data loads I'm suggesting above; if you can point at the specific implementation you're referencing, so much the better!

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  • APC PHP cache size does not exceed 32MB, even though settings allow for more

    - by hardy101
    I am setting up APC (v 3.1.9) on a high-traffic WordPress installation on CentOS 6.0 64 bit. I have figured out many of the quirks with APC, but something is still not quite right. No matter what settings I change, APC never actually caches more than 32MB. I'm trying to bump it up to 256 MB. 32MB is a default amount for apc.shm_size, so I am wondering if it's stuck there somehow. I have run the following echo '2147483648' > /proc/sys/kernel/shmmax to increase my system's shared memory to 2G (half of my 4G box). Then ran ipcs -lm which returns ------ Shared Memory Limits -------- max number of segments = 4096 max seg size (kbytes) = 2097152 max total shared memory (kbytes) = 8388608 min seg size (bytes) = 1 Also made a change in /etc/sysctl.conf then ran sysctl -p to make the settings stick on the server. Rebooted, too, for good measure. In my APC settings, I have mmap enabled (which happens by default in recent versions of APC). php.ini looks like: apc.stat=0 apc.shm_size="256M" apc.max_file_size="10M" apc.mmap_file_mask="/tmp/apc.XXXXXX" apc.ttl="7200" I am aware that mmap mode will ignore references to apc.shm_segments, so I have left it out with default 1. phpinfo() indicates the following about APC: Version 3.1.9 APC Debugging Disabled MMAP Support Enabled MMAP File Mask /tmp/apc.bPS7rB Locking type pthread mutex Locks Serialization Support php Revision $Revision: 308812 $ Build Date Oct 11 2011 22:55:02 Directive Local Value apc.cache_by_default On apc.canonicalize O apc.coredump_unmap Off apc.enable_cli Off apc.enabled On On apc.file_md5 Off apc.file_update_protection 2 apc.filters no value apc.gc_ttl 3600 apc.include_once_override Off apc.lazy_classes Off apc.lazy_functions Off apc.max_file_size 10M apc.mmap_file_mask /tmp/apc.bPS7rB apc.num_files_hint 1000 apc.preload_path no value apc.report_autofilter Off apc.rfc1867 Off apc.rfc1867_freq 0 apc.rfc1867_name APC_UPLOAD_PROGRESS apc.rfc1867_prefix upload_ apc.rfc1867_ttl 3600 apc.serializer default apc.shm_segments 1 apc.shm_size 256M apc.slam_defense On apc.stat Off apc.stat_ctime Off apc.ttl 7200 apc.use_request_time On apc.user_entries_hint 4096 apc.user_ttl 0 apc.write_lock On apc.php reveals the following graph, no matter how long the server runs (cache size fluctuates and hovers at just under 32MB. See image http://i.stack.imgur.com/2bwMa.png You can see that the cache is trying to allocate 256MB, but the brown piece of the pie keeps getting recycled at 32MB. This is confirmed as refreshing the apc.php page shows cached file counts that move up and down (implying that the cache is not holding onto all of its files). Does anyone have an idea of how to get APC to use more than 32 MB for its cache size?? **Note that the identical behavior occurs for eaccelerator, xcache, and APC. I read here: http://www.litespeedtech.com/support/forum/archive/index.php/t-5072.html that suEXEC could cause this problem.

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  • a value that shows in select mode disappears in edit mode from a gridview column

    - by Jbob Johan
    i have a gridview(GridView1) with a few Bound Fields first one is Date (ActivityDate) from a table named "tblTime" i have managed to add one extra colum (manually), that is not bound that shows dayInWeek value according to the "ActivityDate" field programtically in CodeBehind but when i enter into Edit Mode , all Bound fields are showing their values correctly but the one column i have added manually will not show the value as it did in "select mode"(first mode b4 trying to edit) while im not a great dibbagger i have manged to view the cell's value (GridView1.Rows[e.NewEditIndex].Cells[1].Text) which does hold on to the day in week value but it does not appear in gridview edit mode only this is some of the code protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.Header) { e.Row.Cells[0].Text = "?????"; //Activity Date (in hebrew) e.Row.Cells[1].Text = "??? ?????"; //DayinWeek e.Row.Cells[2].Text = "??????"; //ActivityType (work seek vacation) named Reason e.Row.Cells[3].Text = "??? ?????"; //time finish (to Work) e.Row.Cells[4].Text = "??? ?????"; //Time out (of work) } if (e.Row.RowType == DataControlRowType.DataRow) { if (Convert.ToBoolean(ViewState["theSubIsclckd"]) == true) //if submit button clicked { try { string twekday1 = Convert.ToString(DataBinder.Eval(e.Row.DataItem, "ActiveDate")); twekday1 = twekday1.Remove(9, 11); //geting date only without the time- portion string[] arymd = twekday1.Split('/'); // spliting [d m y] in order to make int day = Convert.ToInt32(arymd[1]); // it into [m d y] ...also requierd int month = Convert.ToInt32(arymd[0]); // when i update the table int year = Convert.ToInt32(arymd[2]); DateTime ILDateInit = new DateTime(year, month, day); //finally extracting Day CultureInfo ILci = CultureInfo.CreateSpecificCulture("he-IL"); // in week //from the converted activity date string MyIL_DayInWeek = ILDateInit.ToString("dddd", ILci); ViewState["MyIL_DayInWeek"] = MyIL_DayInWeek; e.Row.Cells[1].Text = MyIL_DayInWeek; string displayReason = DataBinder.Eval(e.Row.DataItem, "Reason").ToString(); e.Row.Cells[2].Text = displayReason; } catch (System.Exception excep) { Js.functions.but bb = new Js.functions.but(); bb.buttonName = "rex"; bb.documentwrite = true; bb.testCsVar = excep.ToString(); bb.f1(bb); // this was supposed to throw exep in javaScript injected from code behid - alert } // just in case.. } } so that works for the non edit period of time then when i hit the edit ... no day in week shows THE aspX - after selcting date... name etc' , click on button to display gridview: <asp:Button ID="TheSubB" runat="server" Text="???" onclick="TheSubB_Click" /> <asp:GridView ID="GridView1" runat="server" OnRowDataBound="GridView1_RowDataBound" onrowediting="GridView1_RowEditing" onrowcancelingedit="GridView1_RowCancelingEdit" OnRowUpdating="GridView1_RowUpdating" BackColor="LightGoldenrodYellow" BorderColor="Tan" BorderWidth="1px" CellPadding="2" ForeColor="Black" GridLines="None" AutoGenerateColumns="False" DataKeyNames="tId" DataSourceID="SqlDataSource1" style="z-index: 1; left: 0%; top: 0%; position: relative; width: 812px; height: 59px; font-family:Arial; text-align: center;" AllowSorting="True" > <AlternatingRowStyle BackColor="PaleGoldenrod" /> <Columns> <asp:BoundField DataField="ActiveDate" HeaderText="ActiveDate" SortExpression="ActiveDate" ControlStyle-Width="70" DataFormatString="{0:dd/MM/yyyy}" > <ControlStyle Width="70px" /> </asp:BoundField> <asp:TemplateField HeaderText="???.???.??"> <EditItemTemplate> <asp:TextBox ID="dayinW_EditTB" runat="server"></asp:TextBox> </EditItemTemplate> <ItemTemplate> <asp:Label ID="dayInW_editLabel" runat="server"></asp:Label> </ItemTemplate> </asp:TemplateField> <asp:BoundField DataField="Reason" HeaderText="???? ?????" SortExpression="Reason" ControlStyle-Width="50"> <ControlStyle Width="50px" /> </asp:BoundField> <asp:BoundField DataField="TimeOut" HeaderText="TimeOut" SortExpression="TimeOut" ControlStyle-Width="50" DataFormatString="{0:HH:mm}" > <ControlStyle Width="50px"></ControlStyle> </asp:BoundField> <asp:BoundField DataField="TimeIn" HeaderText="TimeIn" SortExpression="TimeIn" ControlStyle-Width="50" DataFormatString="{0:HH:mm}" > <ControlStyle Width="50px"></ControlStyle> </asp:BoundField> <asp:TemplateField HeaderText="????" > <EditItemTemplate> <asp:ImageButton width="15" Height="15" ImageUrl="~/images/edit.png" runat="server" CausesValidation="True" CommandName="Update" Text="Update"> </asp:ImageButton> <asp:ImageButton Width="15" Height="15" ImageUrl="images/cancel.png" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel"> </asp:ImageButton> </EditItemTemplate> <ItemTemplate> <asp:ImageButton width="25" Height="15" ImageUrl="images/edit.png" ID="EditIB" runat="server" CausesValidation="False" CommandName="Edit" AlternateText="????"></asp:ImageButton> </ItemTemplate> </asp:TemplateField> <asp:TemplateField HeaderText="???"> <ItemTemplate> <asp:ImageButton width="15" Height="15" ImageUrl="images/Delete.png" ID="DeleteIB" runat="server" CommandName="Delete" AlternateText="???" /> </ItemTemplate> </asp:TemplateField> </Columns> <FooterStyle BackColor="Tan" /> <HeaderStyle BackColor="Tan" Font-Bold="True" /> <PagerStyle BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue" HorizontalAlign="Center" /> <SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" /> <SortedAscendingCellStyle BackColor="#FAFAE7" /> <SortedAscendingHeaderStyle BackColor="#DAC09E" /> <SortedDescendingCellStyle BackColor="#E1DB9C" /> <SortedDescendingHeaderStyle BackColor="#C2A47B" /> </asp:GridView>

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  • Having trouble returning a value from a method call when sending an array and the program is error out when run in reference to the sort

    - by programmerNOOB
    I am getting the following output when this program is run: Please enter the Social Security Number for taxpayer 0: 111111111 Please enter the gross income for taxpayer 0: 20000 Please enter the Social Security Number for taxpayer 1: 555555555 Please enter the gross income for taxpayer 1: 50000 Please enter the Social Security Number for taxpayer 2: 333333333 Please enter the gross income for taxpayer 2: 5464166 Please enter the Social Security Number for taxpayer 3: 222222222 Please enter the gross income for taxpayer 3: 645641 Please enter the Social Security Number for taxpayer 4: 444444444 Please enter the gross income for taxpayer 4: 29000 Taxpayer # 1 SSN: 111111111, Income is $20,000.00, Tax is $0.00 Taxpayer # 2 SSN: 555555555, Income is $50,000.00, Tax is $0.00 Taxpayer # 3 SSN: 333333333, Income is $5,464,166.00, Tax is $0.00 Taxpayer # 4 SSN: 222222222, Income is $645,641.00, Tax is $0.00 Taxpayer # 5 SSN: 444444444, Income is $29,000.00, Tax is $0.00 Unhandled Exception: System.InvalidOperationException: Failed to compare two elements in the array. --- System.ArgumentException: At least one object must implement IComparable. at System.Collections.Comparer.Compare(Object a, Object b) at System.Collections.Generic.ObjectComparer`1.Compare(T x, T y) at System.Collections.Generic.ArraySortHelper`1.SwapIfGreaterWithItems(T[] keys, IComparer`1 comparer, Int32 a, Int32 b) at System.Collections.Generic.ArraySortHelper`1.QuickSort(T[] keys, Int32 left, Int32 right, IComparer`1 comparer) at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, IComparer`1 comparer) --- End of inner exception stack trace --- at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, IComparer`1 comparer) at System.Array.Sort[T](T[] array, Int32 index, Int32 length, IComparer`1 comparer) at System.Array.Sort[T](T[] array) at Assignment5.Taxpayer.Main(String[] args) in Program.cs:line 150 Notice the 0s at the end of the line that should be the tax amount??? Here is the code: using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace taxes { class Rates { // Create a class named rates that has the following data members: private int incLimit; private double lowTaxRate; private double highTaxRate; // use read-only accessor public int IncomeLimit { get { return incLimit; } } public double LowTaxRate { get { return lowTaxRate; } } public double HighTaxRate { get { return highTaxRate; } } //A class constructor that assigns default values public Rates() { int limit = 30000; double lowRate = .15; double highRate = .28; incLimit = limit; lowTaxRate = lowRate; highTaxRate = highRate; } //A class constructor that takes three parameters to assign input values for limit, low rate and high rate. public Rates(int limit, double lowRate, double highRate) { } // A CalculateTax method that takes an income parameter and computes the tax as follows: public int CalculateTax(int income) { int limit = 0; double lowRate = 0; double highRate = 0; int taxOwed = 0; // If income is less than the limit then return the tax as income times low rate. if (income < limit) taxOwed = Convert.ToInt32(income * lowRate); // If income is greater than or equal to the limit then return the tax as income times high rate. if (income >= limit) taxOwed = Convert.ToInt32(income * highRate); return taxOwed; } } //end class Rates // Create a class named Taxpayer that has the following data members: public class Taxpayer { //Use get and set accessors. string SSN { get; set; } int grossIncome { get; set; } // Use read-only accessor. public int taxOwed { get { return taxOwed; } } // The Taxpayer class should be set up so that its objects are comparable to each other based on tax owed. class taxpayer : IComparable { public int taxOwed { get; set; } public int income { get; set; } int IComparable.CompareTo(Object o) { int returnVal; taxpayer temp = (taxpayer)o; if (this.taxOwed > temp.taxOwed) returnVal = 1; else if (this.taxOwed < temp.taxOwed) returnVal = -1; else returnVal = 0; return returnVal; } // End IComparable.CompareTo } //end taxpayer IComparable class // **The tax should be calculated whenever the income is set. // The Taxpayer class should have a getRates class method that has the following. public static void GetRates() { // Local method data members for income limit, low rate and high rate. int incLimit = 0; double lowRate; double highRate; string userInput; // Prompt the user to enter a selection for either default settings or user input of settings. Console.Write("Would you like the default values (D) or would you like to enter the values (E)?: "); /* If the user selects default the default values you will instantiate a rates object using the default constructor * and set the Taxpayer class data member for tax equal to the value returned from calling the rates object CalculateTax method.*/ userInput = Convert.ToString(Console.ReadLine()); if (userInput == "D" || userInput == "d") { Rates rates = new Rates(); rates.CalculateTax(incLimit); } // end if /* If the user selects to enter the rates data then prompt the user to enter values for income limit, low rate and high rate, * instantiate a rates object using the three-argument constructor passing those three entries as the constructor arguments and * set the Taxpayer class data member for tax equal to the valuereturned from calling the rates object CalculateTax method. */ if (userInput == "E" || userInput == "e") { Console.Write("Please enter the income limit: "); incLimit = Convert.ToInt32(Console.ReadLine()); Console.Write("Please enter the low rate: "); lowRate = Convert.ToDouble(Console.ReadLine()); Console.Write("Please enter the high rate: "); highRate = Convert.ToDouble(Console.ReadLine()); Rates rates = new Rates(incLimit, lowRate, highRate); rates.CalculateTax(incLimit); } } static void Main(string[] args) { Taxpayer[] taxArray = new Taxpayer[5]; Rates taxRates = new Rates(); // Implement a for-loop that will prompt the user to enter the Social Security Number and gross income. for (int x = 0; x < taxArray.Length; ++x) { taxArray[x] = new Taxpayer(); Console.Write("Please enter the Social Security Number for taxpayer {0}: ", x + 1); taxArray[x].SSN = Console.ReadLine(); Console.Write("Please enter the gross income for taxpayer {0}: ", x + 1); taxArray[x].grossIncome = Convert.ToInt32(Console.ReadLine()); } Taxpayer.GetRates(); // Implement a for-loop that will display each object as formatted taxpayer SSN, income and calculated tax. for (int i = 0; i < taxArray.Length; ++i) { Console.WriteLine("Taxpayer # {0} SSN: {1}, Income is {2:c}, Tax is {3:c}", i + 1, taxArray[i].SSN, taxArray[i].grossIncome, taxRates.CalculateTax(taxArray[i].grossIncome)); } // end for // Implement a for-loop that will sort the five objects in order by the amount of tax owed Array.Sort(taxArray); Console.WriteLine("Sorted by tax owed"); for (int i = 0; i < taxArray.Length; ++i) { Console.WriteLine("Taxpayer # {0} SSN: {1}, Income is {2:c}, Tax is {3:c}", i + 1, taxArray[i].SSN, taxArray[i].grossIncome, taxRates.CalculateTax(taxArray[i].grossIncome)); } } //end main } // end Taxpayer class } //end Any clues as to why the dollar amount is coming up as 0 and why the sort is not working?

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  • My VPS ubuntu server is very slow

    - by askmike
    I just installed a frech copy of Ubuntu 12.04 on my vps because my old installation was very slow, unfortunately this did not fix the problem. With slow I mean requests for my PHP websites take a long time, very slow (30 sec per request) to slow (3+ sec per request). When it's really bad SSH is also laggish. The websites are: askmike.org (pretty standard Wordpress) mvr.me (own PHP) slow? very slow: Here is a picture of loading a clean install of wordpress slow: here is a picture of loading a small PHP based website the vps The VPS has 256mb ram and an 25GB hdd. Besides serving the 2 small websites it isn't doing anything AFAIK. What have I installed Clean Ubuntu server 12.04 LAMP stack few things like git and nodejs (not using both) ossec (because I thought my server was getting hammered) munin What I already tried / done I installed munin so that I could watch io speed and such. The problem is that I don't know where to look for in the munin report. I checked logs and don't see anything strange (although I don't really know where to look for besides strange / repetitive errors and GET requests). I configured Apache MPM to: <IfModule mpm_prefork_module> StartServers 5 MinSpareServers 5 MaxSpareServers 10 MaxClients 40 MaxRequestsPerChild 0 </IfModule> (apache is using prefork, the default) Stats I copied the munin report as it appeared at 4:50 last night to a site hosted on a shared webhost. Note that tonight my mysql crashed somewhere after 1:00 (which is a new problem altogether), so therefor the graph for last night might look strange. Can anyone help me get my VPS up to normal speed? EDIT: Thanks for the replies. The VPS is 10 bucks a month and is from directvps.nl (Dutch host and I'm also dutch). I did two speed tests for disk IO: $ dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync 1073741824 bytes (1.1 GB) copied, 23.1506 s, 46.4 MB/s $ dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync 1073741824 bytes (1.1 GB) copied, 39.3796 s, 27.3 MB/s Anyway: how can I prove to my VPS host that it is to slow? I can understand a server being busy slowing a website down. But 5-30 sec loadtime for a normal PHP webpage?

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  • The Microsoft Ajax Library and Visual Studio Beta 2

    - by Stephen Walther
    Visual Studio 2010 Beta 2 was released this week and one of the first things that I hope you notice is that it no longer contains the latest version of ASP.NET AJAX. What happened? Where did AJAX go? Just like Sting and The Police, just like Phil Collins and Genesis, just like Greg Page and the Wiggles, AJAX has gone out of band! We are starting a solo career. A Name Change First things first. In previous releases, our Ajax framework was named ASP.NET AJAX. We now have changed the name of the framework to the Microsoft Ajax Library. There are two reasons behind this name change. First, the members of the Ajax team got tired of explaining to everyone that our Ajax framework is not tied to the server-side ASP.NET framework. You can use the Microsoft Ajax Library with ASP.NET Web Forms, ASP.NET MVC, PHP, Ruby on RAILS, and even pure HTML applications. Our framework can be used as a client-only framework and having the word ASP.NET in our name was confusing people. Second, it was time to start spelling the word Ajax like everyone else. Notice that the name is the Microsoft Ajax Library and not the Microsoft AJAX library. Originally, Microsoft used upper case AJAX because AJAX originally was an acronym for Asynchronous JavaScript and XML. And, according to Strunk and Wagnell, acronyms should be all uppercase. However, Ajax is one of those words that have migrated from acronym status to “just a word” status. So whenever you hear one of your co-workers talk about ASP.NET AJAX, gently correct your co-worker and say “It is now called the Microsoft Ajax Library.” Why OOB? But why move out-of-band (OOB)? The short answer is that we have had approximately 6 preview releases of the Microsoft Ajax Library over the last year. That’s a lot. We pride ourselves on being agile. Client-side technology evolves quickly. We want to be able to get a preview version of the Microsoft Ajax Library out to our customers, get feedback, and make changes to the library quickly. Shipping the Microsoft Ajax Library out-of-band keeps us agile and enables us to continue to ship new versions of the library even after ASP.NET 4 ships. Showing Love for JavaScript Developers One area in which we have received a lot of feedback is around making the Microsoft Ajax Library easier to use for developers who are comfortable with JavaScript. We also wanted to make it easy for jQuery developers to take advantage of the innovative features of the Microsoft Ajax Library. To achieve these goals, we’ve added the following features to the Microsoft Ajax Library (these features are included in the latest preview release that you can download right now): A simplified imperative syntax – We wanted to make it brain-dead simple to create client-side Ajax controls when writing JavaScript. A client script loader – We wanted the Microsoft Ajax Library to load all of the scripts required by a component or control automatically. jQuery integration – We love the jQuery selector syntax. We wanted to make it easy for jQuery developers to use the Microsoft Ajax Library without changing their programming style. If you are interested in learning about these new features of the Microsoft Ajax Library, I recommend that you read the following blog post by Scott Guthrie: http://weblogs.asp.net/scottgu/archive/2009/10/15/announcing-microsoft-ajax-library-preview-6-and-the-microsoft-ajax-minifier.aspx Downloading the Latest Version of the Microsoft Ajax Library Currently, the best place to download the latest version of the Microsoft Ajax Library is directly from the ASP.NET CodePlex project: http://aspnet.codeplex.com/ As I write this, the current version is Preview 6. The next version is coming out at the PDC. Summary I’m really excited about the future of the Microsoft Ajax Library. Moving outside of the ASP.NET framework provides us the flexibility to remain agile and continue to innovate aggressively. The latest preview release of the Microsoft Ajax Library includes several major new features including a client script loader, jQuery integration, and a simplified client control creation syntax.

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  • Links to my “Best of 2010” Posts

    - by ScottGu
    I hope everyone is having a Happy New Years! 2010 has been a busy blogging year for me (this is the 100th blog post I’ve done in 2010).  Several people this week suggested I put together a summary post listing/organizing my favorite posts from the year.  Below is a quick listing of some of my favorite posts organized by topic area: VS 2010 and .NET 4 Below is a series of posts I wrote (some in late 2009) about the VS 2010 and .NET 4 (including ASP.NET 4 and WPF 4) release we shipped in April: Visual Studio 2010 and .NET 4 Released Clean Web.Config Files Starter Project Templates Multi-targeting Multiple Monitor Support New Code Focused Web Profile Option HTML / ASP.NET / JavaScript Code Snippets Auto-Start ASP.NET Applications URL Routing with ASP.NET 4 Web Forms Searching and Navigating Code in VS 2010 VS 2010 Code Intellisense Improvements WPF 4 Add Reference Dialog Improvements SEO Improvements with ASP.NET 4 Output Cache Extensibility with ASP.NET 4 Built-in Charting Controls for ASP.NET and Windows Forms Cleaner HTML Markup with ASP.NET 4 - Client IDs Optional Parameters and Named Arguments in C# 4 - and a cool scenarios with ASP.NET MVC 2 Automatic Properties, Collection Initializers and Implicit Line Continuation Support with VB 2010 New <%: %> Syntax for HTML Encoding Output using ASP.NET 4 JavaScript Intellisense Improvements with VS 2010 VS 2010 Debugger Improvements (DataTips, BreakPoints, Import/Export) Box Selection and Multi-line Editing Support with VS 2010 VS 2010 Extension Manager (and the cool new PowerCommands Extension) Pinning Projects and Solutions VS 2010 Web Deployment Debugging Tips/Tricks with Visual Studio Search and Navigation Tips/Tricks with Visual Studio Visual Studio Below are some additional Visual Studio posts I’ve done (not in the first series above) that I thought were nice: Download and Share Visual Studio Color Schemes Visual Studio 2010 Keyboard Shortcuts VS 2010 Productivity Power Tools Fun Visual Studio 2010 Wallpapers Silverlight We shipped Silverlight 4 in April, and announced Silverlight 5 the beginning of December: Silverlight 4 Released Silverlight 4 Tools for VS 2010 and WCF RIA Services Released Silverlight 4 Training Kit Silverlight PivotViewer Now Available Silverlight Questions Announcing Silverlight 5 Silverlight for Windows Phone 7 We shipped Windows Phone 7 this fall and shipped free Visual Studio development tools with great Silverlight and XNA support in September: Windows Phone 7 Developer Tools Released Building a Windows Phone 7 Twitter Application using Silverlight ASP.NET MVC We shipped ASP.NET MVC 2 in March, and started previewing ASP.NET MVC 3 this summer.  ASP.NET MVC 3 will RTM in less than 2 weeks from today: ASP.NET MVC 2: Strongly Typed Html Helpers ASP.NET MVC 2: Model Validation Introducing ASP.NET MVC 3 (Preview 1) Announcing ASP.NET MVC 3 Beta and NuGet (nee NuPack) Announcing ASP.NET MVC 3 Release Candidate 1  Announcing ASP.NET MVC 3 Release Candidate 2 Introducing Razor – A New View Engine for ASP.NET ASP.NET MVC 3: Layouts with Razor ASP.NET MVC 3: New @model keyword in Razor ASP.NET MVC 3: Server-Side Comments with Razor ASP.NET MVC 3: Razor’s @: and <text> syntax ASP.NET MVC 3: Implicit and Explicit code nuggets with Razor ASP.NET MVC 3: Layouts and Sections with Razor IIS and Web Server Stack The IIS and Web Stack teams have made a bunch of great improvements to the core web server this year: Fix Common SEO Problems using the URL Rewrite Extension Introducing the Microsoft Web Farm Framework Automating Deployment with Microsoft Web Deploy Introducing IIS Express SQL CE 4 (New Embedded Database Support with ASP.NET) Introducing Web Matrix EF Code First EF Code First is a really nice new data option that enables a very clean code-oriented data workflow: Announcing Entity Framework Code-First CTP5 Release Class-Level Model Validation with EF Code First and ASP.NET MVC 3 Code-First Development with Entity Framework 4 EF 4 Code First: Custom Database Schema Mapping Using EF Code First with an Existing Database jQuery and AJAX Contributions My team began making some significant source code contributions to the jQuery project this year: jQuery Templates, Data Link and Globalization Accepted as Official jQuery Plugins jQuery Templates and Data Linking (and Microsoft contributing to jQuery) jQuery Globalization Plugin from Microsoft Patches and Hot Fixes Some useful fixes you can download prior to VS 2010 SP1: Patch for Cut/Copy “Insufficient Memory” issue with VS 2010 Patch for VS 2010 Find and Replace Dialog Growing Patch for VS 2010 Scrolling Context Menu Videos of My Talks Some recordings of technical talks I’ve done this year: ASP.NET 4, ASP.NET MVC, and Silverlight 4 Talks I did in Europe VS 2010 and ASP.NET 4 Web Forms Talk in Arizona Other About Technical Debates (and ASP.NET Web Forms and ASP.NET MVC debates in particular) ASP.NET Security Fix Now on Windows Update Upcoming Web Camps I’d like to say a big thank you to everyone who follows my blog – I really appreciate you reading it (the comments you post help encourage me to write it).  See you in the New Year! Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • What is the Oracle Utilities Application Framework?

    - by Anthony Shorten
    The Oracle Utilities Application Framework is a reusable, scalable and flexible java based framework which allows other products to be built, configured and implemented in a standard way. Note: Even though the Framework is built in java it can be integrated with COBOL based extensions for backward compatibility. When Oracle Utilities Customer Care & Billing was migrated from V1 to V2, it was decided that the technical aspects of that product be separated to allow for reuse and independence from technical issues. The idea was that all the technical aspects would be concentrated in this separate product (i.e. a framework) and allow all products using the framework to concentrate on delivering superior functionality. The product was named the Oracle Utilities Application Framework (oufw is the product code). The technical components are contained in the Oracle Utilities Application Framework which can be summarized as follows: Metadata - The Oracle Utilities Application Framework is responsible for defining and using the metadata to define the runtime behavior of the product. All the metadata definition and management is contained within the Oracle Utilities Application Framework. UI Management - The Oracle Utilities Application Framework is responsible for defining and rendering the pages and responsible for ensuring the pages are in the appropriate format for the locale. Integration - The Oracle Utilities Application Framework is responsible for providing the integration points to the architecture. Refer to the Oracle Utilities Application Framework Integration Overview for more details Tools - The Oracle Utilities Application Framework provides a common set of facilities and tools that can be used across all products. Technology - The Oracle Utilities Application Framework is responsible for all technology standards compliance, platform support and integration. There are a number of products from the Tax and Utilities Global Business Unit as well as from the Financial Services Global Business Unit that are built upon the Oracle Utilities Application Framework. These products require the Oracle Utilities Application Framework to be installed first and then the product itself installed onto the framework to complete the installation process. There are a number of key benefits that the Oracle Utilities Application Framework provides to these products: Common facilities - The Oracle Utilities Application Framework provides a standard set of technical facilities that mean that products can concentrate in the unique aspects of their markets rather than making technical decisions. Common methods of configuration - The Oracle Utilities Application Framework standardizes the technical configuration process for a product. Customers can effectively reuse the configuration process across products. Multi-lingual and Multi-platform - The Oracle Utilities Application Framework allows the products to be offered in more markets and across multiple platforms for maximized flexibility. Common methods of implementation - The Oracle Utilities Application Framework standardizes the technical aspects of a product implementation. Customers can effectively reuse the technical implementation process across products. Quicker adoption of new technologies - As new technologies and standards are identified as being important for the product line, they can be integrated centrally benefiting multiple products. Cross product reuse - As enhancements to the Oracle Utilities Application Framework are identified by a particular product, all products can potentially benefit from the enhancement. Note: Use of the Oracle Utilities Application Framework does not preclude the introduction of product specific technologies or facilities to satisfy market needs. The framework minimizes the need and assists in the quick integration of a new product specific piece of technology (if necessary). The Framework is not available as a product itself and is bundled with Tax and Utilities Global Business Unit prodicts. At the present time the following products are on the Framework: Oracle Utilities Customer Care And Billing (V2 and above) Oracle Enterprise Taxation Management (V2 and above) Oracle Utilities Business Intelligence (V2 and above) Oracle Utilities Mobile Workforice Management (V2 and above)

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  • BizTalk and IBM WebSphere MQ Errors

    - by Christopher House
    The project I'm currently working on is going to make heavy use of IBM WebShere MQ to send messages from BizTalk to the client's iSeries box.  I'd never previously worked with WebSphere MQ, so I didn't really have any idea what it would take to get this to work.  I was pleasantly surprised that it wasn't too difficult to configure a send port and pass messages through it to a queue.  Or so I thought... A couple of weeks ago, the client gave me the name of a host, queue manager and queue that I'd been using for my development.  Everything was going great, I was able to put messages onto the queue, I was happy, the client was happy.  Life was good.  Then the client tells me that the host I've been connecting to is actually a Solaris box and that in prod, we'll actually be sending to an iSeries.  We both agree that it would behoove us to start pointing my dev environment to their dev iSeries box in order to flush out any weirdness there might be.  As it turns out, it was a good thing we made the change.  As soon as I reconfigured my BRE policy that sets endpoint information to point to the iSeries queue, we started seeing failures in the event log.  An example from the event log: Event Type: Error Event Source: BizTalk Server 2009 Event Category: BizTalk Server 2009 Event ID: 5754 Date:  6/9/2010 Time:  10:16:41 AM User:  N/A Computer: WINDOWS2003 Description: A message sent to adapter "MQSC" on send port "<my dynamic sendport name>" with URI "mqsc://client/tcp/<hostname>(1414)/<queue manager name>/<queue name>" is suspended.  Error details: Failure encountered while attempting to open queue. queue = <queue name> queueManager = <queue manager name>, reasonCode = 6124  MessageId:  {76825C7C-611A-4A56-8A6F-35E1124BDB5C}  InstanceID: {BA389103-DF9B-493F-8C61-44574822AAD6} The key piece of information in the event entry is the reasonCode, 6124.  A quick Google search shows that reasonCode 6124 is the code for MQRC_NOT_CONNECTED.  According to IBM's docs, this means that you've tried to send a message without first opening a connection to the queue manager.  Obviously, in the context of BizTalk, this is an unexpected error, since this sort of thing should be managed entirely by the send adapter. Perusing IBM's documentation a bit more, I came across some info on how to turn on tracing for MQ.  With tracing enabled, I tried sending a message again, then went and reviewed the trace files.  The bulk of the information in the trace files didn't mean a thing to me, but at the end of one of the files, I did notice this: 00006257 15:40:20.327795   3500.4      RSESS:000009 ------{  reqReleaseConn 00006258 15:40:20.328714   3500.4      RSESS:000009 ------}  reqReleaseConn (rc=OK) 00006259 15:40:20.328727   3500.4      RSESS:000009 ------{  xcsClearTraceIdent 0000625A 15:40:20.328739   3500.4           :       ------}  xcsClearTraceIdent (rc=OK) 0000625B 15:40:20.328752   3500.4           :       -----}! trmzstMQCONNX (rc=MQRC_NOT_AUTHORIZED) 0000625C 15:40:20.328765   3500.4           :       ----}! MQCONNX (rc=MQRC_NOT_AUTHORIZED) 0000625D 15:40:20.328766   3500.4           :       ---}! ImqQueueManager::connect (rc=MQRC_NOT_AUTHORIZED) 0000625E 15:40:20.328767   3500.4           :       --}! ImqObject::open (rc=MQRC_NOT_CONNECTED) 0000625F 15:40:20.328768   3500.4           :       --{  ImqQueue::lock 00006260 15:40:20.328769   3500.4           :       --}! ImqQueue::lock (rc=Unknown(1)) 00006261 15:40:20.328769   3500.4           :       --{  ImqQueue::unlock 00006262 15:40:20.328769   3500.4           :       --}! ImqQueue::unlock (rc=Unknown(1)) It seemed like the MQRC_NOT_CONNECTED error was being caused by a security related issue (MQRC_NOT_AUTHORIZED).  I did notice something earlier in the log where it appeared that MQ was passing a field named UID with a value equal to the account name that my BizTalk service was running under.  I ended up creating a new local account on the BizTalk server that had the same name as a user which had access to the queue manager on the iSeries.  I then created a new host instance that ran under this new account, created a send handler for the MQSC adapter on this new host instance and reconfigured my orchestration to run on the new host instance.  After bouncing all my host instances, I was now able to send messages to the iSeries. It's still not clear to me why we were able to connect to the Solaris server.  I ended up contacting IBM's support and they did confirm that the process sending to MQ does in fact pass the identity to the queue manager it's connecting to.

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  • Control to Control Binding in WPF/Silverlight

    - by psheriff
    In the past if you had two controls that you needed to work together, you would have to write code. For example, if you want a label control to display any text a user typed into a text box you would write code to do that. If you want turn off a set of controls when a user checks a check box, you would also have to write code. However, with XAML, these operations become very easy to do. Bind Text Box to Text Block As a basic example of this functionality, let’s bind a TextBlock control to a TextBox. When the user types into a TextBox the value typed in will show up in the TextBlock control as well. To try this out, create a new Silverlight or WPF application in Visual Studio. On the main window or user control type in the following XAML. <StackPanel>  <TextBox Margin="10" x:Name="txtData" />  <TextBlock Margin="10"              Text="{Binding ElementName=txtData,                             Path=Text}" /></StackPanel> Now run the application and type into the TextBox control. As you type you will see the data you type also appear in the TextBlock control. The {Binding} markup extension is responsible for this behavior. You set the ElementName attribute of the Binding markup to the name of the control that you wish to bind to. You then set the Path attribute to the name of the property of that control you wish to bind to. That’s all there is to it! Bind the IsEnabled Property Now let’s apply this concept to something that you might use in a business application. Consider the following two screen shots. The idea is that if the Add Benefits check box is un-checked, then the IsEnabled property of the three “Benefits” check boxes will be set to false (Figure 1). If the Add Benefits check box is checked, then the IsEnabled property of the “Benefits” check boxes will be set to true (Figure 2). Figure 1: Uncheck Add Benefits and the Benefits will be disabled. Figure 2: Check Add Benefits and the Benefits will be enabled. To accomplish this, you would write XAML to bind to each of the check boxes in the “Benefits To Add” section to the check box named chkBenefits. Below is a fragment of the XAML code that would be used. <CheckBox x:Name="chkBenefits" /> <CheckBox Content="401k"           IsEnabled="{Binding ElementName=chkBenefits,                               Path=IsChecked}" /> Since the IsEnabled property is a boolean type and the IsChecked property is also a boolean type, you can bind these two together. If they were different types, or if you needed them to set the IsEnabled property to the inverse of the IsChecked property then you would need to use a ValueConverter class. SummaryOnce you understand the basics of data binding in XAML, you can eliminate a lot code. Connecting controls together is as easy as just setting the ElementName and Path properties of the Binding markup extension. NOTE: You can download the complete sample code at my website. http://www.pdsa.com/downloads. Choose Tips & Tricks, then "SL – Basic Control Binding" from the drop-down. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **Visit http://www.pdsa.com/Event/Blog for a free eBook on "Fundamentals of N-Tier".

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  • March 21st Links: ASP.NET, ASP.NET MVC, AJAX, Visual Studio, Silverlight

    - by ScottGu
    Here is the latest in my link-listing series. If you haven’t already, check out this month’s "Find a Hoster” page on the www.asp.net website to learn about great (and very inexpensive) ASP.NET hosting offers.  [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] ASP.NET URL Routing in ASP.NET 4: Scott Mitchell has a nice article that talks about the new URL routing features coming to Web Forms applications with ASP.NET 4.  Also check out my previous blog post on this topic. Control of Web Control ClientID Values in ASP.NET 4: Scott Mitchell has a nice article that describes how it is now easy to control the client “id” value emitted by server controls with ASP.NET 4. Web Deployment Made Awesome: Very nice MIX10 talk by Scott Hanselman on the new web deployment features coming with VS 2010, MSDeploy, and .NET 4.  Makes deploying web applications much, much easier. ASP.NET 4’s Browser Capabilities Support: Nice blog post by Stephen Walther that talks about the new browser definition capabilities support coming with ASP.NET 4. Integrating Twitter into an ASP.NET Website: Nice article by Scott Mitchell that demonstrates how to call and integrate Twitter from within your ASP.NET applications. Improving CSS with .LESS: Nice article by Scott Mitchell that describes how to optimize CSS using .LESS – a free, open source library. ASP.NET MVC Upgrading ASP.NET MVC 1 applications to ASP.NET MVC 2: Eilon Lipton from the ASP.NET team has a nice post that describes how to easily upgrade your ASP.NET MVC 1 applications to ASP.NET MVC 2.  He has an automated tool that makes this easy. Note that automated MVC upgrade support is also built-into VS 2010.  Use the tool in this blog post for updating existing MVC projects using VS 2008. Advanced ASP.NET MVC 2: Nice video talk by Brad Wilson of the ASP.NET MVC team.  In it he describes some of the more advanced features in ASP.NET MVC 2 and how to maximize your productivity with them. Dynamic Select Lists with ASP.NET MVC and jQuery: Michael Ceranski has a nice blog post that describes how to dynamically populate dropdownlists on the client using AJAX. AJAX Microsoft AJAX Minifier: We recently shipped an updated minifier utility that allows you to shrink/minify both JavaScript and CSS files – which can improve the performance of your web applications.  You can run this either manually as a command-line tool or now automatically integrate it using a Visual Studio build task.  You can download it for free here. Visual Studio VS 2010 Tip: Quickly Closing Documents: Nice blog post that describes some techniques for optimizing how windows are closed with the new VS 2010 IDE. Collpase to Definitions with Outlining: Nice tip from Zain on how to collapse your code editor to outline mode using Ctrl + M, Ctrl + O.  Also check out his post on copy/paste with outlining here. $299 VS 2010 Upgrade Offer for VS 2005/2008 Standard Users: Soma blogs about a nice VS 2010 upgrade offer you can take advantage of if you have VS 2005 or VS 2008 Standard editions.  For $299 you can upgrade to VS 2010 Professional edition. Dependency Graphics: Jason Zander (who runs the VS team) has a nice blog post that covers the new dependency graph support within VS 2010.  This makes it easier to visualize the dependencies within your application.  Also check out this video here. Layer Validation: Jason Zander has a nice blog post that talks about the new layer validation features in VS 2010.  This enables you to enforce cleaner layering within your projects and solutions.  VS 2010 Profiler Blog: The VS 2010 Profiler Team has their own blog and on it you can find a bunch of nice posts from the last few months that talk about a lot of the new features coming with VS 2010’s Profiler support.  Some really nice features coming. Silverlight Silverlight 4 Training Course: Nice free set of training courses from Microsoft that can help bring you up to speed on all of the new Silverlight 4 features and how to build applications with them.  Updated and current with the recently released Silverlight 4 RC build and tools. Getting Started with Silverlight and Windows Phone 7 Development: Nice blog post by Tim Heuer that summarizes how to get started building Windows Phone 7 applications using Silverlight.  Also check out my blog post from last week on how to build a Windows Phone 7 Twitter application using Silverlight. A Guide to What Has Changed with the Silverlight 4 RC: Nice summary post by Tim Heuer that describes all of the things that have changed between the Silverlight 4 Beta and the Silverlight 4 RC. Path Based Layout - Part 1 and Part 2: Christian Schormann has a nice blog post about a really cool new feature in Expression Blend 4 and Silverlight 4 called Path Layout. Also check out Andy Beaulieu’s blog post on this. Hope this helps, Scott

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