Search Results

Search found 28459 results on 1139 pages for 'task base programming'.

Page 307/1139 | < Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >

• Exclude nodes based on attribute wildcard in XSL node selection

  - by C A

  Using cruisecontrol for continuous integration, I have some annoyances with Weblogic Ant tasks and how they think that server debug information are warnings rather than debug, so are shown in my build report emails. The XML output from cruise is similar to: <cruisecontrol> <build> <target name="compile-xxx"> <task name="xxx" /> </target> <target name="xxx.weblogic"> <task name="wldeploy"> <message priority="warn">Message which isn't really a warning"</message> </task> </target> </build> </cruisecontrol> In the cruisecontrol XSL template the current selection for the task list is: <xsl:variable name="tasklist" select="/cruisecontrol/build//target/task"/> What I would like is something which selects the tasklist in the same way, but doesn't include any target nodes which have the attribute name="*weblogic" where * is a wildcard. I have tried <xsl:variable name="tasklist" select="/cruisecontrol/build//target[@name!='*weblogic']/task"/> but this doesn't seem to have worked. I'm not an expert with XSLT, and just want to get this fixed so I can carry on the real development of the project. Any help is much appreciated.

  Read the article

• Logic in the db for maintaining a points system relationship?

  - by MarcusBooster

  I'm making a little web based game and need to determine where to put logic that checks the integrity of some underlying data in the sql database. Each user keeps track of points assigned to him, and points are awarded by various tasks. I keep a record of each task transaction to make sure they're not repeated, and to keep track of the value of the task at the time of completion, since an individual award level my fluctuate over time. My schema looks like this so far: create table player ( player_ID serial primary key, player_Points int not null default 0 ); create table task ( task_ID serial primary key, task_PointsAwarded int not null ); create table task_list ( player_ID int references player(player_ID), task_ID int references task(task_ID), when_completed timestamp default current_timestamp, point_value int not null, --not fk because task value may change later constraint pk_player_task_id primary key (player_ID, task_ID) ); So, the player.player_Points should be the total of all his cumulative task points in the task_list. Now where do I put the logic to enforce this? Should I do away with player.player_Points altogether and do queries every time I want to know the total score? Which seems wasteful since I'll be doing that query a lot over the course of a game. Or, put a trigger in the task_list that automatically updates the player.player_Points? Is that too much logic to have in the database and should just maintain this relationship in the application? Thanks.

  Read the article

• Write out to text file using T-SQL

  - by sasfrog

  I am creating a basic data transfer task using TSQL where I am retrieving certain records from one database that are more recent than a given datetime value, and loading them into another database. This will happen periodically throughout the day. It's such a small task that SSIS seems like overkill - I want to just use a scheduled task which runs a .sql file. Where I need guidance is that I need to persist the datetime from the last run of this task, then use this to filter the records next time the task runs. My initial thought is to just store the datetime in a text file, and update (overwrite) it as part of the task each time it runs. I can read the file in without problems using T-SQL, but writing back out has got me stuck. I've seen plenty of examples which make use of a dynamically-built bcp command, which is then executed using xp_cmdshell. Trouble is, security on the server I'm deploying to precludes the use of xp_cmdshell. So, my question is, are there other ways to simply write a datetime value to a file using TSQL, or should I be thinking about a different approach? EDIT: happy to be corrected about SSIS being "overkill"...

  Read the article

• When using a repository is it possible for a type to return a Func that the repository uses to test for existing entities?

  - by Scott Rickman

  For example given a Factory with a method public static T Save<T>(T item) where T : Base, new() { /* item.Id == Guid.Empty therefore item is new */ if (item.Id == Guid.Empty && repository.GetAll<T>(t => t.Name == item.Name)) { throw new Exception("Name is not unique"); } } how do I create a property of Base (say MustNotAlreadyExist) so that I can change the method above to public static T Save<T>(T item) where T : Base, new() { /* item.Id == Guid.Empty therefore item is new */ if (item.Id == Guid.Empty && repository.GetAll<T>(t.MustNotAlreadyExist)) { throw new Exception("Name is not unique"); } } public class Base { ... public virtual Expression<Func<T, bool>> MustNotAlreadyExist() { return (b => b.Name == name); /* <- this clearly doesn't work */ } } and then how can I override MustNotAlreadyExist in Account : Base public class Account : Base { ... public override Expression<Func<T, bool>> MustNotAlreadyExist() { return (b => b.Name == name && b.AccountCode == accountCode); /* <- this doesn't work */ } ... }

  Read the article

• Loop through Array with conditional output based on key/value pair

  - by Daniel C

  I have an array with the following columns: Task Status I would like to print out a table that shows a list of the Tasks, but not the Status column. Instead, for Tasks where the Status = 0, I want to add a tag <del> to make the completed task be crossed out. Here's my current code: foreach ($row as $key => $val){ if ($key != 'Status') print "<td>$val</td>"; else if ($val == '0') print "<td><del>$val</del></td>"; } This seems to be correct, but when I print it out, it prints all the tasks with the <del> tag. So basically the "else" clause is being run every time. Here is the var_dump($row): array 'Task' => string 'Task A' (length=6) 'Status' => string '3' (length=1) array 'Task' => string 'Task B' (length=6) 'Status' => string '0' (length=1)

  Read the article

• Merging rows with uniqueness constraints

  - by Flambino

  I've got a little time-tracking web app (implemented in Rails 3.2.8 & MySQL). The app has several users who add their time to specific tasks, on a given date. The system is set up so a user can only have 1 time entry (i.e. row) per task per date. I.e. if you add time twice on the same task and date, it'll add time to the existing row, rather than create a new one. Now I'm looking to merge 2 tasks. In the simplest terms, merging task ID 2 into task ID 1 would take this time | user_id | task_id | date ------+----------+----------+----------- 10 | 1 | 1 | 2012-10-29 15 | 2 | 1 | 2012-10-29 10 | 1 | 2 | 2012-10-29 5 | 3 | 2 | 2012-10-29 and change it into this time | user_id | task_id | date ------+----------+----------+----------- 20 | 1 | 1 | 2012-10-29 <-- time values merged (summed) 15 | 2 | 1 | 2012-10-29 <-- no change 5 | 3 | 1 | 2012-10-29 <-- task_id changed (no merging necessary) I.e. merge by summing the time values, where the given user_id/date/task combo would conflict. I figure I can use a unique constraint to do a ON DUPLICATE KEY UPDATE ... if I do an insert for every task_id=2 entry. But that seems pretty inelegant. I've also tried to figure a way to first update all the rows in task 1 with the summed-up times, but I can't quite figure that one out. Any ideas?

  Read the article

• SQL SERVER – Index Created on View not Used Often – Observation of the View – Part 2

  - by pinaldave

  Earlier, I have written an article about SQL SERVER – Index Created on View not Used Often – Observation of the View. I received an email from one of the readers, asking if there would no problems when we create the Index on the base table. Well, we need to discuss this situation in two different cases. Before proceeding to the discussion, I strongly suggest you read my earlier articles. To avoid the duplication, I am not going to repeat the code and explanation over here. In all the earlier cases, I have explained in detail how Index created on the View is not utilized. SQL SERVER – Index Created on View not Used Often – Limitation of the View 12 SQL SERVER – Index Created on View not Used Often – Observation of the View SQL SERVER – Indexed View always Use Index on Table As per earlier blog posts, so far we have done the following: Create a Table Create a View Create Index On View Write SELECT with ORDER BY on View However, the blog reader who emailed me suggests the extension of the said logic, which is as follows: Create a Table Create a View Create Index On View Write SELECT with ORDER BY on View Create Index on the Base Table Write SELECT with ORDER BY on View After doing the last two steps, the question is “Will the query on the View utilize the Index on the View, or will it still use the Index of the base table?“ Let us first run the Create example. USE tempdb GO IF EXISTS (SELECT * FROM sys.views WHERE OBJECT_ID = OBJECT_ID(N'[dbo].[SampleView]')) DROP VIEW [dbo].[SampleView] GO IF EXISTS (SELECT * FROM sys.objects WHERE OBJECT_ID = OBJECT_ID(N'[dbo].[mySampleTable]') AND TYPE IN (N'U')) DROP TABLE [dbo].[mySampleTable] GO -- Create SampleTable CREATE TABLE mySampleTable (ID1 INT, ID2 INT, SomeData VARCHAR(100)) INSERT INTO mySampleTable (ID1,ID2,SomeData) SELECT TOP 100000 ROW_NUMBER() OVER (ORDER BY o1.name), ROW_NUMBER() OVER (ORDER BY o2.name), o2.name FROM sys.all_objects o1 CROSS JOIN sys.all_objects o2 GO -- Create View CREATE VIEW SampleView WITH SCHEMABINDING AS SELECT ID1,ID2,SomeData FROM dbo.mySampleTable GO -- Create Index on View CREATE UNIQUE CLUSTERED INDEX [IX_ViewSample] ON [dbo].[SampleView] ( ID2 ASC ) GO -- Select from view SELECT ID1,ID2,SomeData FROM SampleView ORDER BY ID2 GO -- Create Index on Original Table -- On Column ID1 CREATE UNIQUE CLUSTERED INDEX [IX_OriginalTable] ON mySampleTable ( ID1 ASC ) GO -- On Column ID2 CREATE UNIQUE NONCLUSTERED INDEX [IX_OriginalTable_ID2] ON mySampleTable ( ID2 ) GO -- Select from view SELECT ID1,ID2,SomeData FROM SampleView ORDER BY ID2 GO Now let us see the execution plans for both of the SELECT statement. Before Index on Base Table (with Index on View): After Index on Base Table (with Index on View): Looking at both executions, it is very clear that with or without, the View is using Indexes. Alright, I have written 11 disadvantages of the Views. Now I have written one case where the View is using Indexes. Anybody who says that I am being harsh on Views can say now that I found one place where Index on View can be helpful. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL View, SQLServer, T SQL, Technology

  Read the article

• Keep Track of Your Tasks with toDoo

  - by Asian Angel

  A tasks list can be convenient but most times you can not include details for those tasks or have to have an online account to do so. If you want to keep your tasks list with you on your computer or laptop and be able to add plenty of details then you might want to look at toDoo. Note: Requires Adobe AIR (download link at bottom of article). toDoo in Action Once you have installed toDoo everything is rather straightforward for getting started. The first time that you start toDoo there will be a temporary “fill-in” for the “Subject & Details Areas”. Simply highlight over the temporary text and add your information. Notice that if desired you can easily set a custom date and time for your tasks right below the “Details Area”. Note: toDoo does not minimize to the “System Tray”. Once you have everything set all that you need to do is click on “add task”. Here was our first new task being viewed in the “toDoo Description Tab”. Time to add a second task…here you can see the drop-down calendar. You can scroll through and select a different month very easily…just click on the desired day and it will be automatically set. Adding our second task… If you need to edit any of the details for a particular task you can do so in the “Edit toDoo Tab”. This nice little app is convenient and easy to use. Conclusion ToDoo is a simple straightforward app that lets you keep track of your tasks list and relevant details without an online account (especially helpful if you are without a wireless connection at a given moment). If you are looking for more of a list approach that runs on your desktop, then check out our article on Doomi here. Links Download ToDoo at Softpedia Download ToDoo at Adobe Marketplace Download Adobe AIR Similar Articles Productive Geek Tips Turn Chrome’s New Tab Page into a Google Tasks PageMake To-Do Bar in Outlook 2007 Show Only Today’s TasksAdd a non-Google Tasks List to ChromeKeep Track of Homework Assignments with SoshikuTrack the Amount of Time You Spend Online in Firefox TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Download Videos from Hulu Pixels invade Manhattan Convert PDF files to ePub to read on your iPad Hide Your Confidential Files Inside Images Get Wildlife Photography Tips at BBC’s PhotoMasterClasses Mashpedia is a Real-time Encyclopedia

  Read the article

• Mono for Android Book has been Released!!!!!

  - by Wallym

  If I understand things correctly, and I make no guarantees that I do, our Mono for Android book has been RELEASED!  I'm not quite sure what this means, but my guess is that that it has been printed and is being shipped to various book sellers.So, if you have pre-ordered a copy, its now up to Amazon to send it to you.  Its fully out of my control, Wrox, Wiley, as well as everyone but Amazon.If you haven't bought a copy already, why?  Seriously, go order 8-10 copies for the ones you love.  They'll make great romantic gifts for the ones you love.  Just think at the look on the other person's face when you give them a copy of our book. Here's a little about the book:The wait is over! For the millions of .NET/C# developers who have been eagerly awaiting the book that will guide them through the white-hot field of Android application programming, this is the book. As the first guide to focus on Mono for Android, this must-have resource dives into writing applications against Mono with C# and compiling executables that run on the Android family of devices.Putting the proven Wrox Professional format into practice, the authors provide you with the knowledge you need to become a successful Android application developer without having to learn another programming language. You'll explore screen controls, UI development, tables and layouts, and MonoDevelop as you become adept at developing Android applications with Mono for Android.Develop Android apps using tools you already know—C# and .NETAimed at providing readers with a thorough, reliable resource that guides them through the field of Android application programming, this must-have book shows how to write applications using Mono with C# that run on the Android family of devices. A team of authors provides you with the knowledge you need to become a successful Android application developer without having to learn another programming language. You'll explore screen controls, UI development, tables and layouts, and MonoDevelop as you become adept at planning, building, and developing Android applications with Mono for Android.Professional Android Programming with Mono for Android and .NET/C#:Shows you how to use your existing C# and .NET skills to build Android appsDetails optimal ways to work with data and bind data to controlsExplains how to program with Android device hardwareDives into working with the file system and application preferencesDiscusses how to share code between Mono for Android, MonoTouch, and Windows® Phone 7Reveals tips for globalizing your apps with internationalization and localization supportCovers development of tablet apps with Android 4Wrox Professional guides are planned and written by working programmers to meet the real-world needs of programmers, developers, and IT professionals. Focused and relevant, they address the issues technology professionals face every day. They provide examples, practical solutions, and expert education in new technologies, all designed to help programmers do a better job.Now, go buy a bunch of copies!!!!!If you are interested in iPhone and Android and would like to get a little more knowledgeable in the area of development, you can purchase the 3 pack of books from Wrox on Mobile Development with Mono.  This will cover MonoTouch, Mono for Android, and cross platform methods for using both tools.  A great package in and of itself.  The name of that package is: Wrox Cross Platform Android and iOS Mobile Development Three-Pack 

  Read the article

• How to sort a ListView control by a column in Visual C#

  - by bconlon

  Microsoft provide an article of the same name (previously published as Q319401) and it shows a nice class 'ListViewColumnSorter ' for sorting a standard ListView when the user clicks the column header. This is very useful for String values, however for Numeric or DateTime data it gives odd results. E.g. 100 would come before 99 in an ascending sort as the string compare sees 1 < 9. So my challenge was to allow other types to be sorted. This turned out to be fairly simple as I just needed to create an inner class in ListViewColumnSorter which extends the .Net CaseInsensitiveComparer class, and then use this as the ObjectCompare member's type. Note: Ideally we would be able to use IComparer as the member's type, but the Compare method is not virtual in CaseInsensitiveComparer , so we have to create an exact type: public class ListViewColumnSorter : IComparer {     private CaseInsensitiveComparer ObjectCompare;     private MyComparer ObjectCompare;     ... rest of Microsofts class implementation... } Here is my private inner comparer class, note the 'new int Compare' as Compare is not virtual, and also note we pass the values to the base compare as the correct type (e.g. Decimal, DateTime) so they compare correctly: private class MyComparer : CaseInsensitiveComparer {     public new int Compare(object x, object y)     {         try         {             string s1 = x.ToString();             string s2 = y.ToString();               // check for a numeric column             decimal n1, n2 = 0;             if (Decimal.TryParse(s1, out n1) && Decimal.TryParse(s2, out n2))                 return base.Compare(n1, n2);             else             {                 // check for a date column                 DateTime d1, d2;                 if (DateTime.TryParse(s1, out d1) && DateTime.TryParse(s2, out d2))                     return base.Compare(d1, d2);             }         }         catch (ArgumentException) { }           // just use base string compare         return base.Compare(x, y);     } } You could extend this for other types, even custom classes as long as they support ICompare. Microsoft also have another article How to: Sort a GridView Column When a Header Is Clicked that shows this for WPF, which looks conceptually very similar. I need to test it out to see if it handles non-string types. #

  Read the article

• Why is my laptop so sluggish? Or Damn You Facebook and Twitter! Or All Hail Chrome!

  - by John Conwell

  In the past three weeks, I've noticed that my laptop (dual core 2.1GHz, 2Gb RAM) has become amazingly sluggish.  I only uses for communications and data lookup workflows, so the slowness was tolerable.  But today I finally got fed up with the suckyness and decided to get to the root of the problem (I do have strong performance roots after all). It actually didn't take all that long to figure it out.  About a year ago I converted to Google Chrome (away from FireFox).  One of the great tools Chrome has is a "Task Manager" tool, that gives you Windows Task Manager like details for all the tabs open in the browser (Shift + Esc).  Since every tab runs in its own process, its easy from Task Manager (both Windows or Chrome) to identify and kill a single performance offending tab.  This is unlike IE, where you only get aggregate data about all tabs open.  Anyway, I digress.  Today my laptop sucked.  Windows Task Manager told me that I had two memory hogging Chrome tabs, but couldn't tell me which web page those tabs are showing.  Enter Chrome Task Manager which tells you the page title, along with CPU, memory and network utilization of each tab.  Enter my amazement.  Turns out Facebook was using just shy of half a Gb of RAM.  Half a Gigabyte!  That's 512 Megabytes!524,288 Kilobytes! 536,870,912 Bytes!  Or 4,294,967,296 Bits!  In other words, that's a frackin boat load of memory.  Now consider that Facebook is running on pretty much 96.3% (statistics based on absolutely nothing) of every house hold desktop, laptop, netbook, and mobile device in America, that is pretty horrific! And I wasn't playing any Facebook games like FarmWars or MafiaVille.  I just had my normal, default home page up showing me who just had breakfast, or just got finished with their morning run. I'm sorry...let me say that again...HALF A GIG OF RAM!  That is just unforgivable. I can just see my mom calling me up:  Mom: "John...I think I need a new computer.  Mine is really slow these days" John: "What do you have running?" Mom: "Oh, just Facebook" John: "Ok, close Facebook and tell me how fast your computer feels" Mom: "Well...I don't know how fast it is.  All I do is use Facebook" John: "Ok Mom, I'll send you a new computer by Tuesday" Oh yea...and the other offending web page?  It was Twitter, using a quarter of a Gigabyte. God I love social networks!

  Read the article

• Interconnect nodes in a Java distributed infrastructure for tweet processing

  - by David Moreno García

  I'm working in a new version of an old project that I used to download and process user statuses from Twitter. The main problem of that project was its infrastructure. I used multiple instances of a java application (trackers) to download from Twitter given an specific task (basically terms to search for), connected with a central node (a web application) that had to process all tweets once per day and generate a new task for each trackers once each 15 minutes. The central node also had to monitor all trackers and enable/disable them under user petition. This, as I said, was too slow because I had multiple bottlenecks, so in this new version I want to improve the infrastructure and isolate all functionalities in specific nodes. I also need a good notification system to receive notifications for any node. So, in the next diagram I show the components that I'll need in this new version: As you can see, there are more nodes. Here are some notes about them: Dashboard: Controls trackers statuses and send a single task to each of them (under user request). The trackers will use this task until replaced with a new one (if done, not each 15 minutes like before). Search engine: I need to store all the tweets. They are firstly stored in a local database for each tracker but after that I'm thinking on using something like Elasticsearch to be able to do fast searches. Tweet processor: Just and isolated component with its own database (maybe something like the search engine to have fast access to info generated by the module). In the future more could be added. Application UI: A web application with a shared database with the Dashboard (mainly to store users information and preferences). Indeed, both could be merged into a single web. The main difference with the previous version of the project is that now they will be isolated and they will only show information and send requests. I will not do any heavy task in them (like process tweets as I did before). So, having this components, my main headache is how to structure all to not have to rewrite a lot of code every time I need to access any new data. Another headache is how can I interconnect nodes. I could use sockets but that is a pain in the ass. Maybe a REST layer? And finally, if all the nodes are isolated, how could I generate notifications for each user which info is only in the database used by the Application UI? I'm programming this using Java and Spring (at least I used them in the last version) but I have no problems with changing the language if I can take advantage of a tool/library/engine to make my life easier and have a better platform. Any comment will be appreciated.

  Read the article

• Interesting Topics in Comp. Sci. for New Students?

  - by SoulBeaver

  I hope this is the right forum to ask this question. Last friday I was in a discussion with my professors about the students' lack of motivation and interest in the field of Computer Science. All of the students are enrolled, but through questionnaires and other questions that my professor posed it was revealed that over 90% of all enrolled students are just in it for the reward of getting a job sometime in the future (since it's a growing field with high job potential) I asked my professor for the permission to take over the first couple of lectures and try and motivate, interest and inspire students for the field of Computer Science and programming in particular (this is the Intro to Programming course). This request was granted and I now have a week to come up with a lecture topic for my professor's five groups. My main goal isn't to teach, I just want to get students to be as interested in the field as I am. I want to show them what's possible, what awesome magical things have been done in the field, the future we are heading towards using programming and Comp. Sci. Therefore, I would like to pose this question: I have a few topics, materials and sample projects that I would like to talk about: -- Grace Hopper (It is my hope to interest the female programmers in the class. There are never more than two or three per group and they, more than males, are prone to jumping ship and abandoning Comp. Sci.) -- The Singularity Institute -- Alan Turing -- Robotics -- Programming not as a chore or a must, but the idea that we are, at our core, the nexus to which anything anybody does in the digital world is connected to. We are the problem solvers; we assemble all the parts together and we are the ones that, essentially, make the vision a reality. -- Give them an idea for a programming project which, through the help of the professor, could be significant to every student (I want students to not only feel interested in the topic, but they should feel important, that what they do here makes a difference) Do you have interesting topics worthy of discussion, something I can tell the students which they can get interested about? How would you approach the lecture? If you had 90 minutes worth of time to try and get students interested in the project, what would you do?

  Read the article

• How to interview a natural scientist for a dev position?

  - by Silas

  I already did some interviews for my company, mostly computer scientists for dev positions but also some testers and project managers. Now I have to fill a vacancy in our research group within the R&D department (side note: “research” means that we try to solve problems in our professional domain/market niche using software in research projects together with universities, other companies, research centres and end user organisations. It’s not computer science research; we’re not going to solve the P=NP problem). Now we invited a guy holding an MSc in chemistry (with a lot of physics in his CV, too), who never had any computer science lesson. I already talked with him about half an hour at a local university’s career days and there’s no doubt the guy is smart. Also his marks are excellent and he graduated with distinction. For his BSc he needed to teach himself programming in Mathematica and told me believably that he liked programming a lot. Also he solved some physical chemistry problem that I probably don’t understand using his own software, implemented in Mathematica, for his MSc thesis. It includes a GUI and a notable size of 8,000 LoC. He seems to be very attracted by what we’re doing in our research group and to be honest it’s quite difficult for an SME like us to get good people. I also am very interested in hiring him since he could assist me in writing project proposals, reports, doing presentations and so on. He would probably fit to our team, too. The only question left is: How can I check if he will get the programming skills he needs to do software implementation in our projects since this will be a significant part of the job? Of course I will ask him what it is, that is fascinating him about programming. I’ll also ask how he proceeded to write his natural science software and how he structured it. I’ll ask about how he managed to obtain the skills and information about software development he needed. But is there something more I could ask? Something more concrete perhaps? Should I ask him to explain his Mathematica solution? To be clear: I’m not looking for knowledge in a particular language or technology stack. We’re a .NET shop in product development but I want to have a free choice for our research projects. So I’m interested in the meta-competence being able to learn whatever is actually needed. I hope this question is answerable and not open-ended since I really like to know if there is a default way to check for the ability to get further programming skills on the job. If something is not clear to you please give me some comments and let me improve my question.

  Read the article

• Alternatives to multiple inheritance for my architecture (NPCs in a Realtime Strategy game)?

  - by Brettetete

  Coding isn't that hard actually. The hard part is to write code that makes sense, is readable and understandable. So I want to get a better developer and create some solid architecture. So I want to do create an architecture for NPCs in a video-game. It is a Realtime Strategy game like Starcraft, Age of Empires, Command & Conquers, etc etc.. So I'll have different kinds of NPCs. A NPC can have one to many abilities (methods) of these: Build(), Farm() and Attack(). Examples: Worker can Build() and Farm() Warrior can Attack() Citizen can Build(), Farm() and Attack() Fisherman can Farm() and Attack() I hope everything is clear so far. So now I do have my NPC Types and their abilities. But lets come to the technical / programmatical aspect. What would be a good programmatic architecture for my different kinds of NPCs? Okay I could have a base class. Actually I think this is a good way to stick with the DRY principle. So I can have methods like WalkTo(x,y) in my base class since every NPC will be able to move. But now lets come to the real problem. Where do I implement my abilities? (remember: Build(), Farm() and Attack()) Since the abilities will consists of the same logic it would be annoying / break DRY principle to implement them for each NPC (Worker,Warrior, ..). Okay I could implement the abilities within the base class. This would require some kind of logic that verifies if a NPC can use ability X. IsBuilder, CanBuild, .. I think it is clear what I want to express. But I don't feel very well with this idea. This sounds like a bloated base class with too much functionality. I do use C# as programming language. So multiple inheritance isn't an opinion here. Means: Having extra base classes like Fisherman : Farmer, Attacker won't work.

  Read the article

• Attaching new animations onto skeleton via props, a good idea?

  - by Cardin

  I'm thinking of coding a game with an idea of mine. I've coded 2D games before, but I'm new to 3D programming, so I'd like to ask if this idea of mine is feasible or out of my depth. I'm making a game where there are many different characters for the player to choose from (JRPG style). So to save time, I have an idea of creating many different varied characters using a completely naked body mesh and animation skeleton, standardised across all characters. For example, by placing different hair, boots, armor props on the character mesh, new characters can be formed. Kinda like playing dress-up with a barbie doll. I'm thinking this can be done by having a bone on the prop that I can programmically attach to the main mesh. Also, I plan to have some props add new animations to the base skeleton, so equipping some particular props would give it new attack, damage, idle animations. This is because I can't expect the character to have the same swinging animation if he had a big sword or an axe. I think this might be possible if the prop has its own instance of the animation skeleton with just only the new animations, and parenting the base body mesh to this new skeleton. So all the base body mesh has are just the basic animations, other animations come from the props. My concerns are, 1) the props might not attach to the mesh properly and jitter a lot, 2) since prop and body are animated differently, the props and base mesh will cause visual artefacts, like the naked thighs showing through the pants when the character walks, 3) a custom pipeline have to be developed to export skeletons without mesh, and also to attach the base body mesh to a new skeleton during runtime in the game. So my question: are these features considered 'easy' to code? Or am I trying to do something few have ever succeeded with on their own? It feels like all these can be done given enough time and I know I definitely have to do a bit of bone matrix calculations, but I really don't want to drag out the development timeline unnecessarily from coding mathematically intense things or analyzing how to parse 3D export formats. I'm currently only at the Game Design stage, so if these features aren't a good idea, I can simply change the design of the game. (Unrelated to question) I could always, as last resort, have the characters have predetermined outfit and weapon selections so as to animate everything manually.

  Read the article

• Multi-step Workflows: make Workflow A depend on results of Workflow B and/or Workflow C

  - by Joey

  I have been tasked with creating a Software Installation Approval section for our Intranet. When a person requests that a particular piece of software be installed on their workstation, we need to get IT approval and then business approval. Once those are obtained, it is to be installed. I am using Sharepoint Designer to do this. I have List A, where the user enters the information on the requested software. Workflow A then creates a Task in List B, which is then assigned to the IT approver. Workflow B works on List B on item creation, setting the due dates, titles, and other fields, and then pauses until the due date. The IT approver works with the business side and completes the task. Once List B task is complete, the item in List A should be marked as complete -- I have everything up to this point working fine. I want to make this more robust in 2 ways. As the only real option is to mark List B task as "completed", which essentially means "Approved", we have no way of really denying a request. What I want to add is the option to approve or deny a request through the task on List B -- if it is approved, I want the item in List A to continue to show "In Progress" with a custom status of "Approved", and I want to create a new task for software installation; once the installation task is marked as completed, then I want List A to show "Completed" with a status of "Installed". If it is denied, I want the item in List A to show as "Completed", with a status of "Denied". The problem is, I'm not even sure where to start making these modifications. Creating and modifying the custom status fields isn't that big of an issue -- I have messed around with this and I'm fairly confident I can do this easily. My main concern is that I know I will need a Workflow C, but I don't know where or how to trigger this to get the results I need. I've managed to get Workflows A and B working fine, but anything beyond this is really pushing the limit of my knowledge. It's probably obvious that I am rather new to Sharepoint workflows. I was very much thrust into this position and I am still feeling my way around. Thanks in advance for any help!

  Read the article

• fresh_when in ruby not working with xml rendering

  - by Guilherme Silveira

  While trying to implement support for conditional GETting in a rest system, we have come across the fresh_when and stale? methods. The following code works fine with 304 and not further rendering: if stale?(:etag = resource, :last_modified = resource.updated_at.utc) respond_to do |format| format.html # show.html.erb } end end But accessing 1.xml will try to render the resource twice: if stale?(:etag => resource, :last_modified => resource.updated_at.utc) respond_to do |format| format.html # show.html.erb format.xml { render :xml => @order.to_xml(:controller => self, :except => [:paid_at]) } end end The error message: ActionController::DoubleRenderError in OrdersController#show Can only render or redirect once per action RAILS_ROOT: /Users/guilherme/Documents/ruby/restfulie-test Application Trace | Framework Trace | Full Trace /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/base.rb:900:in render_without_benchmark' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/benchmarking.rb:51:in render' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/core_ext/benchmark.rb:17:in ms' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/core_ext/benchmark.rb:10:in realtime' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/core_ext/benchmark.rb:17:in ms' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/benchmarking.rb:51:in render' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/base.rb:1331:in send' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/base.rb:1331:in perform_action_without_filters' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/filters.rb:617:in call_filters' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/filters.rb:610:in perform_action_without_benchmark' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/core_ext/benchmark.rb:17:in ms' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/core_ext/benchmark.rb:10:in realtime' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/core_ext/benchmark.rb:17:in ms' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/rescue.rb:160:in perform_action_without_flash' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/flash.rb:146:in perform_action' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/base.rb:532:in send' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/base.rb:532:in process_without_filters' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/filters.rb:606:in process' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/base.rb:391:in process' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/base.rb:386:in call' /Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:437:in `call' Any suggestions? Regards

  Read the article

• User Mailer Failing

  - by Trevor Nederlof

  I have setup a process in my User model to send a bunch of @users to a mailing script, user_mailer.rb I am using the http://postageapp.com app to send out emails. The users are getting to the User_mailer but I am getting an error from there. Can anyone please point me in the right direction. User Model: class User < ActiveRecord::Base acts_as_authentic def self.mail_out weekday = Date.today.strftime('%A').downcase @users = find(:all, :conditions => {"#{weekday}sub".to_sym => 't'}) UserMailer.deliver_mail_out(@users) end end User_mailer.rb class UserMailer < ActionMailer::Base def mail_out(users) @recipients = { } users.each do |user| @recipients[user.email] = { :zipcode => user.zipcode } end from "[email protected]" subject "Check out the trailer of the day!" body :user => user end end mail_out.html.erb {{zipcode}}, Please check out the trailer of the day at http://www.dailytrailer.net Thank you! -- The DailyTrailer.net Team User db schema create_table "users", :force => true do |t| t.string "email" t.date "birthday" t.string "gender" t.string "zipcode" t.datetime "created_at" t.datetime "updated_at" t.string "crypted_password" t.string "password_salt" t.string "persistence_token" t.string "mondaysub", :default => "f", :null => false t.string "tuesdaysub", :default => "f", :null => false t.string "wednesdaysub", :default => "f", :null => false t.string "thursdaysub", :default => "f", :null => false t.string "fridaysub", :default => "f", :null => false t.string "saturdaysub", :default => "f", :null => false t.string "sundaysub", :default => "f", :null => false end Error: /var/lib/gems/1.8/gems/rails-2.3.5/lib/commands/runner.rb:48: undefined method `name' for #<User:0xb6e8ae48> (NoMethodError) from /home/tnederlof/Dropbox/Ruby/daily_trailer/app/models/user_mailer.rb:5:in `mail_out' from /home/tnederlof/Dropbox/Ruby/daily_trailer/app/models/user_mailer.rb:4:in `each' from /home/tnederlof/Dropbox/Ruby/daily_trailer/app/models/user_mailer.rb:4:in `mail_out' from /home/tnederlof/.gem/ruby/1.8/gems/actionmailer-2.3.5/lib/action_mailer/base.rb:459:in `__send__' from /home/tnederlof/.gem/ruby/1.8/gems/actionmailer-2.3.5/lib/action_mailer/base.rb:459:in `create!' from /home/tnederlof/.gem/ruby/1.8/gems/actionmailer-2.3.5/lib/action_mailer/base.rb:452:in `initialize' from /home/tnederlof/.gem/ruby/1.8/gems/actionmailer-2.3.5/lib/action_mailer/base.rb:395:in `new' from /home/tnederlof/.gem/ruby/1.8/gems/actionmailer-2.3.5/lib/action_mailer/base.rb:395:in `method_missing' from /home/tnederlof/Dropbox/Ruby/daily_trailer/app/models/user.rb:13:in `mail_out' from (eval):1 from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `eval' from /var/lib/gems/1.8/gems/rails-2.3.5/lib/commands/runner.rb:48 from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require' from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require' from script/runner:3

  Read the article

• help me "dry" out this .net XML serialization code

  - by Sarah Vessels

  I have a base collection class and a child collection class, each of which are serializable. In a test, I discovered that simply having the child class's ReadXml method call base.ReadXml resulted in an InvalidCastException later on. First, here's the class structure: Base Class // Collection of Row objects [Serializable] [XmlRoot("Rows")] public class Rows : IList<Row>, ICollection<Row>, IEnumerable<Row>, IEquatable<Rows>, IXmlSerializable { public Collection<Row> Collection { get; protected set; } public void ReadXml(XmlReader reader) { reader.ReadToFollowing(XmlNodeName); do { using (XmlReader rowReader = reader.ReadSubtree()) { var row = new Row(); row.ReadXml(rowReader); Collection.Add(row); } } while (reader.ReadToNextSibling(XmlNodeName)); } } Derived Class // Acts as a collection of SpecificRow objects, which inherit from Row. Uses the same // Collection<Row> that Rows defines which is fine since SpecificRow : Row. [Serializable] [XmlRoot("MySpecificRowList")] public class SpecificRows : Rows, IXmlSerializable { public new void ReadXml(XmlReader reader) { // Trying to just do base.ReadXml(reader) causes a cast exception later reader.ReadToFollowing(XmlNodeName); do { using (XmlReader rowReader = reader.ReadSubtree()) { var row = new SpecificRow(); row.ReadXml(rowReader); Collection.Add(row); } } while (reader.ReadToNextSibling(XmlNodeName)); } public new Row this[int index] { // The cast in this getter is what causes InvalidCastException if I try // to call base.ReadXml from this class's ReadXml get { return (Row)Collection[index]; } set { Collection[index] = value; } } } And here's the code that causes a runtime InvalidCastException if I do not use the version of ReadXml shown in SpecificRows above (i.e., I get the exception if I just call base.ReadXml from within SpecificRows.ReadXml): TextReader reader = new StringReader(serializedResultStr); SpecificRows deserializedResults = (SpecificRows)xs.Deserialize(reader); SpecificRow = deserializedResults[0]; // this throws InvalidCastException So, the code above all compiles and runs exception-free, but it bugs me that Rows.ReadXml and SpecificRows.ReadXml are essentially the same code. The value of XmlNodeName and the new Row()/new SpecificRow() are the differences. How would you suggest I extract out all the common functionality of both versions of ReadXml? Would it be silly to create some generic class just for one method? Sorry for the lengthy code samples, I just wanted to provide the reason I can't simply call base.ReadXml from within SpecificRows.

  Read the article

• Polymorphic :has_many, :through as module in Rails 3.1 plugin

  - by JohnMetta

  I've search everywhere for a pointer to this, but can't find one. Basically, I want to do what everyone else wants to do when they create a polymorphic relationship in a :has_many, :through way… but I want to do it in a module. I keep getting stuck and think I must be overlooking something simple. To wit: module ActsPermissive module PermissiveUser def self.included(base) base.extend ClassMethods end module ClassMethods def acts_permissive has_many :ownables has_many :owned_circles, :through => :ownables end end end class PermissiveCircle < ActiveRecord::Base belongs_to :ownable, :polymorphic => true end end With a migration that looks like this: create_table :permissive_circles do |t| t.string :ownable_type t.integer :ownable_id t.timestamps end The idea, of course, is that whatever loads acts_permissive will be able to have a list of circles that it owns. For simple tests, I have it "should have a list of circles" do user = Factory :user user.owned_circles.should be_an_instance_of Array end which fails with: Failure/Error: @user.circles.should be_an_instance_of Array NameError: uninitialized constant User::Ownable I've tried: using :class_name => 'ActsPermissive::PermissiveCircle' on the has_many :ownables line, which fails with: Failure/Error: @user.circles.should be_an_instance_of Array ActiveRecord::HasManyThroughSourceAssociationNotFoundError: Could not find the source association(s) :owned_circle or :owned_circles in model ActsPermissive::PermissiveCircle. Try 'has_many :owned_circles, :through => :ownables, :source => <name>'. Is it one of :ownable? while following the suggestion and setting :source => :ownable fails with Failure/Error: @user.circles.should be_an_instance_of Array ActiveRecord::HasManyThroughAssociationPolymorphicSourceError: Cannot have a has_many :through association 'User#owned_circles' on the polymorphic object 'Ownable#ownable' Which seems to suggest that doing things with a non-polymorphic-through is necessary. So I added a circle_owner class similar to the setup here: module ActsPermissive class CircleOwner < ActiveRecord::Base belongs_to :permissive_circle belongs_to :ownable, :polymorphic => true end module PermissiveUser def self.included(base) base.extend ClassMethods end module ClassMethods def acts_permissive has_many :circle_owners, :as => :ownable has_many :circles, :through => :circle_owners, :source => :ownable, :class_name => 'ActsPermissive::PermissiveCircle' end end class PermissiveCircle < ActiveRecord::Base has_many :circle_owners end end With a migration: create_table :permissive_circles do |t| t.string :name t.string :guid t.timestamps end create_table :circle_owner do |t| t.string :ownable_type t.string :ownable_id t.integer :permissive_circle_id end which still fails with: Failure/Error: @user.circles.should be_an_instance_of Array NameError: uninitialized constant User::CircleOwner Which brings us back to the beginning. How can I do what seems to be a rather common polymorphic :has_many, :through on a module? Alternatively, is there a good way to allow an object to be collected by arbitrary objects in a similar way that will work with a module?

  Read the article

• using dictionaries with WebServices

  - by umit-alba

  Hi! I tried to pass a dictionary via WebServices. However it is not serializeable. So i wrote an Own Class that makes it serializeable: using System; using System.Net; using System.Windows; using System.Collections.Generic; using System.Xml.Serialization; using System.Xml; using System.Xml.Schema; namespace Platform { public class SaDictionary<TKey, TValue> : Dictionary<TKey, TValue>, IXmlSerializable { #region Constructors public SaDictionary() : base() { } public SaDictionary(IDictionary<TKey, TValue> dictionary) : base(dictionary) { } public SaDictionary(IEqualityComparer<TKey> comparer) : base(comparer) { } public SaDictionary(int capacity) : base(capacity) { } public SaDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer) : base(dictionary, comparer) { } public SaDictionary(int capacity, IEqualityComparer<TKey> comparer) : base(capacity, comparer) { } //protected SaDictionary(SerializationInfo info, StreamingContext context) // : base(info, context) //{ //} #endregion public XmlSchema GetSchema() { return null; } public void ReadXml(XmlReader reader) { XmlSerializer keySerializer = new XmlSerializer(typeof(TKey)); XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue)); bool wasEmpty = reader.IsEmptyElement; reader.Read(); if (wasEmpty) return; while (reader.NodeType != XmlNodeType.EndElement) { reader.ReadStartElement("item"); reader.ReadStartElement("key"); TKey key = (TKey)keySerializer.Deserialize(reader); reader.ReadEndElement(); //key reader.ReadStartElement("value"); TValue value = (TValue)valueSerializer.Deserialize(reader); reader.ReadEndElement(); //value this.Add(key, value); reader.ReadEndElement(); //item // reader.MoveToContent(); } reader.ReadEndElement(); } public void WriteXml(XmlWriter writer) { XmlSerializer keySerializer = new XmlSerializer(typeof(TKey)); XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue)); foreach (TKey key in this.Keys) { writer.WriteStartElement("item"); writer.WriteStartElement("key"); keySerializer.Serialize(writer, key); writer.WriteEndElement(); //key writer.WriteStartElement("value"); TValue value = this[key]; valueSerializer.Serialize(writer, value); writer.WriteEndElement(); //value writer.WriteEndElement(); //item } } } } However i get an ArrayOfXElement back. Is there a way to cast it back to a Dictionary? greets

  Read the article

• How to use method hiding (new) with generic constrained class

  - by ongle

  I have a container class that has a generic parameter which is constrained to some base class. The type supplied to the generic is a sub of the base class constraint. The sub class uses method hiding (new) to change the behavior of a method from the base class (no, I can't make it virtual as it is not my code). My problem is that the 'new' methods do not get called, the compiler seems to consider the supplied type to be the base class, not the sub, as if I had upcast it to the base. Clearly I am misunderstanding something fundamental here. I thought that the generic where T: xxx was a constraint, not an upcast type. This sample code basically demonstrates what I'm talking about. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace GenericPartialTest { class ContextBase { public string GetValue() { return "I am Context Base: " + this.GetType().Name; } public string GetOtherValue() { return "I am Context Base: " + this.GetType().Name; } } partial class ContextSub : ContextBase { public new string GetValue() { return "I am Context Sub: " + this.GetType().Name; } } partial class ContextSub { public new string GetOtherValue() { return "I am Context Sub: " + this.GetType().Name; } } class Container<T> where T: ContextBase, new() { private T _context = new T(); public string GetValue() { return this._context.GetValue(); } public string GetOtherValue() { return this._context.GetOtherValue(); } } class Program { static void Main(string[] args) { Console.WriteLine("Simple"); ContextBase myBase = new ContextBase(); ContextSub mySub = new ContextSub(); Console.WriteLine(myBase.GetValue()); Console.WriteLine(myBase.GetOtherValue()); Console.WriteLine(mySub.GetValue()); Console.WriteLine(mySub.GetOtherValue()); Console.WriteLine("Generic Container"); Container<ContextBase> myContainerBase = new Container<ContextBase>(); Container<ContextSub> myContainerSub = new Container<ContextSub>(); Console.WriteLine(myContainerBase.GetValue()); Console.WriteLine(myContainerBase.GetOtherValue()); Console.WriteLine(myContainerSub.GetValue()); Console.WriteLine(myContainerSub.GetOtherValue()); Console.ReadKey(); } } }

  Read the article

• Log message Request and Response in ASP.NET WebAPI

  - by Fredrik N

  By logging both incoming and outgoing messages for services can be useful in many scenarios, such as debugging, tracing, inspection and helping customers with request problems etc.  I have a customer that need to have both incoming and outgoing messages to be logged. They use the information to see strange behaviors and also to help customers when they call in  for help (They can by looking in the log see if the customers sends in data in a wrong or strange way).   Concerns Most loggings in applications are cross-cutting concerns and should not be  a core concern for developers. Logging messages like this:   // GET api/values/5 public string Get(int id) { //Cross-cutting concerns Log(string.Format("Request: GET api/values/{0}", id)); //Core-concern var response = DoSomething(); //Cross-cutting concerns Log(string.Format("Reponse: GET api/values/{0}\r\n{1}", id, response)); return response; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } will only result in duplication of code, and unnecessarily concerns for the developers to be aware of, if they miss adding the logging code, no logging will take place. Developers should focus on the core-concern, not the cross-cutting concerns. By just focus on the core-concern the above code will look like this: // GET api/values/5 public string Get(int id) { return DoSomething(); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The logging should then be placed somewhere else so the developers doesn’t need to focus care about the cross-concern. Using Message Handler for logging There are different ways we could place the cross-cutting concern of logging message when using WebAPI. We can for example create a custom ApiController and override the ApiController’s ExecutingAsync method, or add a ActionFilter, or use a Message Handler. The disadvantage with custom ApiController is that we need to make sure we inherit from it, the disadvantage of ActionFilter, is that we need to add the filter to the controllers, both will modify our ApiControllers. By using a Message Handler we don’t need to do any changes to our ApiControllers. So the best suitable place to add our logging would be in a custom Message Handler. A Message Handler will be used before the HttpControllerDispatcher (The part in the WepAPI pipe-line that make sure the right controller is used and called etc). Note: You can read more about message handlers here, it will give you a good understanding of the WebApi pipe-line. To create a Message Handle we can inherit from the DelegatingHandler class and override the SendAsync method: public class MessageHandler : DelegatingHandler { protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) { return base.SendAsync(request, cancellationToken); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   If we skip the call to the base.SendAsync our ApiController’s methods will never be invoked, nor other Message Handlers. Everything placed before base.SendAsync will be called before the HttpControllerDispatcher (before WebAPI will take a look at the request which controller and method it should be invoke), everything after the base.SendAsync, will be executed after our ApiController method has returned a response. So a message handle will be a perfect place to add cross-cutting concerns such as logging. To get the content of our response within a Message Handler we can use the request argument of the SendAsync method. The request argument is of type HttpRequestMessage and has a Content property (Content is of type HttpContent. The HttpContent has several method that can be used to read the incoming message, such as ReadAsStreamAsync, ReadAsByteArrayAsync and ReadAsStringAsync etc. Something to be aware of is what will happen when we read from the HttpContent. When we read from the HttpContent, we read from a stream, once we read from it, we can’t be read from it again. So if we read from the Stream before the base.SendAsync, the next coming Message Handlers and the HttpControllerDispatcher can’t read from the Stream because it’s already read, so our ApiControllers methods will never be invoked etc. The only way to make sure we can do repeatable reads from the HttpContent is to copy the content into a buffer, and then read from that buffer. This can be done by using the HttpContent’s LoadIntoBufferAsync method. If we make a call to the LoadIntoBufferAsync method before the base.SendAsync, the incoming stream will be read in to a byte array, and then other HttpContent read operations will read from that buffer if it’s exists instead directly form the stream. There is one method on the HttpContent that will internally make a call to the  LoadIntoBufferAsync for us, and that is the ReadAsByteArrayAsync. This is the method we will use to read from the incoming and outgoing message. public abstract class MessageHandler : DelegatingHandler { protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) { var requestMessage = await request.Content.ReadAsByteArrayAsync(); var response = await base.SendAsync(request, cancellationToken); var responseMessage = await response.Content.ReadAsByteArrayAsync(); return response; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The above code will read the content of the incoming message and then call the SendAsync and after that read from the content of the response message. The following code will add more logic such as creating a correlation id to combine the request with the response, and create a log entry etc: public abstract class MessageHandler : DelegatingHandler { protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) { var corrId = string.Format("{0}{1}", DateTime.Now.Ticks, Thread.CurrentThread.ManagedThreadId); var requestInfo = string.Format("{0} {1}", request.Method, request.RequestUri); var requestMessage = await request.Content.ReadAsByteArrayAsync(); await IncommingMessageAsync(corrId, requestInfo, requestMessage); var response = await base.SendAsync(request, cancellationToken); var responseMessage = await response.Content.ReadAsByteArrayAsync(); await OutgoingMessageAsync(corrId, requestInfo, responseMessage); return response; } protected abstract Task IncommingMessageAsync(string correlationId, string requestInfo, byte[] message); protected abstract Task OutgoingMessageAsync(string correlationId, string requestInfo, byte[] message); } public class MessageLoggingHandler : MessageHandler { protected override async Task IncommingMessageAsync(string correlationId, string requestInfo, byte[] message) { await Task.Run(() => Debug.WriteLine(string.Format("{0} - Request: {1}\r\n{2}", correlationId, requestInfo, Encoding.UTF8.GetString(message)))); } protected override async Task OutgoingMessageAsync(string correlationId, string requestInfo, byte[] message) { await Task.Run(() => Debug.WriteLine(string.Format("{0} - Response: {1}\r\n{2}", correlationId, requestInfo, Encoding.UTF8.GetString(message)))); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The code above will show the following in the Visual Studio output window when the “api/values” service (One standard controller added by the default WepAPI template) is requested with a Get http method : 6347483479959544375 - Request: GET http://localhost:3208/api/values 6347483479959544375 - Response: GET http://localhost:3208/api/values ["value1","value2"] .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Register a Message Handler To register a Message handler we can use the Add method of the GlobalConfiguration.Configration.MessageHandlers in for example Global.asax: public class WebApiApplication : System.Web.HttpApplication { protected void Application_Start() { GlobalConfiguration.Configuration.MessageHandlers.Add(new MessageLoggingHandler()); ... } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Summary By using a Message Handler we can easily remove cross-cutting concerns like logging from our controllers. You can also find the source code used in this blog post on ForkCan.com, feel free to make a fork or add comments, such as making the code better etc. Feel free to follow me on twitter @fredrikn if you want to know when I will write other blog posts etc.

  Read the article

• R Package Installation with Oracle R Enterprise

  - by Sherry LaMonica-Oracle

  Normal 0 false false false EN-US X-NONE X-NONE Programming languages give developers the opportunity to write reusable functions and to bundle those functions into logical deployable entities. In R, these are called packages. R has thousands of such packages provided by an almost equally large group of third-party contributors. To allow others to benefit from these packages, users can share packages on the CRAN system for use by the vast R development community worldwide. R's package system along with the CRAN framework provides a process for authoring, documenting and distributing packages to millions of users. In this post, we'll illustrate the various ways in which such R packages can be installed for use with R and together with Oracle R Enterprise. In the following, the same instructions apply when using either open source R or Oracle R Distribution. In this post, we cover the following package installation scenarios for: R command line Linux shell command line Use with Oracle R Enterprise Installation on Exadata or RAC Installing all packages in a CRAN Task View Troubleshooting common errors 1. R Package Installation BasicsR package installation basics are outlined in Chapter 6 of the R Installation and Administration Guide. There are two ways to install packages from the command line: from the R command line and from the shell command line. For this first example on Oracle Linux using Oracle R Distribution, we’ll install the arules package as root so that packages will be installed in the default R system-wide location where all users can access it, /usr/lib64/R/library.Within R, using the install.packages function always attempts to install the latest version of the requested package available on CRAN:R> install.packages("arules")If the arules package depends upon other packages that are not already installed locally, the R installer automatically downloads and installs those required packages. This is a huge benefit that frees users from the task of identifying and resolving those dependencies.You can also install R from the shell command line. This is useful for some packages when an internet connection is not available or for installing packages not uploaded to CRAN. To install packages this way, first locate the package on CRAN and then download the package source to your local machine. For example:$ wget http://cran.r-project.org/src/contrib/arules_1.1-2.tar.gz Then, install the package using the command R CMD INSTALL:$ R CMD INSTALL arules_1.1-2.tar.gzA major difference between installing R packages using the R package installer at the R command line and shell command line is that package dependencies must be resolved manually at the shell command line. Package dependencies are listed in the Depends section of the package’s CRAN site. If dependencies are not identified and installed prior to the package’s installation, you will see an error similar to:ERROR: dependency ‘xxx’ is not available for package ‘yyy’As a best practice and to save time, always refer to the package’s CRAN site to understand the package dependencies prior to attempting an installation. If you don’t run R as root, you won’t have permission to write packages into the default system-wide location and you will be prompted to create a personal library accessible by your userid. You can accept the personal library path chosen by R, or specify the library location by passing parameters to the install.packages function. For example, to create an R package repository in your home directory: R> install.packages("arules", lib="/home/username/Rpackages")or$ R CMD INSTALL arules_1.1-2.tar.gz --library=/home/username/RpackagesRefer to the install.packages help file in R or execute R CMD INSTALL --help at the shell command line for a full list of command line options.To set the library location and avoid having to specify this at every package install, simply create the R startup environment file .Renviron in your home area if it does not already exist, and add the following piece of code to it:R_LIBS_USER = "/home/username/Rpackages" 2. Setting the RepositoryEach time you install an R package from the R command line, you are asked which CRAN mirror, or server, R should use. To set the repository and avoid having to specify this during every package installation, create the R startup command file .Rprofile in your home directory and add the following R code to it:cat("Setting Seattle repository")r = getOption("repos") r["CRAN"] = "http://cran.fhcrc.org/"options(repos = r)rm(r) This code snippet sets the R package repository to the Seattle CRAN mirror at the start of each R session. 3. Installing R Packages for use with Oracle R EnterpriseEmbedded R execution with Oracle R Enterprise allows the use of CRAN or other third-party R packages in user-defined R functions executed on the Oracle Database server. The steps for installing and configuring packages for use with Oracle R Enterprise are the same as for open source R. The database-side R engine just needs to know where to find the R packages.The Oracle R Enterprise installation is performed by user oracle, which typically does not have write permission to the default site-wide library, /usr/lib64/R/library. On Linux and UNIX platforms, the Oracle R Enterprise Server installation provides the ORE script, which is executed from the operating system shell to install R packages and to start R. The ORE script is a wrapper for the default R script, a shell wrapper for the R executable. It can be used to start R, run batch scripts, and build or install R packages. Unlike the default R script, the ORE script installs packages to a location writable by user oracle and accessible by all ORE users - $ORACLE_HOME/R/library.To install a package on the database server so that it can be used by any R user and for use in embedded R execution, an Oracle DBA would typically download the package source from CRAN using wget. If the package depends on any packages that are not in the R distribution in use, download the sources for those packages, also.  For a single Oracle Database instance, replace the R script with ORE to install the packages in the same location as the Oracle R Enterprise packages. $ wget http://cran.r-project.org/src/contrib/arules_1.1-2.tar.gz$ ORE CMD INSTALL arules_1.1-2.tar.gzBehind the scenes, the ORE script performs the equivalent of setting R_LIBS_USER to the value of $ORACLE_HOME/R/library, and all R packages installed with the ORE script are installed to this location. For installing a package on multiple database servers, such as those in an Oracle Real Application Clusters (Oracle RAC) or a multinode Oracle Exadata Database Machine environment, use the ORE script in conjunction with the Exadata Distributed Command Line Interface (DCLI) utility.$ dcli -g nodes -l oracle ORE CMD INSTALL arules_1.1-1.tar.gz The DCLI -g flag designates a file containing a list of nodes to install on, and the -l flag specifies the user id to use when executing the commands. For more information on using DCLI with Oracle R Enterprise, see Chapter 5 in the Oracle R Enterprise Installation Guide.If you are using an Oracle R Enterprise client, install the package the same as any R package, bearing in mind that you must install the same version of the package on both the client and server machines to avoid incompatibilities. 4. CRAN Task ViewsCRAN also maintains a set of Task Views that identify packages associated with a particular task or methodology. Task Views are helpful in guiding users through the huge set of available R packages. They are actively maintained by volunteers who include detailed annotations for routines and packages. If you find one of the task views is a perfect match, you can install every package in that view using the ctv package - an R package for automating package installation. To use the ctv package to install a task view, first, install and load the ctv package.R> install.packages("ctv")R> library(ctv)Then query the names of the available task views and install the view you choose.R> available.views() R> install.views("TimeSeries") 5. Using and Managing R packages To use a package, start up R and load packages one at a time with the library command.Load the arules package in your R session. R> library(arules)Verify the version of arules installed.R> packageVersion("arules")[1] '1.1.2'Verify the version of arules installed on the database server using embedded R execution.R> ore.doEval(function() packageVersion("arules"))View the help file for the apropos function in the arules packageR> ?aproposOver time, your package repository will contain more and more packages, especially if you are using the system-wide repository where others are adding additional packages. It’s good to know the entire set of R packages accessible in your environment. To list all available packages in your local R session, use the installed.packages command:R> myLocalPackages <- row.names(installed.packages())R> myLocalPackagesTo access the list of available packages on the ORE database server from the ORE client, use the following embedded R syntax: R> myServerPackages <- ore.doEval(function() row.names(installed.packages()) R> myServerPackages 6. Troubleshooting Common ProblemsInstalling Older Versions of R packagesIf you immediately upgrade to the latest version of R, you will have no problem installing the most recent versions of R packages. However, if your version of R is older, some of the more recent package releases will not work and install.packages will generate a message such as: Warning message: In install.packages("arules") : package ‘arules’ is not availableThis is when you have to go to the Old sources link on the CRAN page for the arules package and determine which version is compatible with your version of R.Begin by determining what version of R you are using:$ R --versionOracle Distribution of R version 3.0.1 (--) -- "Good Sport" Copyright (C) The R Foundation for Statistical Computing Platform: x86_64-unknown-linux-gnu (64-bit)Given that R-3.0.1 was released May 16, 2013, any version of the arules package released after this date may work. Scanning the arules archive, we might try installing version 0.1.1-1, released in January of 2014:$ wget http://cran.r-project.org/src/contrib/Archive/arules/arules_1.1-1.tar.gz$ R CMD INSTALL arules_1.1-1.tar.gzFor use with ORE:$ ORE CMD INSTALL arules_1.1-1.tar.gzThe "package not available" error can also be thrown if the package you’re trying to install lives elsewhere, either another R package site, or it’s been removed from CRAN. A quick Google search usually leads to more information on the package’s location and status.Oracle R Enterprise is not in the R library pathOn Linux hosts, after installing the ORE server components, starting R, and attempting to load the ORE packages, you may receive the error:R> library(ORE)Error in library(ORE) : there is no package called ‘ORE’If you know the ORE packages have been installed and you receive this error, this is the result of not starting R with the ORE script. To resolve this problem, exit R and restart using the ORE script. After restarting R and ">running the command to load the ORE packages, you should not receive any errors.$ ORER> library(ORE)On Windows servers, the solution is to make the location of the ORE packages visible to R by adding them to the R library paths. To accomplish this, exit R, then add the following lines to the .Rprofile file. On Windows, the .Rprofile file is located in R\etc directory C:\Program Files\R\R-<version>\etc. Add the following lines:.libPaths("<path to $ORACLE_HOME>/R/library")The above line will tell R to include the R directory in the Oracle home as part of its search path. When you start R, the path above will be included, and future R package installations will also be saved to $ORACLE_HOME/R/library. This path should be writable by the user oracle, or the userid for the DBA tasked with installing R packages.Binary package compiled with different version of RBy default, R will install pre-compiled versions of packages if they are found. If the version of R under which the package was compiled does not match your installed version of R you will get an error message:Warning message: package ‘xxx’ was built under R version 3.0.0The solution is to download the package source and build it for your version of R.$ wget http://cran.r-project.org/src/contrib/Archive/arules/arules_1.1-1.tar.gz$ R CMD INSTALL arules_1.1-1.tar.gzFor use with ORE:$ ORE CMD INSTALL arules_1.1-1.tar.gzUnable to execute files in /tmp directoryBy default, R uses the /tmp directory to install packages. On security conscious machines, the /tmp directory is often marked as "noexec" in the /etc/fstab file. This means that no file under /tmp can ever be executed, and users who attempt to install R package will receive an error:ERROR: 'configure' exists but is not executable -- see the 'R Installation and Administration Manual’The solution is to set the TMP and TMPDIR environment variables to a location which R will use as the compilation directory. For example:$ mkdir <some path>/tmp$ export TMPDIR= <some path>/tmp$ export TMP= <some path>/tmpThis error typically appears on Linux client machines and not database servers, as Oracle Database writes to the value of the TMP environment variable for several tasks, including holding temporary files during database installation. 7. Creating your own R packageCreating your own package and submitting to CRAN is for advanced users, but it is not difficult. The procedure to follow, along with details of R's package system, is detailed in the Writing R Extensions manual.

  Read the article

< Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >