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  • Can I use a method as a lambda?

    - by NewAlexandria
    I have an interface the defines a group of conditions. it is one of several such interfaces that will live with other models. These conditions will be called by a message queue handler to determine completeness of an alert. All the alert calls will be the same, and so I seek to DRY up the enqueue calls a bit, by abstracting the the conditions into their own methods (i question if methods is the right technique). I think that by doing this I will be able to test each of these conditions. class Loan module AlertTriggers def self.included(base) base.extend LifecycleScopeEnqueues # this isn't right Loan::AlertTriggers::LifecycleScopeEnqueues.instance_method.each do |cond| class << self def self.cond ::AlertHandler.enqueue_alerts( {:trigger => Loan.new}, cond ) end end end end end module LifecycleScopeEnqueues def student_awaiting_cosigner lambda { |interval, send_limit, excluding| excluding ||= '' Loan.awaiting_cosigner. where('loans.id not in (?)', excluding.map(&:id) ). joins(:petitions). where('petitions.updated_at > ?', interval.days.ago). where('petitions.updated_at <= ?', send_limit.days.ago) } end end I've considered alternatives, where each of these methods act like a scope. Down that road, I'm not sure how to have AlertHandler be the source of interval, send_limit, and excluding, which it passes to the block/proc when calling it.

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  • pxe boot fails with message: no DEFAULT or UI configuration directive found

    - by spockaroo
    I am trying to pxe-boot a machine (client), and in the process I am trying to setup a tftp server that this machine can boot off. On the server, which runs Ubuntu 10.10, I have setup dhcp, dns, nfs, and tftp-hpa servers. All the servers/deamons start fine. I tested the tftp server by using a tftp client and downloading a file that the server directory hosts. My /etc/xinet.d/tftp looks like this service tftp { disable = no socket_type = dgram wait = yes user = nobody server = /usr/sbin/in.tftpd server_args = -v -s /var/lib/tftpboot only_from = 10.1.0.0/24 interface = 10.1.0.1 } My /etc/default/tftpd-hpa looks like this RUN_DAEMON="yes" OPTIONS="-l -s /var/lib/tftpboot" TFTP_USERNAME="tftp" TFTP_DIRECTORY="/var/lib/tftpboot" TFTP_ADDRESS="0.0.0.0:69" TFTP_OPTIONS="--secure" My /var/lib/tftpboot/ directory looks like this initrd.img-2.6.35-25-generic-pae vmlinuz-2.6.35-25-generic-pae pxelinux.0 pxelinux.cfg -- default I did sudo chmod 644 /var/lib/tftpboot/pxelinux.cfg/default chmod 755 /var/lib/tftpboot/initrd.img-2.6.35-25-generic-pae chmod 755 /var/lib/tftpboot/vmlinuz-2.6.35-25-generic-pae /var/lib/tftpboot/pxelinux.cfg has the following contents SERIAL 0 19200 0 LABEL linux KERNEL vmlinuz-2.6.35-25-generic-pae APPEND root=/dev/nfs initrd=initrd.img-2.6.35-25-generic-pae nfsroot=10.1.0.1:/nfsroot ip=dhcp console=ttyS0,19200n8 rw I copied /var/lib/tftpboot/pxelinux.0 from /usr/lib/syslinux/ after installing the package syslinux-common. Also just for completeness, /etc/dhcp3/dhcpd.conf the following lines (relevant to this interface) subnet 10.1.0.0 netmask 255.255.255.0 { range 10.1.0.100 10.1.0.240; option routers 10.1.0.1; option broadcast-address 10.1.0.255; option domain-name-servers 10.1.0.1; filename "pxelinux.0"; } When I boot the client machine, and watch the output over the serial port, I notice that the client requests an ip address from the server and gets it. Then I see TFTP being displayed - indicating that it is trying to connect to the TFTP server. This succeeds, and I see TFTP.|, which return immediately displaying the following message PXELINUX 4.01 debian-20100714 Copyright (C) 1994-2010 H. Peter Anvin et al No DEFAULT or UI configuration directive found! boot: /var/log/syslog shows Feb 20 15:24:05 ch in.tftpd[2821]: tftp: client does not accept options What option is it talking about in the syslog? I assume it is referring to OPTIONS or TFTP_OPTIONS, but what am I doing wrong?

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  • Windows Update and IE fail to connect, but Chrome fine?

    - by I Gottlieb
    Out of ideas on this one. (Running Windows Vista.) I have a program that accesses the internet to retrieve financial market data. One day it tells me that it can't log in -- timeout error. I check the documentation and it says must have a working copy of IE browser installed. I check IE (have IE9) and sure enough -- it just spins. No error message, not timeout, no 'try later' -- just spins -- as far as I can tell, indefinitely. Any page, any address. Even access to a localhost site just spins. Chrome works fine. So does another program I have that fetches market data. Windows 'diagnose and repair' says my internet connection is working fine. I tried uninstall/re-install of IE. Same spinning. I tried to install Windows Updates, and guess what? I can't. I comes up with error 80072efd; checked documentation for the error and it says I should check firewall blockage. Thing is, the only firewall I have is Windows Firewall, and obviously it wouldn't be blocking Windows Update. In contrast, Windows 'Help' in all programs has no problem accessing the Internet. I had a filter on the internet connection, and this was updated just prior to first appearance of the problem. But I uninstalled the filter entirely (official, with passwd from the company's service rep) -- and no difference. I'm guessing that a high level Windows network service file is corrupted -- used only by MS programs and their ilk, but how do I find it? I'd like to avoid having to do a clean install of Windows. Much obliged for any insight. IG Ramhound -- Thanks for reply. I'm familiar with virtual machines as in e.g. JVM or an emulator for an alternative architecture or (theoretical) Turing Machine equivalence. But I'm not familiar with the way you're using the term. Please clarify -- what one needs for this VM 'test' and why you expect it will provide an advantage of insight into the problem. And what sort of 'configuration issue' are you referring to? IG

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  • Searching for tasks with code – Executables and Event Handlers

    Searching packages or just enumerating through all tasks is not quite as straightforward as it may first appear, mainly because of the way you can nest tasks within other containers. You can see this illustrated in the sample package below where I have used several sequence containers and loops. To complicate this further all containers types, including packages and tasks, can have event handlers which can then support the full range of nested containers again. Towards the lower right, the task called SQL In FEL also has an event handler not shown, within which is another Execute SQL Task, so that makes a total of 6 Execute SQL Tasks 6 tasks spread across the package. In my previous post about such as adding a property expressionI kept it simple and just looked at tasks at the package level, but what if you wanted to find any or all tasks in a package? For this post I've written a console program that will search a package looking at all tasks no matter how deeply nested, and check to see if the name starts with "SQL". When it finds a matching task it writes out the hierarchy by name for that task, starting with the package and working down to the task itself. The output for our sample package is shown below, note it has found all 6 tasks, including the one on the OnPreExecute event of the SQL In FEL task TaskSearch v1.0.0.0 (1.0.0.0) Copyright (C) 2009 Konesans Ltd Processing File - C:\Projects\Alpha\Packages\MyPackage.dtsx MyPackage\FOR Counter Loop\SQL In Counter Loop MyPackage\SEQ For Each Loop Wrapper\FEL Simple Loop\SQL In FEL MyPackage\SEQ For Each Loop Wrapper\FEL Simple Loop\SQL In FEL\OnPreExecute\SQL On Pre Execute for FEL SQL Task MyPackage\SEQ Top Level\SEQ Nested Lvl 1\SEQ Nested Lvl 2\SQL In Nested Lvl 2 MyPackage\SEQ Top Level\SEQ Nested Lvl 1\SQL In Nested Lvl 1 #1 MyPackage\SEQ Top Level\SEQ Nested Lvl 1\SQL In Nested Lvl 1 #2 6 matching tasks found in package. The full project and code is available for download below, but first we can walk through the project to highlight the most important sections of code. This code has been abbreviated for this description, but is complete in the download. First of all we load the package, and then start by looking at the Executables for the package. // Load the package file Application application = new Application(); using (Package package = application.LoadPackage(filename, null)) { int matchCount = 0; // Look in the package's executables ProcessExecutables(package.Executables, ref matchCount); ... // // ... // Write out final count Console.WriteLine("{0} matching tasks found in package.", matchCount); } The ProcessExecutables method is a key method, as an executable could be described as the the highest level of a working functionality or container. There are several of types of executables, such as tasks, or sequence containers and loops. To know what to do next we need to work out what type of executable we are dealing with as the abbreviated version of method shows below. private static void ProcessExecutables(Executables executables, ref int matchCount) { foreach (Executable executable in executables) { TaskHost taskHost = executable as TaskHost; if (taskHost != null) { ProcessTaskHost(taskHost, ref matchCount); ProcessEventHandlers(taskHost.EventHandlers, ref matchCount); continue; } ... // // ... ForEachLoop forEachLoop = executable as ForEachLoop; if (forEachLoop != null) { ProcessExecutables(forEachLoop.Executables, ref matchCount); ProcessEventHandlers(forEachLoop.EventHandlers, ref matchCount); continue; } } } As you can see if the executable we find is a task we then call out to our ProcessTaskHost method. As with all of our executables a task can have event handlers which themselves contain more executables such as task and loops, so we also make a call out our ProcessEventHandlers method. The other types of executables such as loops can also have event handlers as well as executables. As shown with the example for the ForEachLoop we call the same ProcessExecutables and ProcessEventHandlers methods again to drill down into the hierarchy of objects that the package may contain. This code needs to explicitly check for each type of executable (TaskHost, Sequence, ForLoop and ForEachLoop) because whilst they all have an Executables property this is not from a common base class or interface. This example was just a simple find a task by its name, so ProcessTaskHost really just does that. We also get the hierarchy of objects so we can write out for information, obviously you can adapt this method to do something more interesting such as adding a property expression. private static void ProcessTaskHost(TaskHost taskHost, ref int matchCount) { if (taskHost == null) { return; } // Check if the task matches our match name if (taskHost.Name.StartsWith(TaskNameFilter, StringComparison.OrdinalIgnoreCase)) { // Build up the full object hierarchy of the task // so we can write it out for information StringBuilder path = new StringBuilder(); DtsContainer container = taskHost; while (container != null) { path.Insert(0, container.Name); container = container.Parent; if (container != null) { path.Insert(0, "\\"); } } // Write the task path // e.g. Package\Container\Event\Task Console.WriteLine(path); Console.WriteLine(); // Increment match counter for info matchCount++; } } Just for completeness, the other processing method we covered above is for event handlers, but really that just calls back to the executables. This same method is called in our main package method, but it was omitted for brevity here. private static void ProcessEventHandlers(DtsEventHandlers eventHandlers, ref int matchCount) { foreach (DtsEventHandler eventHandler in eventHandlers) { ProcessExecutables(eventHandler.Executables, ref matchCount); } } As hopefully the code demonstrates, executables (Microsoft.SqlServer.Dts.Runtime.Executable) are the workers, but within them you can nest more executables (except for task tasks).Executables themselves can have event handlers which can in turn hold more executables. I have tried to illustrate this highlight the relationships in the following diagram. Download Sample code project TaskSearch.zip (11KB)

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  • Searching for tasks with code – Executables and Event Handlers

    Searching packages or just enumerating through all tasks is not quite as straightforward as it may first appear, mainly because of the way you can nest tasks within other containers. You can see this illustrated in the sample package below where I have used several sequence containers and loops. To complicate this further all containers types, including packages and tasks, can have event handlers which can then support the full range of nested containers again. Towards the lower right, the task called SQL In FEL also has an event handler not shown, within which is another Execute SQL Task, so that makes a total of 6 Execute SQL Tasks 6 tasks spread across the package. In my previous post about such as adding a property expressionI kept it simple and just looked at tasks at the package level, but what if you wanted to find any or all tasks in a package? For this post I've written a console program that will search a package looking at all tasks no matter how deeply nested, and check to see if the name starts with "SQL". When it finds a matching task it writes out the hierarchy by name for that task, starting with the package and working down to the task itself. The output for our sample package is shown below, note it has found all 6 tasks, including the one on the OnPreExecute event of the SQL In FEL task TaskSearch v1.0.0.0 (1.0.0.0) Copyright (C) 2009 Konesans Ltd Processing File - C:\Projects\Alpha\Packages\MyPackage.dtsx MyPackage\FOR Counter Loop\SQL In Counter Loop MyPackage\SEQ For Each Loop Wrapper\FEL Simple Loop\SQL In FEL MyPackage\SEQ For Each Loop Wrapper\FEL Simple Loop\SQL In FEL\OnPreExecute\SQL On Pre Execute for FEL SQL Task MyPackage\SEQ Top Level\SEQ Nested Lvl 1\SEQ Nested Lvl 2\SQL In Nested Lvl 2 MyPackage\SEQ Top Level\SEQ Nested Lvl 1\SQL In Nested Lvl 1 #1 MyPackage\SEQ Top Level\SEQ Nested Lvl 1\SQL In Nested Lvl 1 #2 6 matching tasks found in package. The full project and code is available for download below, but first we can walk through the project to highlight the most important sections of code. This code has been abbreviated for this description, but is complete in the download. First of all we load the package, and then start by looking at the Executables for the package. // Load the package file Application application = new Application(); using (Package package = application.LoadPackage(filename, null)) { int matchCount = 0; // Look in the package's executables ProcessExecutables(package.Executables, ref matchCount); ... // // ... // Write out final count Console.WriteLine("{0} matching tasks found in package.", matchCount); } The ProcessExecutables method is a key method, as an executable could be described as the the highest level of a working functionality or container. There are several of types of executables, such as tasks, or sequence containers and loops. To know what to do next we need to work out what type of executable we are dealing with as the abbreviated version of method shows below. private static void ProcessExecutables(Executables executables, ref int matchCount) { foreach (Executable executable in executables) { TaskHost taskHost = executable as TaskHost; if (taskHost != null) { ProcessTaskHost(taskHost, ref matchCount); ProcessEventHandlers(taskHost.EventHandlers, ref matchCount); continue; } ... // // ... ForEachLoop forEachLoop = executable as ForEachLoop; if (forEachLoop != null) { ProcessExecutables(forEachLoop.Executables, ref matchCount); ProcessEventHandlers(forEachLoop.EventHandlers, ref matchCount); continue; } } } As you can see if the executable we find is a task we then call out to our ProcessTaskHost method. As with all of our executables a task can have event handlers which themselves contain more executables such as task and loops, so we also make a call out our ProcessEventHandlers method. The other types of executables such as loops can also have event handlers as well as executables. As shown with the example for the ForEachLoop we call the same ProcessExecutables and ProcessEventHandlers methods again to drill down into the hierarchy of objects that the package may contain. This code needs to explicitly check for each type of executable (TaskHost, Sequence, ForLoop and ForEachLoop) because whilst they all have an Executables property this is not from a common base class or interface. This example was just a simple find a task by its name, so ProcessTaskHost really just does that. We also get the hierarchy of objects so we can write out for information, obviously you can adapt this method to do something more interesting such as adding a property expression. private static void ProcessTaskHost(TaskHost taskHost, ref int matchCount) { if (taskHost == null) { return; } // Check if the task matches our match name if (taskHost.Name.StartsWith(TaskNameFilter, StringComparison.OrdinalIgnoreCase)) { // Build up the full object hierarchy of the task // so we can write it out for information StringBuilder path = new StringBuilder(); DtsContainer container = taskHost; while (container != null) { path.Insert(0, container.Name); container = container.Parent; if (container != null) { path.Insert(0, "\\"); } } // Write the task path // e.g. Package\Container\Event\Task Console.WriteLine(path); Console.WriteLine(); // Increment match counter for info matchCount++; } } Just for completeness, the other processing method we covered above is for event handlers, but really that just calls back to the executables. This same method is called in our main package method, but it was omitted for brevity here. private static void ProcessEventHandlers(DtsEventHandlers eventHandlers, ref int matchCount) { foreach (DtsEventHandler eventHandler in eventHandlers) { ProcessExecutables(eventHandler.Executables, ref matchCount); } } As hopefully the code demonstrates, executables (Microsoft.SqlServer.Dts.Runtime.Executable) are the workers, but within them you can nest more executables (except for task tasks).Executables themselves can have event handlers which can in turn hold more executables. I have tried to illustrate this highlight the relationships in the following diagram. Download Sample code project TaskSearch.zip (11KB)

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  • An Alphabet of Eponymous Aphorisms, Programming Paradigms, Software Sayings, Annoying Alliteration

    - by Brian Schroer
    Malcolm Anderson blogged about “Einstein’s Razor” yesterday, which reminded me of my favorite software development “law”, the name of which I can never remember. It took much Wikipedia-ing to find it (Hofstadter’s Law – see below), but along the way I compiled the following list: Amara’s Law: We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run. Brook’s Law: Adding manpower to a late software project makes it later. Clarke’s Third Law: Any sufficiently advanced technology is indistinguishable from magic. Law of Demeter: Each unit should only talk to its friends; don't talk to strangers. Einstein’s Razor: “Make things as simple as possible, but not simpler” is the popular paraphrase, but what he actually said was “It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience”, an overly complicated quote which is an obvious violation of Einstein’s Razor. (You can tell by looking at a picture of Einstein that the dude was hardly an expert on razors or other grooming apparati.) Finagle's Law of Dynamic Negatives: Anything that can go wrong, will—at the worst possible moment. - O'Toole's Corollary: The perversity of the Universe tends towards a maximum. Greenspun's Tenth Rule: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. (Morris’s Corollary: “…including Common Lisp”) Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law. Issawi’s Omelet Analogy: One cannot make an omelet without breaking eggs - but it is amazing how many eggs one can break without making a decent omelet. Jackson’s Rules of Optimization: Rule 1: Don't do it. Rule 2 (for experts only): Don't do it yet. Kaner’s Caveat: A program which perfectly meets a lousy specification is a lousy program. Liskov Substitution Principle (paraphrased): Functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it Mason’s Maxim: Since human beings themselves are not fully debugged yet, there will be bugs in your code no matter what you do. Nils-Peter Nelson’s Nil I/O Rule: The fastest I/O is no I/O.    Occam's Razor: The simplest explanation is usually the correct one. Parkinson’s Law: Work expands so as to fill the time available for its completion. Quentin Tarantino’s Pie Principle: “…you want to go home have a drink and go and eat pie and talk about it.” (OK, he was talking about movies, not software, but I couldn’t find a “Q” quote about software. And wouldn’t it be cool to write a program so great that the users want to eat pie and talk about it?) Raymond’s Rule: Computer science education cannot make anybody an expert programmer any more than studying brushes and pigment can make somebody an expert painter.  Sowa's Law of Standards: Whenever a major organization develops a new system as an official standard for X, the primary result is the widespread adoption of some simpler system as a de facto standard for X. Turing’s Tenet: We shall do a much better programming job, provided we approach the task with a full appreciation of its tremendous difficulty, provided that we respect the intrinsic limitations of the human mind and approach the task as very humble programmers.  Udi Dahan’s Race Condition Rule: If you think you have a race condition, you don’t understand the domain well enough. These rules didn’t exist in the age of paper, there is no reason for them to exist in the age of computers. When you have race conditions, go back to the business and find out actual rules. Van Vleck’s Kvetching: We know about as much about software quality problems as they knew about the Black Plague in the 1600s. We've seen the victims' agonies and helped burn the corpses. We don't know what causes it; we don't really know if there is only one disease. We just suffer -- and keep pouring our sewage into our water supply. Wheeler’s Law: All problems in computer science can be solved by another level of indirection... Except for the problem of too many layers of indirection. Wheeler also said “Compatibility means deliberately repeating other people's mistakes.”. The Wrong Road Rule of Mr. X (anonymous): No matter how far down the wrong road you've gone, turn back. Yourdon’s Rule of Two Feet: If you think your management doesn't know what it's doing or that your organisation turns out low-quality software crap that embarrasses you, then leave. Zawinski's Law of Software Envelopment: Every program attempts to expand until it can read mail. Zawinski is also responsible for “Some people, when confronted with a problem, think 'I know, I'll use regular expressions.' Now they have two problems.” He once commented about X Windows widget toolkits: “Using these toolkits is like trying to make a bookshelf out of mashed potatoes.”

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  • College Courses through distance learning

    - by Matt
    I realize this isn't really a programming question, but didn't really know where to post this in the stackexchange and because I am a computer science major i thought id ask here. This is pretty unique to the programmer community since my degree is about 95% programming. I have 1 semester left, but i work full time. I would like to finish up in December, but to make things easier i like to take online classes whenever I can. So, my question is does anyone know of any colleges that offer distance learning courses for computer science? I have been searching around and found a few potential classes, but not sure yet. I would like to gather some classes and see what i can get approval for. Class I need: Only need one C SC 437 Geometric Algorithms C SC 445 Algorithms C SC 473 Automata Only need one C SC 452 Operating Systems C SC 453 Compilers/Systems Software While i only need of each of the above courses i still need to take two more electives. These also have to be upper 400 level classes. So i can take multiple in each category. Some other classes I can take are: CSC 447 - Green Computing CSC 425 - Computer Networking CSC 460 - Database Design CSC 466 - Computer Security I hoping to take one or two of these courses over the summer. If not, then online over the regular semester would be ok too. Any help in helping find these classes would be awesome. Maybe you went to a college that offered distance learning. Some of these classes may be considered to be graduate courses too. Descriptions are listed below if you need. Thanks! Descriptions Computer Security This is an introductory course covering the fundamentals of computer security. In particular, the course will cover basic concepts of computer security such as threat models and security policies, and will show how these concepts apply to specific areas such as communication security, software security, operating systems security, network security, web security, and hardware-based security. Computer Networking Theory and practice of computer networks, emphasizing the principles underlying the design of network software and the role of the communications system in distributed computing. Topics include routing, flow and congestion control, end-to-end protocols, and multicast. Database Design Functions of a database system. Data modeling and logical database design. Query languages and query optimization. Efficient data storage and access. Database access through standalone and web applications. Green Computing This course covers fundamental principles of energy management faced by designers of hardware, operating systems, and data centers. We will explore basic energy management option in individual components such as CPUs, network interfaces, hard drives, memory. We will further present the energy management policies at the operating system level that consider performance vs. energy saving tradeoffs. Finally we will consider large scale data centers where energy management is done at multiple layers from individual components in the system to shutting down entries subset of machines. We will also discuss energy generation and delivery and well as cooling issues in large data centers. Compilers/Systems Software Basic concepts of compilation and related systems software. Topics include lexical analysis, parsing, semantic analysis, code generation; assemblers, loaders, linkers; debuggers. Operating Systems Concepts of modern operating systems; concurrent processes; process synchronization and communication; resource allocation; kernels; deadlock; memory management; file systems. Algorithms Introduction to the design and analysis of algorithms: basic analysis techniques (asymptotics, sums, recurrences); basic design techniques (divide and conquer, dynamic programming, greedy, amortization); acquiring an algorithm repertoire (sorting, median finding, strong components, spanning trees, shortest paths, maximum flow, string matching); and handling intractability (approximation algorithms, branch and bound). Automata Introduction to models of computation (finite automata, pushdown automata, Turing machines), representations of languages (regular expressions, context-free grammars), and the basic hierarchy of languages (regular, context-free, decidable, and undecidable languages). Geometric Algorithms The study of algorithms for geometric objects, using a computational geometry approach, with an emphasis on applications for graphics, VLSI, GIS, robotics, and sensor networks. Topics may include the representation and overlaying of maps, finding nearest neighbors, solving linear programming problems, and searching geometric databases.

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  • A little primer on using TFS with a small team

    - by johndoucette
    The scenario; A small team of 3 developers mostly in maintenance mode with traditional ASP.net, classic ASP, .Net integration services and utilities with the company’s third party packages, and a bunch of java-based Coldfusion web applications all under Visual Source Safe (VSS). They are about to embark on a huge SharePoint 2010 new construction project and wanted to use subversion instead VSS. TFS was a foreign word and smelled of “high cost” and of an “over complicated process”. Since they had no preconditions about the old TFS versions (‘05 & ‘08), it was fun explaining how simple it was to install a TFS server and get the ball rolling, with or without all the heavy stuff one sometimes associates with such a huge and powerful application management lifecycle product. So, how does a small team begin using TFS? 1. Start by using source control and migrate current VSS source trees into TFS. You can take the latest version or migrate the entire version history. It’s up to you on whether you want a clean start or need quick access to all the version notes and history of the bits. 2. Since most shops are mainly in maintenance mode with existing applications, begin using bug workitems for everything. When you receive an issue/bug from your current tracking system, manually enter the workitem in TFS right through Visual Studio. You can automate the integration to the current tracking system later or replace it entirely. Believe me, this thing is powerful and can handle even the largest of help desks. 3. With new construction, begin work with requirements and task workitems and follow the traditional sprint-based development lifecycle. Obviously, some minor training will be needed, but don’t fear, this is very intuitive and MSDN has a ton of lesson based labs and videos. 4. For the java developers, use the new Team Explorer Everywhere 2010 plugin (recently known as Teamprise). There is a seamless interface in Eclipse, but also a good command-line utility for other environments such as Dreamweaver. 5. Wait to fully integrate the whole workitem/project management/testing process until your team is familiar with the integrated workitems for bugs and code. After a while, you will see the team wanting more transparency into the work they are all doing and naturally, everyone will want workitems to help them organize the chaos! 6. Management will be limited in the value of the reports until you have a fully blown implementation of project planning, construction, build, deployment and testing. However, there are some basic “bug rate” reports and current backlog listings that can provide good information. Some notable explanations of TFS; Work Item Tracking and Project Management - A workitem represents the unit of work within the system which enables tracking of all activities produced by a user, whether it is a developer, business user, project manager or tester. The properties of a workitem such as linked changesets (checked-in code), who updated the data and when, the states and reasons for change, are all transitioned to a data warehouse within TFS for reporting purposes. A workitem can be defines as a "bug", "requirement", test case", or a "change request". They drive the work effort by the individual assigned to it and also provide a key role in defining what needs to be done. Workitems are the things the team needs to do to accomplish a goal. Test Case Management - Starting with a workitem known as a "test case", a tester (or developer) can now author and manage test cases within a formal test plan subsystem. Although TFS supports the test case workitem type, there is a new product known as the VS Test Professional 2010 which allows a tester to facilitate manual tests including fast forwarding steps in the process to arrive at the assertion point quickly. This repeatable process provides quick regression tests and can be conducted by the business user to ensure completeness during UAT. In addition, developers no longer can provide a response to a bug with the line "cannot reproduce". With every test run, attachments including the recorded session, captured environment configurations and settings, screen shots, intellitrace (debugging history), and in some cases if the lab manager is being used, a snapshot of the tested environment is available. Version Control - A modern system allowing shared check-in/check-out, excellent merge conflict resolution, Shelvesets (personal check-ins), branching/merging visualization, public workspaces, gated check-ins, security hierarchy capabilities, and changeset/workitem tracking. Knowing what was done with the code by any developer has become much easier to picture and resolve issues. Team Build - Automate the compilation process whether you need it to be whenever a developer checks-in code, periodically such as nightly builds for testers in the morning, or manual builds to be deployed into production. Each build can run through pre-determined tests, perform code analysis to see if the developer conforms to the team standards, and reject the build if either fails. Project Portal & Reporting - Provide management with a dashboard with insight into the project(s). "Where are we" in each step of the way including past iterations and the current burndown rate. Enabling this feature is easy as it seamlessly interfaces with existing SharePoint implementations.

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  • Adopt-a-JSR for Java EE 7 - Getting Started

    - by arungupta
    Adopt-a-JSR is an initiative started by JUG leaders to encourage JUG members to get involved in a JSR, in order to increase grass roots participation. This allows JUG members to provide early feedback to specifications before they are finalized in the JCP. The standards in turn become more complete and developer-friendly after getting feedback from a wide variety of audience. adoptajsr.org provide more details about the logistics and benefits for you and your JUG. A similar activity was conducted for OpenJDK as well. Markus Eisele also provide a great introduction to the program (in German). Java EE 7 (JSR 342) is scheduled to go final in Q2 2013. There are several new JSRs that are getting included in the platform (e.g. WebSocket, JSON, and Batch), a few existing ones are getting an overhaul (e.g. JAX-RS 2 and JMS 2), and several other getting minor updates (e.g. JPA 2.1 and Servlets 3.1). Each Java EE 7 JSR can leverage your expertise and would love your JUG to adopt a JSR. What does it mean to adopt a JSR ? Your JUG is going to identify a particular JSR, or multiple JSRs, that is of interest to the JUG members. This is mostly done by polling/discussing on your local JUG members list. Your JUG will download and review the specification(s) and javadocs for clarity and completeness. The complete set of Java EE 7 specifications, their download links, and EG archives are listed here. glassfish.org/adoptajsr provide specific areas where different specification leads are looking for feedback. Your JUG can then think of a sample application that can be built using the chosen specification(s). An existing use case (from work or a personal hobby project) may be chosen to be implemented instead. This is where your creativity and uniqueness comes into play. Most of the implementations are already integrated in GlassFish 4 and others will be integrated soon. You can also explore integration of multiple technologies and provide feedback on the simplicity and ease-of-use of the programming model. Especially look for integration with existing Java EE technologies and see if you find any discrepancies. Report any missing features that may be included in future release of the specification. The most important part is to provide feedback by filing bugs on the corresponding spec or RI project. Any thing that is not clear either in the spec or implementation should be filed as a bug. This is what will ensure that specification and implementation leads are getting the required feedback and improving the quality of the final deliverable of the JSR. How do I get started ? A simple way to get started can be achieved by following S.M.A.R.T. as explained below. Specific Identify who all will be involved ? What would you like to accomplish ? For example, even though building a sample app will provide real-world validity of the API but because of time constraints you may identify that reviewing the specification and javadocs only can be accomplished. Establish a time frame by which the activities need to be complete. Measurable Define a success for metrics. For example, this could be the number of bugs filed. Remember, quality of bugs is more important that quantity of bugs. Define your end goal, for example, reviewing 4 chapters of the specification or completing the sample application. Create a dashboard that will highlight your JUG's contribution to this effort. Attainable Make sure JUG members understand the time commitment required for providing feedback. This can vary based upon the level of involvement (any is good!) and the number of specifications picked. adoptajsr.org defines different categories of involvement. Once again, any level of involvement is good. Just reviewing a chapter, a section, or javadocs for your usecase is helpful. Relevant Pick JSRs that JUG members are willing and able to work. If the JUG members are not interested then they might loose motivation half-way through. The "able" part is tricky as you can always stretch yourself and learn a new skill ;-) Time-bound Define a time table of activities with clearly defined tasks. A tentative time table may look like: Dec 25: Discuss and agree upon the specifications with JUG Jan 1: Start Adopt-a-JSR for Java EE 7 Jan 15: Initial spec reading complete. Keep thinking through the application that will be implemented. Jan 22: Early design of the sample application is ready Jan 29: JUG members agree upon the application Next 4 weeks: Implement the application Of course, you'll need to alter this based upon your commitment. Maintaining an activity dashboard will help you monitor and track the progress. Make sure to keep filing bugs through out the process! 12 JUGs from around the world (SouJava, Campinas JUG, Chennai JUG, London Java Community, BeJUG, Morocco JUG, Peru JUG, Indonesia JUG, Congo JUG, Silicon Valley JUG, Madrid JUG, and Houston JUG) have already adopted one of the Java EE 7 JSRs. I'm already helping some JUGs bootstrap and would love to help your JUG too. What are you waiting for ?

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  • WebLogic JDBC Use of Oracle Wallet for SSL

    - by Steve Felts
    Introduction Secure Sockets Layer (SSL) can be used to secure the connection between the middle tier “client”, WebLogic Server (WLS) in this case, and the Oracle database server.  Data between WLS and database can be encrypted.  The server can be authenticated so you have proof that the database can be trusted by validating a certificate from the server.  The client can be authenticated so that the database only accepts connections from clients that it trusts. Similar to the discussion in an earlier article about using the Oracle wallet for database credentials, the Oracle wallet can also be used with SSL to store the keys and certificates.  By using it correctly, clear text passwords can be eliminated from the JDBC configuration and client/server configuration can be simplified by sharing the wallet across multiple datasources. There is a very good Oracle Technical White Paper on using SSL with the Oracle thin driver at http://www.oracle.com/technetwork/database/enterprise-edition/wp-oracle-jdbc-thin-ssl-130128.pdf [LINK1].  The link http://www.oracle.com/technetwork/middleware/weblogic/index-087556.html [LINK2] describes how to use WebLogic Server with Oracle JDBC Driver SSL. The information in this article is a guide on what steps need to be taken in the variety of available options; use the links above for details. SSL from the driver to the database server is basically turned on by specifying a protocol of “tcps” in the URL.  However, there is a fair amount of setup needed.  Also remember that there is an overhead in performance. Creating the wallets The common use cases are 1. “data encryption and server-only authentication”, requiring just a trust store, or 2. “data encryption and authentication of both tiers” (client and server), requiring a trust store and a key store. It is recommended to use the auto-login wallet type so that clear text passwords are not needed in the datasource configuration to open the wallet.  The store type for an auto-login wallet is “SSO” (Single Sign On), not “JKS” or “PKCS12” as in [LINK2].  The file name is “cwallet.sso”. Wallets are created using the orapki tool.  They need to be created based on the usage (encryption and/or authentication).  This is discussed in detail in [LINK1] in Appendix B or in the Advanced Security Administrator’s Guide of the Database documentation. Database Server Configuration It is necessary to update the sqlnet.ora and listener.ora files with the directory location of the wallet using WALLET_LOCATION.  These files also indicate whether or not SSL_CLIENT_AUTHENTICATION is being used (true or false). The Oracle Listener must also be configured to use the TCPS protocol.  The recommended port is 2484. LISTENER = (ADDRESS_LIST= (ADDRESS=(PROTOCOL=tcps)(HOST=servername)(PORT=2484))) WebLogic Server Classpath The WebLogic Server CLASSPATH must have three additional security files. The files that need to be added to the WLS CLASSPATH are $MW_HOME/modules/com.oracle.osdt_cert_1.0.0.0.jar $MW_HOME/modules/com.oracle.osdt_core_1.0.0.0.jar $MW_HOME/modules/com.oracle.oraclepki_1.0.0.0.jar One way to do this is to add them to PRE_CLASSPATH environment variable for use with the standard WebLogic scripts. Setting the Oracle Security Provider It’s necessary to enable the Oracle PKI provider on the client side.  This can either be done statically by updating the java.security file under the JRE or dynamically by setting it in a WLS startup class using java.security.Security.insertProviderAt(new oracle.security.pki.OraclePKIProvider (), 3); See the full example of the startup class in [LINK2]. Datasource Configuration When creating a WLS datasource, set the PROTOCOL in the URL to tcps as in the following. jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=host)(PORT=port))(CONNECT_DATA=(SERVICE_NAME=myservice))) For encryption and server authentication, use the datasource connection properties: - javax.net.ssl.trustStore=location of wallet file on the client - javax.net.ssl.trustStoreType=”SSO” For client authentication, use the datasource connection properties: - javax.net.ssl.keyStore=location of wallet file on the client - javax.net.ssl.keyStoreType=”SSO” Note that the driver connection properties for the wallet require a file name, not a directory name. Active GridLink ONS over SSL For completeness, there is another SSL usage for WLS datasources.  The communication with the Oracle Notification Service (ONS) for load balancing information and node up/down events can use SSL also. Create an auto-login wallet and use the wallet on the client and server.  The following is a sample sequence to create a test wallet for use with ONS. orapki wallet create -wallet ons -auto_login -pwd ONS_Wallet orapki wallet add -wallet ons -dn "CN=ons_test,C=US" -keysize 1024 -self_signed -validity 9999 -pwd ONS_Wallet orapki wallet export -wallet ons -dn "CN=ons_test,C=US" -cert ons/cert.txt -pwd ONS_Wallet On the database server side, it’s necessary to define the walletfile directory in the file $CRS_HOME/opmn/conf/ons.config and run onsctl stop/start. When configuring an Active GridLink datasource, the connection to the ONS must be defined.  In addition to the host and port, the wallet file directory must be specified.  By not giving a password, a SSO wallet is assumed. Summary To use SSL with the Oracle thin driver without any clear text passwords, use an SSO Oracle Wallet.  SSL support in the Oracle thin driver is available starting in 10g Release 2.

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  • NetBeans, JSF, and MySQL Primary Keys using AUTO_INCREMENT

    - by MarkH
    I recently had the opportunity to spin up a small web application using JSF and MySQL. Having developed JSF apps with Oracle Database back-ends before and possessing some small familiarity with MySQL (sans JSF), I thought this would be a cakewalk. Things did go pretty smoothly...but there was one little "gotcha" that took more time than the few seconds it really warranted. The Problem Every DBMS has its own way of automatically generating primary keys, and each has its pros and cons. For the Oracle Database, you use a sequence and point your Java classes to it using annotations that look something like this: @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="POC_ID_SEQ") @SequenceGenerator(name="POC_ID_SEQ", sequenceName="POC_ID_SEQ", allocationSize=1) Between creating the actual sequence in the database and making sure you have your annotations right (watch those typos!), it seems a bit cumbersome. But it typically "just works", without fuss. Enter MySQL. Designating an integer-based field as PRIMARY KEY and using the keyword AUTO_INCREMENT makes the same task seem much simpler. And it is, mostly. But while NetBeans cranks out a superb "first cut" for a basic JSF CRUD app, there are a couple of small things you'll need to bring to the mix in order to be able to actually (C)reate records. The (RUD) performs fine out of the gate. The Solution Omitting all design considerations and activity (!), here is the basic sequence of events I followed to create, then resolve, the JSF/MySQL "Primary Key Perfect Storm": Fire up NetBeans. Create JSF project. Create Entity Classes from Database. Create JSF Pages from Entity Classes. Test run. Try to create record and hit error. It's a simple fix, but one that was fun to find in its completeness. :-) Even though you've told it what to do for a primary key, a MySQL table requires a gentle nudge to actually generate that new key value. Two things are needed to make the magic happen. First, you need to ensure the following annotation is in place in your Java entity classes: @GeneratedValue(strategy = GenerationType.IDENTITY) All well and good, but the real key is this: in your controller class(es), you'll have a create() function that looks something like this, minus the comment line and the setId() call in bold red type:     public String create() {         try {             // Assign 0 to ID for MySQL to properly auto_increment the primary key.             current.setId(0);             getFacade().create(current);             JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("CategoryCreated"));             return prepareCreate();         } catch (Exception e) {             JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));             return null;         }     } Setting the current object's primary key attribute to zero (0) prior to saving it tells MySQL to get the next available value and assign it to that record's key field. Short and simple…but not inherently obvious if you've never used that particular combination of NetBeans/JSF/MySQL before. Hope this helps! All the best, Mark

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  • Data Source Security Part 1

    - by Steve Felts
    I’ve written a couple of articles on how to store data source security credentials using the Oracle wallet.  I plan to write a few articles on the various types of security available to WebLogic Server (WLS) data sources.  There are more options than you might think! There have been several enhancements in this area in WLS 10.3.6.  There are a couple of more enhancements planned for release WLS 12.1.2 that I will include here for completeness.  This isn’t intended as a teaser.  If you call your Oracle support person, you can get them now as minor patches to WLS 10.3.6.   The current security documentation is scattered in a few places, has a few incorrect statements, and is missing a few topics.  It also seems that the knowledge of how to apply some of these features isn’t written down.  The goal of these articles is to talk about WLS data source security in a unified way and to introduce some approaches to using the available features.  Introduction to WebLogic Data Source Security Options By default, you define a single database user and password for a data source.  You can store it in the data source descriptor or make use of the Oracle wallet.  This is a very simple and efficient approach to security.  All of the connections in the connection pool are owned by this user and there is no special processing when a connection is given out.  That is, it’s a homogeneous connection pool and any request can get any connection from a security perspective (there are other aspects like affinity).  Regardless of the end user of the application, all connections in the pool use the same security credentials to access the DBMS.   No additional information is needed when you get a connection because it’s all available from the data source descriptor (or wallet). java.sql.Connection conn =  mydatasource.getConnection(); Note: You can enter the password as a name-value pair in the Properties field (this not permitted for production environments) or you can enter it in the Password field of the data source descriptor. The value in the Password field overrides any password value defined in the Properties passed to the JDBC Driver when creating physical database connections. It is recommended that you use the Password attribute in place of the password property in the properties string because the Password value is encrypted in the configuration file (stored as the password-encrypted attribute in the jdbc-driver-params tag in the module file) and is hidden in the administration console.  The Properties and Password fields are located on the administration console Data Source creation wizard or Data Source Configuration tab. The JDBC API can also be used to programmatically specify a database user name and password as in the following.  java.sql.Connection conn = mydatasource.getConnection(“user”, “password”); According to the JDBC specification, it’s supposed to take a database user and associated password but different vendors implement this differently.  WLS, by default, treats this as an application server user and password.  The pair is authenticated to see if it’s a valid user and that user is used for WLS security permission checks.  By default, the user is then mapped to a database user and password using the data source credential mapper, so this API sort of follows the specification but database credentials are one-step removed from the application code.  More details and the rationale are described later. While the default approach is simple, it does mean that only one database user is doing all of the work.  You can’t figure out who actually did the update and you can’t restrict SQL operations by who is running the operation, at least at the database level.   Any type of per-user logic will need to be in the application code instead of having the database do it.  There are various WLS data source features that can be configured to provide some per-user information about the operations to the database. WebLogic Data Source Security Options This table describes the features available for WebLogic data sources to configure database security credentials and a brief description.  It also captures information about the compatibility of these features with one another. Feature Description Can be used with Can’t be used with User authentication (default) Default getConnection(user, password) behavior – validate the input and use the user/password in the descriptor. Set client identifier Proxy Session, Identity pooling, Use database credentials Use database credentials Instead of using the credential mapper, use the supplied user and password directly. Set client identifier, Proxy session, Identity pooling User authentication, Multi Data Source Set Client Identifier Set a client identifier property associated with the connection (Oracle and DB2 only). Everything Proxy Session Set a light-weight proxy user associated with the connection (Oracle-only). Set client identifier, Use database credentials Identity pooling, User authentication Identity pooling Heterogeneous pool of connections owned by specified users. Set client identifier, Use database credentials Proxy session, User authentication, Labeling, Multi-datasource, Active GridLink Note that all of these features are available with both XA and non-XA drivers. Currently, the Proxy Session and Use Database Credentials options are on the Oracle tab of the Data Source Configuration tab of the administration console (even though the Use Database Credentials feature is not just for Oracle databases – oops).  The rest of the features are on the Identity tab of the Data Source Configuration tab in the administration console (plan on seeing them all in one place in the future). The subsequent articles will describe these features in more detail.  Keep referring back to this table to see the big picture.

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  • XSLT Document function returns empty result on Maven POM

    - by user328618
    Greetings! I want to extract some properties from different Maven POMs in a XSLT via the document function. The script itself works fine but the document function returns an empty result for the POM as long as I have the xmlns="http://maven.apache.org/POM/4.0.0" in the project tag. If I remove it, everything works fine. Any idea how the make this work while leaving the xmlns attribute where it belongs or why this doesn't work with the attribute in place? Here comes the relevant portion of my XSLT: <xsl:template match="abcs"> <xsl:variable name="artifactCoordinate" select="abc"/> <xsl:choose> <xsl:when test="document(concat($artifactCoordinate,'-pom.xml'))"> <abc> <ID><xsl:value-of select="$artifactCoordinate"/></ID> <xsl:copy-of select="document(concat($artifactCoordinate,'-pom.xml'))/project/properties"/> </abc> </xsl:when> <xsl:otherwise> <xsl:message terminate="yes"> Transformation failed: POM "<xsl:value-of select="concat($artifactCoordinate,'-pom.xml')"/>" doesn't exist. </xsl:message> </xsl:otherwise> </xsl:choose> And, for completeness, a POM extract with the "bad" attribute: <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/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <!-- ... --> <properties> <proalpha.version>[5.2a]</proalpha.version> <proalpha.openedge.version>[10.1B]</proalpha.openedge.version> <proalpha.optimierer.version>[1.1]</proalpha.optimierer.version> <proalpha.sonic.version>[7.6.1]</proalpha.sonic.version> </properties> </project>

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  • CSS text-decoration rule ignored

    - by Ferdy
    I have found similar questions to mine but none of the suggestions seems to apply to my situation, so here goes... I have a webpage with a buch of images on them. Each image has a title which in markup is between h2 tags. The title is a link, so the resulting markup is like this: <ul class="imagelist"> <li> <a href=""><h2>Title 1</h2></a> <a href=""><img src="" /></a> </li> <li> Image 2, etc... </li> </ul> All I want is for the title links to not be underlined. I tried to address this like this: .imagelist li a h2 { color:#333; text-decoration:none; } It completely ignores the text-decoration rule, yet respects the color rule. From other questions I learned that this could be because a child element cannot overrule the text-decoration of any of its parents. So, I went looking for the parent elements to see if any explicit text-decoration rules are applied. I found none. This is driving me crazy, any help? For the sake of completeness, here is the Firebug CSS output, which shows the full inheritance and such. Probably more than you want, but I cannot see anything conflicting here. .imagelist li a h2 { color:#333333; text-decoration:none; } main.css (line 417) h2 { font-size:14px; } main.css (line 40) h1, h2, h3, h4, h5, h6 { display:block; font-weight:bold; margin-bottom:10px; } main.css (line 38) h1, h2, h3, h4, h5, h6 { font-size:100%; font-weight:normal; } reset-min.css (line 7) body, div, dl, dt, dd, ul, ol, li, h1, h2, h3, h4, h5, h6, pre, code, form, fieldset, legend, input, textarea, p, blockquote, th, td { margin:0; padding:0; } reset-min.css (line 7) Inherited froma /apps/ju...mage/745 a { color:#0063E2; } main.css (line 55) Inherited fromli .imagelist li { list-style-type:none; } main.css (line 411) li { list-style:none outside none; } reset-min.css (line 7) Inherited fromul.imagelist .imagelist { border-collapse:collapse; font-size:9px; } main.css (line 410) Inherited frombody body, form { color:#333333; font:12px arial,helvetica,clean,sans-serif; } main.css (line 36) Inherited fromhtml html { color:#000000;

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  • Delphi interface cast using TValue

    - by conciliator
    I've recently experimented extensively with interfaces and D2010 RTTI. I don't know at runtime the actual type of the interface; although I will have access to it's qualified name using a string. Consider the following: program rtti_sb_1; {$APPTYPE CONSOLE} uses SysUtils, Rtti, TypInfo, mynamespace in 'mynamespace.pas'; var ctx: TRttiContext; InterfaceType: TRttiType; Method: TRttiMethod; ActualParentInstance: IParent; ChildInterfaceValue: TValue; ParentInterfaceValue: TValue; begin ctx := TRttiContext.Create; // Instantiation ActualParentInstance := TChild.Create as IParent; {$define WORKAROUND} {$ifdef WORKAROUND} InterfaceType := ctx.GetType(TypeInfo(IParent)); InterfaceType := ctx.GetType(TypeInfo(IChild)); {$endif} // Fetch interface type InterfaceType := ctx.FindType('mynamespace.IParent'); // This cast is OK and ChildMethod is executed (ActualParentInstance as IChild).ChildMethod(100); // Create a TValue holding the interface TValue.Make(@ActualParentInstance, InterfaceType.Handle, ParentInterfaceValue); InterfaceType := ctx.FindType('mynamespace.IChild'); // This cast doesn't work if ParentInterfaceValue.TryCast(InterfaceType.Handle, ChildInterfaceValue) then begin Method := InterfaceType.GetMethod('ChildMethod'); if (Method <> nil) then begin Method.Invoke(ChildInterfaceValue, [100]); end; end; ReadLn; end. The contents of mynamespace.pas is as follows: {$M+} IParent = interface ['{2375F59E-D432-4D7D-8D62-768F4225FFD1}'] procedure ParentMethod(const Id: integer); end; {$M-} IChild = interface(IParent) ['{6F89487E-5BB7-42FC-A760-38DA2329E0C5}'] procedure ChildMethod(const Id: integer); end; TParent = class(TInterfacedObject, IParent) public procedure ParentMethod(const Id: integer); end; TChild = class(TParent, IChild) public procedure ChildMethod(const Id: integer); end; For completeness, the implementation goes as procedure TParent.ParentMethod(const Id: integer); begin WriteLn('ParentMethod executed. Id is ' + IntToStr(Id)); end; procedure TChild.ChildMethod(const Id: integer); begin WriteLn('ChildMethod executed. Id is ' + IntToStr(Id)); end; The reason for {$define WORKAROUND} may be found in this post. Question: is there any way for me to make the desired type cast using RTTI? In other words: is there a way for me to invoke IChild.ChildMethod from knowing 1) the qualified name of IChild as a string, and 2) a reference to the TChild instance as a IParent interface? (After all, the hard-coded cast works fine. Is this even possible?) Thanks!

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  • Why is numpy's einsum faster than numpy's built in functions?

    - by Ophion
    Lets start with three arrays of dtype=np.double. Timings are performed on a intel CPU using numpy 1.7.1 compiled with icc and linked to intel's mkl. A AMD cpu with numpy 1.6.1 compiled with gcc without mkl was also used to verify the timings. Please note the timings scale nearly linearly with system size and are not due to the small overhead incurred in the numpy functions if statements these difference will show up in microseconds not milliseconds: arr_1D=np.arange(500,dtype=np.double) large_arr_1D=np.arange(100000,dtype=np.double) arr_2D=np.arange(500**2,dtype=np.double).reshape(500,500) arr_3D=np.arange(500**3,dtype=np.double).reshape(500,500,500) First lets look at the np.sum function: np.all(np.sum(arr_3D)==np.einsum('ijk->',arr_3D)) True %timeit np.sum(arr_3D) 10 loops, best of 3: 142 ms per loop %timeit np.einsum('ijk->', arr_3D) 10 loops, best of 3: 70.2 ms per loop Powers: np.allclose(arr_3D*arr_3D*arr_3D,np.einsum('ijk,ijk,ijk->ijk',arr_3D,arr_3D,arr_3D)) True %timeit arr_3D*arr_3D*arr_3D 1 loops, best of 3: 1.32 s per loop %timeit np.einsum('ijk,ijk,ijk->ijk', arr_3D, arr_3D, arr_3D) 1 loops, best of 3: 694 ms per loop Outer product: np.all(np.outer(arr_1D,arr_1D)==np.einsum('i,k->ik',arr_1D,arr_1D)) True %timeit np.outer(arr_1D, arr_1D) 1000 loops, best of 3: 411 us per loop %timeit np.einsum('i,k->ik', arr_1D, arr_1D) 1000 loops, best of 3: 245 us per loop All of the above are twice as fast with np.einsum. These should be apples to apples comparisons as everything is specifically of dtype=np.double. I would expect the speed up in an operation like this: np.allclose(np.sum(arr_2D*arr_3D),np.einsum('ij,oij->',arr_2D,arr_3D)) True %timeit np.sum(arr_2D*arr_3D) 1 loops, best of 3: 813 ms per loop %timeit np.einsum('ij,oij->', arr_2D, arr_3D) 10 loops, best of 3: 85.1 ms per loop Einsum seems to be at least twice as fast for np.inner, np.outer, np.kron, and np.sum regardless of axes selection. The primary exception being np.dot as it calls DGEMM from a BLAS library. So why is np.einsum faster that other numpy functions that are equivalent? The DGEMM case for completeness: np.allclose(np.dot(arr_2D,arr_2D),np.einsum('ij,jk',arr_2D,arr_2D)) True %timeit np.einsum('ij,jk',arr_2D,arr_2D) 10 loops, best of 3: 56.1 ms per loop %timeit np.dot(arr_2D,arr_2D) 100 loops, best of 3: 5.17 ms per loop The leading theory is from @sebergs comment that np.einsum can make use of SSE2, but numpy's ufuncs will not until numpy 1.8 (see the change log). I believe this is the correct answer, but have not been able to confirm it. Some limited proof can be found by changing the dtype of input array and observing speed difference and the fact that not everyone observes the same trends in timings.

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  • Subroutine & GoTo design

    - by sub
    I have a strange question concerning subroutines: As I'm creating a minimal language and I don't want to add high-level loops like while or for I was planning on just adding gotos to keep it Turing-Complete. Now I thought, eww - gotos - I wouldn't want to program in that language if I had to use gotos so often. So I thought about adding subroutines instead. I see the difference as the following: gotos Go to (captain obvious) a previously defined point and continue executing the program from there. Leads to hardly understandable and buggy code, I think that's a fact. subroutines Similiar: You define their starting point somewhere, as you call them the program jumps there - but the subroutine can go back to the point it was called from with return. Okay. Why didn't I just add the more function-like, nice looking subroutines? Because: In order to make return work if I call subroutines from within subroutines from within other subroutines, I'd have to use a stack containing the point where the currently running subroutine came from at top. That would then mean that I would, if I create loops using the subroutines, end up with an extremely memory-eating, overflowing stack with return locations. Not good. Don't think of my subroutines as functions. They are just gotos that return to the point they were called from, they don't actually give back values like the return x; statement in nearly all today's languages. Now to my actual questions: How can I solve the above problem with the stack overflow on loops with subroutines? Do I have to add a separate goto language construct without the return option? Assembler doesn't have loops but as I have seen myJumpPoint:, jnz, jz, retn. That means to me that there must also be a stack containing all the return locations. Am I right with that? What about long running loops then? Don't they overflow the stack/eat memory then? Am I getting the retn symbol in assembler totally wrong? If yes, please explain it to me.

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  • NSXMLDocument objectByApplyingXSLT with XSL Include

    - by Kristof
    I'm having some trouble with XSL-processing when there are stylesheets that include other stylesheets relatively. (the XML-files may be irrelevant but are included for completeness - code is at the bottom). Given the XML-file: <?xml version="1.0" ?> <famous-persons> <persons category="medicine"> <person> <firstname> Edward </firstname> <name> Jenner </name> </person> <person> <firstname> Gertrude </firstname> <name> Elion </name> </person> </persons> </famous-persons> and the XSL-file: <?xml version="1.0" ?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xi="http://www.w3.org/2001/XInclude" version="1.0"> <xsl:template match="/"> <html><head><title>Sorting example</title></head><body> <xsl:apply-templates select="famous-persons/persons"> <xsl:sort select="@category" /> </xsl:apply-templates> </body></html> </xsl:template> <xsl:include href="included.xsl" /> </xsl:stylesheet> referencing this stylesheet in included.xsl: <?xml version="1.0"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xi="http://www.w3.org/2001/XInclude" version="1.0"> <xsl:template match="persons"> <h2><xsl:value-of select="@category" /></h2> <ul>Irrelevant</ul> </xsl:template> </xsl:stylesheet> how can I make it that the following code fragment: NSError *lError = nil; NSXMLDocument *lDocument = [ [ NSXMLDocument alloc ] initWithContentsOfURL: [ NSURL URLWithString: @"file:///pathto/data.xml" ] options: 0 error: &lError ]; NSXMLDocument *lResult = [ lDocument objectByApplyingXSLTAtURL: [ NSURL URLWithString: @"file:///pathto/style.xsl" ] arguments: nil error: nil ]; does not give me the error: I/O warning : failed to load external entity "included.xsl" compilation error: element include xsl:include : unable to load included.xsl I have been trying all sorts of options. Also loading XML documents with NSXMLDocumentXInclude beforehand does not seem to help. Is there any way to make the XSL processing so that a stylesheet can include another stylesheet in its local path?

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  • Purpose of Explicit Default Constructors

    - by Dennis Zickefoose
    I recently noticed a class in C++0x that calls for an explicit default constructor. However, I'm failing to come up with a scenario in which a default constructor can be called implicitly. It seems like a rather pointless specifier. I thought maybe it would disallow Class c; in favor of Class c = Class(); but that does not appear to be the case. Some relevant quotes from the C++0x FCD, since it is easier for me to navigate [similar text exists in C++03, if not in the same places] 12.3.1.3 [class.conv.ctor] A default constructor may be an explicit constructor; such a constructor will be used to perform default-initialization or value initialization (8.5). It goes on to provide an example of an explicit default constructor, but it simply mimics the example I provided above. 8.5.6 [decl.init] To default-initialize an object of type T means: — if T is a (possibly cv-qualified) class type (Clause 9), the default constructor for T is called (and the initialization is ill-formed if T has no accessible default constructor); 8.5.7 [decl.init] To value-initialize an object of type T means: — if T is a (possibly cv-qualified) class type (Clause 9) with a user-provided constructor (12.1), then the default constructor for T is called (and the initialization is ill-formed if T has no accessible default constructor); In both cases, the standard calls for the default constructor to be called. But that is what would happen if the default constructor were non-explicit. For completeness sake: 8.5.11 [decl.init] If no initializer is specified for an object, the object is default-initialized; From what I can tell, this just leaves conversion from no data. Which doesn't make sense. The best I can come up with would be the following: void function(Class c); int main() { function(); //implicitly convert from no parameter to a single parameter } But obviously that isn't the way C++ handles default arguments. What else is there that would make explicit Class(); behave differently from Class();? The specific example that generated this question was std::function [20.8.14.2 func.wrap.func]. It requires several converting constructors, none of which are marked explicit, but the default constructor is.

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  • How hard programming is? Really. [closed]

    - by Bubba88
    Hi! The question is about your perception of programming activity. How hard/exacting this task is? There is much buzz about programming nowadays, people say that programmers are smart, very technical and abstract at a time, know much about world, psychology etc.. They say, that programmers got really powerful brain thing, cause there is much to keep in consideration simultaneously again with much information folded into each other associatively (up 10 levels of folding they say))) Still, there are some terms to specify at our own.. So that is the question: What do you think about programming in general? Is it hard? Is it 'for everyone' or for the particular kind of people only? How much non-CS background do you need to program (just to program, really; enterprise applications for example)? How long is the learning curve? (again, for programming in general) And another bunch of random questions: - If you were not to like/love programming, would that be a serious trouble bothering your current employment? - If you were to start from the beginning, would you chose that direction this time? - What other areas (jobs or maybe hobbies) are comparable to programming in the way they can explode someone's lovely brain? - Is 'non turing-complete programming' (SQL, XML, etc.) comparable to what we do or is it really way easier, less requiring, cheap and akin to cooking :)? Well, the essence is: How would you describe programming activity WRT to its difficulty? Or, on the other hand: Did you ever catch yourself thinking at some point: OMG, it's sooo hard! I don't know how would I ever program, even carried away this way and doing programming just for fun? It's very interesting to know your opinion, your'e the programmers after all. I mean much people must be exaggerating/speculating about the thing they do not really know about. But that musn't be the case here on SO :) P.S.: I'll try my best to update this post later, and you please edit it too. At least I'll get decent English in my question text :)

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  • Adding GestureOverlayView to my SurfaceView class, how to add to view hierarchy?

    - by Codejoy
    I was informed in a later answer that I have to add the GestureOverlayView I create in code to my view hierarchy, and I am not 100% how to do that. Below is the original question for completeness. I want my game to be able to recognize gestures. I have this nice SurfaceView class that I do an onDraw to draw my sprites, and I have a thread thats running it to call the onDraw etc . This all works great. I am trying to add the GestureOverlayView to this and it just isn't working. Finally hacked to where it doesn't crash but this is what i have public class Panel extends SurfaceView implements SurfaceHolder.Callback, OnGesturePerformedListener { public Panel(Context context) { theContext=context; mLibrary = GestureLibraries.fromRawResource(context, R.raw.myspells); GestureOverlayView gestures = new GestureOverlayView(theContext); gestures.setOrientation(gestures.ORIENTATION_VERTICAL); gestures.setEventsInterceptionEnabled(true); gestures.setGestureStrokeType(gestures.GESTURE_STROKE_TYPE_MULTIPLE); gestures.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); //GestureOverlayView gestures = (GestureOverlayView) findViewById(R.id.gestures); gestures.addOnGesturePerformedListener(this); } ... ... onDraw... surfaceCreated(..); ... ... public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) { ArrayList<Prediction> predictions = mLibrary.recognize(gesture); // We want at least one prediction if (predictions.size() > 0) { Prediction prediction = predictions.get(0); // We want at least some confidence in the result if (prediction.score > 1.0) { // Show the spell Toast.makeText(theContext, prediction.name, Toast.LENGTH_SHORT).show(); } } } } The onGesturePerformed is never called. Their example has the GestureOverlay in the xml, I am not using that, my activity is simple: @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); Panel p = new Panel(this); setContentView(p); } So I am at a bit of a loss of the missing piece of information here, it doesn't call the onGesturePerformed and the nice pretty yellow "you are drawing a gesture" never shows up.

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  • Connect to SQLite Database using Eclipse (Java)

    - by bnabilos
    Hello, I'm trying to connect to SQLite database with Ecplise but I have some errors. This is my Java code and the errors that I get on output. Please see if you can help me. Thank you in advance. package jdb; import java.sql.*; public class Test { public static void main(String[] args) throws Exception { Class.forName("org.sqlite.JDBC"); Connection conn = DriverManager.getConnection("jdbc:sqlite:/Applications/MAMP/db/sqlite/test.sqlite"); Statement stat = conn.createStatement(); stat.executeUpdate("drop table if exists people;"); stat.executeUpdate("create table people (name, occupation);"); PreparedStatement prep = conn.prepareStatement( "insert into people values (?, ?);"); prep.setString(1, "Gandhi"); prep.setString(2, "politics"); prep.addBatch(); prep.setString(1, "Turing"); prep.setString(2, "computers"); prep.addBatch(); prep.setString(1, "Wittgenstein"); prep.setString(2, "smartypants"); prep.addBatch(); conn.setAutoCommit(false); prep.executeBatch(); conn.setAutoCommit(true); ResultSet rs = stat.executeQuery("select * from people;"); while (rs.next()) { System.out.println("name = " + rs.getString("name")); System.out.println("job = " + rs.getString("occupation")); } rs.close(); conn.close(); } } ans that what I get in Ecplise : Exception in thread "main" java.lang.ClassNotFoundException: org.sqlite.JDBC at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:315) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:330) at java.lang.ClassLoader.loadClass(ClassLoader.java:250) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:398) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:169) at jdb.Test.main(Test.java:7) Thank you

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  • User Control as container at design time

    - by Luca
    I'm designing a simple expander control. I've derived from UserControl, drawn inner controls, built, run; all ok. Since an inner Control is a Panel, I'd like to use it as container at design time. Indeed I've used the attributes: [Designer(typeof(ExpanderControlDesigner))] [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] Great I say. But it isn't... The result is that I can use it as container at design time but: The added controls go back the inner controls already embedded in the user control Even if I push to top a control added at design time, at runtime it is back again on controls embedded to the user control I cannot restrict the container area at design time into a Panel area What am I missing? Here is the code for completeness... why this snippet of code is not working? [Designer(typeof(ExpanderControlDesigner))] [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] public partial class ExpanderControl : UserControl { public ExpanderControl() { InitializeComponent(); .... [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")] internal class ExpanderControlDesigner : ControlDesigner { private ExpanderControl MyControl; public override void Initialize(IComponent component) { base.Initialize(component); MyControl = (ExpanderControl)component; // Hook up events ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService)); IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService)); s.SelectionChanged += new EventHandler(OnSelectionChanged); c.ComponentRemoving += new ComponentEventHandler(OnComponentRemoving); } private void OnSelectionChanged(object sender, System.EventArgs e) { } private void OnComponentRemoving(object sender, ComponentEventArgs e) { } protected override void Dispose(bool disposing) { ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService)); IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService)); // Unhook events s.SelectionChanged -= new EventHandler(OnSelectionChanged); c.ComponentRemoving -= new ComponentEventHandler(OnComponentRemoving); base.Dispose(disposing); } public override System.ComponentModel.Design.DesignerVerbCollection Verbs { get { DesignerVerbCollection v = new DesignerVerbCollection(); v.Add(new DesignerVerb("&asd", new EventHandler(null))); return v; } } } I've found many resources (Interaction, designed, limited area), but nothing was usefull for being operative... Actually there is a trick, since System.Windows.Forms classes can be designed (as usual) and have a correct behavior at runtime (TabControl, for example).

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  • How to obtain a pointer out of a C++ vtable?

    - by Josh Haberman
    Say you have a C++ class like: class Foo { public: virtual ~Foo() {} virtual DoSomething() = 0; }; The C++ compiler translates a call into a vtable lookup: Foo* foo; // Translated by C++ to: // foo->vtable->DoSomething(foo); foo->DoSomething(); Suppose I was writing a JIT compiler and I wanted to obtain the address of the DoSomething() function for a particular instance of class Foo, so I can generate code that jumps to it directly instead of doing a table lookup and an indirect branch. My questions are: Is there any standard C++ way to do this (I'm almost sure the answer is no, but wanted to ask for the sake of completeness). Is there any remotely compiler-independent way of doing this, like a library someone has implemented that provides an API for accessing a vtable? I'm open to completely hacks, if they will work. For example, if I created my own derived class and could determine the address of its DoSomething method, I could assume that the vtable is the first (hidden) member of Foo and search through its vtable until I find my pointer value. However, I don't know a way of getting this address: if I write &DerivedFoo::DoSomething I get a pointer-to-member, which is something totally different. Maybe I could turn the pointer-to-member into the vtable offset. When I compile the following: class Foo { public: virtual ~Foo() {} virtual void DoSomething() = 0; }; void foo(Foo *f, void (Foo::*member)()) { (f->*member)(); } On GCC/x86-64, I get this assembly output: Disassembly of section .text: 0000000000000000 <_Z3fooP3FooMS_FvvE>: 0: 40 f6 c6 01 test sil,0x1 4: 48 89 74 24 e8 mov QWORD PTR [rsp-0x18],rsi 9: 48 89 54 24 f0 mov QWORD PTR [rsp-0x10],rdx e: 74 10 je 20 <_Z3fooP3FooMS_FvvE+0x20> 10: 48 01 d7 add rdi,rdx 13: 48 8b 07 mov rax,QWORD PTR [rdi] 16: 48 8b 74 30 ff mov rsi,QWORD PTR [rax+rsi*1-0x1] 1b: ff e6 jmp rsi 1d: 0f 1f 00 nop DWORD PTR [rax] 20: 48 01 d7 add rdi,rdx 23: ff e6 jmp rsi I don't fully understand what's going on here, but if I could reverse-engineer this or use an ABI spec I could generate a fragment like the above for each separate platform, as a way of obtaining a pointer out of a vtable.

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  • Multiple instances of this carousel on a single page - can't get it to work

    - by Andy
    This code comes from a tutorial so it's not originally my own work. What I am trying to do is implement this several times on a single page. I have tried and so far failed - by numbering the id "carousel" and so forth. Any help would be seriously appreciated. I'm tearing my hair out. http://jsfiddle.net/AndyMP/zcKDV/5/ For completeness.. this is the carousel JQuery as it stands. //rotation speed and timer var speed = 5000; var run = setInterval('rotate()', speed); //grab the width and calculate left value var item_width = $('#slides li').outerWidth(); var left_value = item_width * (-1); //move the last item before first item, just in case user click prev button $('#slides li:first').before($('#slides li:last')); //set the default item to the correct position $('#slides ul').css({'left' : left_value}); //if user clicked on prev button $('#prev').click(function() { //get the right position var left_indent = parseInt($('#slides ul').css('left')) + item_width; //slide the item $('#slides ul').animate({'left' : left_indent}, 200,function(){ //move the last item and put it as first item $('#slides li:first').before($('#slides li:last')); //set the default item to correct position $('#slides ul').css({'left' : left_value}); }); //cancel the link behavior return false; }); //if user clicked on next button $('#next').click(function() { //get the right position var left_indent = parseInt($('#slides ul').css('left')) - item_width; //slide the item $('#slides ul').animate({'left' : left_indent}, 200, function () { //move the first item and put it as last item $('#slides li:last').after($('#slides li:first')); //set the default item to correct position $('#slides ul').css({'left' : left_value}); }); //cancel the link behavior return false; }); //if mouse hover, pause the auto rotation, otherwise rotate it $('#slides').hover( function() { clearInterval(run); }, function() { run = setInterval('rotate()', speed); } ); //a simple function to click next link //a timer will call this function, and the rotation will begin :) function rotate() { $('#next').click(); }

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