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  • Need events to execute on timer events, metronome precision.

    - by user295734
    I setup a timer to call an event in my application. The problme is the event execution is being skewed by other windows operations. Ex. openning and window, loading a webpage. I need the event to excute exactly on time, every time. When i first set up the app, used a sound file, like a metronome to listen to the even firing, in a steady state, its firing right on, but as soon do something in the windows environment, the sound fires slower, then sort of sppeds up a bit to catch up. So i added a logging method to the event to ctahc the timer ticks. From that data, it appears that the timer is not being affected by the windows app, but my application event calls are being affected. I figured this out by checking the datetime.now in the event, and if i set it to 250 milliseconds, which is 4 clicks per second. You get data something like below. (sec):(ms) 1:000 1:250 1:500 1:750 2:000 2:250 2:500 2:750 3:000 3:250 3:500 3:750 (lets say i execute some windows event)(time will skew) 4:122 4:388 4:600 4:876 (stop doing what i was doing in windows) (going to shorten the data for simplicit, my list was 30sec long) 5:124 5:268 5:500 5:750 (you would se the time go back the same milliseconds it was at the begining) 6:000 6:250 6:500 6:750 7:000 7:250 7:500 7:750 So i'm thinking the timer continues to fire on the same millisecond every time, but its the event that is being skewed to fire off time by other windows operations. Its not a huge skew, but for what i need to accomplish, its unacceptable. Is there anyhting i can do in .NET, hoping to use XAML/WPF application, thats will correct the skewing of events? thx.

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  • Cross-platform and language (de)serialization

    - by fwgx
    I'm looking for a way to serialize a bunch of C++ structs in the most convenient way so that the serialization is portable across C++ and Java (at a minimum) and across 32bit/64bit, big/little endian platforms. The structures to be serialized just contain data, i.e. they're pure data objects with no state or behavior. The idea being that we serialize the structs into an octet blob that we can store in a database "generically" and be read out later on. Thus avoiding changing the database whenever a struct changes and also avoiding assigning each data member to a field - i.e. we only want one table to hold everything "generically" as a binary blob. This should make less work for developers and require less changes when structures change. I've looked at boost.serialize but don't think there's a way to enable compatibility with Java. And likewise for inheriting Serializable in Java. If there is a way to do it by starting with an IDL file that would be best as we already have IDL files that describe the structures. Cheers in advance!

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  • How to verify the SSL connection when calling an URI?

    - by robertokl
    Hello, I am developing an web application that is authenticated using CAS (A single-sign-on solution: http://www.ja-sig.org/wiki/display/CAS/Home). For security reasons, I need two things to work: The communication between CAS and my application needs to be secure My application needs to accept the certification coming with CAS, so that I can guarantee that the CAS responding is the real CAS Server. This is what I got so far: uri = URI.parse("https://www.google.com/accounts") https = Net::HTTP.new(uri.host, uri.port) https.use_ssl = (uri.scheme == 'https') https.verify_mode = (OpenSSL::SSL::VERIFY_PEER) raw_res = https.start do |conn| conn.get("#{uri.path}?#{uri.query}") end This works just great in my Mac OSX. When I try to reach an insecure uri, it raises an exception, and when I try to reach a secure uri, it allow me normally, just like expected. The problem starts when I deploy my application on my Linux server. I tried in both Ubuntu and Red Hat. Independing of what uri I try to reach, it always raises me this exception: OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed from /usr/local/lib/ruby/1.8/net/http.rb:586:in `connect' from /usr/local/lib/ruby/1.8/net/http.rb:586:in `connect' from /usr/local/lib/ruby/1.8/net/http.rb:553:in `do_start' from /usr/local/lib/ruby/1.8/net/http.rb:542:in `start' from (irb):7 I think this have something to do with my installed OpenSSL package, but I can't be sure. This are my installed OpenSSL packages: openssl.x86_64 0.9.8e-12.el5 installed openssl-devel.x86_64 0.9.8e-12.el5 installed I tried using HTTParty as well, but it just ignores the SSL certificated. I hope someone can help me, either by telling me a gem that works the way I need. Thanks.

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  • WPF abnormal CPU usage for animation

    - by 0xDEAD BEEF
    HI! I am developing WPF application and client reports extreamly high CPU usage (90%) (whereas i am unable to repeat that behavior). I have traced bootleneck down to these lines. It is simple glowing animation for small single led control (blinking led). What could be reason for this simple annimation taking up SO huge CPU resources? <Trigger Property="State"> <Trigger.Value> <local:BlinkingLedStatus>Blinking</local:BlinkingLedStatus> </Trigger.Value> <Trigger.EnterActions> <BeginStoryboard Name="beginStoryBoard"> <Storyboard> <DoubleAnimation Storyboard.TargetName="glow" Storyboard.TargetProperty="Opacity" AutoReverse="True" From="0.0" To="1.0" Duration="0:0:0.5" RepeatBehavior="Forever"/> </Storyboard> </BeginStoryboard> </Trigger.EnterActions> <Trigger.ExitActions> <StopStoryboard BeginStoryboardName="beginStoryBoard"/> </Trigger.ExitActions> </Trigger>

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  • Why does the same Getopt::Long code work differently in different programs?

    - by ennuikiller
    The following code works in one script yet in another only works if a specify the -- end of options flag before specifying an option: my $opt; GetOptions( 'help|h' => sub { usage("you want help?? hahaha, hopefully you're not serious!!"); }, 'file|f=s' => \$opt->{FILE}, 'report|r' => \$opt->{REPORT}, ) or usage("Bad Options"); In other words, the same code words in good.pl and bad.pl like so: good.pl -f bad.pl -- -f If I try bad.pl -f I get unknown option:f. Anyone have any clue as to what can cause this behavior? Thanks in advance! I've solved this..... and btw it's a VERY clear question (so why the downvotes)? I'll state it again: What would cause the identical GetOptions block to work in these 2 ways: "good.pl -f" "bad.pl -- -f" see how clear? Maybe you guys should think about it as if it were a TEST!

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  • How to verify the SSL connection when calling a URI?

    - by robertokl
    Hello, I am developing a web application that is authenticated using CAS (A single-sign-on solution: http://www.ja-sig.org/wiki/display/CAS/Home). For security reasons, I need two things to work: The communication between CAS and my application needs to be secure My application needs to accept the certification coming from CAS, so that I can guarantee that the CAS responding is the real CAS server This is what I got so far: uri = URI.parse("https://www.google.com/accounts") https = Net::HTTP.new(uri.host, uri.port) https.use_ssl = (uri.scheme == 'https') https.verify_mode = (OpenSSL::SSL::VERIFY_PEER) raw_res = https.start do |conn| conn.get("#{uri.path}?#{uri.query}") end This works just great in Mac OS X. When I try to reach an insecure URI, it raises an exception, and when I try to reach a secure URI, it allows me normally, just like expected. The problem starts when I deploy my application on my Linux server. I tried in both Ubuntu and Red Hat. Independent of what URI I try to reach, it always raises this exception: OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed from /usr/local/lib/ruby/1.8/net/http.rb:586:in `connect' from /usr/local/lib/ruby/1.8/net/http.rb:586:in `connect' from /usr/local/lib/ruby/1.8/net/http.rb:553:in `do_start' from /usr/local/lib/ruby/1.8/net/http.rb:542:in `start' from (irb):7 I think this have something to do with my installed OpenSSL package, but I can't be sure. This are my installed OpenSSL packages: openssl.x86_64 0.9.8e-12.el5 installed openssl-devel.x86_64 0.9.8e-12.el5 installed I tried using HTTParty as well, but it just ignores the SSL certificate. I hope someone can help me, or tell me about a gem that works the way I need. Thanks.

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  • Caching and accessing configuration data in ASP.NET MVC app.

    - by Sosh
    I'm about to take a look at how to implement internationalisation for an ASP.NET MVC project. I'm looking at how to allow the user to change languages. My initial though is a dropdownlist containing each of the supported langauages. Whoever a few questions have come to mind: How to store the list of supported languages? (e.g. just "en", "English"; "fr", "French" etc.) An xml file? .config files? If I store this in a file I'll have to cache this (at startup I guess). So, what would be best, load the xml data into a list (somehow) and store this list in the System.Web.Cache? Application State? How then to load this data into the view (for display in a dropdown)? Give the view direct access to the cache? Just want to make sure I'm going in the right direction here... Thank you.

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  • WPF Collapsed Grid not Styling

    - by Eric
    So, I have a grid inside a listbox. The purpose is that when the listboxitem is selected, I want the grid to show, having the selected item expand to show more detail information. I set up a style trigger for this and it works great, except for one thing: the labels and textblocks styles are unapplied on the grid. I'm assuming this has something to do with the default state of the listboxitem being collapsed, so wpf skips the styles, I was hoping it would put them on when selected fired, but it doesn't. If I use Style="{StaticResource Mystyle}" on each label/textblock, it styles fine, it just seems to not be doing the inherited style magic like it does with visible grids elsewhere in the app. See code below, the labels don't show up bolded or anything when the grid appears. <Style TargetType="{x:Type Grid}" x:Key="ListBoxItemCollapseGrid"> <Style.Triggers> <DataTrigger Binding="{Binding Path=IsSelected, RelativeSource= { RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBoxItem} } }" Value="False"> <Setter Property="Grid.Visibility" Value="Collapsed" /> </DataTrigger> </Style.Triggers> <Style.Resources> <Style TargetType="{x:Type Label}"> <Setter Property="FontWeight" Value="Bold" /> <Setter Property="Foreground" Value="{StaticResource BaseText}" /> <Setter Property="Padding" Value="3,0,0,0" /> </Style> <Style TargetType="{x:Type TextBlock}"> <Setter Property="Foreground" Value="{StaticResource BaseText}" /> </Style> </Style.Resources> </Style>

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  • PHP: How to store XML data in an array?

    - by tommy
    Below is the XML I am working with - there are more items - this is the first set. How can I get these elements in to an array? I have been trying with PHP's SimpleXML etc. but I just cant do it. <response xmlns:lf="http://api.lemonfree.com/ns/1.0"> <lf:request_type>listing</lf:request_type> <lf:response_code>0</lf:response_code> <lf:result type="listing" count="10"> <lf:item id="56832429"> <lf:attr name="title">Used 2005 Ford Mustang V6 Deluxe</lf:attr> <lf:attr name="year">2005</lf:attr> <lf:attr name="make">FORD</lf:attr> <lf:attr name="model">MUSTANG</lf:attr> <lf:attr name="vin">1ZVFT80N555169501</lf:attr> <lf:attr name="price">12987</lf:attr> <lf:attr name="mileage">42242</lf:attr> <lf:attr name="auction">no</lf:attr> <lf:attr name="city">Grand Rapids</lf:attr> <lf:attr name="state">Michigan</lf:attr> <lf:attr name="image">http://www.lemonfree.com/images/stock_images/thumbnails/2005_38_557_80.jpg</lf:attr> <lf:attr name="link">http://www.lemonfree.com/56832429.html</lf:attr> </lf:item> <!-- more items --> </lf:result> </response> Thanks guys EDIT: I want the first items data in easy to access variables, I've been struggling for a couple of days to get SimpleXML to work as I am new to PHP, so I thought manipulating an array is easier to do.

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  • Generic unit test scheduling

    - by Raphink
    Hello, I'm (re)writing a program that does generic unit test scheduling. The current program is a mono-threaded Perl program, but I'm willing to modularize it and parallelize the tests. I'm also considering rewriting it in Python. Here is what I need to do: I have a list of tests, with the following attributes: uri: a URI to test (could be HTTP/HTTPS/SSH/local) ; depends: an associative array of tests/values that this test depends on ; join: a list of DB joints to be added when selecting items to process in this test ; depends_db: additional conditions to add to the DB request when selecting items to process in this test. The program builds a dependency tree, beginning with the tests that have no dependencies ; for each test: a list of items is selected from the database using the conditions (results of depending tests, joints and depends_db) ; the list of items is sent to the URI (using POST or stdin) ; the result is retrived as a YAML file listing the state and comments for the test for each tested item ; the results are stored in the DB ; the test returns, allowing depending tests to be performed. the program generates reports (CSV, DB, graphviz) of the performed tests. The primary use of this program currently is to test a fleet of machines against services such as backup, DNS, etc. The tests can then be: - backup: hosted on the backup machine(s), called through HTTP, checks if the machines' backup went well ; - DNS: hosted on the local machine, called via stdin, checks if the machines' fqdn have a valid DNS entry. Does such a tool/module already exist? What would be the best implementation to achieve this (using Perl or Python)?

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  • Can I compare a template variable to an integer in App Engine templates?

    - by matt b
    Using Django templates in Google App Engine (on Python), is it possible to compare a template variable to an integer in an {% if %} block? views.py: class MyHandler(webapp.RequestHandler): def get(self): foo_list = db.GqlQuery(...) ... template_values['foos'] = foo_list template_values['foo_count'] = len(foo_list) handler.response.out.write(template.render(...)) My template: {% if foo_count == 1 %} There is one foo. {% endif %} This blows up with 'if' statement improperly formatted. What I was attempting to do in my template was build a simple if/elif/else tree to be grammatically correct to be able to state #foo_count == 0: There are no foos. #foo_count == 1: There is one foo. #else: There are {{ foos|length }} foos. Browsing the Django template documents (this link provided in the GAE documentation appears to be for versions of Django far newer than what is supported on GAE), it appears as if I can only actually use boolean operators (if in fact boolean operators are supported in this older version of Django) with strings or other template variables. Is it not possible to compare variables to integers or non-strings with Django templates? I'm sure there is an easy way to workaround this - built up the message string on the Python side rather than within the template - but this seems like such a simple operation you ought to be able to handle in a template. It sounds like I should be switching to a more advanced templating engine, but as I am new to Django (templates or any part of it), I'd just like some confirmation first.

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  • Code golf: combining multiple sorted lists into a single sorted list

    - by Alabaster Codify
    Implement an algorithm to merge an arbitrary number of sorted lists into one sorted list. The aim is to create the smallest working programme, in whatever language you like. For example: input: ((1, 4, 7), (2, 5, 8), (3, 6, 9)) output: (1, 2, 3, 4, 5, 6, 7, 8, 9) input: ((1, 10), (), (2, 5, 6, 7)) output: (1, 2, 5, 6, 7, 10) Note: solutions which concatenate the input lists then use a language-provided sort function are not in-keeping with the spirit of golf, and will not be accepted: sorted(sum(lists,[])) # cheating: out of bounds! Apart from anything else, your algorithm should be (but doesn't have to be) a lot faster! Clearly state the language, any foibles and the character count. Only include meaningful characters in the count, but feel free to add whitespace to the code for artistic / readability purposes. To keep things tidy, suggest improvement in comments or by editing answers where appropriate, rather than creating a new answer for each "revision". EDIT: if I was submitting this question again, I would expand on the "no language provided sort" rule to be "don't concatenate all the lists then sort the result". Existing entries which do concatenate-then-sort are actually very interesting and compact, so I won't retro-actively introduce a rule they break, but feel free to work to the more restrictive spec in new submissions. Inspired by http://stackoverflow.com/questions/464342/combining-two-sorted-lists-in-python

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  • Java: Is clone() really ever used? What about defensive copying in getters/setters?

    - by GreenieMeanie
    Do people practically ever use defensive getters/setters? To me, 99% of the time you intend for the object you set in another object to be a copy of the same object reference, and you intend for changes you make to it to also be made in the object it was set in. If you setDate(Date dt) and modify dt later, who cares? Unless I want some basic immutable data bean that just has primitives and maybe something simple like a Date, I never use it. As far as clone, there are issues as to how deep or shallow the copy is, so it seems kind of "dangerous" to know what is going to come out when you clone an Object. I think I have only used clone() once or twice, and that was to copy the current state of the object because another thread (ie another HTTP request accessing the same object in Session) could be modifying it. Edit - A comment I made below is more the question: But then again, you DID change the Date, so it's kind of your own fault, hence whole discussion of term "defensive". If it is all application code under your own control among a small to medium group of developers, will just documenting your classes suffice as an alternative to making object copies? Or is this not necessary, since you should always assume something ISN'T copied when calling a setter/getter?

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  • Does LaTeX have an array data structure?

    - by drasto
    Are there arrays in LaTeX? I don't mean the way to typeset arrays. I mean arrays as the data structure in LaTeX/TeX as a "programming language". I need to store a number of vbox-es or hbox-es in an array. It may be something like "an array of macros". More details: I have an environment that should typeset songs. I need to store some songs' paragraphs given as arguments to my macro \songparagraph (so I will not typeset them, just store those paragraphs). As I don't know how many paragraphs can be in one particular song I need an array for this. When the environment is closed, all the paragraphs will be typeset - but they will be first measured and the best placement for each paragraph will be computed (for example, some paragraphs can be put one aside the other in two columns to make the song look more compact and save some space). Any ideas would be welcome. Please, if you know about arrays in LaTeX, post a link to some basic documentation, tutorial or just state basic commands.

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  • Are there arrays in Latex(not asking for the way to typeset them but to use for programing)

    - by drasto
    Are there arrays in Latex ? I don't mean the way to typeset arrays. I mean arrays as the data structure in latex/tex as a "programming language". I need to store a number of vbox-es or hbox-es in array. Or it may by something like "an array of macros". More details: I have an environment that should typeset songs. I need to store some songs paragraphs given as arguments to my macro \songparagraph(so I will not typeset them, just store those paragraphs). As I don't know how many paragraphs can by in one particular song I need an array for this... When the environment is closed all the paragraphs will be typeset - but they will be first measured and the best placement for each paragraph will be computed(for example, some paragraphs can be put one aside other in two columns to make the song look more compact and save some space). Any ides would be welcome. Please if you know about that there are some arrays in latex post a link to some basic documentation, tutorial or just state basic commands.

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  • Visual Studio: How to attach a debugger dynamically to a specific process

    - by Jeff Cyr
    I am building an internal dev tool to manage different processes commonly used in our development environment. The tool show the list the monitored processes, indicate their running state and allow to start or stop each process. I'd like to add the functionality of attaching a debugger to a monitored process from my tool instead of going in 'Debug-Attach to process' in visual studio and finding the process. My goal is to have something like Debugger.Launch() that would show a list of the available visual studio. I can't use Debugger.Launch() because it lauches the debugger on the process that make the call. I would need something like Debugger.Launch(processId). Does anyone know how to acheive this functionality? A solution could be to implement a command in each monitored process to call Debugger.Launch() when the command is received from the monitoring tool, but I would prefer something that does not require to modify the code of the monitored processes. Side question: When using Debugger.Launch(), instances of Visual Studio that already have a debugger attached are not listed. Visual Studio is not limited to one attached debugger, you can attach on multiple process when using 'Debug - Attach to process'. Anyone know how to bypass this limitation when using Debugger.Launch() or an alternative?

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  • Java - How to detect that the internet connection has got disconnected through a java desktop applic

    - by Yatendra Goel
    I am developing a Java Desktop Application that access internet. It is a multi-threaded application, each thread do the same work (means each thread is an instance of same Thread class). Now, as all the threads need internet connection to be active, there should be some mechanism that detects whether an internet connection is active or not. Q1. How to detect whether the internet connection is active or not? Q2. Where to implement this internet-status-check-mechanism code? Should I start a separate thread for checking internet status regularly and notifies all the threads when the status changes from one state to another? Or should I let each thread check for the internet-status itself? Q3. This issue should be a very common issue as every application accessing an internet should deal with this problem. So how other developers usually deal with this problem? Q4. If you could give me a reference to a good demo application that addresses this issue then it would greatly help me.

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  • Data Flow Object Graph and An Execution Engine for it

    - by M Dotnet
    I would like to build a custom workflow engine from scratch. The input to this workflow is a data flow diagram which is composed of a series of activities connected together through lines where each each represent the data flow. Each activity can export multiple outputs. Activities are complex math functions but the logic is hidden from the user. My workflow engine job is to execute the given data flow diagram. Each activity within the data flow diagram is a custom activity and each activity can output different outputs. How do you suggest to model the data flow diagram object? I need to be able to construct the data flow diagram problematically (no need for drag and drop) but I need to display the final result graphically (for display and debugging purposes). Are there any libraries out there that I could use? Should I keep the workflow presentable as an xml? I know that there are many projects out there trying to essentially doing similar thing by building such workflow engines but I need something light weight and open source. I do not need any state machine execution engine and mine is primarily sequential workflow with fork and join capabilities. My activities are wrappable as basic C# classes and I do NOT want to use anything as heavy as .NET workflow foundation.

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  • MVVM-Light EventToCommand Behavior for CheckBox Checked/Unchecked in Silverlight

    - by George Durzi
    I would like to handle the Checked and Unchecked events of a Checkbox control and execute a command in my ViewModel. I wired up an EventTrigger for both the Checked and Unchecked events as follows: <CheckBox x:Name="chkIsExtendedHr" IsChecked="{Binding Schedule.Is24Hour, Mode=TwoWay}"> <i:Interaction.Triggers> <i:EventTrigger EventName="Checked"> <GalaSoft_MvvmLight_Command:EventToCommand CommandParameter="{Binding IsChecked, ElementName=chkIsExtendedHr}" Command="{Binding Path=SetCloseTime, Mode=OneWay}" /> </i:EventTrigger> <i:EventTrigger EventName="Unchecked"> <GalaSoft_MvvmLight_Command:EventToCommand CommandParameter="{Binding IsChecked, ElementName=chkIsExtendedHr}" Command="{Binding Path=SetCloseTime, Mode=OneWay}" /> </i:EventTrigger> </i:Interaction.Triggers> </CheckBox> I defined a RelayCommand in my ViewModel and wired up an action for it: public RelayCommand<Boolean> SetCloseTime{ get; private set; } ... SetCloseTime= new RelayCommand<bool>(ExecuteSetCloseTime); The parameter in the action for the command always resolves to the previous state of the CheckBox, e.g. false when the CheckBox is checked, and true when the CheckBox is unchecked. void ExecuteSetCloseTime(bool isChecked) { if (isChecked) { // do something } } Is this expected behavior? I have a workaround where I have separate triggers (and commands) for the Checked and Unchecked and use a RelayCommand instead of RelayCommand<bool>. Each command executes correctly when the CheckBox is checked and unchecked. Feels a little dirty though - even dirtier than having UI code in my ViewModel :) Thanks

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  • Can I use a *.tag from another *.tag file in the same /WEB-INF/tags folder?

    - by Ytsejammer
    Hello, I am trying to refactor my JSP code so that a small conditional test condition gets reused through a *.tag file. There are some big parts of my UI that depend on the value of a two-state property of an object present in the request. Let's say the property is 'gender' and the object is of type Person. Like I said, I would like to simplify & centralize the test on the gender property using a tag. For this purpose, I created two tag files: /WEB-INF/tags/if-male.tag /WEB-INF/tags/if-female.tag Now, I have another tiny spot that gets repeated in all over my application; let's say is the salutation to my site user. With this idea, I created a tag like this: /WEB-INF/tags/salutation.tag As you can imagine, I am trying to use the if-male/if-female test within the salutation.tag file to output 'Mrs.' or 'Mr.' like this: <%@ tag body-content="empty" %> <%@ taglib prefix="g" uri="/WEB-INF/tags" %> <g:if-male> Mr. </g:if-male> <g:if-female> Mrs. </g:if-female> Is the use of the if-male/if-female tags legal within the salutation.tag file? I have tried with such arrangement, but it looks like the JDeveloper 10.1.3.4 compiler gets confused and cannot deal with the salutation.tag tag invoking the other two tags in the same 'library' (folder under /WEB-INF/tags). The reference works perfectly in Jetty 6 and it looks like it works as well if I deploy the application to OC4J directly without relying on JDeveloper to pre-compile all my JSPs. I hope someone can shed some light on this. Thanks, YJ

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  • Optimizing processing and management of large Java data arrays

    - by mikera
    I'm writing some pretty CPU-intensive, concurrent numerical code that will process large amounts of data stored in Java arrays (e.g. lots of double[100000]s). Some of the algorithms might run millions of times over several days so getting maximum steady-state performance is a high priority. In essence, each algorithm is a Java object that has an method API something like: public double[] runMyAlgorithm(double[] inputData); or alternatively a reference could be passed to the array to store the output data: public runMyAlgorithm(double[] inputData, double[] outputData); Given this requirement, I'm trying to determine the optimal strategy for allocating / managing array space. Frequently the algorithms will need large amounts of temporary storage space. They will also take large arrays as input and create large arrays as output. Among the options I am considering are: Always allocate new arrays as local variables whenever they are needed (e.g. new double[100000]). Probably the simplest approach, but will produce a lot of garbage. Pre-allocate temporary arrays and store them as final fields in the algorithm object - big downside would be that this would mean that only one thread could run the algorithm at any one time. Keep pre-allocated temporary arrays in ThreadLocal storage, so that a thread can use a fixed amount of temporary array space whenever it needs it. ThreadLocal would be required since multiple threads will be running the same algorithm simultaneously. Pass around lots of arrays as parameters (including the temporary arrays for the algorithm to use). Not good since it will make the algorithm API extremely ugly if the caller has to be responsible for providing temporary array space.... Allocate extremely large arrays (e.g. double[10000000]) but also provide the algorithm with offsets into the array so that different threads will use a different area of the array independently. Will obviously require some code to manage the offsets and allocation of the array ranges. Any thoughts on which approach would be best (and why)?

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  • rake test not copying development postgres db with sequences

    - by Robert Crida
    I am trying to develop a rails application on postgresql using a sequence to increment a field instead of a default ruby approach based on validates_uniqueness_of. This has proved challenging for a number of reasons: 1. This is a migration of an existing table, not a new table or column 2. Using parameter :default = "nextval('seq')" didn't work because it tries to set it in parenthesis 3. Eventually got migration working in 2 steps: change_column :work_commencement_orders, :wco_number_suffix, :integer, :null => false#, :options => "set default nextval('wco_number_suffix_seq')" execute %{ ALTER TABLE work_commencement_orders ALTER COLUMN wco_number_suffix SET DEFAULT nextval('wco_number_suffix_seq'); } Now this would appear to have done the correct thing in the development database and the schema looks like: wco_number_suffix | integer | not null default nextval('wco_number_suffix_seq'::regclass) However, the tests are failing with PGError: ERROR: null value in column "wco_number_suffix" violates not-null constraint : INSERT INTO "work_commencement_orders" ("expense_account_id", "created_at", "process_id", "vo2_issued_on", "wco_template", "updated_at", "notes", "process_type", "vo_number", "vo_issued_on", "vo2_number", "wco_type_id", "created_by", "contractor_id", "old_wco_type", "master_wco_number", "deadline", "updated_by", "detail", "elective_id", "authorization_batch_id", "delivery_lat", "delivery_long", "operational", "state", "issued_on", "delivery_detail") VALUES(226, '2010-05-31 07:02:16.764215', 728, NULL, E'Default', '2010-05-31 07:02:16.764215', NULL, E'Procurement::Process', NULL, NULL, NULL, 226, NULL, 276, NULL, E'MWCO-213', '2010-06-14 07:02:16.756952', NULL, E'Name 4597', 220, NULL, NULL, NULL, 'f', E'pending', NULL, E'728 Test Road; Test Town; 1234; Test Land') RETURNING "id" The explanation can be found when you inspect the schema of the test database: wco_number_suffix | integer | not null So what happened to the default? I tried adding task: template: smmt_ops_development to the database.yml file which has the effect of issuing create database smmt_ops_test template = "smmt_ops_development" encoding = 'utf8' I have verified that if I issue this then it does in fact copy the default nextval. So clearly rails is doing something after that to suppress it again. Any suggestions as to how to fix this? Thanks Robert

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  • Which single IoC/DI container would you recommend using and why?

    - by Rob G
    I'm asking this question because it's a good way to gauge how the community at large feels about the various containers/frameworks and why. Also, whilst my expertise may lie in .Net development, I am very interested in which frameworks are popular (and why) in other languages. If I feel the need to start digging into Java for instance, then I'd like to hit the ground running with good (comfortable) knowledge that I'm starting in the right direction. Does Ruby even need one with all its magnificent dynamicism? I have my own opinions on the .Net front, and will probably add my own personal favourite in an answer below, but I'm interested in all languages and opinions here. With all that in mind, could you please state only one IoC/DI framework that you use and recommend with the language of choice (Java/Ruby/.Net/Smalltalk etc.) and your reasoning for your choice, and if someone has already answered your particular flavour, then you can just vote it up and add comments to it so that anyone looking for advice in future and see which frameworks are more than likely to work for them once they read your reasoning. I'm hoping that over time, the best ones will bubble up to the top. I realise that this question doesn't have only one correct answer, so I won't be choosing one - the community will decide which framework gets the most votes and why. Of course, if you really feel strongly opposed to a particular brand, you could take the reputation hit and vote it down too, and this question can serve as a true wiki-style entry for research into this field. Remember, only one IoC per answer you write please - if you feel the need to promote two frameworks, then write two answers with your reasoning inside for each choice - then others in the community can agree or disagree with you.

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  • Conversion failed: SqlParameter and DateTime

    - by Tim
    I'm changing old,vulnerable sqlcommands with SqlParameters but get a SqlException: System.Data.SqlClient.SqlException {"Conversion failed when converting datetime from character string."} on sqlCommand.ExecuteScalar() Dim sqlString As String = _ "SELECT TOP 1 " & _ "fiSL " & _ "FROM " & _ "tabData AS D " & _ "WHERE " & _ "D.SSN_Number = '@SSN_Number' " & _ "AND D.fiProductType = 1 " & _ "AND D.Repair_Completion_Date > '@Repair_Completion_Date' " & _ "ORDER BY " & _ "D.Repair_Completion_Date ASC" Dim obj As Object Dim sqlCommand As SqlCommand Try sqlCommand = New SqlCommand(sqlString, Common.MyDB.SqlConn_RM2) sqlCommand.CommandTimeout = 120 sqlCommand.Parameters.AddWithValue("@SSN_Number", myClaim.SSNNumber) sqlCommand.Parameters.AddWithValue("@Repair_Completion_Date", myClaim.RepairCompletionDate) If Common.MyDB.SqlConn_RM2.State <> System.Data.ConnectionState.Open Then Common.MyDB.SqlConn_RM2.Open() obj = sqlCommand.ExecuteScalar() Catch ex As Exception Dim debug As String = ex.ToString Finally Common.MyDB.SqlConn_RM2.Close() End Try myClaim.RepairCompletionDate is a SQLDateTime. Do i have to remove the quotes in the sqlString to compare Date columns? But then i dont get a exception but incorrect results.

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  • Why is this SocketException not caught by a generic catch routine?

    - by Tarnschaf
    Our company provides a network component (DLL) for a GUI application. It uses a Timer that checks for disconnections. If it wants to reconnect, it calls: internal void timClock_TimerCallback(object state) { lock (someLock) { // ... try { DoConnect(); } catch (Exception e) { // Log e.Message omitted // Raise event with e as parameter ErrorEvent(this, new ErrorEventArgs(e)); DoDisconnect(); } // ... } } So the problem is, inside of the DoConnect() routine a SocketException is thrown (and not caught). I would assume, that the catch (Exception e) should catch ALL exceptions but somehow the SocketException was not caught and shows up to the GUI application. protected void DoConnect() { // client = new TcpClient(); client.NoDelay = true; // In the following call the SocketException is thrown client.Connect(endPoint.Address.ToString(), endPoint.Port); // ... (login stuff) } The doc confirmed that SocketException extends Exception. The stacktrace that showed up is: TcpClient.Connect() -> DoConnect() -> timClock_TimerCallback So the exception is not thrown outside the try/catch block. Any ideas why it doesn't work?

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