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  • PHP ZipArchive Empty in IE

    - by Jesse Bunch
    Hi, I am using PHP's ZipArchive class to create a zip file containing photos and then serve it up to the browser for download. Here is my code: /** * Grabs the order, packages the files, and serves them up for download. * * @param string $intEntryID * @return void * @author Jesse Bunch */ public static function download_order_by_entry_id($intUniqueID) { $objCustomer = PhotoCustomer::get_customer_by_unique_id($intUniqueID); if ($objCustomer): if (!class_exists('ZipArchive')): trigger_error('ZipArchive Class does not exist', E_USER_ERROR); endif; $objZip = new ZipArchive(); $strZipFilename = sprintf('%s/application/tmp/%s-%s.zip', $_SERVER['DOCUMENT_ROOT'], $objCustomer->getEntryID(), time()); if ($objZip->open($strZipFilename, ZIPARCHIVE::CREATE) !== TRUE): trigger_error('Unable to create zip archive', E_USER_ERROR); endif; foreach($objCustomer->arrPhotosRequested as $objPhoto): $filename = PhotoCart::replace_ee_file_dir_in_string($objPhoto->strHighRes); $objZip->addFile($filename,sprintf('/press_photos/%s-%s', $objPhoto->getEntryID(), basename($filename))); endforeach; $objZip->close(); header('Last-Modified: '.gmdate('D, d M Y H:i:s', filemtime($strZipFilename)).' GMT', TRUE, 200); header('Cache-Control: no-cache', TRUE); header('Pragma: Public', TRUE); header('Expires: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT', TRUE); header('Content-Length: '.filesize($strZipFilename), TRUE); header('Content-disposition: attachment; filename=press_photos.zip', TRUE); header('Content-Type: application/octet-stream', TRUE); ob_start(); readfile($strZipFilename); ob_end_flush(); exit; else: trigger_error('Invalid Customer', E_USER_ERROR); endif; } This code works really well with all browsers but IE. In IE, the file downloads correctly, but the zip archive is empty. When trying to extract the files, Windows tells me that the zip archive is corrupt. Has anyone had this issue before?

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  • ASP.NET DropDownList posting ""

    - by Daniel
    I am using ASP.NET forms version 3.5 in VB I have a dropdownlist that is filled with data from a DB with a list of countries The code for the dropdown list is <label class="ob_label"> <asp:DropDownList ID="lstCountry" runat="server" CssClass="ob_forminput"> </asp:DropDownList> Country*</label> And the code that the list is Dim selectSQL As String = "exec dbo.*******************" ' Define the ADO.NET objects. Dim con As New SqlConnection(connectionString) Dim cmd As New SqlCommand(selectSQL, con) Dim reader As SqlDataReader ' Try to open database and read information. Try con.Open() reader = cmd.ExecuteReader() ' For each item, add the author name to the displayed ' list box text, and store the unique ID in the Value property. Do While reader.Read() Dim newItem As New ListItem() newItem.Text = reader("AllSites_Countries_Name") newItem.Value = reader("AllSites_Countries_Id") CType(LoginViewCart.FindControl("lstCountry"), DropDownList).Items.Add(newItem) Loop reader.Close() CType(LoginViewCart.FindControl("lstCountry"), DropDownList).SelectedValue = 182 Catch Err As Exception Response.Redirect("~/error-on-page/") MailSender.SendMailMessage("*********************", "", "", OrangeBoxSiteId.SiteName & " Error Catcher", "<p>Error in sub FillCountry</p><p>Error on page:" & HttpContext.Current.Request.Url.AbsoluteUri & "</p><p>Error details: " & Err.Message & "</p>") Response.Redirect("~/error-on-page/") Finally con.Close() End Try When the form is submitted an error occurs which says that the string "" cannot be converted to the datatype integer. For some reason the dropdownlist is posting "" rather than the value for the selected country.

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  • Using clases in PHP to store function

    - by Artur
    Hello! I need some advise on my PHP code organisation. I need classes where I can store different functions, and I need access to those classes in different parts of my project. Making an object of this classes each time is too sadly, so I've found a two ways have to solve it. First is to use static methods, like class car { public static $wheels_count = 4; public static function change_wheels_count($new_count) { car::$wheels_count = $new_count; } } Second is to use singleton pattern: class Example { // Hold an instance of the class private static $instance; // The singleton method public static function singleton() { if (!isset(self::$instance)) { $c = __CLASS__; self::$instance = new $c; } return self::$instance; } } But author of the article about singletons said, that if I have too much singletons in my code I should reconstruct it. But I need a lot of such classes. Can anybody explain prons and cons of each way? Which is mostly used? Are there more beautiful ways?

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  • Directly call distutils' or setuptools' setup() function with command name/options, without parsing

    - by Ryan B. Lynch
    I'd like to call Python's distutils' or setuptools' setup() function in a slightly unconventional way, but I'm not sure whether distutils is meant for this kind of usage. As an example, let's say I currently have a 'setup.py' file, which looks like this (lifted verbatim from the distutils docs--the setuptools usage is almost identical): from distutils.core import setup setup(name='Distutils', version='1.0', description='Python Distribution Utilities', author='Greg Ward', author_email='[email protected]', url='http://www.python.org/sigs/distutils-sig/', packages=['distutils', 'distutils.command'], ) Normally, to build just the .spec file for an RPM of this module, I could run python setup.py bdist_rpm --spec-only, which parses the command line and calls the 'bdist_rpm' code to handle the RPM-specific stuff. The .spec file ends up in './dist'. How can I change my setup() invocation so that it runs the 'bdist_rpm' command with the '--spec-only' option, WITHOUT parsing command-line parameters? Can I pass the command name and options as parameters to setup()? Or can I manually construct a command line, and pass that as a parameter, instead? NOTE: I already know that I could call the script in a separate process, with an actual command line, using os.system() or the subprocess module or something similar. I'm trying to avoid using any kind of external command invocations. I'm looking specifically for a solution that runs setup() in the current interpreter. For background, I'm converting some release-management shell scripts into a single Python program. One of the tasks is running 'setup.py' to generate a .spec file for further pre-release testing. Running 'setup.py' as an external command, with its own command line options, seems like an awkward method, and it complicates the rest of the program. I feel like there may be a more Pythonic way.

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  • svnsync loses revision properties although hook installed

    - by roesslerj
    Hello all! I have a pretty weird problem. We have setup an SVN-Mirror via cronjob (because it needs to go from inside to outside of a firewall, so no post-commit-hook possible) and svnsync. We installed a pre-revprop-hook just as told. Everything seems to work fine, except that it doesn't. E.g. when manually executing the script. # svnsync --non-interactive sync file://<path-to-mirror> --source-username <usr> --source-password <pwd> Committed revision 19817. Copied properties for revision 19817. No error, no complaints. But if checking for the revision properties it says: # svnlook info <path-to-mirror> 0 # svn info -r HEAD file://<path-to-mirror> 2>&1 Path: <root-of-mirror> URL: file://<path-to-mirror> Repository Root: file://<path-to-mirror> Repository UUID: <uid> Revision: 19817 Node Kind: directory Last Changed Rev: 19817 So somehow the author and timestamp information gets lost. But we need that information for our internal processes. Since no error or warning is produced I have absolutely no idea even where to start to look. Everything is local (except for the remote master), so there are no server-logs to look at. I also tried to manually recopy via svnsync copy-revprops (http://chestofbooks.com/computers/revision-control/subversion-svn/svnsync-Copy-revprops-Ref-svnsync-C-Copy-revprops.html). It says Copied properties for revision 19885. But when I query them, it's just the same. Any ideas how I could approach that problem, or even better -- how to solve it? Any ideas appreciated.

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  • Coldbox Security Interceptor

    - by faheem
    Hi I am new to coldbox and working on a guestbook messaging forum. does anyone know how I can apply some rule in coldbox to show edit and delete for specified users of admin or user in the edit page. I am not sure how to specify this as I already have my rules here as shown in securityRules.xml: SecurityRules.XML <?xml version="1.0" encoding="UTF-8"?> <!-- Declare as many rule elements as you want, order is important Remember that the securelist can contain a list of regular expression if you want ex: All events in the user handler user\..* ex: All events .* ex: All events that start with admin ^admin If you are not using regular expression, just write the text that can be found in an event. <whitelist>ehSecurity\.dspLogin,ehSecurity\.doLogin,ehSecurity\.dspLogoff</whitelist> --> <rules> <rule> <whitelist>^entries,ehSecurity\..*,registry\..*</whitelist> <securelist></securelist> <roles>admin</roles> <permissions>read,write</permissions> <redirect>ehSecurity.dspLogin</redirect> </rule> <rule> <whitelist>^entries,ehSecurity\..*,main\..*,^registry</whitelist> <securelist></securelist> <roles>author,admin</roles> <permissions>read</permissions> <redirect>ehSecurity.dspLogin</redirect> </rule> </rules>

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  • Avoid loading unnecessary data from db into objects (web pages)

    - by GmGr
    Really newbie question coming up. Is there a standard (or good) way to deal with not needing all of the information that a database table contains loaded into every associated object. I'm thinking in the context of web pages where you're only going to use the objects to build a single page rather than an application with longer lived objects. For example, lets say you have an Article table containing id, title, author, date, summary and fullContents fields. You don't need the fullContents to be loaded into the associated objects if you're just showing a page containing a list of articles with their summaries. On the other hand if you're displaying a specific article you might want every field loaded for that one article and maybe just the titles for the other articles (e.g. for display in a recent articles sidebar). Some techniques I can think of: Don't worry about it, just load everything from the database every time. Have several different, possibly inherited, classes for each table and create the appropriate one for the situation (e.g. SummaryArticle, FullArticle). Use one class but set unused properties to null at creation if that field is not needed and be careful. Give the objects access to the database so they can load some fields on demand. Something else? All of the above seem to have fairly major disadvantages. I'm fairly new to programming, very new to OOP and totally new to databases so I might be completely missing the obvious answer here. :)

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  • Javascript Rich Display WYSIWYG Component/Methodology

    - by Laramie
    quick back story-- I am working on ASP.Net based template editor that lets authors create text templates using Javascript inserted placeholder tags that will be filled in with dynamic text when the templates are used to display the final results. For example the author might create a template like The word [%12#add] was generated dynamically. The application would eventually replace the tag with a dynamic word down the road (though it's not specifically relevant to this post) The word foo was generated dynmamically. Depending on the circumstances, the template may be created in a text input, textarea or a modified version of the Ajax Control Toolkit HTML Editor. There might be 40 or more of these editable elements on the page, so using lots of stripped down or modified HTML editors would probably bog the page down too much. The problem is that the tags such as [%12#add] are displayed inline with the user text and the result is confusing and aesthetically gross. The goal is parse the contens of the source element and when a tags such as [%12#add] are encountered, display something prettier and less cryptic to the user such as a stylable element or image wherever tags such as [%12#add] occur. The application still needs the template text with the tags on postback. So the user might see The word tag placeholder was generated dynamically. but the original template would still be the value of the text input box The word [%12#add] was generated dynamically. It seems HTML editors like the ACT version and FckEditor accomplish this by rendering their output in an IFrame, but rather than kill myself trying to roll a lighter specialized version myself, I thought I'd ask if anyone knows of an existing free component or approach that has already tackled this. With good reason, I don't think S.O. allows HTML formatting, but the bold "tag placeholder" above would ideally be something like tag placeholder.

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  • How to create instances of related models in Django

    - by sevennineteen
    I'm working on a CMSy app for which I've implemented a set of models which allow for creation of custom Template instances, made up of a number of Fields and tied to a specific Customer. The end-goal is that one or more templates with a set of custom fields can be defined through the Admin interface and associated to a customer, so that customer can then create content objects in the format prescribed by the template. I seem to have gotten this hooked up such that I can create any number of Template objects, but I'm struggling with how to create instances - actual content objects - in those templates. For example, I can define a template "Basic Page" for customer "Acme" which has the fields "Title" and "Body", but I haven't figured out how to create Basic Page instances where these fields can be filled in. Here are my (somewhat elided) models... class Customer(models.Model): ... class Field(models.Model): ... class Template(models.Model): label = models.CharField(max_length=255) clients = models.ManyToManyField(Customer, blank=True) fields = models.ManyToManyField(Field, blank=True) class ContentObject(models.Model): label = models.CharField(max_length=255) template = models.ForeignKey(Template) author = models.ForeignKey(User) customer = models.ForeignKey(Customer) mod_date = models.DateTimeField('Modified Date', editable=False) def __unicode__(self): return '%s (%s)' % (self.label, self.template) def save(self): self.mod_date = datetime.datetime.now() super(ContentObject, self).save() Thanks in advance for any advice!

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  • image not displaying in midlet

    - by user316843
    Hello all,am new here. i have a slight problem; PLease look at the following code and tell me if am doing something wrong because the image is not displaying. i have made it really small so it should fit but its not displaying. i have images displaying in other screens but this main midlet would not. Here is the code: import java.io.IOException; import javax.microedition.midlet.*; import javax.microedition.lcdui.*; /** * @author jay */ public class WShop extends MIDlet implements CommandListener { /* Declare display variables*/ private Form mainForm; private Display display; private Command OK,Exit,wView, mView, myView; /* */ Categories categories = new Categories(this); Image image; public WShop() { /* initialize Screen and Command buttons that will be used when the application starts in the class constructor*/ mainForm = new Form("Wind Shopper"); OK = new Command("OK", Command.OK, 2); Exit = new Command("Exit", Command.EXIT, 0); wview= new Command("wview", Command.OK, 0); mview= new Command("mview", Command.OK, 0); try { /* retrieving the main image of the application*/ image = Image.createImage("/main.png"); } catch (IOException ex) { ex.printStackTrace(); } mainForm.addCommand(OK); mainForm.addCommand(Exit); mainForm.addCommand(wView); mainForm.addCommand(mView); mainForm.setCommandListener(this); } public void startApp() { /* checks to see if the display is currently empty and then sets it to the current screen */ if (display == null) { display = Display.getDisplay(this); } display.setCurrent(mainForm); } /* paused state of the application*/ public void pauseApp() { } /* Destroy Midlet state*/ public void destroyApp(boolean unconditional) { } Thanks in advance.

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  • java: can't use constructors in abstract class

    - by ufk
    Hi. I created the following abstract class for job scheduler in red5: package com.demogames.jobs; import com.demogames.demofacebook.MysqlDb; import org.red5.server.api.IClient; import org.red5.server.api.IConnection; import org.red5.server.api.IScope; import org.red5.server.api.scheduling.IScheduledJob; import org.red5.server.api.so.ISharedObject; import org.apache.log4j.Logger; import org.red5.server.api.Red5; /** * * @author ufk */ abstract public class DemoJob implements IScheduledJob { protected IConnection conn; protected IClient client; protected ISharedObject so; protected IScope scope; protected MysqlDb mysqldb; protected static org.apache.log4j.Logger log = Logger .getLogger(DemoJob.class); protected DemoJob (ISharedObject so, MysqlDb mysqldb){ this.conn=Red5.getConnectionLocal(); this.client = conn.getClient(); this.so=so; this.mysqldb=mysqldb; this.scope=conn.getScope(); } protected DemoJob(ISharedObject so) { this.conn=Red5.getConnectionLocal(); this.client=this.conn.getClient(); this.so=so; this.scope=conn.getScope(); } protected DemoJob() { this.conn=Red5.getConnectionLocal(); this.client=this.conn.getClient(); this.scope=conn.getScope(); } } Then i created a simple class that extends the previous one: public class StartChallengeJob extends DemoJob { public void execute(ISchedulingService service) { log.error("test"); } } The problem is that my main application can only see the constructor without any parameters. with means i can do new StartChallengeJob() why doesn't the main application sees all the constructors ? thanks!

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  • Am I mocking this helper function right in my Django test?

    - by CppLearner
    lib.py from django.core.urlresolvers import reverse def render_reverse(f, kwargs): """ kwargs is a dictionary, usually of the form {'args': [cbid]} """ return reverse(f, **kwargs) tests.py from lib import render_reverse, print_ls class LibTest(unittest.TestCase): def test_render_reverse_is_correct(self): #with patch('webclient.apps.codebundles.lib.reverse') as mock_reverse: with patch('django.core.urlresolvers.reverse') as mock_reverse: from lib import render_reverse mock_f = MagicMock(name='f', return_value='dummy_views') mock_kwargs = MagicMock(name='kwargs',return_value={'args':['123']}) mock_reverse.return_value = '/natrium/cb/details/123' response = render_reverse(mock_f(), mock_kwargs()) self.assertTrue('/natrium/cb/details/' in response) But instead, I get File "/var/lib/graphyte-webclient/graphyte-webenv/lib/python2.6/site-packages/django/core/urlresolvers.py", line 296, in reverse "arguments '%s' not found." % (lookup_view_s, args, kwargs)) NoReverseMatch: Reverse for 'dummy_readfile' with arguments '('123',)' and keyword arguments '{}' not found. Why is it calling reverse instead of my mock_reverse (it is looking up my urls.py!!) The author of Mock library Michael Foord did a video cast here (around 9:17), and in the example he passed the mock object request to the view function index. Furthermore, he patched POll and assigned an expected return value. Isn't that what I am doing here? I patched reverse? Thanks.

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  • C# DynamicMethod prelink

    - by soywiz
    I'm the author of a psp emulator made in C#. I'm generating lots of "DynamicMethod" using ILGenerator. I'm converting assembly code into an AST, and then generating IL code and building that DynamicMethod. I'm doing this in another thread, so I can generate new methods while the program is executing others so it can run smoothly. My problem is that the native code generation is lazy, so the machine code is generated when the function is called, not when the IL is generated. So it generates in the program executing thread, native code generation is prettly slow as it is the asm-ast-il step. I have tried the Marshal.Prelink method that it is suposed to generate the machine code before executing the function. It does work on Mono, but it doesn't work on MS .NET. Marshal.Prelink(MethodInfo); Is there a way of prelinking a DynamicMethod on MS .NET? I thought adding a boolean parameter to the function that if set, exits the function immediately so no code is actually executed. I could "prelink" that way, but I think that's a nasty solution I want to avoid. Any idea?

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  • White space problem while using php proxy

    - by KCC
    Hi, I'm using a php web proxy with my URL already encoded and keep having getting a malformed request error once I have any text after a %20. Any idea why this would be happening? The web proxy code I'm using is just a sample that I took from yahoo services: <?php // PHP Proxy example for Yahoo! Web services. // Responds to both HTTP GET and POST requests // // Author: Jason Levitt // December 7th, 2005 // // Allowed hostname (api.local and api.travel are also possible here) define ('HOSTNAME', 'http://search.yahooapis.com/'); // Get the REST call path from the AJAX application // Is it a POST or a GET? $path = ($_POST['yws_path']) ? $_POST['yws_path'] : $_GET['yws_path']; $url = HOSTNAME.$path; // Open the Curl session $session = curl_init($url); // If it's a POST, put the POST data in the body if ($_POST['yws_path']) { $postvars = ''; while ($element = current($_POST)) { $postvars .= urlencode(key($_POST)).'='.urlencode($element).'&'; next($_POST); } curl_setopt ($session, CURLOPT_POST, true); curl_setopt ($session, CURLOPT_POSTFIELDS, $postvars); } // Don't return HTTP headers. Do return the contents of the call curl_setopt($session, CURLOPT_HEADER, false); curl_setopt($session, CURLOPT_RETURNTRANSFER, true); // Make the call $xml = curl_exec($session); // The web service returns XML. Set the Content-Type appropriately //header("Content-Type: text/xml"); echo $xml; curl_close($session); ?>

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  • Getting input and output from a jar file run from java class?

    - by Jack L.
    Hi, I have a jar file that runs this code: public class InputOutput { /** * @param args * @throws IOException */ public static void main(String[] args) throws IOException { boolean cont = true; BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); while (cont) { System.out.print("Input something: "); String temp = in.readLine(); if (temp.equals("end")) { cont = false; System.out.println("Terminated."); } else System.out.println(temp); } } } I want to program another java class that executes this jar file and can get the input and send output to it. Is it possible? The current code I have is this but it is not working: public class JarTest { /** * Test input and output of jar files * @author Jack */ public static void main(String[] args) { try { Process io = Runtime.getRuntime().exec("java -jar InputOutput.jar"); BufferedReader in = new BufferedReader(new InputStreamReader(io.getInputStream())); OutputStreamWriter out = new OutputStreamWriter(io.getOutputStream()); boolean cont = true; BufferedReader consolein = new BufferedReader(new InputStreamReader(System.in)); while (cont) { String temp = consolein.readLine(); out.write(temp); System.out.println(in.readLine()); } } catch (IOException e) { e.printStackTrace(); } } } Thanks for your help

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  • Add two 32-bit integers in Assembler for use in VB6

    - by Emtucifor
    I would like to come up with the byte code in assembler (assembly?) for Windows machines to add two 32-bit longs and throw away the carry bit. I realize the "Windows machines" part is a little vague, but I'm assuming that the bytes for ADD are pretty much the same in all modern Intel instruction sets. I'm just trying to abuse VB a little and make some things faster. So... if the string "8A4C240833C0F6C1E075068B442404D3E0C20800" is the assembly code for SHL that can be "injected" into a VB6 program for a fast SHL operation expecting two Long parameters (we're ignoring here that 32-bit longs in VB6 are signed, just pretend they are unsigned), what is the hex string of bytes representing assembler instructions that will do the same thing to return the sum? The hex code above for SHL is, according to the author: mov eax, [esp+4] mov cl, [esp+8] shl eax, cl ret 8 I spit those bytes into a file and tried unassembling them in a windows command prompt using the old debug utility, but I figured out it's not working with the newer instruction set because it didn't like EAX when I tried assembling something but it was happy with AX. I know from comments in the source code that SHL EAX, CL is D3E0, but I don't have any reference to know what the bytes are for instruction ADD EAX, CL or I'd try it. I tried flat assembler and am not getting anything I can figure out how to use. I used it to assemble the original SHL code and got a very different result, not the same bytes. Help?

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  • copy rows before updating them to preserve archive in Postgres

    - by punkish
    I am experimenting with creating a table that keeps a version of every row. The idea is to be able to query for how the rows were at any point in time even if the query has JOINs. Consider a system where the primary resource is books, that is, books are queried for, and author info comes along for the ride CREATE TABLE authors ( author_id INTEGER NOT NULL, version INTEGER NOT NULL CHECK (version > 0), author_name TEXT, is_active BOOLEAN DEFAULT '1', modified_on TIMESTAMP DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (author_id, version) ) INSERT INTO authors (author_id, version, author_name) VALUES (1, 1, 'John'), (2, 1, 'Jack'), (3, 1, 'Ernest'); I would like to be able to update the above like so UPDATE authors SET author_name = 'Jack K' WHERE author_id = 1; and end up with 2, 1, Jack, t, 2012-03-29 21:35:00 2, 2, Jack K, t, 2012-03-29 21:37:40 which I can then query with SELECT author_name, modified_on FROM authors WHERE author_id = 2 AND modified_on < '2012-03-29 21:37:00' ORDER BY version DESC LIMIT 1; to get 2, 1, Jack, t, 2012-03-29 21:35:00 Something like the following doesn't really work CREATE OR REPLACE FUNCTION archive_authors() RETURNS TRIGGER AS $archive_author$ BEGIN IF (TG_OP = 'UPDATE') THEN -- The following fails because author_id,version PK already exists INSERT INTO authors (author_id, version, author_name) VALUES (OLD.author_id, OLD.version, OLD.author_name); UPDATE authors SET version = OLD.version + 1 WHERE author_id = OLD.author_id AND version = OLD.version; RETURN NEW; END IF; RETURN NULL; -- result is ignored since this is an AFTER trigger END; $archive_author$ LANGUAGE plpgsql; CREATE TRIGGER archive_author AFTER UPDATE OR DELETE ON authors FOR EACH ROW EXECUTE PROCEDURE archive_authors(); How can I achieve the above? Or, is there a better way to accomplish this? Ideally, I would prefer to not create a shadow table to store the archived rows.

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  • How is a referencing environment generally implemented for closures?

    - by Alexandr Kurilin
    Let's say I have a statically/lexically scoped language with deep binding and I create a closure. The closure will consist of the statements I want executed plus the so called referencing environment, or, to quote this post, the collection of variables which can be used. What does this referencing environment actually look like implementation-wise? I was recently reading about ObjectiveC's implementation of blocks, and the author suggests that behind the scenes you get a copy of all of the variables on the stack and also of all the references to heap objects. The explanation claims that you get a "snapshot" of the referencing environment at the point in time of the closure's creation. Is that more or less what happens, or did I misread that? Is anything done to "freeze" a separate copy of the heap objects, or is it safe to assume that if they get modified between closure creation and the closure executing, the closure will no longer be operating on the original version of the object? If indeed there's copying being made, are there memory usage considerations in situations where one might want to create plenty of closures and store them somewhere? I think that misunderstanding of some of these concepts might lead to tricky issues like the ones Eric Lippert mentions in this blog post. It's interesting because you'd think that it wouldn't make sense to keep a reference to a value type that might be gone by the time the closure is called, but I'm guessing that in C# the compiler will figure out that the variable is needed later and put it into the heap instead. It seems that in most memory-managed languages everything is a reference and thus ObjectiveC is a somewhat unique situation with having to deal with copying what's on the stack.

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  • C headers: compiler specific vs library specific?

    - by leonbloy
    Is there some clear-cut distinction between standard C *.h header files that are provided by the C compiler, as oppossed to those which are provided by a standard C library? Is there some list, or some standard locations? Motivation: int this answer I got a while ago, regarding a missing unistd.h in the latest TinyC compiler, the author argued that unistd.h (contrarily to sys/unistd.h) should not be provided by the compiler but by your C library. I could not make much sense of that response (for one thing shouldn't that also apply to, say, stdio.h?) but I'm still wondering about it. Is that correct? Where is some authoritative reference for this? Looking in other compilers, I see that other "self contained" POSIX C compilers that are hosted in Windows (like the GCC toolchain that comes with MinGW, in several incarnations; or Digital Mars compiler), include all header files. And in a standard Linux distribution (say, Centos 5.10) I see that the gcc package provides a few header files (eg, stdbool.h, syslimits.h) in /usr/lib/gcc/i386-redhat-linux/4.1.1/include/, and the glibc-headers package provides the majority of the headers in /usr/include/ (including stdio.h, /usr/include/unistd.h and /usr/include/sys/unistd.h). So, in neither case I see support for the above claim.

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  • TSQL - make a literal float value

    - by David B
    I understand the host of issues in comparing floats, and lament their use in this case - but I'm not the table author and have only a small hurdle to climb... Someone has decided to use floats as you'd expect GUIDs to be used. I need to retrieve all the records with a specific float value. sp_help MyTable -- Column_name Type Computed Length Prec -- RandomGrouping float no 8 53 Here's my naive attempt: --yields no results SELECT RandomGrouping FROM MyTable WHERE RandomGrouping = 0.867153569942739 And here's an approximately working attempt: --yields 2 records SELECT RandomGrouping FROM MyTable WHERE RandomGrouping BETWEEN 0.867153569942739 - 0.00000001 AND 0.867153569942739 + 0.00000001 -- 0.867153569942739 -- 0.867153569942739 In my naive attempt, is that literal a floating point literal? Or is it really a decimal literal that gets converted later? If my literal is not a floating point literal, what is the syntax for making a floating point literal? EDIT: Another possibility has occurred to me... it may be that a more precise number than is displayed is stored in this column. It may be impossible to create a literal that represents this number. I will accept answers that demonstrate that this is the case. EDIT: response to DVK. TSQL is MSSQLServer's dialect of SQL. This script works, and so equality can be performed deterministically between float types: DECLARE @X float SELECT top 1 @X = RandomGrouping FROM MyTable WHERE RandomGrouping BETWEEN 0.839110948199148 - 0.000000000001 AND 0.839110948199148 + 0.000000000001 --yields two records SELECT * FROM MyTable WHERE RandomGrouping = @X I said "approximately" because that method tests for a range. With that method I could get values that are not equal to my intended value. The linked article doesn't apply because I'm not (intentionally) trying to straddle the world boundaries between decimal and float. I'm trying to work with only floats. This isn't about the non-convertibility of decimals to floats.

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  • Understanding MongoDB(and NoSQL in general) and How to make the best use of it

    - by Earlz
    Hello, I am beginning to think that my next project I am wanting to do would work better with a NoSQL solution. The project would either involve a ton of 2-column tables or a ton of dynamic queries with dynamically generated columns in a traditional SQL database. So I feel a NoSQL database would be much cleaner. I'm looking at MongoDB and it looks pretty promising. Anyway, I'm attempting to make sense of it all. Also, I will be using MongoMapper in Ruby. Anyway though, I'm confused as to how to layout things in such a freeform database. I've read http://stackoverflow.com/questions/2170152/nosql-best-practices and the answer there says that normalization is usually bad in a NoSQL DB. So how would be the best way of laying out say a simple blog with users, posts, and comments? My natural thought was to have 3 collections for each and then link them by a unique ID. But this apparently is wrong? So, what are some of the ways to lay out such a thing? My concern with the answer given in the other question is what if the author's name changed. You'd have to go through updating a ton of posts and comments. But is this an ok thing to do with NoSQL?

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  • Removing specific XML tags

    - by iTayb
    I'd like to make an application that removes duplicates from my wpl (Windows PlayList) files. The wpl struct is something like this: <?wpl version="1.0"?> <smil> <head> <meta name="Generator" content="Microsoft Windows Media Player -- 11.0.5721.5145"/> <meta name="AverageRating" content="55"/> <meta name="TotalDuration" content="229844"/> <meta name="ItemCount" content="978"/> <author/> <title>english</title> </head> <body> <seq> <media src="D:\Anime con 2006\Shits\30 Seconds to Mars - 30 Seconds to Mars\30 Seconds to Mars - Capricorn.mp3" tid="{BCC6E6B9-D0F3-449C-91A9-C6EEBD92FFAE}" cid="{D38701EF-1764-4331-A332-50B5CA690104}"/> <media src="E:\emule.incoming\Ke$ha - Coming Unglued.mp3" tid="{E2DB18E5-0449-4FE3-BA09-9DDE18B523B1}"/> <media src="E:\emule.incoming\Lady Gaga - Bad Romance.mp3" tid="{274BD12B-5E79-4165-9314-00DB045D4CD8}"/> <media src="E:\emule.incoming\David Guetta -Sexy Bitch Feat. Akon.mp3" tid="{46DA1363-3DFB-4030-A7A9-88E13DF30677}"/> </seq> </body> </smil> This looks like standard XML file. How can I load the file and get the src value of each media tag? How can I remove specific media, in case of duplicates? Thank you very much.

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  • How to control the order of module initialization in Prism

    - by Robert Taylor
    I'm using Prism V2 with a DirectoryModuleCatalog and I need the modules to be initialized in a certain order. The desired order is specified with an attribute on each IModule implementation. This is so that as each module is initialized, they add their View into a TabControl region and the order of the tabs needs to be deterministic and controlled by the module author. The order does not imply a dependency, but rather just an order that they should be initialized in. In other words: modules A, B, and C may have priorities of 1, 2, and 3 respectively. B does not have a dependency on A - it just needs to get loaded into the TabControl region after A. So that we have a deterministic and controllable order of the tabs. Also, B might not exist at runtime; so they would load as A, C because the priority should determine the order (1, 3). If i used the ModuleDependency, then module "C" will not be able to load w/o all of it's dependencies. I can manage the logic of how to sort the modules, but i can't figure out where to put said logic.

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  • Why does Microsoft advise against readonly fields with mutable values?

    - by Weeble
    In the Design Guidelines for Developing Class Libraries, Microsoft say: Do not assign instances of mutable types to read-only fields. The objects created using a mutable type can be modified after they are created. For example, arrays and most collections are mutable types while Int32, Uri, and String are immutable types. For fields that hold a mutable reference type, the read-only modifier prevents the field value from being overwritten but does not protect the mutable type from modification. This simply restates the behaviour of readonly without explaining why it's bad to use readonly. The implication appears to be that many people do not understand what "readonly" does and will wrongly expect readonly fields to be deeply immutable. In effect it advises using "readonly" as code documentation indicating deep immutability - despite the fact that the compiler has no way to enforce this - and disallows its use for its normal function: to ensure that the value of the field doesn't change after the object has been constructed. I feel uneasy with this recommendation to use "readonly" to indicate something other than its normal meaning understood by the compiler. I feel that it encourages people to misunderstand the meaning of "readonly", and furthermore to expect it to mean something that the author of the code might not intend. I feel that it precludes using it in places it could be useful - e.g. to show that some relationship between two mutable objects remains unchanged for the lifetime of one of those objects. The notion of assuming that readers do not understand the meaning of "readonly" also appears to be in contradiction to other advice from Microsoft, such as FxCop's "Do not initialize unnecessarily" rule, which assumes readers of your code to be experts in the language and should know that (for example) bool fields are automatically initialised to false, and stops you from providing the redundancy that shows "yes, this has been consciously set to false; I didn't just forget to initialize it". So, first and foremost, why do Microsoft advise against use of readonly for references to mutable types? I'd also be interested to know: Do you follow this Design Guideline in all your code? What do you expect when you see "readonly" in a piece of code you didn't write?

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  • svnsync looses revision properties although hook installed

    - by roesslerj
    Hello all! I have a pretty weird problem. We have setup an SVN-Mirror via cronjob (because it needs to go from inside to outside of a firewall, so no post-commit-hook possible) and svnsync. We installed a pre-revprop-hook just as told. Everything seems to work fine, except that it doesn't. E.g. when manually executing the script. # svnsync --non-interactive sync file://<path-to-mirror> --source-username <usr> --source-password <pwd> Committed revision 19817. Copied properties for revision 19817. No error, no complaints. But if checking for the revision properties it says: # svnlook info <path-to-mirror> 0 # svn info -r HEAD file://<path-to-mirror> 2>&1 Path: <root-of-mirror> URL: file://<path-to-mirror> Repository Root: file://<path-to-mirror> Repository UUID: <uid> Revision: 19817 Node Kind: directory Last Changed Rev: 19817 So somehow the author and timestamp information gets lost. But we need that information for our internal processes. Since no error or warning is produced I have absolutely no idea even where to start to look. Everything is local (except for the remote master), so there are no server-logs to look at. Any ideas how I could approach that problem, or even better -- how to solve it? Any ideas appreciated.

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