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  • Notepad++: Adding color highlighting for PHP functions?

    - by Jebego
    I've recently begun using Notepad++, and have found a part of its styling functionality that confuses me. I'm currently attempting to color all of PHP's defined functions (such as count(), strlen(), etc.). In the Settings-Style Configurator, you cannot add a new style for such a function list. Instead, I have begun editing the stylers.xml and langs.xml. To add the new coloring, in langs.xml, I've modified the php section to the following: <Language name="php" ext="php php3 phtml" commentLine="//" commentStart="/*" commentEnd="*/"> <Keywords name="instre1">[default keywords]</Keywords> <Keywords name="instre2">[my function list]</Keywords> </Language> The [default keywords] and [my function list] are replaced with wordlists. I've also edited the php section in stylers.xml to look like the following: <LexerType name="php" desc="php" ext=""> <WordsStyle name="QUESTION MARK" styleID="18" fgColor="FF0000" bgColor="FDF8E3" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="DEFAULT" styleID="118" fgColor="000000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="STRING" styleID="119" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="STRING VARIABLE" styleID="126" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="1" fontSize="" /> <WordsStyle name="SIMPLESTRING" styleID="120" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="WORD" styleID="121" fgColor="008040" bgColor="FEFCF5" fontName="" fontStyle="1" fontSize="" keywordClass="instre1">True False</WordsStyle> <WordsStyle name="NUMBER" styleID="122" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="VARIABLE" styleID="123" fgColor="0080FF" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="COMMENT" styleID="124" fgColor="FF8040" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="COMMENTLINE" styleID="125" fgColor="FF8040" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="OPERATOR" styleID="127" fgColor="8000FF" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="FUNCTIONS" styleID="128" fgColor="000080" bgColor="FEFCF5" fontName="" fontStyle="1" fontSize="" keywordClass="instre2"></WordsStyle> </LexerType> The changed part is the last "FUNCTIONS" line. When I restart Notepad++ and go into the Settings-Style Configurator section, under the php language, the FUNCTIONS style exists. I can change the style's color, and can see the entire keyword list under 'Default Keywords'. However, it is not changing the coloring of the words in my code. When I edit the WORD style, which contains stuff like 'if', 'and', and 'true', things change accordingly in my code. Any ideas on how to make this work?

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  • How can I add color highlighting for PHP functions?

    - by Jeff Gortmaker
    I've recently begun using Notepad++, and have found a part of its styling functionality that confuses me. I'm currently attempting to color all of PHP's defined functions (such as count(), strlen(), etc.). In the Settings-Style Configurator, you cannot add a new style for such a function list. Instead, I have begun editing the stylers.xml and langs.xml. To add the new coloring, in langs.xml, I've modified the php section to the following: <Language name="php" ext="php php3 phtml" commentLine="//" commentStart="/*" commentEnd="*/"> <Keywords name="instre1">[default keywords]</Keywords> <Keywords name="instre2">[my function list]</Keywords> </Language> The [default keywords] and [my function list] are replaced with wordlists. I've also edited the php section in stylers.xml to look like the following: <LexerType name="php" desc="php" ext=""> <WordsStyle name="QUESTION MARK" styleID="18" fgColor="FF0000" bgColor="FDF8E3" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="DEFAULT" styleID="118" fgColor="000000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="STRING" styleID="119" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="STRING VARIABLE" styleID="126" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="1" fontSize="" /> <WordsStyle name="SIMPLESTRING" styleID="120" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="WORD" styleID="121" fgColor="008040" bgColor="FEFCF5" fontName="" fontStyle="1" fontSize="" keywordClass="instre1">True False</WordsStyle> <WordsStyle name="NUMBER" styleID="122" fgColor="FF0000" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="VARIABLE" styleID="123" fgColor="0080FF" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="COMMENT" styleID="124" fgColor="FF8040" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="COMMENTLINE" styleID="125" fgColor="FF8040" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="OPERATOR" styleID="127" fgColor="8000FF" bgColor="FEFCF5" fontName="" fontStyle="0" fontSize="" /> <WordsStyle name="FUNCTIONS" styleID="128" fgColor="000080" bgColor="FEFCF5" fontName="" fontStyle="1" fontSize="" keywordClass="instre2"></WordsStyle> </LexerType> The changed part is the last "FUNCTIONS" line. When I restart Notepad++ and go into the Settings-Style Configurator section, under the php language, the FUNCTIONS style exists. I can change the style's color, and can see the entire keyword list under 'Default Keywords'. However, it is not changing the coloring of the words in my code. When I edit the WORD style, which contains stuff like 'if', 'and', and 'true', things change accordingly in my code. Any ideas on how to make this work?

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  • Need a script/batch/program that runs a command that won't be killed when the parent is killed

    - by billc.cn
    The scenario I use Zabbix to monitor my servers and recently I wanted to add some more metrics for the Windows ones. For security reasons, I used Zabbix's User Parameter feature, but it limits the execution of external commands to about 3 seconds. After that, the command is forcibly killed. I want to run some long run commands, so I used the trick from Zabbix's forum: run the command in the background, write the results to a file and use Zabbix to collect them. This is rather easy under *nix thanks to the "&" operator, but there is no such support in Windows' shell. To make things worse, when Zabbix kills forcibly kill the cmd.exe it used to evaluate the commands, all child processes die including the unfinished background tasks. Thus I need something that can sever all the ties with its children so they won't be affected in the cascading kill. What I've tried start and start /B - They do nothing as the child always die with the parent WScript.Shell.Run as in invis.vbs from StackOverflow - Sometimes work. If the wscript process is forcibly killed as opposed to quitting on its own, the children will die as well. hstart - similar results to invis.vbs At command - This requires you to set an absolution time for the task to run as opposed to an offset, so the code would be quite messy due to the limited shell scripting capability of Windows. (Edit) PsExec.exe from the SysInternals suite - It uses a service to launch the command, so it is not affected by the kill; however, it prints some banner and log info to StdErr and there's no switch to disable this. When I use 2>NUL to redirect them, Zabbix reports an error. After trying the above in different combinations, I noticed if I call hstart from invis.vbs, the command started by the former will be left alone as a parent-less process when invis.vbs is killed. However, since I need to redirect the output, the command I want to run is always in the form of cmd.exe /c ""command" "args"" >log. The vbs also removes all the quotes, so I have to encode the command with self-defined escape sequences. The end result involves about five levels of escaping/quoting, which is almost impossible to maintain. Anyone know any better solutions? Some requirements Any bat/vbs/js/Win32 binary is acceptable Better not require multiple levels of escaping No .Net (including PowerShell) because it is not installed

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  • Drupal views pane content not visible

    - by jwandborg
    I have a pane on my front page with one content pane and two views panes. I can't see the content of the third view ($pane->pid = "new-3" / comment: # Senaste bilder). Here's my panel <?php $page = new stdClass; $page->disabled = FALSE; /* Edit this to true to make a default page disabled initially */ $page->api_version = 1; $page->name = 'frontpage'; $page->task = 'page'; $page->admin_title = 'Startsida'; $page->admin_description = ''; $page->path = 'hem'; $page->access = array(); $page->menu = array(); $page->arguments = array(); $page->conf = array(); $page->default_handlers = array(); $handler = new stdClass; $handler->disabled = FALSE; /* Edit this to true to make a default handler disabled initially */ $handler->api_version = 1; $handler->name = 'page_frontpage_panel_context'; $handler->task = 'page'; $handler->subtask = 'frontpage'; $handler->handler = 'panel_context'; $handler->weight = 0; $handler->conf = array( 'title' => 'Panel', 'no_blocks' => FALSE, 'css_id' => '', 'css' => '', 'contexts' => array(), 'relationships' => array(), ); $display = new panels_display; $display->layout = 'onecol'; $display->layout_settings = array(); $display->panel_settings = array(); $display->cache = array(); $display->title = ''; $display->content = array(); $display->panels = array(); # Bild $pane = new stdClass; $pane->pid = 'new-1'; $pane->panel = 'middle'; $pane->type = 'custom'; $pane->subtype = 'custom'; $pane->shown = TRUE; $pane->access = array(); $pane->configuration = array( 'admin_title' => '', 'title' => '', 'body' => '<img src="/sites/all/themes/zen/ils-2010/img/graphics-start-text-v3.png" alt="Hej! Vi vet att du och dina klasskompisar har mycket att tänka på under er sista termin i gymnasiet. Därför har vi samlat några saker som vi tror kommer göra er studenttid lite roligare och lite enklare. Välkommen!" />', 'format' => '2', 'substitute' => TRUE, ); $pane->cache = array(); $pane->style = array(); $pane->css = array(); $pane->extras = array(); $pane->position = 0; $display->content['new-1'] = $pane; $display->panels['middle'][0] = 'new-1'; # Topplista $pane = new stdClass; $pane->pid = 'new-2'; $pane->panel = 'middle'; $pane->type = 'views_panes'; $pane->subtype = 'topplista_terms-panel_pane_1'; $pane->shown = TRUE; $pane->access = array(); $pane->configuration = array( 'link_to_view' => 1, 'more_link' => 0, 'use_pager' => 0, 'pager_id' => '', 'items_per_page' => '10', 'offset' => '0', 'path' => 'flaktavling/topplista/klasser', 'override_title' => 0, 'override_title_text' => '', ); $pane->cache = array(); $pane->style = array(); $pane->css = array(); $pane->extras = array(); $pane->position = 1; $display->content['new-2'] = $pane; $display->panels['middle'][1] = 'new-2'; # Senaste bilder $pane = new stdClass; $pane->pid = 'new-3'; $pane->panel = 'middle'; $pane->type = 'views_panes'; $pane->subtype = 'senaste_bilderna-panel_pane_1'; $pane->shown = TRUE; $pane->access = array(); $pane->configuration = array( 'link_to_view' => 0, 'more_link' => 0, 'use_pager' => 0, 'pager_id' => '', 'items_per_page' => '2', 'offset' => '0', 'path' => 'galleri/senaste-bilder', 'override_title' => 0, 'override_title_text' => '', ); $pane->cache = array(); $pane->style = array(); $pane->css = array( 'css_id' => 'pane-senaste-bilderna', 'css_class' => '', ); $pane->extras = array(); $pane->position = 2; $display->content['new-3'] = $pane; $display->panels['middle'][2] = 'new-3'; $display->hide_title = PANELS_TITLE_FIXED; $display->title_pane = 'new-1'; $handler->conf['display'] = $display; $page->default_handlers[$handler->name] = $handler; Here´s the view senaste_bilderna <?php $view = new view; $view->name = 'senaste_bilderna'; $view->description = ''; $view->tag = ''; $view->view_php = ''; $view->base_table = 'node'; $view->is_cacheable = FALSE; $view->api_version = 2; $view->disabled = FALSE; /* Edit this to true to make a default view disabled initially */ $handler = $view->new_display('default', 'Förvalt', 'default'); $handler->override_option('fields', array( 'field_picture_fid' => array( 'id' => 'field_picture_fid', 'table' => 'node_data_field_picture', 'field' => 'field_picture_fid', ), )); $handler->override_option('sorts', array( 'created' => array( 'order' => 'DESC', 'granularity' => 'second', 'id' => 'created', 'table' => 'node', 'field' => 'created', 'relationship' => 'none', ), )); $handler->override_option('filters', array( 'type' => array( 'operator' => 'in', 'value' => array( 'ils_picture' => 'ils_picture', ), 'group' => '0', 'exposed' => FALSE, 'expose' => array( 'operator' => FALSE, 'label' => '', ), 'id' => 'type', 'table' => 'node', 'field' => 'type', 'override' => array( 'button' => 'Åsidosätt', ), 'relationship' => 'none', ), )); $handler->override_option('access', array( 'type' => 'none', )); $handler->override_option('cache', array( 'type' => 'none', )); $handler->override_option('title', 'Senaste bilderna från galleriet'); $handler->override_option('items_per_page', 2); $handler->override_option('row_options', array( 'inline' => array( 'field_picture_fid' => 'field_picture_fid', ), 'separator' => '', 'hide_empty' => 0, )); $handler = $view->new_display('panel_pane', 'Content pane', 'panel_pane_1'); $handler->override_option('pane_title', ''); $handler->override_option('pane_description', ''); $handler->override_option('pane_category', array( 'name' => 'View panes', 'weight' => 0, )); $handler->override_option('allow', array( 'use_pager' => FALSE, 'items_per_page' => FALSE, 'offset' => FALSE, 'link_to_view' => FALSE, 'more_link' => FALSE, 'path_override' => FALSE, 'title_override' => FALSE, 'exposed_form' => FALSE, )); $handler->override_option('argument_input', array()); $handler->override_option('link_to_view', 0); $handler->override_option('inherit_panels_path', 0); $handler = $view->new_display('page', 'Sida', 'page_1'); $handler->override_option('path', 'galleri/senaste-bilderna'); $handler->override_option('menu', array( 'type' => 'none', 'title' => '', 'description' => '', 'weight' => 0, 'name' => 'navigation', )); $handler->override_option('tab_options', array( 'type' => 'none', 'title' => '', 'description' => '', 'weight' => 0, )); I have edited one views template, here's the code in the file views-view-fields--senaste-bilderna.tpl.php <?php // $Id: views-view-fields.tpl.php,v 1.6 2008/09/24 22:48:21 merlinofchaos Exp $ /** * @file views-view-fields.tpl.php * Default simple view template to all the fields as a row. * * - $view: The view in use. * - $fields: an array of $field objects. Each one contains: * - $field->content: The output of the field. * - $field->raw: The raw data for the field, if it exists. This is NOT output safe. * - $field->class: The safe class id to use. * - $field->handler: The Views field handler object controlling this field. Do not use * var_export to dump this object, as it can't handle the recursion. * - $field->inline: Whether or not the field should be inline. * - $field->inline_html: either div or span based on the above flag. * - $field->separator: an optional separator that may appear before a field. * - $row: The raw result object from the query, with all data it fetched. * * @ingroup views_templates */ ?> <?php foreach ($fields as $id => $field): ?> <?php $result = db_query('SELECT * FROM {files} WHERE fid = ' . $row->node_data_field_picture_field_picture_fid ); ?> <?php $data = db_fetch_object( $result ); ?> <div id="senaste-bilderna-first"><img src="<?= imagecache_create_url('senaste_bilderna_thumbnail', $data->filepath) ?>" alt="" /></div> <?php /* if (!empty($field->separator)): <?php print $field->separator; <?php endif; <<?php print $field->inline_html; class="views-field-<?php print $field->class; "> <?php if ($field->label): <label class="views-label-<?php print $field->class; "> <?php print $field->label; : </label> <?php endif; <?php // $field->element_type is either SPAN or DIV depending upon whether or not // the field is a 'block' element type or 'inline' element type. <<?php print $field->element_type; class="field-content"><?php print $field->content; </<?php print $field->element_type; > </<?php print $field->inline_html;> <?php*/ endforeach; ?> This is the result <div class="panel-separator"> </div> <div class="panel-pane pane-views-panes pane-senaste-bilderna-panel-pane-1" id="pane-senaste-bilderna"> <h2 class="pane-title">Senaste bilderna från galleriet </h2> <div class="pane-content"> <div class="view view-senaste-bilderna view-id-senaste_bilderna view-display-id-panel_pane_1 view-dom-id-2"> <div class="view-content"> <div class="views-row views-row-1 views-row-odd views-row-first"> </div> <div class="views-row views-row-2 views-row-even views-row-last"> </div> </div> </div> </div> </div> My Drupal version is 6.16

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  • How to propagate http response code from back-end to client

    - by Manoj Neelapu
    Oracle service bus can be used as for pass through casses. Some use cases require propagating the http-response code back to the caller. http://forums.oracle.com/forums/thread.jspa?messageID=4326052&#4326052 is one such example we will try to accomplish in this tutorial.We will try to demonstrate this feature using Oracle Service Bus (11.1.1.3.0. We will also use commons-logging-1.1.1, httpcomponents-client-4.0.1, httpcomponents-core-4.0.1 for writing the client to demonstrate.First we create a simple JSP which will always set response code to 304.The JSP snippet will look like <%@ page language="java"     contentType="text/xml;     charset=UTF-8"        pageEncoding="UTF-8" %><%      System.out.println("Servlet setting Responsecode=304");    response.setStatus(304);    response.flushBuffer();%>We will now deploy this JSP on weblogic server with URI=http://localhost:7021/reponsecode/For this JSP we will create a simple Any XML BS We will also create proxy service as shown below Once the proxy is created we configure pipeline for the proxy to use route node, which invokes the BS(JSPCaller) created in the first place. So now we will create a error handler for route node and will add a stage. When a HTTP BS sends a request, the JSP sends the response back. If the response code is not 200, then the http BS will consider that as error and the above configured error handler is invoked. We will print $outbound to show the response code sent by the JSP. The next actions. To test this I had create a simple clientimport org.apache.http.Header;import org.apache.http.HttpEntity;import org.apache.http.HttpHost;import org.apache.http.HttpResponse;import org.apache.http.HttpVersion;import org.apache.http.client.methods.HttpGet;import org.apache.http.conn.ClientConnectionManager;import org.apache.http.conn.scheme.PlainSocketFactory;import org.apache.http.conn.scheme.Scheme;import org.apache.http.conn.scheme.SchemeRegistry;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;import org.apache.http.params.BasicHttpParams;import org.apache.http.params.HttpParams;import org.apache.http.params.HttpProtocolParams;import org.apache.http.util.EntityUtils;/** * @author MNEELAPU * */public class TestProxy304{    public static void main(String arg[]) throws Exception{     HttpHost target = new HttpHost("localhost", 7021, "http");     // general setup     SchemeRegistry supportedSchemes = new SchemeRegistry();     // Register the "http" protocol scheme, it is required     // by the default operator to look up socket factories.     supportedSchemes.register(new Scheme("http",              PlainSocketFactory.getSocketFactory(), 7021));     // prepare parameters     HttpParams params = new BasicHttpParams();     HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);     HttpProtocolParams.setContentCharset(params, "UTF-8");     HttpProtocolParams.setUseExpectContinue(params, true);     ClientConnectionManager connMgr = new ThreadSafeClientConnManager(params,              supportedSchemes);     DefaultHttpClient httpclient = new DefaultHttpClient(connMgr, params);     HttpGet req = new HttpGet("/HttpResponseCode/ProxyExposed");     System.out.println("executing request to " + target);     HttpResponse rsp = httpclient.execute(target, req);     HttpEntity entity = rsp.getEntity();     System.out.println("----------------------------------------");     System.out.println(rsp.getStatusLine());     Header[] headers = rsp.getAllHeaders();     for (int i = 0; i < headers.length; i++) {         System.out.println(headers[i]);     }     System.out.println("----------------------------------------");     if (entity != null) {         System.out.println(EntityUtils.toString(entity));     }     // When HttpClient instance is no longer needed,      // shut down the connection manager to ensure     // immediate deallocation of all system resources     httpclient.getConnectionManager().shutdown();     }}On compiling and executing this we see the below output in STDOUT which clearly indicates the response code was propagated from Business Service to Proxy serviceexecuting request to http://localhost:7021----------------------------------------HTTP/1.1 304 Not ModifiedDate: Tue, 08 Jun 2010 16:13:42 GMTContent-Type: text/xml; charset=UTF-8X-Powered-By: Servlet/2.5 JSP/2.1----------------------------------------  

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  • jQuery Selector Tester and Cheat Sheet

    - by SGWellens
    I've always appreciated these tools: Expresso and XPath Builder. They make designing regular expressions and XPath selectors almost fun! Did I say fun? I meant less painful. Being able to paste/load text and then interactively play with the search criteria is infinitely better than the code/compile/run/test cycle. It's faster and you get a much better feel for how the expressions work. So, I decided to make my own interactive tool to test jQuery selectors:  jQuery Selector Tester.   Here's a sneak peek: Note: There are some existing tools you may like better: http://www.woods.iki.fi/interactive-jquery-tester.html http://www.w3schools.com/jquery/trysel.asp?filename=trysel_basic&jqsel=p.intro,%23choose My tool is different: It is one page. You can save it and run it locally without a Web Server. It shows the results as a list of iterated objects instead of highlighted html. A cheat sheet is on the same page as the tester which is handy. I couldn't upload an .htm or .html file to this site so I hosted it on my personal site here: jQuery Selector Tester. Design Highlights: To make the interactive search work, I added a hidden div to the page: <!--Hidden div holds DOM elements for jQuery to search--><div id="HiddenDiv" style="display: none"></div> When ready to search, the searchable html text is copied into the hidden div…this renders the DOM tree in the hidden div: // get the html to search, insert it to the hidden divvar Html = $("#TextAreaHTML").val();$("#HiddenDiv").html(Html); When doing a search, I modify the search pattern to look only in the HiddenDiv. To do that, I put a space between the patterns.  The space is the Ancestor operator (see the Cheat Sheet): // modify search string to only search in our// hidden div and do the searchvar SearchString = "#HiddenDiv " + SearchPattern;try{    var $FoundItems = $(SearchString);}   Big Fat Stinking Faux Pas: I was about to publish this article when I made a big mistake: I tested the tool with Mozilla FireFox. It blowed up…it blowed up real good. In the past I’ve only had to target IE so this was quite a revelation. When I started to learn JavaScript, I was disgusted to see all the browser dependent code. Who wants to spend their time testing against different browsers and versions of browsers? Adding a bunch of ‘if-else’ code is a tedious and thankless task. I avoided client code as much as I could. Then jQuery came along and all was good. It was browser independent and freed us from the tedium of worrying about version N of the Acme browser. Right? Wrong! I had used outerHTML to display the selected elements. The problem is Mozilla FireFox doesn’t implement outerHTML. I replaced this: // encode the html markupvar OuterHtml = $('<div/>').text(this.outerHTML).html(); With this: // encode the html markupvar Html = $('<div>').append(this).html();var OuterHtml = $('<div/>').text(Html).html(); Another problem was that Mozilla FireFox doesn’t implement srcElement. I replaced this: var Row = e.srcElement.parentNode;  With this: var Row = e.target.parentNode; Another problem was the indexing. The browsers have different ways of indexing. I replaced this: // this cell has the search pattern  var Cell = Row.childNodes[1];   // put the pattern in the search box and search                    $("#TextSearchPattern").val(Cell.innerText);  With this: // get the correct cell and the text in the cell// place the text in the seach box and serachvar Cell = $(Row).find("TD:nth-child(2)");var CellText = Cell.text();$("#TextSearchPattern").val(CellText);   So much for the myth of browser independence. Was I overly optimistic and gullible? I don’t think so. And when I get my millions from the deposed Nigerian prince I sent money to, you’ll see that having faith is not futile. Notes: My goal was to have a single standalone file. I tried to keep the features and CSS to a minimum–adding only enough to make it useful and visually pleasing. When testing, I often thought there was a problem with the jQuery selector. Invariable it was invalid html code. If your results aren't what you expect, don't assume it's the jQuery selector pattern: The html may be invalid. To help in development and testing, I added a double-click handler to the rows in the Cheat Sheet table. If you double-click a row, the search pattern is put in the search box, a search is performed and the page is scrolled so you can see the results. I left the test html and code in the page. If you are using a CDN (non-local) version of the jQuery libraray, the designer in Visual Studio becomes extremely slow.  That's why there are two version of the library in the header and one is commented out. For reference, here is the jQuery documentation on selectors: http://api.jquery.com/category/selectors/ Here is a much more comprehensive list of CSS selectors (which jQuery uses): http://www.w3.org/TR/CSS2/selector.html I hope someone finds this useful. Steve WellensCodeProject

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  • Joins in single-table queries

    - by Rob Farley
    Tables are only metadata. They don’t store data. I’ve written something about this before, but I want to take a viewpoint of this idea around the topic of joins, especially since it’s the topic for T-SQL Tuesday this month. Hosted this time by Sebastian Meine (@sqlity), who has a whole series on joins this month. Good for him – it’s a great topic. In that last post I discussed the fact that we write queries against tables, but that the engine turns it into a plan against indexes. My point wasn’t simply that a table is actually just a Clustered Index (or heap, which I consider just a special type of index), but that data access always happens against indexes – never tables – and we should be thinking about the indexes (specifically the non-clustered ones) when we write our queries. I described the scenario of looking up phone numbers, and how it never really occurs to us that there is a master list of phone numbers, because we think in terms of the useful non-clustered indexes that the phone companies provide us, but anyway – that’s not the point of this post. So a table is metadata. It stores information about the names of columns and their data types. Nullability, default values, constraints, triggers – these are all things that define the table, but the data isn’t stored in the table. The data that a table describes is stored in a heap or clustered index, but it goes further than this. All the useful data is going to live in non-clustered indexes. Remember this. It’s important. Stop thinking about tables, and start thinking about indexes. So let’s think about tables as indexes. This applies even in a world created by someone else, who doesn’t have the best indexes in mind for you. I’m sure you don’t need me to explain Covering Index bit – the fact that if you don’t have sufficient columns “included” in your index, your query plan will either have to do a Lookup, or else it’ll give up using your index and use one that does have everything it needs (even if that means scanning it). If you haven’t seen that before, drop me a line and I’ll run through it with you. Or go and read a post I did a long while ago about the maths involved in that decision. So – what I’m going to tell you is that a Lookup is a join. When I run SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 285; against the AdventureWorks2012 get the following plan: I’m sure you can see the join. Don’t look in the query, it’s not there. But you should be able to see the join in the plan. It’s an Inner Join, implemented by a Nested Loop. It’s pulling data in from the Index Seek, and joining that to the results of a Key Lookup. It clearly is – the QO wouldn’t call it that if it wasn’t really one. It behaves exactly like any other Nested Loop (Inner Join) operator, pulling rows from one side and putting a request in from the other. You wouldn’t have a problem accepting it as a join if the query were slightly different, such as SELECT sod.OrderQty FROM Sales.SalesOrderHeader AS soh JOIN Sales.SalesOrderDetail as sod on sod.SalesOrderID = soh.SalesOrderID WHERE soh.SalesPersonID = 285; Amazingly similar, of course. This one is an explicit join, the first example was just as much a join, even thought you didn’t actually ask for one. You need to consider this when you’re thinking about your queries. But it gets more interesting. Consider this query: SELECT SalesOrderID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276 AND CustomerID = 29522; It doesn’t look like there’s a join here either, but look at the plan. That’s not some Lookup in action – that’s a proper Merge Join. The Query Optimizer has worked out that it can get the data it needs by looking in two separate indexes and then doing a Merge Join on the data that it gets. Both indexes used are ordered by the column that’s indexed (one on SalesPersonID, one on CustomerID), and then by the CIX key SalesOrderID. Just like when you seek in the phone book to Farley, the Farleys you have are ordered by FirstName, these seek operations return the data ordered by the next field. This order is SalesOrderID, even though you didn’t explicitly put that column in the index definition. The result is two datasets that are ordered by SalesOrderID, making them very mergeable. Another example is the simple query SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276; This one prefers a Hash Match to a standard lookup even! This isn’t just ordinary index intersection, this is something else again! Just like before, we could imagine it better with two whole tables, but we shouldn’t try to distinguish between joining two tables and joining two indexes. The Query Optimizer can see (using basic maths) that it’s worth doing these particular operations using these two less-than-ideal indexes (because of course, the best indexese would be on both columns – a composite such as (SalesPersonID, CustomerID – and it would have the SalesOrderID column as part of it as the CIX key still). You need to think like this too. Not in terms of excusing single-column indexes like the ones in AdventureWorks2012, but in terms of having a picture about how you’d like your queries to run. If you start to think about what data you need, where it’s coming from, and how it’s going to be used, then you will almost certainly write better queries. …and yes, this would include when you’re dealing with regular joins across multiples, not just against joins within single table queries.

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  • ASP.NET Web Forms Extensibility: Control Adapters

    - by Ricardo Peres
    All ASP.NET controls from version 2.0 can be associated with a control adapter. A control adapter is a class that inherits from ControlAdapter and it has the chance to interact with the control(s) it is targeting so as to change some of its properties or alter its output. I talked about control adapters before and they really a cool feature. The ControlAdapter class exposes virtual methods for some well known lifecycle events, OnInit, OnLoad, OnPreRender and OnUnload that closely match their Control counterparts, but are fired before them. Because the control adapter has a reference to its target Control, it can cast it to its concrete class and do something with it before its lifecycle events are actually fired. The adapter is also notified before the control is rendered (BeginRender), after their children are renderes (RenderChildren) and after itself is rendered (Render): this way the adapter can modify the control’s output. Control adapters may be specified for any class inheriting from Control, including abstract classes, web server controls and even pages. You can, for example, specify a control adapter for the WebControl and UserControl classes, but, curiously, not for Control itself. When specifying a control adapter for a page, it must inherit from PageAdapter instead of ControlAdapter. The adapter for a control, if specified, can be found on the protected Adapter property, and for a page, on the PageAdapter property. The first use of control adapters that came to my attention was for changing the output of standard ASP.NET web controls so that they were more based on CSS and less on HTML tables: it was the CSS Friendly Control Adapters project, now available at http://code.google.com/p/aspnetcontroladapters/. They are interesting because you specify them in one location and they apply anywhere a control of the target type is created. Mind you, it applies to controls declared on markup as well as controls created by code with the new operator. So, how do you use control adapters? The most usual way is through a browser definition file. In it, you specify a set of control adapters and their target controls, for a given browser. This browser definition file is a XML file with extension .Browser, and can either be global (%WINDIR%\Microsoft.NET\Framework64\vXXXX\Config\Browsers) or local to the web application, in which case, it must be placed inside the App_Browsers folder at the root of the web site. It looks like this: 1: <browsers> 2: <browser refID="Default"> 3: <controlAdapters> 4: <adapter controlType="System.Web.UI.WebControls.TextBox" adapterType="MyNamespace.TextBoxAdapter, MyAssembly" /> 5: </controlAdapters> 6: </browser> 7: </browsers> A browser definition file targets a specific browser, so you can have different definitions for Chrome, IE, Firefox, Opera, as well as for specific version of each of those (like IE8, Firefox3). Alternatively, if you set the target to Default, it will apply to all. The reason to pick a specific browser and version might be, for example, in order to circumvent some limitation present in that specific version, so that on markup you don’t need to be concerned with that. Another option is through the the current Browser object of the request: 1: this.Context.Request.Browser.Adapters.Add(typeof(TextBox).FullName, typeof(TextBoxAdapter).FullName); This must go very early on the page lifecycle, for example, on the OnPreInit event, or even on Application_Start. You have to specify the full class name for both the target control and the adapter. Of course, you have to do this for every request, because it won’t be persisted. As an example, you may know that the classic TextBox control renders an HTML input tag if its TextMode is set to SingleLine and a textarea if set to MultiLine. Because the textarea has no notion of maximum length, unlike the input, something must be done in order to enforce this. Here’s a simple suggestion: 1: public class TextBoxControlAdapter : ControlAdapter 2: { 3: protected TextBox Target 4: { 5: get 6: { 7: return (this.Control as TextBox); 8: } 9: } 10:  11: protected override void OnLoad(EventArgs e) 12: { 13: if ((this.Target.MaxLength > 0) && (this.Target.TextMode == TextBoxMode.MultiLine)) 14: { 15: if (this.Target.Page.ClientScript.IsClientScriptBlockRegistered("TextBox_KeyUp") == false) 16: { 17: if (this.Target.Page.ClientScript.IsClientScriptBlockRegistered(this.Target.Page.GetType(), "TextBox_KeyUp") == false) 18: { 19: String script = String.Concat("function TextBox_KeyUp(sender) { if (sender.value.length > ", this.Target.MaxLength, ") { sender.value = sender.value.substr(0, ", this.Target.MaxLength, "); } }\n"); 20:  21: this.Target.Page.ClientScript.RegisterClientScriptBlock(this.Target.Page.GetType(), "TextBox_KeyUp", script, true); 22: } 23:  24: this.Target.Attributes["onkeyup"] = "TextBox_KeyUp(this)"; 25: } 26: } 27: 28: base.OnLoad(e); 29: } 30: } What it does is, for every TextBox control, if it is set for multi line and has a defined maximum length, it injects some JavaScript that will filter out any content that exceeds this maximum length. This will occur for any TextBox that you may have on your site, or any class that inherits from it. You can use any of the previous options to register this adapter. Stay tuned for more ASP.NET Web Forms extensibility tips!

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  • Is this proper OO design for C++?

    - by user121917
    I recently took a software processes course and this is my first time attempting OO design on my own. I am trying to follow OO design principles and C++ conventions. I attempted and gave up on MVC for this application, but I am trying to "decouple" my classes such that they can be easily unit-tested and so that I can easily change the GUI library used and/or the target OS. At this time, I have finished designing classes but have not yet started implementing methods. The function of the software is to log all packets sent and received, and display them on the screen (like WireShark, but for one local process only). The software accomplishes this by hooking the send() and recv() functions in winsock32.dll, or some other pair of analogous functions depending on what the intended Target is. The hooks add packets to SendPacketList/RecvPacketList. The GuiLogic class starts a thread which checks for new packets. When new packets are found, it utilizes the PacketFilter class to determine the formatting for the new packet, and then sends it to MainWindow, a native win32 window (with intent to later port to Qt).1 Full size image of UML class diagram Here are my classes in skeleton/header form (this is my actual code): class PacketModel { protected: std::vector<byte> data; int id; public: PacketModel(); PacketModel(byte* data, unsigned int size); PacketModel(int id, byte* data, unsigned int size); int GetLen(); bool IsValid(); //len >= sizeof(opcode_t) opcode_t GetOpcode(); byte* GetData(); //returns &(data[0]) bool GetData(byte* outdata, int maxlen); void SetData(byte* pdata, int len); int GetId(); void SetId(int id); bool ParseData(char* instr); bool StringRepr(char* outstr); byte& operator[] (const int index); }; class SendPacket : public PacketModel { protected: byte* returnAddy; public: byte* GetReturnAddy(); void SetReturnAddy(byte* addy); }; class RecvPacket : public PacketModel { protected: byte* callAddy; public: byte* GetCallAddy(); void SetCallAddy(byte* addy); }; //problem: packets may be added to list at any time by any number of threads //solution: critical section associated with each packet list class Synch { public: void Enter(); void Leave(); }; template<class PacketType> class PacketList { private: static const int MAX_STORED_PACKETS = 1000; public: static const int DEFAULT_SHOWN_PACKETS = 100; private: vector<PacketType> list; Synch synch; //wrapper for critical section public: void AddPacket(PacketType* packet); PacketType* GetPacket(int id); int TotalPackets(); }; class SendPacketList : PacketList<SendPacket> { }; class RecvPacketList : PacketList<RecvPacket> { }; class Target //one socket { bool Send(SendPacket* packet); bool Inject(RecvPacket* packet); bool InitSendHook(SendPacketList* sendList); bool InitRecvHook(RecvPacketList* recvList); }; class FilterModel { private: opcode_t opcode; int colorID; bool bFilter; char name[41]; }; class FilterFile { private: FilterModel filter; public: void Save(); void Load(); FilterModel* GetFilter(opcode_t opcode); }; class PacketFilter { private: FilterFile filters; public: bool IsFiltered(opcode_t opcode); bool GetName(opcode_t opcode, char* namestr); //return false if name does not exist COLORREF GetColor(opcode_t opcode); //return default color if no custom color }; class GuiLogic { private: SendPacketList sendList; RecvPacketList recvList; PacketFilter packetFilter; void GetPacketRepr(PacketModel* packet); void ReadNew(); void AddToWindow(); public: void Refresh(); //called from thread void GetPacketInfo(int id); //called from MainWindow }; I'm looking for a general review of my OO design, use of UML, and use of C++ features. I especially just want to know if I'm doing anything considerably wrong. From what I've read, design review is on-topic for this site (and off-topic for the Code Review site). Any sort of feedback is greatly appreciated. Thanks for reading this.

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  • Blog Buzz - Devoxx 2011

    - by Janice J. Heiss
    Some day I will make it to Devoxx – for now, I’m content to vicariously follow the blogs of attendees and pick up on what’s happening.  I’ve been doing more blog "fishing," looking for the best commentary on 2011 Devoxx. There’s plenty of food for thought – and the ideas are not half-baked.The bloggers are out in full, offering useful summaries and commentary on Devoxx goings-on.Constantin Partac, a Java developer and a member of Transylvania JUG, a community from Cluj-Napoca/Romania, offers an excellent summary of the Devoxx keynotes. Here’s a sample:“Oracle Opening Keynote and JDK 7, 8, and 9 Presentation•    Oracle is committed to Java and wants to provide support for it on any device.•    JSE 7 for Mac will be released next week.•    Oracle would like Java developers to be involved in JCP, to adopt a JSR and to attend local JUG meetings.•    JEE 7 will be released next year.•    JEE 7 is focused on cloud integration, some of the features are already implemented in glassfish 4 development branch.•    JSE 8 will be release in summer of 2013 due to “enterprise community request” as they can not keep the pace with an 18    month release cycle.•    The main features included in JSE8 are lambda support, project Jigsaw, new Date/Time API, project Coin++ and adding   support for sensors. JSE 9 probably will focus on some of these features:1.    self tuning JVM2.    improved native language integration3.    processing enhancement for big data4.    reification (adding runtime class type info for generic types)5.    unification of primitive and corresponding object classes6.    meta-object protocol in order to use type and methods define in other JVM languages7.    multi-tenancy8.    JVM resource management” Thanks Constantin! Ivan St. Ivanov, of SAP Labs Bulgaria, also commented on the keynotes with a different focus.  He summarizes Henrik Stahl’s look ahead to Java SE 8 and JavaFX 3.0; Cameron Purdy on Java EE and the cloud; celebrated Java Champion Josh Bloch on what’s good and bad about Java; Mark Reinhold’s quick look ahead to Java SE 9; and Brian Goetz on lambdas and default methods in Java SE 8. Here’s St. Ivanov’s account of Josh Bloch’s comments on the pluses of Java:“He started with the virtues of the platform. To name a few:    Tightly specified language primitives and evaluation order – int is always 32 bits and operations are executed always from left  to right, without compilers messing around    Dynamic linking – when you change a class, you need to recompile and rebuild just the jar that has it and not the whole application    Syntax  similarity with C/C++ – most existing developers at that time felt like at home    Object orientations – it was cool at that time as well as functional programming is today    It was statically typed language – helps in faster runtime, better IDE support, etc.    No operator overloading – well, I’m not sure why it is good. Scala has it for example and that’s why it is far better for defining DSLs. But I will not argue with Josh.”It’s worth checking out St. Ivanov’s summary of Bloch’s views on what’s not so great about Java as well. What's Coming in JAX-RS 2.0Marek Potociar, Principal Software Engineer at Oracle and currently specification lead of Java EE RESTful web services API (JAX-RS), blogged on his talk about what's coming in JAX-RS 2.0, scheduled for final release in mid-2012.  Here’s a taste:“Perhaps the most wanted addition to the JAX-RS is the Client API, that would complete the JAX-RS story, that is currently server-side only. In JAX-RS 2.0 we are adding a completely interface-based and fluent client API that blends nicely in with the existing fluent response builder pattern on the server-side. When we started with the client API, the first proposal contained around 30 classes. Thanks to the feedback from our Expert Group we managed to reduce the number of API classes to 14 (2 of them being exceptions)! The resulting is compact while at the same time we still managed to create an API that reflects the method invocation context flow (e.g. once you decide on the target URI and start setting headers on the request, your IDE will not try to offer you a URI setter in the code completion). This is a subtle but very important usability aspect of an API…” Obviously, Devoxx is a great Java conference, one that is hitting this year at a time when much is brewing in the platform and beginning to be anticipated.

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  • Why enumerator structs are a really bad idea

    - by Simon Cooper
    If you've ever poked around the .NET class libraries in Reflector, I'm sure you would have noticed that the generic collection classes all have implementations of their IEnumerator as a struct rather than a class. As you will see, this design decision has some rather unfortunate side effects... As is generally known in the .NET world, mutable structs are a Very Bad Idea; and there are several other blogs around explaining this (Eric Lippert's blog post explains the problem quite well). In the BCL, the generic collection enumerators are all mutable structs, as they need to keep track of where they are in the collection. This bit me quite hard when I was coding a wrapper around a LinkedList<int>.Enumerator. It boils down to this code: sealed class EnumeratorWrapper : IEnumerator<int> { private readonly LinkedList<int>.Enumerator m_Enumerator; public EnumeratorWrapper(LinkedList<int> linkedList) { m_Enumerator = linkedList.GetEnumerator(); } public int Current { get { return m_Enumerator.Current; } } object System.Collections.IEnumerator.Current { get { return Current; } } public bool MoveNext() { return m_Enumerator.MoveNext(); } public void Reset() { ((System.Collections.IEnumerator)m_Enumerator).Reset(); } public void Dispose() { m_Enumerator.Dispose(); } } The key line here is the MoveNext method. When I initially coded this, I thought that the call to m_Enumerator.MoveNext() would alter the enumerator state in the m_Enumerator class variable and so the enumeration would proceed in an orderly fashion through the collection. However, when I ran this code it went into an infinite loop - the m_Enumerator.MoveNext() call wasn't actually changing the state in the m_Enumerator variable at all, and my code was looping forever on the first collection element. It was only after disassembling that method that I found out what was going on The MoveNext method above results in the following IL: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000, [1] valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator CS$0$0001) L_0000: nop L_0001: ldarg.0 L_0002: ldfld valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: stloc.1 L_0008: ldloca.s CS$0$0001 L_000a: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000f: stloc.0 L_0010: br.s L_0012 L_0012: ldloc.0 L_0013: ret } Here, the important line is 0002 - m_Enumerator is accessed using the ldfld operator, which does the following: Finds the value of a field in the object whose reference is currently on the evaluation stack. So, what the MoveNext method is doing is the following: public bool MoveNext() { LinkedList<int>.Enumerator CS$0$0001 = this.m_Enumerator; bool CS$1$0000 = CS$0$0001.MoveNext(); return CS$1$0000; } The enumerator instance being modified by the call to MoveNext is the one stored in the CS$0$0001 variable on the stack, and not the one in the EnumeratorWrapper class instance. Hence why the state of m_Enumerator wasn't getting updated. Hmm, ok. Well, why is it doing this? If you have a read of Eric Lippert's blog post about this issue, you'll notice he quotes a few sections of the C# spec. In particular, 7.5.4: ...if the field is readonly and the reference occurs outside an instance constructor of the class in which the field is declared, then the result is a value, namely the value of the field I in the object referenced by E. And my m_Enumerator field is readonly! Indeed, if I remove the readonly from the class variable then the problem goes away, and the code works as expected. The IL confirms this: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000) L_0000: nop L_0001: ldarg.0 L_0002: ldflda valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000c: stloc.0 L_000d: br.s L_000f L_000f: ldloc.0 L_0010: ret } Notice on line 0002, instead of the ldfld we had before, we've got a ldflda, which does this: Finds the address of a field in the object whose reference is currently on the evaluation stack. Instead of loading the value, we're loading the address of the m_Enumerator field. So now the call to MoveNext modifies the enumerator stored in the class rather than on the stack, and everything works as expected. Previously, I had thought enumerator structs were an odd but interesting feature of the BCL that I had used in the past to do linked list slices. However, effects like this only underline how dangerous mutable structs are, and I'm at a loss to explain why the enumerators were implemented as structs in the first place. (interestingly, the SortedList<TKey, TValue> enumerator is a struct but is private, which makes it even more odd - the only way it can be accessed is as a boxed IEnumerator!). I would love to hear people's theories as to why the enumerators are implemented in such a fashion. And bonus points if you can explain why LinkedList<int>.Enumerator.Reset is an explicit implementation but Dispose is implicit... Note to self: never ever ever code a mutable struct.

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  • Using Delegates in C# (Part 1)

    - by rajbk
    This post provides a very basic introduction of delegates in C#. Part 2 of this post can be read here. A delegate is a class that is derived from System.Delegate.  It contains a list of one or more methods called an invocation list. When a delegate instance is “invoked” with the arguments as defined in the signature of the delegate, each of the methods in the invocation list gets invoked with the arguments. The code below shows example with static and instance methods respectively: Static Methods 1: using System; 2: using System.Linq; 3: using System.Collections.Generic; 4: 5: public delegate void SayName(string name); 6: 7: public class Program 8: { 9: [STAThread] 10: static void Main(string[] args) 11: { 12: SayName englishDelegate = new SayName(SayNameInEnglish); 13: SayName frenchDelegate = new SayName(SayNameInFrench); 14: SayName combinedDelegate =(SayName)Delegate.Combine(englishDelegate, frenchDelegate); 15: 16: combinedDelegate.Invoke("Tom"); 17: Console.ReadLine(); 18: } 19: 20: static void SayNameInFrench(string name) { 21: Console.WriteLine("J'ai m'appelle " + name); 22: } 23: 24: static void SayNameInEnglish(string name) { 25: Console.WriteLine("My name is " + name); 26: } 27: } We have declared a delegate of type SayName with return type of void and taking an input parameter of name of type string. On line 12, we create a new instance of this delegate which refers to a static method - SayNameInEnglish.  SayNameInEnglish has the same return type and parameter list as the delegate declaration.  Once a delegate is instantiated, the instance will always refer to the same target. Delegates are immutable. On line 13, we create a new instance of the delegate but point to a different static method. As you may recall, a delegate instance encapsulates an invocation list. You create an invocation list by combining delegates using the Delegate.Combine method (there is an easier syntax as you will see later). When two non null delegate instances are combined, their invocation lists get combined to form a new invocation list. This is done in line 14.  On line 16, we invoke the delegate with the Invoke method and pass in the required string parameter. Since the delegate has an invocation list with two entries, each of the method in the invocation list is invoked. If an unhandled exception occurs during the invocation of one of these methods, the exception gets bubbled up to the line where the invocation was made (line 16). If a delegate is null and you try to invoke it, you will get a System.NullReferenceException. We see the following output when the method is run: My name is TomJ'ai m'apelle Tom Instance Methods The code below outputs the same results as before. The only difference here is we are creating delegates that point to a target object (an instance of Translator) and instance methods which have the same signature as the delegate type. The target object can never be null. We also use the short cut syntax += to combine the delegates instead of Delegate.Combine. 1: public delegate void SayName(string name); 2: 3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: Translator translator = new Translator(); 9: SayName combinedDelegate = new SayName(translator.SayNameInEnglish); 10: combinedDelegate += new SayName(translator.SayNameInFrench); 11:  12: combinedDelegate.Invoke("Tom"); 13: Console.ReadLine(); 14: } 15: } 16: 17: public class Translator { 18: public void SayNameInFrench(string name) { 19: Console.WriteLine("J'ai m'appelle " + name); 20: } 21: 22: public void SayNameInEnglish(string name) { 23: Console.WriteLine("My name is " + name); 24: } 25: } A delegate can be removed from a combination of delegates by using the –= operator. Removing a delegate from an empty list or removing a delegate that does not exist in a non empty list will not result in an exception. Delegates are invoked synchronously using the Invoke method. We can also invoke them asynchronously using the BeginInvoke and EndInvoke methods which are compiler generated.

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  • Polite busy-waiting with WRPAUSE on SPARC

    - by Dave
    Unbounded busy-waiting is an poor idea for user-space code, so we typically use spin-then-block strategies when, say, waiting for a lock to be released or some other event. If we're going to spin, even briefly, then we'd prefer to do so in a manner that minimizes performance degradation for other sibling logical processors ("strands") that share compute resources. We want to spin politely and refrain from impeding the progress and performance of other threads — ostensibly doing useful work and making progress — that run on the same core. On a SPARC T4, for instance, 8 strands will share a core, and that core has its own L1 cache and 2 pipelines. On x86 we have the PAUSE instruction, which, naively, can be thought of as a hardware "yield" operator which temporarily surrenders compute resources to threads on sibling strands. Of course this helps avoid intra-core performance interference. On the SPARC T2 our preferred busy-waiting idiom was "RD %CCR,%G0" which is a high-latency no-nop. The T4 provides a dedicated and extremely useful WRPAUSE instruction. The processor architecture manuals are the authoritative source, but briefly, WRPAUSE writes a cycle count into the the PAUSE register, which is ASR27. Barring interrupts, the processor then delays for the requested period. There's no need for the operating system to save the PAUSE register over context switches as it always resets to 0 on traps. Digressing briefly, if you use unbounded spinning then ultimately the kernel will preempt and deschedule your thread if there are other ready threads than are starving. But by using a spin-then-block strategy we can allow other ready threads to run without resorting to involuntary time-slicing, which operates on a long-ish time scale. Generally, that makes your application more responsive. In addition, by blocking voluntarily we give the operating system far more latitude regarding power management. Finally, I should note that while we have OS-level facilities like sched_yield() at our disposal, yielding almost never does what you'd want or naively expect. Returning to WRPAUSE, it's natural to ask how well it works. To help answer that question I wrote a very simple C/pthreads benchmark that launches 8 concurrent threads and binds those threads to processors 0..7. The processors are numbered geographically on the T4, so those threads will all be running on just one core. Unlike the SPARC T2, where logical CPUs 0,1,2 and 3 were assigned to the first pipeline, and CPUs 4,5,6 and 7 were assigned to the 2nd, there's no fixed mapping between CPUs and pipelines in the T4. And in some circumstances when the other 7 logical processors are idling quietly, it's possible for the remaining logical processor to leverage both pipelines. Some number T of the threads will iterate in a tight loop advancing a simple Marsaglia xor-shift pseudo-random number generator. T is a command-line argument. The main thread loops, reporting the aggregate number of PRNG steps performed collectively by those T threads in the last 10 second measurement interval. The other threads (there are 8-T of these) run in a loop busy-waiting concurrently with the T threads. We vary T between 1 and 8 threads, and report on various busy-waiting idioms. The values in the table are the aggregate number of PRNG steps completed by the set of T threads. The unit is millions of iterations per 10 seconds. For the "PRNG step" busy-waiting mode, the busy-waiting threads execute exactly the same code as the T worker threads. We can easily compute the average rate of progress for individual worker threads by dividing the aggregate score by the number of worker threads T. I should note that the PRNG steps are extremely cycle-heavy and access almost no memory, so arguably this microbenchmark is not as representative of "normal" code as it could be. And for the purposes of comparison I included a row in the table that reflects a waiting policy where the waiting threads call poll(NULL,0,1000) and block in the kernel. Obviously this isn't busy-waiting, but the data is interesting for reference. _table { border:2px black dotted; margin: auto; width: auto; } _tr { border: 2px red dashed; } _td { border: 1px green solid; } _table { border:2px black dotted; margin: auto; width: auto; } _tr { border: 2px red dashed; } td { background-color : #E0E0E0 ; text-align : right ; } th { text-align : left ; } td { background-color : #E0E0E0 ; text-align : right ; } th { text-align : left ; } Aggregate progress T = #worker threads Wait Mechanism for 8-T threadsT=1T=2T=3T=4T=5T=6T=7T=8 Park thread in poll() 32653347334833483348334833483348 no-op 415 831 124316482060249729303349 RD %ccr,%g0 "pause" 14262429269228623013316232553349 PRNG step 412 829 124616702092251029303348 WRPause(8000) 32443361333133483349334833483348 WRPause(4000) 32153308331533223347334833473348 WRPause(1000) 30853199322432513310334833483348 WRPause(500) 29173070315032223270330933483348 WRPause(250) 26942864294930773205338833483348 WRPause(100) 21552469262227902911321433303348

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  • Cardinality Estimation Bug with Lookups in SQL Server 2008 onward

    - by Paul White
    Cost-based optimization stands or falls on the quality of cardinality estimates (expected row counts).  If the optimizer has incorrect information to start with, it is quite unlikely to produce good quality execution plans except by chance.  There are many ways we can provide good starting information to the optimizer, and even more ways for cardinality estimation to go wrong.  Good database people know this, and work hard to write optimizer-friendly queries with a schema and metadata (e.g. statistics) that reduce the chances of poor cardinality estimation producing a sub-optimal plan.  Today, I am going to look at a case where poor cardinality estimation is Microsoft’s fault, and not yours. SQL Server 2005 SELECT th.ProductID, th.TransactionID, th.TransactionDate FROM Production.TransactionHistory AS th WHERE th.ProductID = 1 AND th.TransactionDate BETWEEN '20030901' AND '20031231'; The query plan on SQL Server 2005 is as follows (if you are using a more recent version of AdventureWorks, you will need to change the year on the date range from 2003 to 2007): There is an Index Seek on ProductID = 1, followed by a Key Lookup to find the Transaction Date for each row, and finally a Filter to restrict the results to only those rows where Transaction Date falls in the range specified.  The cardinality estimate of 45 rows at the Index Seek is exactly correct.  The table is not very large, there are up-to-date statistics associated with the index, so this is as expected. The estimate for the Key Lookup is also exactly right.  Each lookup into the Clustered Index to find the Transaction Date is guaranteed to return exactly one row.  The plan shows that the Key Lookup is expected to be executed 45 times.  The estimate for the Inner Join output is also correct – 45 rows from the seek joining to one row each time, gives 45 rows as output. The Filter estimate is also very good: the optimizer estimates 16.9951 rows will match the specified range of transaction dates.  Eleven rows are produced by this query, but that small difference is quite normal and certainly nothing to worry about here.  All good so far. SQL Server 2008 onward The same query executed against an identical copy of AdventureWorks on SQL Server 2008 produces a different execution plan: The optimizer has pushed the Filter conditions seen in the 2005 plan down to the Key Lookup.  This is a good optimization – it makes sense to filter rows out as early as possible.  Unfortunately, it has made a bit of a mess of the cardinality estimates. The post-Filter estimate of 16.9951 rows seen in the 2005 plan has moved with the predicate on Transaction Date.  Instead of estimating one row, the plan now suggests that 16.9951 rows will be produced by each clustered index lookup – clearly not right!  This misinformation also confuses SQL Sentry Plan Explorer: Plan Explorer shows 765 rows expected from the Key Lookup (it multiplies a rounded estimate of 17 rows by 45 expected executions to give 765 rows total). Workarounds One workaround is to provide a covering non-clustered index (avoiding the lookup avoids the problem of course): CREATE INDEX nc1 ON Production.TransactionHistory (ProductID) INCLUDE (TransactionDate); With the Transaction Date filter applied as a residual predicate in the same operator as the seek, the estimate is again as expected: We could also force the use of the ultimate covering index (the clustered one): SELECT th.ProductID, th.TransactionID, th.TransactionDate FROM Production.TransactionHistory AS th WITH (INDEX(1)) WHERE th.ProductID = 1 AND th.TransactionDate BETWEEN '20030901' AND '20031231'; Summary Providing a covering non-clustered index for all possible queries is not always practical, and scanning the clustered index will rarely be optimal.  Nevertheless, these are the best workarounds we have today. In the meantime, watch out for poor cardinality estimates when a predicate is applied as part of a lookup. The worst thing is that the estimate after the lookup join in the 2008+ plans is wrong.  It’s not hopelessly wrong in this particular case (45 versus 16.9951 is not the end of the world) but it easily can be much worse, and there’s not much you can do about it.  Any decisions made by the optimizer after such a lookup could be based on very wrong information – which can only be bad news. If you think this situation should be improved, please vote for this Connect item. © 2012 Paul White – All Rights Reserved twitter: @SQL_Kiwi email: [email protected]

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  • When is my View too smart?

    - by Kyle Burns
    In this posting, I will discuss the motivation behind keeping View code as thin as possible when using patterns such as MVC, MVVM, and MVP.  Once the motivation is identified, I will examine some ways to determine whether a View contains logic that belongs in another part of the application.  While the concepts that I will discuss are applicable to most any pattern which favors a thin View, any concrete examples that I present will center on ASP.NET MVC. Design patterns that include a Model, a View, and other components such as a Controller, ViewModel, or Presenter are not new to application development.  These patterns have, in fact, been around since the early days of building applications with graphical interfaces.  The reason that these patterns emerged is simple – the code running closest to the user tends to be littered with logic and library calls that center around implementation details of showing and manipulating user interface widgets and when this type of code is interspersed with application domain logic it becomes difficult to understand and much more difficult to adequately test.  By removing domain logic from the View, we ensure that the View has a single responsibility of drawing the screen which, in turn, makes our application easier to understand and maintain. I was recently asked to take a look at an ASP.NET MVC View because the developer reviewing it thought that it possibly had too much going on in the view.  I looked at the .CSHTML file and the first thing that occurred to me was that it began with 40 lines of code declaring member variables and performing the necessary calculations to populate these variables, which were later either output directly to the page or used to control some conditional rendering action (such as adding a class name to an HTML element or not rendering another element at all).  This exhibited both of what I consider the primary heuristics (or code smells) indicating that the View is too smart: Member variables – in general, variables in View code are an indication that the Model to which the View is being bound is not sufficient for the needs of the View and that the View has had to augment that Model.  Notable exceptions to this guideline include variables used to hold information specifically related to rendering (such as a dynamically determined CSS class name or the depth within a recursive structure for indentation purposes) and variables which are used to facilitate looping through collections while binding. Arithmetic – as with member variables, the presence of arithmetic operators within View code are an indication that the Model servicing the View is insufficient for its needs.  For example, if the Model represents a line item in a sales order, it might seem perfectly natural to “normalize” the Model by storing the quantity and unit price in the Model and multiply these within the View to show the line total.  While this does seem natural, it introduces a business rule to the View code and makes it impossible to test that the rounding of the result meets the requirement of the business without executing the View.  Within View code, arithmetic should only be used for activities such as incrementing loop counters and calculating element widths. In addition to the two characteristics of a “Smart View” that I’ve discussed already, this View also exhibited another heuristic that commonly indicates to me the need to refactor a View and make it a bit less smart.  That characteristic is the existence of Boolean logic that either does not work directly with properties of the Model or works with too many properties of the Model.  Consider the following code and consider how logic that does not work directly with properties of the Model is just another form of the “member variable” heuristic covered earlier: @if(DateTime.Now.Hour < 12) {     <div>Good Morning!</div> } else {     <div>Greetings</div> } This code performs business logic to determine whether it is morning.  A possible refactoring would be to add an IsMorning property to the Model, but in this particular case there is enough similarity between the branches that the entire branching structure could be collapsed by adding a Greeting property to the Model and using it similarly to the following: <div>@Model.Greeting</div> Now let’s look at some complex logic around multiple Model properties: @if (ModelPageNumber + Model.NumbersToDisplay == Model.PageCount         || (Model.PageCount != Model.CurrentPage             && !Model.DisplayValues.Contains(Model.PageCount))) {     <div>There's more to see!</div> } In this scenario, not only is the View code difficult to read (you shouldn’t have to play “human compiler” to determine the purpose of the code), but it also complex enough to be at risk for logical errors that cannot be detected without executing the View.  Conditional logic that requires more than a single logical operator should be looked at more closely to determine whether the condition should be evaluated elsewhere and exposed as a single property of the Model.  Moving the logic above outside of the View and exposing a new Model property would simplify the View code to: @if(Model.HasMoreToSee) {     <div>There’s more to see!</div> } In this posting I have briefly discussed some of the more prominent heuristics that indicate a need to push code from the View into other pieces of the application.  You should now be able to recognize these symptoms when building or maintaining Views (or the Models that support them) in your applications.

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  • Training a 'replacement', how to enforce standards?

    - by Mohgeroth
    Not sure that this is the right stack exchange site to ask this of, but here goes... Scope I work for a small company that employs a few hundred people. The development team for the company is small and works out of visual foxpro. A specific department in the company hired me in as a 'lone gunman' to fix and enhance a pre-existing invoicing system. I've successfully taken an Access application that suffered from a lot of risks and limitations and converted it into a C# application driven off of a SQL server backend. I have recently obtained my undergraduate and am no expert by any means. To help make up for that I've felt that earning microsoft certifications will force me to understand more about .net and how it functions. So, after giving my notice with 9 months in advance, 3 months ago a replacement finally showed up. Their role is to learn what I have been designing to an attempt to support the applications designed in C#. The Replacement Fresh out of college with no real-world work experience, the first instinct for anything involving data was and still is listboxes... any time data is mentioned the list box is the control of choice for the replacement. This has gotten to the point, no matter how many times I discuss other controls, where I've seen 5 listboxes on a single form. Classroom experience was almost all C++ console development. So, an example of where I have concern is in a winforms application: Users need to key Reasons into a table to select from later. Given that I know that a strongly typed data set exists, I can just drag the data source from the toolbox and it would create all of this for me. I realize this is a simple example but using databinding is the key. For the past few months now we have been talking about the strongly typed dataset, how to use it and where it interacts with other controls. Data sets, how they work in relation to binding sources, adapters and data grid views. After handing this project off I expected questions about how to implement these since for me this is the way to do it. What happened next simply floors me: An instance of an adapter from the strongly typed dataset was created in the activate event of the form, a table was created and filled with data. Then, a loop was made to manually add rows to a listbox from this table. Finally, a variable was kept to do lookups to figure out what ID the record was for updates if required. How do they modify records you ask? That was my first question too. You won't believe how simple it is, all you do it double click and they type into a pop-up prompt the new value to change it to. As a data entry operator, all the modal popups would drive me absolutely insane. The final solution exceeds 100 lines of code that must be maintained. So my concern is that none of this is sinking in... the department is only allowed 20 hours a week of their time. Up until last week, we've only been given 4-5 hours a week if I'm lucky. The past week or so, I've been lucky to get 10. Question WHAT DO I DO?! I have 4 weeks left until I leave and they fully 'support' this application. I love this job and the opportunity it has given me but it's time for me to spread my wings and find something new. I am in no way, shape or form convinced that they are ready to take over. I do feel that the replacement has the technical ability to 'figure it out' but instead of learning they just write code to do all of this stuff manually. If the replacement wants to code differently in the end, as long as it works I'm fine with that as horrifiying at it looks. However to support what I have designed they MUST to understand how it works and how I have used controls and the framework to make 'magic' happen. This project has about 40 forms, a database with over 30 some odd tables, triggers and stored procedures. It relates labor to invoices to contracts to projections... it's not as simple as it was three years ago when I began this project and the department is now in a position where they cannot survive without it. How in the world can I accomplish any of the following?: Enforce standards or understanding in constent design when the department manager keeps telling them they can do it however they want to Find a way to engage the replacement in active learning of the framework and system design that support must be given for Gracefully inform sr. management that 5-9 hours a week is simply not enough time to learn about the department, pre-existing processes, applications that need to be supported AND determine where potential enhancements to the system go... Yes I know this is a wall of text, thanks for reading through me but I simply don't know what I should be doing. For me, this job is a monster of a reference and things would look extremely bad if I left and things fell apart. How do I handle this?

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  • Data management in unexpected places

    - by Ashok_Ora
    Normal 0 false false false EN-US X-NONE X-NONE Data management in unexpected places When you think of network switches, routers, firewall appliances, etc., it may not be obvious that at the heart of these kinds of solutions is an engine that can manage huge amounts of data at very high throughput with low latencies and high availability. Consider a network router that is processing tens (or hundreds) of thousands of network packets per second. So what really happens inside a router? Packets are streaming in at the rate of tens of thousands per second. Each packet has multiple attributes, for example, a destination, associated SLAs etc. For each packet, the router has to determine the address of the next “hop” to the destination; it has to determine how to prioritize this packet. If it’s a high priority packet, then it has to be sent on its way before lower priority packets. As a consequence of prioritizing high priority packets, lower priority data packets may need to be temporarily stored (held back), but addressed fairly. If there are security or privacy requirements associated with the data packet, those have to be enforced. You probably need to keep track of statistics related to the packets processed (someone’s sure to ask). You have to do all this (and more) while preserving high availability i.e. if one of the processors in the router goes down, you have to have a way to continue processing without interruption (the customer won’t be happy with a “choppy” VoIP conversation, right?). And all this has to be achieved without ANY intervention from a human operator – the router is most likely to be in a remote location – it must JUST CONTINUE TO WORK CORRECTLY, even when bad things happen. How is this implemented? As soon as a packet arrives, it is interpreted by the receiving software. The software decodes the packet headers in order to determine the destination, kind of packet (e.g. voice vs. data), SLAs associated with the “owner” of the packet etc. It looks up the internal database of “rules” of how to process this packet and handles the packet accordingly. The software might choose to hold on to the packet safely for some period of time, if it’s a low priority packet. Ah – this sounds very much like a database problem. For each packet, you have to minimally · Look up the most efficient next “hop” towards the destination. The “most efficient” next hop can change, depending on latency, availability etc. · Look up the SLA and determine the priority of this packet (e.g. voice calls get priority over data ftp) · Look up security information associated with this data packet. It may be necessary to retrieve the context for this network packet since a network packet is a small “slice” of a session. The context for the “header” packet needs to be stored in the router, in order to make this work. · If the priority of the packet is low, then “store” the packet temporarily in the router until it is time to forward the packet to the next hop. · Update various statistics about the packet. In most cases, you have to do all this in the context of a single transaction. For example, you want to look up the forwarding address and perform the “send” in a single transaction so that the forwarding address doesn’t change while you’re sending the packet. So, how do you do all this? Berkeley DB is a proven, reliable, high performance, highly available embeddable database, designed for exactly these kinds of usage scenarios. Berkeley DB is a robust, reliable, proven solution that is currently being used in these scenarios. First and foremost, Berkeley DB (or BDB for short) is very very fast. It can process tens or hundreds of thousands of transactions per second. It can be used as a pure in-memory database, or as a disk-persistent database. BDB provides high availability – if one board in the router fails, the system can automatically failover to another board – no manual intervention required. BDB is self-administering – there’s no need for manual intervention in order to maintain a BDB application. No need to send a technician to a remote site in the middle of nowhere on a freezing winter day to perform maintenance operations. BDB is used in over 200 million deployments worldwide for the past two decades for mission-critical applications such as the one described here. You have a choice of spending valuable resources to implement similar functionality, or, you could simply embed BDB in your application and off you go! I know what I’d do – choose BDB, so I can focus on my business problem. What will you do? /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

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  • Most Innovative IDM Projects: Awards at OpenWorld

    - by Tanu Sood
    On Tuesday at Oracle OpenWorld 2012, Oracle recognized the winners of Innovation Awards 2012 at a ceremony presided over by Hasan Rizvi, Executive Vice President at Oracle. Oracle Fusion Middleware Innovation Awards recognize customers for achieving significant business value through innovative uses of Oracle Fusion Middleware offerings. Winners are selected based on the uniqueness of their business case, business benefits, level of impact relative to the size of the organization, complexity and magnitude of implementation, and the originality of architecture. This year’s Award honors customers for their cutting-edge solutions driving business innovation and IT modernization using Oracle Fusion Middleware. The program has grown over the past 6 years, receiving a record number of nominations from customers around the globe. The winners were selected by a panel of judges that ranked each nomination across multiple different scoring categories. Congratulations to both Avea and ETS for winning this year’s Innovation Award for Identity Management. Identity Management Innovation Award 2012 Winner – Avea Company: Founded in 2004, AveA is the sole GSM 1800 mobile operator of Turkey and has reached a nationwide customer base of 12.8 million as of the end of 2011 Region: Turkey (EMEA) Products: Oracle Identity Manager, Oracle Identity Analytics, Oracle Access Management Suite Business Drivers: ·         To manage the agility and scale required for GSM Operations and enable call center efficiency by enabling agents to change their identity profiles (accounts and entitlements) rapidly based on call load. ·         Enhance user productivity and call center efficiency with self service password resets ·         Enforce compliance and audit reporting ·         Seamless identity management between AveA and parent company Turk Telecom Innovation and Results: ·         One of the first Sun2Oracle identity management migrations designed for high performance provisioning and trusted reconciliation built with connectors developed on the ICF architecture that provides custom user interfaces for  dynamic and rapid management of roles and entitlements along with entitlement level attestation using closed loop remediation between Oracle Identity Manager and Oracle Identity Analytics. ·         Dramatic reduction in identity administration and call center password reset tasks leading to 20% reduction in administration costs and 95% reduction in password related calls. ·         Enhanced user productivity by up to 25% to date ·         Enforced enterprise security and reduced risk ·         Cost-effective compliance management ·         Looking to seamlessly integrate with parent and sister companies’ infrastructure securely. Identity Management Innovation Award 2012 Winner – Education Testing Service (ETS)       See last year's winners here --Company: ETS is a private nonprofit organization devoted to educational measurement and research, primarily through testing. Region: U.S.A (North America) Products: Oracle Access Manager, Oracle Identity Federation, Oracle Identity Manager Business Drivers: ETS develops and administers more than 50 million achievement and admissions tests each year in more than 180 countries, at more than 9,000 locations worldwide.  As the business becomes more globally based, having a robust solution to security and user management issues becomes paramount. The organizations was looking for: ·         Simplified user experience for over 3000 company users and more than 6 million dynamic student and staff population ·         Infrastructure and administration cost reduction ·         Managing security risk by controlling 3rd party access to ETS systems ·         Enforce compliance and manage audit reporting ·         Automate on-boarding and decommissioning of user account to improve security, reduce administration costs and enhance user productivity ·         Improve user experience with simplified sign-on and user self service Innovation and Results: 1.    Manage Risk ·         Centralized system to control user access ·         Provided secure way of accessing service providers' application using federated SSO. ·         Provides reporting capability for auditing, governance and compliance. 2.    Improve efficiency ·         Real-Time provisioning to target systems ·         Centralized provisioning system for user management and access controls. ·         Enabling user self services. 3.    Reduce cost ·         Re-using common shared services for provisioning, SSO, Access by application reducing development cost and time. ·         Reducing infrastructure and maintenance cost by decommissioning legacy/redundant IDM services. ·         Reducing time and effort to implement security functionality in business applications (“onboard” instead of new development). ETS was able to fold in new and evolving requirement in addition to the initial stated goals realizing quick ROI and successfully meeting business objectives. Congratulations to the winners once again. We will be sure to bring you more from these Innovation Award winners over the next few months.

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  • How can I implement a database TableView like thing in C++?

    - by Industrial-antidepressant
    How can I implement a TableView like thing in C++? I want to emulating a tiny relation database like thing in C++. I have data tables, and I want to transform it somehow, so I need a TableView like class. I want filtering, sorting, freely add and remove items and transforming (ex. view as UPPERCASE and so on). The whole thing is inside a GUI application, so datatables and views are attached to a GUI (or HTML or something). So how can I identify an item in the view? How can I signal it when the table is changed? Is there some design pattern for this? Here is a simple table, and a simple data item: #include <string> #include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/random_access_index.hpp> using boost::multi_index_container; using namespace boost::multi_index; struct Data { Data() {} int id; std::string name; }; struct row{}; struct id{}; struct name{}; typedef boost::multi_index_container< Data, indexed_by< random_access<tag<row> >, ordered_unique<tag<id>, member<Data, int, &Data::id> >, ordered_unique<tag<name>, member<Data, std::string, &Data::name> > > > TDataTable; class DataTable { public: typedef Data item_type; typedef TDataTable::value_type value_type; typedef TDataTable::const_reference const_reference; typedef TDataTable::index<row>::type TRowIndex; typedef TDataTable::index<id>::type TIdIndex; typedef TDataTable::index<name>::type TNameIndex; typedef TRowIndex::iterator iterator; DataTable() : row_index(rule_table.get<row>()), id_index(rule_table.get<id>()), name_index(rule_table.get<name>()), row_index_writeable(rule_table.get<row>()) { } TDataTable::const_reference operator[](TDataTable::size_type n) const { return rule_table[n]; } std::pair<iterator,bool> push_back(const value_type& x) { return row_index_writeable.push_back(x); } iterator erase(iterator position) { return row_index_writeable.erase(position); } bool replace(iterator position,const value_type& x) { return row_index_writeable.replace(position, x); } template<typename InputIterator> void rearrange(InputIterator first) { return row_index_writeable.rearrange(first); } void print_table() const; unsigned size() const { return row_index.size(); } TDataTable rule_table; const TRowIndex& row_index; const TIdIndex& id_index; const TNameIndex& name_index; private: TRowIndex& row_index_writeable; }; class DataTableView { DataTableView(const DataTable& source_table) {} // How can I implement this? // I want filtering, sorting, signaling upper GUI layer, and sorting, and ... }; int main() { Data data1; data1.id = 1; data1.name = "name1"; Data data2; data2.id = 2; data2.name = "name2"; DataTable table; table.push_back(data1); DataTable::iterator it1 = table.row_index.iterator_to(table[0]); table.erase(it1); table.push_back(data1); Data new_data(table[0]); new_data.name = "new_name"; table.replace(table.row_index.iterator_to(table[0]), new_data); for (unsigned i = 0; i < table.size(); ++i) std::cout << table[i].name << std::endl; #if 0 // using scenarios: DataTableView table_view(table); table_view.fill_from_source(); // synchronization with source table_view.remove(data_item1); // remove item from view table_view.add(data_item2); // add item from source table table_view.filter(filterfunc); // filtering table_view.sort(sortfunc); // sorting // modifying from source_able, hot to signal the table_view? // FYI: Table view is atteched to a GUI item table.erase(data); table.replace(data); #endif return 0; }

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  • C++ strongly typed typedef

    - by Kian
    I've been trying to think of a way of declaring strongly typed typedefs, to catch a certain class of bugs in the compilation stage. It's often the case that I'll typedef an int into several types of ids, or a vector to position or velocity: typedef int EntityID; typedef int ModelID; typedef Vector3 Position; typedef Vector3 Velocity; This can make the intent of code more clear, but after a long night of coding one might make silly mistakes like comparing different kinds of ids, or adding a position to a velocity perhaps. EntityID eID; ModelID mID; if ( eID == mID ) // <- Compiler sees nothing wrong { /*bug*/ } Position p; Velocity v; Position newP = p + v; // bug, meant p + v*s but compiler sees nothing wrong Unfortunately, suggestions I've found for strongly typed typedefs include using boost, which at least for me isn't a possibility (I do have c++11 at least). So after a bit of thinking, I came upon this idea, and wanted to run it by someone. First, you declare the base type as a template. The template parameter isn't used for anything in the definition, however: template < typename T > class IDType { unsigned int m_id; public: IDType( unsigned int const& i_id ): m_id {i_id} {}; friend bool operator==<T>( IDType<T> const& i_lhs, IDType<T> const& i_rhs ); }; Friend functions actually need to be forward declared before the class definition, which requires a forward declaration of the template class. We then define all the members for the base type, just remembering that it's a template class. Finally, when we want to use it, we typedef it as: class EntityT; typedef IDType<EntityT> EntityID; class ModelT; typedef IDType<ModelT> ModelID; The types are now entirely separate. Functions that take an EntityID will throw a compiler error if you try to feed them a ModelID instead, for example. Aside from having to declare the base types as templates, with the issues that entails, it's also fairly compact. I was hoping anyone had comments or critiques about this idea? One issue that came to mind while writing this, in the case of positions and velocities for example, would be that I can't convert between types as freely as before. Where before multiplying a vector by a scalar would give another vector, so I could do: typedef float Time; typedef Vector3 Position; typedef Vector3 Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; With my strongly typed typedef I'd have to tell the compiler that multypling a Velocity by a Time results in a Position. class TimeT; typedef Float<TimeT> Time; class PositionT; typedef Vector3<PositionT> Position; class VelocityT; typedef Vector3<VelocityT> Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; // Compiler error To solve this, I think I'd have to specialize every conversion explicitly, which can be kind of a bother. On the other hand, this limitation can help prevent other kinds of errors (say, multiplying a Velocity by a Distance, perhaps, which wouldn't make sense in this domain). So I'm torn, and wondering if people have any opinions on my original issue, or my approach to solving it.

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  • InteropServices COMException when executing a .net app from a web CGI script on Windows Server 2003

    - by Kurt W. Leucht
    Disclaimer: I'm completely clueless about .net and COM. I have a vendor's application that appears to be written in .net and I'm trying to wrap it with a web form (a cgi-bin Perl script) so I can eventually launch this vendor's app from a separate computer. I'm on a Windows Server 2003 R2 SE SP1 system and I'm using Apache 2.2 for the web server and ActivePerl 5.10.0.1004 for the cgi script. My cgi script calls the vendor's app that resides on the same machine using the Perl backtick operator. ... $result = "Result: " . `$vendorsPath/$vendorsExecutable $arg1 $arg2`; ... Right now I'm just running IE web browser locally on the server machine and accessing "http://localhost/cgi-bin/myPerlScript.pl". The vendor's app fails and logs a debug message that includes the following stack trace (I changed a couple names so as to not give away the vendor's identity): ... System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Runtime.InteropServices.COMException (0x80043A1D): 0x80040154 - Class not registered --- End of inner exception stack trace --- at System.RuntimeType.InvokeDispMethod(String name, BindingFlags invokeAttr, Object target, Object[] args, Boolean[] byrefModifiers, Int32 culture, String[] namedParameters) at System.RuntimeType.InvokeMember(String name, BindingFlags invokeAttr, Binder binder, Object target, Object[] args, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParameters) at VendorsTool.Engine.Core.VendorsEngine.LoadVendorsServices(String fileName, String& projectCommPath) ... When I run the vendors app from the Windows command line on the server machine with the exact same arguments that the cgi script is passing it runs just fine, so there's something about invoking their app via the web script that is causing a problem. This problem is likely security related because the whole thing runs just fine on a Windows XP Pro machine (both command line and web invocation). I actually developed my web script there and got it completely working there before I tried moving it to the Windows Server 2003 machine. So what's different about the Windows Server 2003 machine that would keep the vendor's .net app from being executed successfully by a web cgi script? Can I fix this problem somehow to make it work on my server or will the vendor have to make a change to their .net app and ship out a new version? I'm probably the only person in the world who is trying to execute this vendor's app from a separate program, so I hate to bother the vendor with the issue if there's a workaround that I can implement myself here on my server machine. Plus, I'm in kind of a hurry and I don't want to wait 4 or 6 months for the vendor to put in a fix and deploy a new version. Thanks for any advise you can give.

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  • Extracting pair member in lambda expressions and template typedef idiom

    - by Nazgob
    Hi, I have some complex types here so I decided to use nifty trick to have typedef on templated types. Then I have a class some_container that has a container as a member. Container is a vector of pairs composed of element and vector. I want to write std::find_if algorithm with lambda expression to find element that have certain value. To get the value I have to call first on pair and then get value from element. Below my std::find_if there is normal loop that does the trick. My lambda fails to compile. How to access value inside element which is inside pair? I use g++ 4.4+ and VS 2010 and I want to stick to boost lambda for now. #include <vector> #include <algorithm> #include <boost\lambda\lambda.hpp> #include <boost\lambda\bind.hpp> template<typename T> class element { public: T value; }; template<typename T> class element_vector_pair // idiom to have templated typedef { public: typedef std::pair<element<T>, std::vector<T> > type; }; template<typename T> class vector_containter // idiom to have templated typedef { public: typedef std::vector<typename element_vector_pair<T>::type > type; }; template<typename T> bool operator==(const typename element_vector_pair<T>::type & lhs, const typename element_vector_pair<T>::type & rhs) { return lhs.first.value == rhs.first.value; } template<typename T> class some_container { public: element<T> get_element(const T& value) const { std::find_if(container.begin(), container.end(), bind(&typename vector_containter<T>::type::value_type::first::value, boost::lambda::_1) == value); /*for(size_t i = 0; i < container.size(); ++i) { if(container.at(i).first.value == value) { return container.at(i); } }*/ return element<T>(); //whatever } protected: typename vector_containter<T>::type container; }; int main() { some_container<int> s; s.get_element(5); return 0; }

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  • gcc 4.5 installation problem under ubuntu

    - by Claire Huang
    I tried to install gcc 4.5 on ubuntu 10.04 but failed. Here is a compile error that I don't know how to solve. Is there anyone successfully install the latest gcc on ubuntu? Following is my steps and the error message, I'd like to know where is the problem.... Step1: download these files: gcc-core-4.5.0.tar.gz gcc-g++-4.5.0.tar.gz gmp-4.3.2.tar.bz2 mpc-0.8.1.tar.gz mpfr-2.4.2.tar.gz Step2: Unzip above files Step3: move gmp, mpc, mpfr to the gcc-4.5.0/ directory. mv gmp-4.3.2 gcc-4.5.0/gmp mv mpc-0.8.1 gcc-4.5.0/mpc mv mpfr-2.4.2 gcc-4.5.0/mpfr Step4: go to gcc-4.5.0 directory and do configuration: sudo ./configure Step5: compile and install sudo make sudo make install The first 4 steps is OK, I can configure it successfully. However, when I try to compile it, following error message comes out, I cannot figure out what the problem is. Should I change the name from "gcc 4.5" to "gcc"?? It's a little strange that we need to do this by ourself. Is there anything I missed during the installation? xxx@xxx-laptop:/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0$ sudo make [sudo] password for xxx: [ -f stage_final ] || echo stage3 > stage_final /bin/bash: line 2: test: /media/Data/Tool/linux/gcc: binary operator expected /bin/bash: /media/Data/Tool/linux/gcc: No such file or directory make[1]: Entering directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' make[2]: Entering directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' make[3]: Entering directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' rm -f stage_current make[3]: Leaving directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' make[2]: Leaving directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' make[2]: Entering directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' Configuring stage 1 in host-x86_64-unknown-linux-gnu/intl /bin/bash: /media/Data/Tool/linux/gcc: No such file or directory make[2]: *** [configure-stage1-intl] Error 127 make[2]: Leaving directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' make[1]: *** [stage1-bubble] Error 2 make[1]: Leaving directory `/media/Data/Tool/linux/gcc 4.5/gcc-4.5.0' make: *** [all] Error 2

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  • Hive NR map progress inconsistent and regurlarly restart from 0%

    - by user92471
    I have a Yarn MR (with two ec2 instances to mapreduce) job on a dataset of approximately a thousand avro records, and the map phase is behaving erratically. See the progress below. Of course i checked the logs on resourcemanager and nodemanagers and saw nothing suspicious, but these logs are too verbose What is going on there ? hive> select * from nikon where qs_cs_s_aid='VIEW' limit 10; Total MapReduce jobs = 1 Launching Job 1 out of 1 Number of reduce tasks is set to 0 since there's no reduce operator Starting Job = job_1352281315350_0020, Tracking URL = http://blabla.ec2.internal:8088/proxy/application_1352281315350_0020/ Kill Command = /usr/lib/hadoop/bin/hadoop job -Dmapred.job.tracker=blabla.com:8032 -kill job_1352281315350_0020 Hadoop job information for Stage-1: number of mappers: 4; number of reducers: 0 2012-11-07 11:14:40,976 Stage-1 map = 0%, reduce = 0% 2012-11-07 11:15:06,136 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 10.38 sec 2012-11-07 11:15:07,253 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 12.18 sec 2012-11-07 11:15:08,371 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 12.18 sec 2012-11-07 11:15:09,491 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 12.18 sec 2012-11-07 11:15:10,643 Stage-1 map = 2%, reduce = 0%, Cumulative CPU 15.42 sec (...) 2012-11-07 11:15:35,441 Stage-1 map = 28%, reduce = 0%, Cumulative CPU 37.77 sec 2012-11-07 11:15:36,486 Stage-1 map = 28%, reduce = 0%, Cumulative CPU 37.77 sec here restart at 16% ? 2012-11-07 11:15:37,692 Stage-1 map = 16%, reduce = 0%, Cumulative CPU 21.15 sec 2012-11-07 11:15:38,815 Stage-1 map = 16%, reduce = 0%, Cumulative CPU 21.15 sec 2012-11-07 11:15:39,865 Stage-1 map = 16%, reduce = 0%, Cumulative CPU 21.15 sec 2012-11-07 11:15:41,064 Stage-1 map = 18%, reduce = 0%, Cumulative CPU 22.4 sec 2012-11-07 11:15:42,181 Stage-1 map = 18%, reduce = 0%, Cumulative CPU 22.4 sec 2012-11-07 11:15:43,299 Stage-1 map = 18%, reduce = 0%, Cumulative CPU 22.4 sec here restart at 0% ? 2012-11-07 11:15:44,418 Stage-1 map = 0%, reduce = 0% 2012-11-07 11:16:02,076 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 6.86 sec 2012-11-07 11:16:03,193 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 6.86 sec 2012-11-07 11:16:04,259 Stage-1 map = 2%, reduce = 0%, Cumulative CPU 8.45 sec (...) 2012-11-07 11:16:31,291 Stage-1 map = 22%, reduce = 0%, Cumulative CPU 35.34 sec 2012-11-07 11:16:32,414 Stage-1 map = 26%, reduce = 0%, Cumulative CPU 37.93 sec here restart at 11% ? 2012-11-07 11:16:33,459 Stage-1 map = 11%, reduce = 0%, Cumulative CPU 19.53 sec 2012-11-07 11:16:34,507 Stage-1 map = 11%, reduce = 0%, Cumulative CPU 19.53 sec 2012-11-07 11:16:35,731 Stage-1 map = 13%, reduce = 0%, Cumulative CPU 21.47 sec (...) 2012-11-07 11:16:46,839 Stage-1 map = 17%, reduce = 0%, Cumulative CPU 24.14 sec here restart at 0% ? 2012-11-07 11:16:47,939 Stage-1 map = 0%, reduce = 0% 2012-11-07 11:16:56,653 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 7.54 sec 2012-11-07 11:16:57,814 Stage-1 map = 1%, reduce = 0%, Cumulative CPU 7.54 sec (...) Needless to say the job crashes after some time with an Error: java.io.IOException: java.io.IOException: java.lang.ArrayIndexOutOfBoundsException: -56

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  • problem with template inheritance

    - by amiad
    I'm trying to understand whay i get an error on this code: (the error is under g++ unix compiler. VS is compiling OK) template<class T> class A { public: T t; public: A(const T& t1) : t(t1) {} virtual void Print() const { cout<<*this<<endl;} friend ostream& operator<<(ostream& out, const A<T>& a) { out<<"I'm "<<typeid(a).name()<<endl; out<<"I hold "<<typeid(a.t).name()<<endl; out<<"The inner value is: "<<a.t<<endl; return out; } }; template<class T> class B : public A<T> { public: B(const T& t1) : A<T>(t1) {} const T& get() const { return t; } }; int main() { A<int> a(9); a.Print(); B<A<int> > b(a); b.Print(); (b.get()).Print(); return 0; } This code is giving the following error: main.cpp: In member function 'const T& B::get() const': main.cpp:23: error: 't' was not declared in this scope It did compiled when i changed the code of B to this: template<class T> class B : public A<T> { public: B(const T& t1) : A<T>(t1) {} const T& get() const { return A<T>::t; } }; I just cant understand what is the problem with the first code... It doesn't make sense that i really need to write "A::" every time...

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