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  • Please Explain Drupal schema and drupal_write_record

    - by Aaron
    Hi. A few questions. 1) Where is the best place to populate a new database table when a module is first installed, enabled? I need to go and get some data from an external source and want to do it transparently when the user installs/enables my custom module. I create the schema in {mymodule}_schema(), do drupal_install_schema({tablename}); in hook_install. Then I try to populate the table in hook_enable using drupal_write_record. I confirmed the table was created, I get no errors when hook_enable executes, but when I query the new table, I get no rows back--it's empty. Here's one variation of the code I've tried: /** * Implementation of hook_schema() */ function ncbi_subsites_schema() { // we know it's MYSQL, so no need to check $schema['ncbi_subsites_sites'] = array( 'description' => 'The base table for subsites', 'fields' => array( 'site_id' => array( 'description' => 'Primary id for site', 'type' => 'serial', 'unsigned' => TRUE, 'not null' => TRUE, ), // end site_id 'title' => array( 'description' => 'The title of the subsite', 'type' => 'varchar', 'length' => 255, 'not null' => TRUE, 'default' => '', ), //end title field 'url' => array( 'description' => 'The URL of the subsite in Production', 'type' => 'varchar', 'length' => 255, 'default' => '', ), //end url field ), //end fields 'unique keys' => array( 'site_id'=> array('site_id'), 'title' => array('title'), ), //end unique keys 'primary_key' => array('site_id'), ); // end schema return $schema; } Here's hook_install: function ncbi_subsites_install() { drupal_install_schema('ncbi_subsites'); } Here's hook_enable: function ncbi_subsites_enable() { drupal_get_schema('ncbi_subsites_site'); // my helper function to get data for table (not shown) $subsites = ncbi_subsites_get_subsites(); foreach( $subsites as $name=>$attrs ) { $record = new stdClass(); $record->title = $name; $record->url = $attrs['homepage']; drupal_write_record( 'ncbi_subsites_sites', $record ); } } Can someone tell me what I'm missing?

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  • Playing dynamically embedded sound object via Javascript

    - by Vikram Goyal
    I need to background load some WAV files for an HTML page using AJAX. I use AJAX to get the details of the WAV files, then use the embed tag, and I can confirm that the files have loaded successfully because when I set autostart to true, the files play. However, I need the files to play only when the user clicks on a button (or an event is fired). The following is my code to preload these files: function preloadMedia() { for(var i = 0; i < testQuestions.length; i++) { var soundEmbed = document.createElement("embed"); soundEmbed.setAttribute("src", "/media/sounds/" + testQuestions[i].mediaFile); soundEmbed.setAttribute("hidden", true); soundEmbed.setAttribute("id", testQuestions[i].id); soundEmbed.setAttribute("autostart", false); soundEmbed.setAttribute("width", 0); soundEmbed.setAttribute("height", 0); soundEmbed.setAttribute("enablejavascript", true); document.body.appendChild((soundEmbed)); } } I use the following code to play the file (based on what sound file that user wants to play) function soundPlay(which) { var sounder = document.getElementById(which); sounder.Play(); } Something is wrong here, as none of the browsers I have tested on play the files using the code above. There are no errors, and the code just returns. I would have left it at that (that is - I would have convinced the client to convert all WAV's to MP3 and use MooTools). But I realized that I could play the sound files, which were not dynamically embeded. Thus, the same soundPlay function would work for a file embeded in the following manner: <embed src="/media/sounds/hug_sw1.wav" id="sound2" width="0" heigh="0" autostart="false" enablejavascript="true"/> anywhere within the HTML. And it plays well in all the browsers. Anyone have a clue on this? Is this some sort of undocumented security restriction in all the browsers? (Please remember that the files do get preloaded dynamically, as I can confirm by setting the autostart property to true - They all play). Any help appreciated.

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  • Psychology researcher wants to learn new language

    - by user273347
    I'm currently considering R, matlab, or python, but I'm open to other options. Could you help me pick the best language for my needs? Here are the criteria I have in mind (not in order): Simple to learn. I don't really have a lot of free time, so I'm looking for something that isn't extremely complicated and/or difficult to pick up. I know some C, FWIW. Good for statistics/psychometrics. I do a ton of statistics and psychometrics analysis. A lot of it is basic stuff that I can do with SPSS, but I'd like to play around with the more advanced stuff too (bootstrapping, genetic programming, data mining, neural nets, modeling, etc). I'm looking for a language/environment that can help me run my simpler analyses faster and give me more options than a canned stat package like SPSS. If it can even make tables for me, then it'll be perfect. I also do a fair bit of experimental psychology. I use a canned experiment "programming" software (SuperLab) to make most of my experiments, but I want to be able to program executable programs that I can run on any computer and that can compile the data from the experiments in a spreadsheet. I know python has psychopy and pyepl and matlab has psychtoolbox, but I don't know which one is best. If R had something like this, I'd probably be sold on R already. I'm looking for something regularly used in academe and industry. Everybody else here (including myself, so far) uses canned stat and experiment programming software. One of the reasons I'm trying to learn a programming language is so that I can keep up when I move to another lab. Looking forward to your comments and suggestions. Thank you all for your kind and informative replies. I appreciate it. It's still a tough choice because of so many strong arguments for each language. Python - Thinking about it, I've forgotten so much about C already (I don't even remember what to do with an array) that it might be better for me to start from scratch with a simple program that does what it's supposed to do. It looks like it can do most of the things I'll need it to do, though not as cleanly as R and MATLAB. R - I'm really liking what I'm reading about R. The packages are perfect for my statistical work now. Given the purpose of R, I don't think it's suited to building psychological experiments though. To clarify, what I mean is making a program that presents visual and auditory stimuli to my specifications (hundreds of them in a preset and/or randomized sequence) and records the response data gathered from participants. MATLAB - It's awesome that cognitive and neuro folk are recommending MATLAB, because I'm preparing for the big leap from social and personality psychology to cognitive neuro. The problem is the Uni where I work doesn't have MATLAB licenses (and 3750 GBP for a compiler license is not an option for me haha). Octave looks like a good alternative. PsychToolbox is compatible with Octave, thankfully. SQL - Thanks for the tip. I'll explore that option, too. Python will be the least backbreaking and most useful in the short term. R is well suited to my current work. MATLAB is well suited to my prospective work. It's a tough call, but I think I am now equipped to make a more well-informed decision about where to go next. Thanks again!

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  • Variables are "lost" somewhere, then reappear... all with no error thrown.

    - by rob - not a robber
    Hi All, I'm probably going to make myself look like a fool with my horrible scripting but here we go. I have a form that I am collecting a bunch of checkbox info from using a binary method. ON/SET=1 !ISSET=0 Anyway, all seems to be going as planned except for the query bit. When I run the script, it runs through and throws no errors, but it's not doing what I think I am telling it to. I've hard coded the values in the query and left them in the script and it DOES update the DB. I've also tried echoing all the needed variables after the script runs and exiting right after so I can audit them... and they're all there. Here's an example. ####FEATURES RECORD UPDATE ### HERE I DECIDE TO RUN THE SCRIPT BASED ON WHETHER AN IMAGE BUTTON WAS USED if (isset($_POST["button_x"])) { ### HERE I AM ASSIGNING 1 OR 0 TO A VAR BASED ON WHTER THE CHECKBOX WAS SET if (isset($_POST["pool"])) $pool=1; if (!isset($_POST["pool"])) $pool=0; if (isset($_POST["darts"])) $darts=1; if (!isset($_POST["darts"])) $darts=0; if (isset($_POST["karaoke"])) $karaoke=1; if (!isset($_POST["karaoke"])) $karaoke=0; if (isset($_POST["trivia"])) $trivia=1; if (!isset($_POST["trivia"])) $trivia=0; if (isset($_POST["wii"])) $wii=1; if (!isset($_POST["wii"])) $wii=0; if (isset($_POST["guitarhero"])) $guitarhero=1; if (!isset($_POST["guitarhero"])) $guitarhero=0; if (isset($_POST["megatouch"])) $megatouch=1; if (!isset($_POST["megatouch"])) $megatouch=0; if (isset($_POST["arcade"])) $arcade=1; if (!isset($_POST["arcade"])) $arcade=0; if (isset($_POST["jukebox"])) $jukebox=1; if (!isset($_POST["jukebox"])) $jukebox=0; if (isset($_POST["dancefloor"])) $dancefloor=1; if (!isset($_POST["dancefloor"])) $dancefloor=0; ### I'VE DONE LOADS OF PERMUTATIONS HERE... HARD SET THE 1/0 VARS AND LEFT THE $estab_id TO BE PICKED UP. SET THE $estab_id AND LEFT THE COLUMN DATA TO BE PICKED UP. ALL NO GOOD. IT _DOES_ WORK IF I HARD SET ALL VARS THOUGH mysql_query("UPDATE thedatabase SET pool_table='$pool', darts='$darts', karoke='$karaoke', trivia='$trivia', wii='$wii', megatouch='$megatouch', guitar_hero='$guitarhero', arcade_games='$arcade', dancefloor='$dancefloor' WHERE establishment_id='22'"); ###WEIRD THING HERE IS IF I ECHO THE VARS AT THIS POINT AND THEN EXIT(); they all show up as intended. header("location:theadminfilething.php"); exit(); THANKS ALL!!!

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  • OSX, G/AWK, Bash - "illegal statement, unterminated string" and no file output.

    - by S1syphus
    I have a script that somebody from SO kindly provided to solve an issue I was having, However, I'm having some issues getting it to work on OSX. gawk --version GNU Awk 3.1.6 awk --version awk version 20100208 The original source is: awk -F, -vOFS=, -vc=1 ' NR == 1 { for (i=1; i<NF; i++) { if ($i != "") { g[c]=i; f[c++]=$i } } } NR>2 { for (i=1; i < c; i++) { print $1,$2, $g[i] > "output_"f[i]".csv } }' data.csv When I run the script it gives the following error: awk: syntax error at source line 12 context is print $1,$2, $g[i] > >>> "output_"f <<< [i]".csv awk: illegal statement at source line 13 From the look of it the variable of [i] isn't been amended to the output file, but I don't know why. If I change AWK to GAWK and run the original script here is the output: gawk: cmd. line:11: print $1,$2, $g[i] > "output_"f[i]".csv gawk: cmd. line:11: ^ unterminated string So I edit the relevant line to fix the unterminated string print $1,$2, $g[i] > "output_"f[i]".csv" Then it runs through fine produces no errors, but there is no output files. Any ideas? I spent the majority of last night and this morning pouring over this. A sample input file: ,,L1,,,L2,,,L3,,,L4,,,L5,,,L6,,,L7,,,L8,,,L9,,,L10,,,L11, Title,r/t,needed,actual,Inst,needed,actual,Inst,needed,actual,Inst,needed,actual,Inst,neede d,actual,Inst,needed,actual,Inst,needed,actual,Inst,needed,actual,Inst,needed,actual,Inst,needed,actual,Inst,needed,actual,Inst EXAMPLEfoo,60,6,6,6,0,0,0,0,0,0,6,6,6,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 EXAMPLEbar,30,6,6,12,6,7,14,6,6,12,6,6,12,6,8,16,6,7,14,6,7.5,15,6,6,12,6,8,16,6,0,0,6,7,14 EXAMPLE1,60,3,3,3,3,5,5,3,4,4,3,3,3,3,6,6,3,4,4,3,3,3,3,4,4,3,8,8,3,0,0,3,4,4 EXAMPLE2,120,6,6,3,0,0,0,6,8,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 EXAMPLE3,60,6,6,6,6,8,8,6,6,6,6,6,6,0,0,0,0,0,0,6,8,8,6,6,6,0,0,0,0,0,0,0,10,10 EXAMPLE4,30,6,6,12,6,7,14,6,6,12,6,6,12,3,5.5,11,6,7.5,15,6,6,12,6,0,0,6,9,18,6,0,0,6,6.5,13 And the example out put should be So for L1 an example out put would look like: EXAMPLEfoo,60,6 EXAMPLEbar,30,6 EXAMPLE1,60,3 EXAMPLE2,120,6 EXAMPLE3,60,6 EXAMPLE4,30,6 And for L2: EXAMPLEfoo,60,0 EXAMPLEbar,30,6 EXAMPLE1,60,3 EXAMPLE2,120,0 EXAMPLE3,60,6 EXAMPLE4,30,6

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  • Why C# doesn't implement indexed properties ?

    - by Thomas Levesque
    I know, I know... Eric Lippert's answer to this kind of question is usually something like "because it wasn't worth the cost of designing, implementing, testing and documenting it". But still, I'd like a better explanation... I was reading this blog post about new C# 4 features, and in the section about COM Interop, the following part caught my attention : By the way, this code uses one more new feature: indexed properties (take a closer look at those square brackets after Range.) But this feature is available only for COM interop; you cannot create your own indexed properties in C# 4.0. OK, but why ? I already knew and regretted that it wasn't possible to create indexed properties in C#, but this sentence made me think again about it. I can see several good reasons to implement it : the CLR supports it (for instance, PropertyInfo.GetValue has an index parameter), so it's a pity we can't take advantage of it in C# it is supported for COM interop, as shown in the article (using dynamic dispatch) it is implemented in VB.NET it is already possible to create indexers, i.e. to apply an index to the object itself, so it would probably be no big deal to extend the idea to properties, keeping the same syntax and just replacing this with a property name It would allow to write that kind of things : public class Foo { private string[] _values = new string[3]; public string Values[int index] { get { return _values[index]; } set { _values[index] = value; } } } Currently the only workaround that I know is to create an inner class (ValuesCollection for instance) that implements an indexer, and change the Values property so that it returns an instance of that inner class. This is very easy to do, but annoying... So perhaps the compiler could do it for us ! An option would be to generate an inner class that implements the indexer, and expose it through a public generic interface : // interface defined in the namespace System public interface IIndexer<TIndex, TValue> { TValue this[TIndex index] { get; set; } } public class Foo { private string[] _values = new string[3]; private class <>c__DisplayClass1 : IIndexer<int, string> { private Foo _foo; public <>c__DisplayClass1(Foo foo) { _foo = foo; } public string this[int index] { get { return _foo._values[index]; } set { _foo._values[index] = value; } } } private IIndexer<int, string> <>f__valuesIndexer; public IIndexer<int, string> Values { get { if (<>f__valuesIndexer == null) <>f__valuesIndexer = new <>c__DisplayClass1(this); return <>f__valuesIndexer; } } } But of course, in that case the property would actually return a IIndexer<int, string>, and wouldn't really be an indexed property... It would be better to generate a real CLR indexed property. What do you think ? Would you like to see this feature in C# ? If not, why ?

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  • JPA @ManyToOne and composite PK

    - by Fleuri F
    Good Morning, I am working on project using JPA. I need to use a @ManyToOne mapping on a class that has three primary keys. You can find the errors and the classes after this. If anyone has an idea! Thanks in advance! FF javax.persistence.PersistenceException: No Persistence provider for EntityManager named JTA_pacePersistence: Provider named oracle.toplink.essentials.PersistenceProvider threw unexpected exception at create EntityManagerFactory: javax.persistence.PersistenceException javax.persistence.PersistenceException: Exception [TOPLINK-28018] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.EntityManagerSetupException Exception Description: predeploy for PersistenceUnit [JTA_pacePersistence] failed. Internal Exception: Exception [TOPLINK-7220] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.ValidationException Exception Description: The @JoinColumns on the annotated element [private java.util.Set isd.pacepersistence.common.Action.permissions] from the entity class [class isd.pacepersistence.common.Action] is incomplete. When the source entity class uses a composite primary key, a @JoinColumn must be specified for each join column using the @JoinColumns. Both the name and the referenceColumnName elements must be specified in each such @JoinColumn. at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:643) at oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider.createEntityManagerFactory(EntityManagerFactoryProvider.java:196) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:110) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83) at isd.pacepersistence.common.DataMapper.(Unknown Source) at isd.pacepersistence.server.MainServlet.getDebugCase(Unknown Source) at isd.pacepersistence.server.MainServlet.doGet(Unknown Source) at javax.servlet.http.HttpServlet.service(HttpServlet.java:718) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:411) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:290) at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:271) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:202) There is the source code of my classes : Action : @Entity @Table(name="action") public class Action { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int num; @ManyToOne(cascade= { CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH }) @JoinColumn(name="domain_num") private Domain domain; private String name; private String description; @OneToMany @JoinTable(name="permission", joinColumns= { @JoinColumn(name="action_num", referencedColumnName="action_num", nullable=false, updatable=false) }, inverseJoinColumns= { @JoinColumn(name="num") }) private Set<Permission> permissions; public Action() { } Permission : @SuppressWarnings("serial") @Entity @Table(name="permission") public class Permission implements Serializable { @EmbeddedId private PermissionPK primaryKey; @ManyToOne @JoinColumn(name="action_num", insertable=false, updatable=false) private Action action; @ManyToOne @JoinColumn(name="entity_num", insertable=false, updatable=false) private isd.pacepersistence.common.Entity entity; @ManyToOne @JoinColumn(name="class_num", insertable=false, updatable=false) private Clazz clazz; private String kondition; public Permission() { } PermissionPK : @SuppressWarnings("serial") @Entity @Table(name="permission") public class Permission implements Serializable { @EmbeddedId private PermissionPK primaryKey; @ManyToOne @JoinColumn(name="action_num", insertable=false, updatable=false) private Action action; @ManyToOne @JoinColumn(name="entity_num", insertable=false, updatable=false) private isd.pacepersistence.common.Entity entity; @ManyToOne @JoinColumn(name="class_num", insertable=false, updatable=false) private Clazz clazz; private String kondition; public Permission() { }

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  • Rational Application Developer (RAD) 7.5+ and websphere runtime will not pick up jars from projects

    - by Berlin Brown
    With RAD Version: 7.5.3, Java 1.5. I have a couple of different projects. I needed to break out the java code and turn the *.class files into a jar. So basically, same *.class files I just removed the code and then jarred the class files into a jar. I broke the classes into a jar and then included the jar in the project. And I also did an order/export on the jar so that other projects can see the jar. At this point, ideally my project should not have changed because I am using class files in a jar instead of the java code. When I visit my web application in websphere, I get class not found errors on the classes that are now in the jar. Project Structure: A. Project earApp -- will need the webapp B. Project webapp -- will need the project (no jar files or *.java files are found in this project) C. Project javasrc -- the java source and the NEW JAR file are found here. I don't think websphere is acknowledging the jar. Here is the error: java.lang.NoClassDefFoundError: com.MyApp at java.lang.ClassLoader.defineClassImpl(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:258) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:151) at com.ibm.ws.classloader.CompoundClassLoader._defineClass(CompoundClassLoader.java:675) at com.ibm.ws.classloader.CompoundClassLoader.findClass(CompoundClassLoader.java:614) at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:431) at java.lang.ClassLoader.loadClass(ClassLoader.java:597) at java.lang.Class.getDeclaredMethodsImpl(Native Method) at java.lang.Class.getDeclaredMethods(Class.java:664) at com.ibm.ws.webcontainer.annotation.data.ScannedAnnotationData.collectMethodAnnotations(ScannedAnnotationData.java:130) at com.ibm.ws.webcontainer.annotation.data.ScannedAnnotationData.<init>(ScannedAnnotationData.java:47) at com.ibm.ws.webcontainer.annotation.AnnotationScanner.scanClass(AnnotationScanner.java:61) at com.ibm.ws.wswebcontainer.webapp.WebApp.processRuntimeAnnotationHelpers(WebApp.java:711) at com.ibm.ws.wswebcontainer.webapp.WebApp.populateJavaNameSpace(WebApp.java:624) at com.ibm.ws.wswebcontainer.webapp.WebApp.initialize(WebApp.java:289) at com.ibm.ws.wswebcontainer.webapp.WebGroup.addWebApplication(WebGroup.java:93) at com.ibm.ws.wswebcontainer.VirtualHost.addWebApplication(VirtualHost.java:162) at com.ibm.ws.wswebcontainer.WebContainer.addWebApp(WebContainer.java:671) at com.ibm.ws.wswebcontainer.WebContainer.addWebApplication(WebContainer.java:624) at com.ibm.ws.webcontainer.component.WebContainerImpl.install(WebContainerImpl.java:395) at com.ibm.ws.webcontainer.component.WebContainerImpl.start(WebContainerImpl.java:611) at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:1274) at com.ibm.ws.runtime.component.DeployedApplicationImpl.fireDeployedObjectStart(DeployedApplicationImpl.java:1165) at com.ibm.ws.runtime.component.DeployedModuleImpl.start(DeployedModuleImpl.java:587) at com.ibm.ws.runtime.component.DeployedApplicationImpl.start(DeployedApplicationImpl.java:832) at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:921) at com.ibm.ws.runtime.component.ApplicationMgrImpl$AppInitializer.run(ApplicationMgrImpl.java:2124) at com.ibm.wsspi.runtime.component.WsComponentImpl$_AsynchInitializer.run(WsComponentImpl.java:342) at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1497) What do you think I need to do?

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  • Global Entity Framework Context in WPF Application

    - by OffApps Cory
    Good day, I am in the middle of development of a WPF application that is using Entity Framework (.NET 3.5). It accesses the entities in several places throughout. I am worried about consistency throughout the application in regard to the entities. Should I be instancing separate contexts in my different views, or should I (and is a a good way to do this) instance a single context that can be accessed globally? For instance, my entity model has three sections, Shipments (with child packages and further child contents), Companies/Contacts (with child addresses and telephones), and disk specs. The Shipments and EditShipment views access the DiskSpecs, and the OptionsView manages the DiskSpecs (Create, Edit, Delete). If I edit a DiskSpec, I have to have something in the ShipmentsView to retrieve the latest specs if I have separate contexts right? If it is safe to have one overall context from which the rest of the app retrieves it's objects, then I imagine that is the way to go. If so, where would that instance be put? I am using VB.NET, but I can translate from C# pretty good. Any help would be appreciated. I just don't want one of those applications where the user has to hit reload a dozen times in different parts of the app to get the new data. Update: OK so I have changed my app as follows: All contexts are created in Using Blocks to dispose of them after they are no longer needed. When loaded, all entities are detatched from context before it is disposed. A new property in the MainViewModel (ContextUpdated) raises an event that all of the other ViewModels subscribe to which runs that ViewModels RefreshEntities method. After implementing this, I started getting errors saying that an entity can only be referenced by one ChangeTracker at a time. Since I could not figure out which context was still referencing the entity (shouldn't be any context right?) I cast the object as IEntityWithChangeTracker, and set SetChangeTracker to nothing (Null). This has let to the current problem: When I Null the changeTracker on the Entity, and then attach it to a context, it loses it's changed state and does not get updated to the database. However if I do not null the change tracker, I can't attach. I have my own change tracking code, so that is not a problem. My new question is, how are you supposed to do this. A good example Entity query and entity save code snipped would go a long way, cause I am beating my head in trying to get what I once thought was a simple transaction to work. Any help would elevate you to near god-hood.

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  • NSFetchedResultsController - Delegate methods crashing under iPhone OS 3.0, but NOT UNDER 3.1

    - by Scott Langendyk
    Hey guys, so I've got my NSFetchedResultsController working fine under the 3.1 SDK, however I start getting some weird errors, specifically in the delegate methods when I try it under 3.0. I've determined that this is related to the NSFetchedResultsControllerDelegate methods. This is what I have set up. The inEditingMode stuff has to do with the way I've implemented adding another static section to the table. - (void)controllerWillChangeContent:(NSFetchedResultsController*)controller { [self.tableView beginUpdates]; } - (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type{ NSIndexSet *sectionSet = [NSIndexSet indexSetWithIndex:sectionIndex]; if(self.inEditingMode){ sectionSet = [NSIndexSet indexSetWithIndex:sectionIndex + 1]; } switch (type) { case NSFetchedResultsChangeInsert: [self.tableView insertSections:sectionSet withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteSections:sectionSet withRowAnimation:UITableViewRowAnimationFade]; break; default: [self.tableView reloadData]; break; } } - (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath{ NSIndexPath *relativeIndexPath = indexPath; NSIndexPath *relativeNewIndexPath = newIndexPath; if(self.inEditingMode){ relativeIndexPath = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section + 1]; relativeNewIndexPath = [NSIndexPath indexPathForRow:newIndexPath.row inSection:newIndexPath.section + 1]; } switch(type) { case NSFetchedResultsChangeInsert: [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:relativeNewIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:relativeIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; default: [self.tableView reloadData]; break; } } -(void)controllerDidChangeContent:(NSFetchedResultsController *)controller{ [self.tableView endUpdates]; } When I add an entity to the managed object context, I get the following error: Serious application error. Exception was caught during Core Data change processing: *** -[NSCFArray objectAtIndex:]: index (1) beyond bounds (1) with userInfo (null) I put a breakpoint on objc_exception_throw, and the crash seems to be occuring inside of controllerDidChangeContent. If I comment out all of the self.tableView methods, and put a single [self.tableView reloadData] inside of controllerDidChangeContent, everything works as expected. Anybody have any idea as to why this is happening?

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  • Can't access a map member from a pointer

    - by fjfnaranjo
    Hi. That's my first question :) I'm storing the configuration of my program in a Group->Key->Value form, like the old INIs. I'm storing the information in a pair of structures. First one, I'm using a std::map with string+ptr for the groups info (the group name in the string key). The second std::map value is a pointer to the sencond structure, a std::list of std::maps, with the finish Key->Value pairs. The Key-Value pairs structure is created dynamically, so the config structure is: std::map< std::string , std::list< std::map<std::string,std::string> >* > lv1; Well, I'm trying to implement two methods to check the existence of data in the internal config. The first one, check the existence of a group in the structure: bool isConfigLv1(std::string); bool ConfigManager::isConfigLv1(std::string s) { return !(lv1.find(s)==lv1.end()); } The second method, is making me crazy... It check the existence for a key inside a group. bool isConfigLv2(std::string,std::string); bool ConfigManager::isConfigLv2(std::string s,std::string d) { if(!isConfigLv1(s)) return false; std::map< std::string , std::list< std::map<std::string,std::string> >* >::iterator it; std::list< std::map<std::string,std::string> >* keyValue; std::list< std::map<std::string,std::string> >::iterator keyValueIt; it = lv1.find(s); keyValue = (*it).second; for ( keyValueIt = keyValue->begin() ; keyValueIt != keyValue->end() ; keyValueIt++ ) if(!((*keyValueIt).second.find(d)==(*keyValueIt).second.end())) return true; return false; } I don't understand what is wrong. The compiler says: ConfigManager.cpp||In member function ‘bool ConfigManager::isConfigLv2(std::string, std::string)’:| ConfigManager.cpp|(line over return true)|error: ‘class std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >’ has no member named ‘second’| But it has to have the second member, because it's a map iterator... Any suggestion about what's happening? Sorry for my English :P, and consider I'm doing it as a exercise, I know there are a lot of cool configuration managers.

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  • NSXMLParser Memory Allocation Efficiency for the iPhone

    - by Staros
    Hello, I've recently been playing with code for an iPhone app to parse XML. Sticking to Cocoa, I decided to go with the NSXMLParser class. The app will be responsible for parsing 10,000+ "computers", all which contain 6 other strings of information. For my test, I've verified that the XML is around 900k-1MB in size. My data model is to keep each computer in an NSDictionary hashed by a unique identifier. Each computer is also represented by a NSDictionary with the information. So at the end of the day, I end up with a NSDictionary containing 10k other NSDictionaries. The problem I'm running into isn't about leaking memory or efficient data structure storage. When my parser is done, the total amount of allocated objects only does go up by about 1MB. The problem is that while the NSXMLParser is running, my object allocation is jumping up as much as 13MB. I could understand 2 (one for the object I'm creating and one for the raw NSData) plus a little room to work, but 13 seems a bit high. I can't imaging that NSXMLParser is that inefficient. Thoughts? Code... The code to start parsing... NSXMLParser *parser = [[NSXMLParser alloc] initWithData: data]; [parser setDelegate:dictParser]; [parser parse]; output = [[dictParser returnDictionary] retain]; [parser release]; [dictParser release]; And the parser's delegate code... -(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict { if(mutableString) { [mutableString release]; mutableString = nil; } mutableString = [[NSMutableString alloc] init]; } -(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { if(self.mutableString) { [self.mutableString appendString:string]; } } -(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { if([elementName isEqualToString:@"size"]){ //The initial key, tells me how many computers returnDictionary = [[NSMutableDictionary alloc] initWithCapacity:[mutableString intValue]]; } if([elementName isEqualToString:hashBy]){ //The unique identifier if(mutableDictionary){ [mutableDictionary release]; mutableDictionary = nil; } mutableDictionary = [[NSMutableDictionary alloc] initWithCapacity:6]; [returnDictionary setObject:[NSDictionary dictionaryWithDictionary:mutableDictionary] forKey:[NSMutableString stringWithString:mutableString]]; } if([fields containsObject:elementName]){ //Any of the elements from a single computer that I am looking for [mutableDictionary setObject:mutableString forKey:elementName]; } } Everything initialized and released correctly. Again, I'm not getting errors or leaking. Just inefficient. Thanks for any thoughts!

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  • Correct XML serialization and deserialization of "mixed" types in .NET

    - by Stefan
    My current task involves writing a class library for processing HL7 CDA files. These HL7 CDA files are XML files with a defined XML schema, so I used xsd.exe to generate .NET classes for XML serialization and deserialization. The XML Schema contains various types which contain the mixed="true" attribute, specifying that an XML node of this type may contain normal text mixed with other XML nodes. The relevant part of the XML schema for one of these types looks like this: <xs:complexType name="StrucDoc.Paragraph" mixed="true"> <xs:sequence> <xs:element name="caption" type="StrucDoc.Caption" minOccurs="0"/> <xs:choice minOccurs="0" maxOccurs="unbounded"> <xs:element name="br" type="StrucDoc.Br"/> <xs:element name="sub" type="StrucDoc.Sub"/> <xs:element name="sup" type="StrucDoc.Sup"/> <!-- ...other possible nodes... --> </xs:choice> </xs:sequence> <xs:attribute name="ID" type="xs:ID"/> <!-- ...other attributes... --> </xs:complexType> The generated code for this type looks like this: /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.3038")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(TypeName="StrucDoc.Paragraph", Namespace="urn:hl7-org:v3")] public partial class StrucDocParagraph { private StrucDocCaption captionField; private object[] itemsField; private string[] textField; private string idField; // ...fields for other attributes... /// <remarks/> public StrucDocCaption caption { get { return this.captionField; } set { this.captionField = value; } } /// <remarks/> [System.Xml.Serialization.XmlElementAttribute("br", typeof(StrucDocBr))] [System.Xml.Serialization.XmlElementAttribute("sub", typeof(StrucDocSub))] [System.Xml.Serialization.XmlElementAttribute("sup", typeof(StrucDocSup))] // ...other possible nodes... public object[] Items { get { return this.itemsField; } set { this.itemsField = value; } } /// <remarks/> [System.Xml.Serialization.XmlTextAttribute()] public string[] Text { get { return this.textField; } set { this.textField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute(DataType="ID")] public string ID { get { return this.idField; } set { this.idField = value; } } // ...properties for other attributes... } If I deserialize an XML element where the paragraph node looks like this: <paragraph>first line<br /><br />third line</paragraph> The result is that the item and text arrays are read like this: itemsField = new object[] { new StrucDocBr(), new StrucDocBr(), }; textField = new string[] { "first line", "third line", }; From this there is no possible way to determine the exact order of the text and the other nodes. If I serialize this again, the result looks exactly like this: <paragraph> <br /> <br />first linethird line </paragraph> The default serializer just serializes the items first and then the text. I tried implementing IXmlSerializable on the StrucDocParagraph class so that I could control the deserialization and serialization of the content, but it's rather complex since there are so many classes involved and I didn't come to a solution yet because I don't know if the effort pays off. Is there some kind of easy workaround to this problem, or is it even possible by doing custom serialization via IXmlSerializable? Or should I just use XmlDocument or XmlReader/XmlWriter to process these documents?

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  • Prism Commands - binding error when binding to list element ?

    - by Maciek
    I've got a ItemsControl (to be replaced by listbox) which has it's ItemsSource bound to an ObservableCollection<User> which is located in the view model. The View Model contains some DelegateCommand<T> delegates for handling commands (for instance UpdateUserCommand and RemoveUserCommand). All works fine if the buttons linked to those commands are placed outside of the DataTemplate of the control which is presenting the items. <ItemsControl ItemsSource="{Binding Users, Mode=TwoWay}" HorizontalContentAlignment="Stretch"> <ItemsControl.ItemTemplate> <DataTemplate> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="0.2*"/> <ColumnDefinition Width="0.2*"/> <ColumnDefinition Width="0.2*"/> <ColumnDefinition Width="0.2*"/> <ColumnDefinition Width="0.2*"/> </Grid.ColumnDefinitions> <TextBlock Grid.Column="0" Text="{Binding UserName}"/> <PasswordBox Grid.Column="1" Password="{Binding UserPass}"/> <TextBox Grid.Column="2" Text="{Binding UserTypeId}"/> <Button Grid.Column="3" Content="Update" cal:Click.Command="{Binding UpdateUserCommand}" cal:Click.CommandParameter="{Binding}"/> <Button Grid.Column="4" Content="Remove" cal:Click.Command="{Binding RemoveUserCommand}" cal:Click.CommandParameter="{Binding}"/> </Grid> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> What I'm trying to achieve, is : Have each row - generated by the ListView/ItemsControl - contain buttons to manage the item represented that particular row. During the runtime, the VS's output panel generated the following messages for each listbox element System.Windows.Data Error: BindingExpression path error: 'UpdateUserCommand' property not found on 'ModuleAdmin.Services.User' 'ModuleAdmin.Services.User' (HashCode=35912612). BindingExpression: Path='UpdateUserCommand' DataItem='ModuleAdmin.Services.User' (HashCode=35912612); target element is 'System.Windows.Controls.Button' (Name=''); target property is 'Command' (type 'System.Windows.Input.ICommand').. System.Windows.Data Error: BindingExpression path error: 'RemoveUserCommand' property not found on 'ModuleAdmin.Services.User' 'ModuleAdmin.Services.User' (HashCode=35912612). BindingExpression: Path='RemoveUserCommand' DataItem='ModuleAdmin.Services.User' (HashCode=35912612); target element is 'System.Windows.Controls.Button' (Name=''); target property is 'Command' (type 'System.Windows.Input.ICommand').. Which would imply that there are binding errors present. Is there any way to make this right? or is this not the way?

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  • Minimum permission required to access Site Columns page and edit site columns

    - by ParanoidMike
    We've started to adopt SharePoint 2010, and are starting to manually migrate content from SharePoint 2007 sites to new sites we're rebuilding from scratch in SP2010. One of the things we previously had supported was to delegate responsibility for managing some of our site columns to a member of the team. The team member is not familiar with SharePoint internals, and doesn't want the responsibility of full permissions to the site and all its objects. We're now trying to figure out what the minimum permission is that we need to grant our team member, so they can continue to edit (& propagate) the content of the site columns we've defined. Permissions he currently has (which are obviously insufficient): Site permissions (according to _layouts/user.aspx): Read, Contribute, Manage Lists Permissions for specific objects in the site (according to _layouts/people.aspxMembershipGroupId=xxx, then choosing Settings, View Group Permissions): server/sites/[sitename]: Contribute server/sites/[sitename]/Lists/[a list with columns that inherit from site columns]: "Contribute No Delete" Note: the "Contribute No Delete" permission is a custom permission I designed by copying the SharePoint-native "Contribute" permission set and deselecting the Delete permission. The "Manage Lists" permission is a custom permission I designed that includes the following specific permissions: (List Permissions) Manage Lists, View Items; (Site Permissions) View Pages, Open. Operations that are throwing access denied errors: _layouts/mngfield.aspx: SharePoint returns the "Error: Access Denied" dialog, and provides three clickable options: "Sign in as a different user", "Request access", and "Go back to site" _layouts/fldedit.aspx?field=Level%5Fx0020%5F3 [one of the site columns we've defined]: can load the page and type in changes to the textboxes "...but when I press OK (save changes) I get the same message above." When our team member clicks the "Request access" link, the email I receive sends me to a page that recommends that I grant the user membership in the "[sitename] Users" group - of which he's already a member. So while SP2010 tries to request access, it doesn't actually direct me to either (a) a valid group that has the correct permissions or (b) the specific object to which I need to grant our team member access. Also note: on the SP2007 (MOSS) site (where our team member was successful in managing Site Column edits), they had dozens of additional permissions throughout the site that we do not wish to blindly re-allocate in SP2010 until we know they're necessary. Any help anyone can provide would be greatly appreciated.

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  • Spring ROO issue with UrlRewrite in STS (eclipse)

    - by user224270
    Hi. I'm having trouble figuring out how to solve this issue. I have a file called: "urlrewrite.xml" which was automatically generated by spring ROO after running the "controller" command in ROO Shell. However, I still get the following error: "Referenced file contains errors (http://tuckey.org/res/dtds/urlrewrite3.0.dtd). For more information, right click on the message in the Problems View and select "Show Details..." Here's the content of the urlrewrite.xml file: <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE urlrewrite PUBLIC "-//tuckey.org//DTD UrlRewrite 3.0//EN" "http://tuckey.org/res/dtds/urlrewrite3.0.dtd"> <urlrewrite default-match-type="wildcard"> <rule> <from>/resources/**</from> <to last="true">/resources/$1</to> </rule> <rule> <from>/static/WEB-INF/**</from> <set type="status">403</set> <to last="true">/static/WEB-INF/$1</to> </rule> <rule> <from>/static/**</from> <to last="true">/$1</to> </rule> <rule> <from>/</from> <to last="true">/app/index</to> </rule> <rule> <from>/app/**</from> <to last="true">/app/$1</to> </rule> <rule> <from>/**</from> <to>/app/$1</to> </rule> <outbound-rule> <from>/app/**</from> <to>/$1</to> </outbound-rule> </urlrewrite> Any thoughts on how to get rid of this error?

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  • Cascade Saves with Fluent NHibernate AutoMapping - Old Anwser Still Valid?

    - by Glenn
    I want to do exactly what this question asks: http://stackoverflow.com/questions/586888/cascade-saves-with-fluent-nhibernate-automapping Using Fluent Nhibernate Mappings to turn on "cascade" globally once for all classes and relation types using one call rather than setting it for each mapping individually. The answer to the earlier question looks great, but I'm afraid that the Fluent Nhibernate API altered its .WithConvention syntax last year and broke the answer... either that or I'm missing something. I keep getting a bunch of name space not found errors relating to the IOneToOnePart, IManyToOnePart and all their variations: "The type or namespace name 'IOneToOnePart' could not be found (are you missing a using directive or an assembly reference?)" I've tried the official example dll's, the RTM dll's and the latest build and none of them seem to make VS 2008 see the required namespace. The second problem is that I want to use the class with my AutoPersistenceModel but I'm not sure where to this line: .ConventionDiscovery.AddFromAssemblyOf() in my factory creation method. private static ISessionFactory CreateSessionFactory() { return Fluently.Configure() .Database(SQLiteConfiguration.Standard.UsingFile(DbFile)) .Mappings(m => m.AutoMappings .Add(AutoMap.AssemblyOf<Shelf>(type => type.Namespace.EndsWith("Entities")) .Override<Shelf>(map => { map.HasManyToMany(x => x.Products).Cascade.All(); }) ) )//emd mappings .ExposeConfiguration(BuildSchema) .BuildSessionFactory();//finalizes the whole thing to send back. } Below is the class and using statements I'm trying using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; using FluentNHibernate.Conventions; using FluentNHibernate.Cfg; using FluentNHibernate.Cfg.Db; using NHibernate; using NHibernate.Cfg; using NHibernate.Tool.hbm2ddl; using FluentNHibernate.Mapping; namespace TestCode { public class CascadeAll : IHasOneConvention, IHasManyConvention, IReferenceConvention { public bool Accept(IOneToOnePart target) { return true; } public void Apply(IOneToOnePart target) { target.Cascade.All(); } public bool Accept(IOneToManyPart target) { return true; } public void Apply(IOneToManyPart target) { target.Cascade.All(); } public bool Accept(IManyToOnePart target) { return true; } public void Apply(IManyToOnePart target) { target.Cascade.All(); } } }

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  • How to make the selected testcript is run in selenium grid

    - by Yui
    Hi, I can launch some remote control by using: ant launch-remote-control but I dont know how my script connect to hub? I set up ant, selenium-grid on the same computer. I have an grid.dll which is written by C# and run through NUnit. The test data is read from xml file (ValidData.xml) The example code is below : using System.Collections.Generic; using System.Linq; using System.Text; using System; using System.Xml; using System.Text.RegularExpressions; using System.Threading; using NUnit.Framework; using Selenium; namespace Grid { public class Class1 { //User defined private string strURL = "http://gmail.com/"; private string[] strBrowser = new string[3] { "*iehta", "*firefox", "*safari" }; string hubAddress = "192.168.20.131"; // IP of my computer // System defined private ISelenium selenium; private StringBuilder verificationErrors; [SetUp] public void SetupTest() { selenium = new DefaultSelenium(hubAddress, 4444, this.strBrowser[1], this.strURL);// do i need to identify browser when I defined it when launching a remote control selenium.Start(); verificationErrors = new StringBuilder(); } [TearDown] public void TeardownTest() { try { selenium.Stop(); } catch (Exception) { // Ignore errors if unable to close the browser } Assert.AreEqual("", verificationErrors.ToString()); } private string[] name; [Test] public void LoginPassedTest() { try { XmlDocument doc = new XmlDocument(); XmlNode docNode; doc.Load("ValidData.xml"); docNode = doc["TestCase"]; foreach (XmlNode node in docNode) { selenium.Open("/"); selenium.WaitForPageToLoad("50000"); selenium.Type("Email", node["username"].InnerText); selenium.Type("Passwd", node["password"].InnerText); selenium.Click("signIn"); selenium.WaitForPageToLoad("100000"); name = (selenium.GetText("//div[@id='guser']/nobr/b").Split('@')); try { Assert.AreEqual(node["username"].InnerText, name[0]); Assert.AreEqual("Sign out", selenium.GetText(":r6")); } catch (AssertionException e) { verificationErrors.Append(e.Message); } selenium.Click(":r6"); } } catch (AssertionException e) { verificationErrors.Append(e.Message); } } } } Step I run this script: 1.I build that script into DLL 2.I start hub by using command "ant lauch-hub" 3.I start 2 remote controls by using command : ant -Dport=5566 -Denvironment="*chrome" launch-remote-control ant -Dport=5577 -Denvironment="*iexplore" launch-remote-control 4.Then I open Nunit and load DLL (code above) and run 5.The NUNit doesnot respond anything. I think there are some missing things but I dont know. How can the test script (DLL) know which is sequence of remote control is selected to run the test???? Please help me!! Thank you so much Yui.

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  • groovy compile error

    - by Bunny Rabbit
    class x{ public static void main(String[] args){ String x="<html><head></head></html>"; String arr[]=x.split("<head>"); String script="hi"; x=arr[0]+"<head>"+script+arr[1]; System.out.println(x); } } the above code when compiled as a java file compiles fine but when used a s a groovy file spits the error : org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed: D:\Garage\groovy-binary-1.7.1\groovy-1.7.1\bin\x.groovy: 4: Apparent variable 'a rr' was found in a static scope but doesn't refer to a local variable, static fi eld or class. Possible causes: You attempted to reference a variable in the binding or an instance variable fro m a static context. You misspelled a classname or statically imported field. Please check the spelli ng. You attempted to use a method 'arr' but left out brackets in a place not allowed by the grammar. @ line 4, column 10. String arr[]=x.split(""); ^ D:\Garage\groovy-binary-1.7.1\groovy-1.7.1\bin\x.groovy: 6: Apparent variable 'a rr' was found in a static scope but doesn't refer to a local variable, static fi eld or class. Possible causes: You attempted to reference a variable in the binding or an instance variable fro m a static context. You misspelled a classname or statically imported field. Please check the spelli ng. You attempted to use a method 'arr' but left out brackets in a place not allowed by the grammar. @ line 6, column 5. x=arr[0]+""+script+arr[1]; ^ D:\Garage\groovy-binary-1.7.1\groovy-1.7.1\bin\x.groovy: 6: Apparent variable 'a rr' was found in a static scope but doesn't refer to a local variable, static fi eld or class. Possible causes: You attempted to reference a variable in the binding or an instance variable fro m a static context. You misspelled a classname or statically imported field. Please check the spelli ng. You attempted to use a method 'arr' but left out brackets in a place not allowed by the grammar. @ line 6, column 28. x=arr[0]+""+script+arr[1]; ^ 3 errors D:\Garage\groovy-binary-1.7.1\groovy-1.7.1\bin

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  • Visitor and templated virtual methods

    - by Thomas Matthews
    In a typical implementation of the Visitor pattern, the class must account for all variations (descendants) of the base class. There are many instances where the same method content in the visitor is applied to the different methods. A templated virtual method would be ideal in this case, but for now, this is not allowed. So, can templated methods be used to resolve virtual methods of the parent class? Given (the foundation): struct Visitor_Base; // Forward declaration. struct Base { virtual accept_visitor(Visitor_Base& visitor) = 0; }; // More forward declarations struct Base_Int; struct Base_Long; struct Base_Short; struct Base_UInt; struct Base_ULong; struct Base_UShort; struct Visitor_Base { virtual void operator()(Base_Int& b) = 0; virtual void operator()(Base_Long& b) = 0; virtual void operator()(Base_Short& b) = 0; virtual void operator()(Base_UInt& b) = 0; virtual void operator()(Base_ULong& b) = 0; virtual void operator()(Base_UShort& b) = 0; }; struct Base_Int : public Base { void accept_visitor(Visitor_Base& visitor) { visitor(*this); } }; struct Base_Long : public Base { void accept_visitor(Visitor_Base& visitor) { visitor(*this); } }; struct Base_Short : public Base { void accept_visitor(Visitor_Base& visitor) { visitor(*this); } }; struct Base_UInt : public Base { void accept_visitor(Visitor_Base& visitor) { visitor(*this); } }; struct Base_ULong : public Base { void accept_visitor(Visitor_Base& visitor) { visitor(*this); } }; struct Base_UShort : public Base { void accept_visitor(Visitor_Base& visitor) { visitor(*this); } }; Now that the foundation is laid, here is where the kicker comes in (templated methods): struct Visitor_Cout : public Visitor { template <class Receiver> void operator() (Receiver& r) { std::cout << "Visitor_Cout method not implemented.\n"; } }; Intentionally, Visitor_Cout does not contain the keyword virtual in the method declaration. All the other attributes of the method signatures match the parent declaration (or perhaps specification). In the big picture, this design allows developers to implement common visitation functionality that differs only by the type of the target object (the object receiving the visit). The implementation above is my suggestion for alerts when the derived visitor implementation hasn't implement an optional method. Is this legal by the C++ specification? (I don't trust when some says that it works with compiler XXX. This is a question against the general language.)

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  • Template inheritence c++

    - by Chris Condy
    I have made a template singleton class, I have also made a data structure that is templated. My question is; how do I make my templated data structure inherit from a singleton so you can only have one float type of this structure? I have tested both seperate and have found no problems. Code provided under... (That is the problem) template <class Type> class AbstractRManagers : public Singleton<AbstractRManagers<Type> > The problem is the code above doesn't work I get alot of errors. I cant get it to no matter what I do template a templated singleton class... I was asking for maybe advice or maybe if the code above is incorrect guidence? #ifndef SINGLETON_H #define SINGLETON_H template <class Type> class Singleton { public: virtual ~Singleton(); Singleton(); static Type* m_instance; }; template <class Type> Type* Singleton<Type>::m_instance = 0; #include "Singleton.cpp" #endif #ifndef SINGLETON_CPP #define SINGLETON_CPP #include "Singleton.h" template <class Type> Singleton<Type>::Singleton() { } template <class Type> Singleton<Type>::~Singleton() { } template <class Type> Type* Singleton<Type>::getInstance() { if(m_instance==nullptr) { m_instance = new Type; } return m_instance; } #endif #ifndef ABSTRACTRMANAGERS_H #define ABSTRACTRMANAGERS_H #include <vector> #include <map> #include <stack> #include "Singleton.h" template <class Type> class AbstractRManagers : public Singleton<AbstractRManagers<Type> > { public: virtual ~AbstractRManagers(); int insert(Type* type, std::string name); Type* remove(int i); Type* remove(std::string name); Type* get(int i); Type* getS(std::string name); int get(std::string name); int get(Type* i); bool check(std::string name); int resourceSize(); protected: private: std::vector<Type*> m_resources; std::map<std::string,int> m_map; std::stack<int> m_freePos; }; #include "AbstractRManagers.cpp" #endif #ifndef ABSTRACTRMANAGERS_CPP #define ABSTRACTRMANAGERS_CPP #include "AbstractRManagers.h" template <class Type> int AbstractRManagers<Type>::insert(Type* type, std::string name) { int i=0; if(!check(name)) { if(m_freePos.empty()) { m_resources.push_back(type); i = m_resources.size()-1; m_map[name] = i; } else { i = m_freePos.top(); m_freePos.pop(); m_resources[i] = type; m_map[name] = i; } } else i = -1; return i; } template <class Type> int AbstractRManagers<Type>::resourceSize() { return m_resources.size(); } template <class Type> bool AbstractRManagers<Type>::check(std::string name) { std::map<std::string,int>::iterator it; it = m_map.find(name); if(it==m_map.end()) return false; return true; } template <class Type> Type* AbstractRManagers<Type>::remove(std::string name) { Type* temp = m_resources[m_map[name]]; if(temp!=NULL) { std::map<std::string,int>::iterator it; it = m_map[name]; m_resources[m_map[name]] = NULL; m_freePos.push(m_map[name]); delete (*it).second; delete (*it).first; return temp; } return NULL; } template <class Type> Type* AbstractRManagers<Type>::remove(int i) { if((i < m_resources.size())&&(i > 0)) { Type* temp = m_resources[i]; m_resources[i] = NULL; m_freePos.push(i); std::map<std::string,int>::iterator it; for(it=m_map.begin();it!=m_map.end();it++) { if((*it).second == i) { delete (*it).second; delete (*it).first; return temp; } } return temp; } return NULL; } template <class Type> int AbstractRManagers<Type>::get(Type* i) { for(int i2=0;i2<m_resources.size();i2++) { if(i == m_resources[i2]) { return i2; } } return -1; } template <class Type> Type* AbstractRManagers<Type>::get(int i) { if((i < m_resources.size())&&(i >= 0)) { return m_resources[i]; } return NULL; } template <class Type> Type* AbstractRManagers<Type>::getS(std::string name) { return m_resources[m_map[name]]; } template <class Type> int AbstractRManagers<Type>::get(std::string name) { return m_map[name]; } template <class Type> AbstractRManagers<Type>::~AbstractRManagers() { } #endif #include "AbstractRManagers.h" struct b { float x; }; int main() { b* a = new b(); AbstractRManagers<b>::getInstance()->insert(a,"a"); return 0; } This program produces next errors when compiled : 1> main.cpp 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1> c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(124) : while compiling class template member function 'bool std::less<_Ty>::operator ()(const _Ty &,const _Ty &) const' 1> with 1> [ 1> _Ty=std::string 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\map(71) : see reference to class template instantiation 'std::less<_Ty>' being compiled 1> with 1> [ 1> _Ty=std::string 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(451) : see reference to class template instantiation 'std::_Tmap_traits<_Kty,_Ty,_Pr,_Alloc,_Mfl>' being compiled 1> with 1> [ 1> _Kty=std::string, 1> _Ty=int, 1> _Pr=std::less<std::string>, 1> _Alloc=std::allocator<std::pair<const std::string,int>>, 1> _Mfl=false 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(520) : see reference to class template instantiation 'std::_Tree_nod<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(659) : see reference to class template instantiation 'std::_Tree_val<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\map(81) : see reference to class template instantiation 'std::_Tree<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\users\chris\desktop\311\ideas\idea1\idea1\abstractrmanagers.h(28) : see reference to class template instantiation 'std::map<_Kty,_Ty>' being compiled 1> with 1> [ 1> _Kty=std::string, 1> _Ty=int 1> ] 1> c:\users\chris\desktop\311\ideas\idea1\idea1\abstractrmanagers.h(30) : see reference to class template instantiation 'AbstractRManagers<Type>' being compiled 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2676: binary '<' : 'const std::string' does not define this operator or a conversion to a type acceptable to the predefined operator ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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  • ASP.NET MVC 2.0 Unused Model Property being called when posting a product to the server?

    - by Erx_VB.NExT.Coder
    i have my auto-generated linq to sql classes, and i extend this class using partial classing (instead of using inheritance), and i have properties that that i've put in later which are not part of the database model and should not be. these are things like "FinalPrice" and "DisplayFinalPrice" - in the dbase, there is only RetailPrice and WholesalePrice so FinalPrice etc are more like extensions of the dbase fields. when i submit the form with nothing filled in, "FinalPrice" gets called (the 'get' of the property) even tho i never ask for it to be, and even tho it is not needed. this happens before validation, so i don't even get the validation errors i would get. i've tried using and on the FinalPrice and FinalPriceDisplay properties - no go! why does this happen and how can i stop it from happening? is the modelstate just trying to validate everything so therefore it calls every item no matter what? for those interested, here is all the code... Partial Public Class tProduct 'Inherits tProduct Private Const CommissionMultiplier As Decimal = CDec(1.18) Private _FinalPrice As Decimal? Private _DisplayFinalPrice As String Private _DisplayNormalPrice As String Public Property CategoryComplete As Short <ScaffoldColumn(False)> Public ReadOnly Property FinalPrice As Decimal Get 'If RetailPrice IsNot Nothing OrElse WholesalePrice IsNot Nothing Then If _FinalPrice Is Nothing Then If RetailPrice IsNot Nothing Then _FinalPrice = RetailPrice Else _FinalPrice = WholesalePrice * CommissionMultiplier ' TODO: this should be rounded to the nearest 5th cent so prices don't look weird. End If Dim NormalPart = Decimal.Floor(_FinalPrice.Value) Dim DecimalPart = _FinalPrice.Value - NormalPart If DecimalPart = 0 OrElse DecimalPart = 0.5 Then Return _FinalPrice ElseIf DecimalPart > 0 AndAlso DecimalPart < 0.5 Then DecimalPart = 0.5 ' always rounded up to the nearest 50 cents. ElseIf DecimalPart > 0.5 AndAlso DecimalPart < 1 Then ' Only in this case round down if its about to be rounded up to a valeu like 20, 30 or 50 etc as we want most prices to end in 9. If NormalPart.ToString.LastChr.ToInt = 9 Then DecimalPart = 0.5 Else DecimalPart = 1 End If End If _FinalPrice = NormalPart + DecimalPart End If Return _FinalPrice 'End If End Get End Property <ScaffoldColumn(False)> Public ReadOnly Property DisplayFinalPrice As String Get If _DisplayFinalPrice.IsNullOrEmpty Then _DisplayFinalPrice = FormatCurrency(FinalPrice, 2, TriState.True) End If Return _DisplayFinalPrice End Get End Property Public ReadOnly Property DisplayNormalPrice As String Get If _DisplayNormalPrice.IsNullOrEmpty Then _DisplayNormalPrice = FormatCurrency(NormalPrice, 2, TriState.True) End If Return _DisplayNormalPrice End Get End Property Public ReadOnly Property DivID As String Get Return "pdiv" & ProductID End Get End Property End Class more... i get busted here, with a null reference exception telling me it should contain a value... Dim NormalPart = Decimal.Floor(_FinalPrice.Value)

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  • ASP MVC 2: Error with dropdownlist on POST

    - by wh0emPah
    Okay i'm new to asp mvc2 and i'm experiencing some problems with the htmlhelper called Html.dropdownlistfor(); I want to present the user a list of days in the week. And i want the selected item to be bound to my model. I have created this little class to generate a list of days + a short notation which i will use to store it in the database. public static class days { public static List<Day> getDayList() { List<Day> daylist = new List<Day>(); daylist.Add(new Day("Monday", "MO")); daylist.Add(new Day("Tuesday", "TU")); // I left the other days out return daylist; } public class Dag{ public string DayName{ get; set; } public string DayShortName { get; set; } public Dag(string name, string shortname) { this.DayName= name; this.DayShortName = shortname; } } } I really have now idea if this is the correct way to do it Then i putted this in my controller: SelectList _list = new SelectList(Days.getDayList(), "DayShortName", "DayName"); ViewData["days"] = _list; return View(""); I have this line in my model public string ChosenDay { get; set; } And this in my view to display the list: <div class="editor-field"> <%: Html.DropDownListFor(model => model.ChosenDay, ViewData["days"] as SelectList, "--choose Day--")%> </div> Now this all works perfect. On the first visit, But then when i'm doing a [HttpPost] Which looks like the following: [HttpPost] public ActionResult Registreer(EventRegistreerViewModel model) { // I removed some unrelated code here // The code below executes when modelstate.isvalid == false SelectList _list = new SelectList(Days.getDayList(), "DayShortName", "DayName"); ViewData["days"] = _list; return View(model); } Then i will have the following exception thrown: The ViewData item that has the key 'ChosenDay' is of type 'System.String' but must be of type 'IEnumerable<SelectListItem>'. This errors gets thrown at the line in my view where i display the dropdown list. I really have no idea how to solve this and tried several solutions i found online. but none of them really worked. Ty in advance!

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  • CakePHP Help with Blog Tutorial

    - by Cameron
    I've just been following the tutorial on the CakePHP website to create a simple Blog as a way to learn a bit about Cake. However I have run into an error and not sure why as I have followed exactly what the tutorial says. The errors: Notice (8): Undefined property: View::$Html [APP/views/posts/index.ctp, line 17] Fatal error: Call to a member function link() on a non-object in /Users/cameron/Sites/dentist/app/views/posts/index.ctp on line 17 Here is my posts_controller <?php class PostsController extends AppController { var $helpers = array('Html', 'Form'); var $name = 'Posts'; function index() { $this->set('posts', $this->Post->find('all')); } function view($id = null) { $this->Post->id = $id; $this->set('post', $this->Post->read()); } } ?> and here is my model <?php class Post extends AppModel { var $name = 'Post'; } ?> and here are my views <!-- File: /app/views/posts/index.ctp --> <h1>Blog posts</h1> <table> <tr> <th>Id</th> <th>Title</th> <th>Created</th> </tr> <!-- Here is where we loop through our $posts array, printing out post info --> <?php foreach ($posts as $post): ?> <tr> <td><?php echo $post['Post']['id']; ?></td> <td> <?php echo $this->Html->link($post['Post']['title'], array('controller' => 'posts', 'action' => 'view', $post['Post']['id'])); ?> </td> <td><?php echo $post['Post']['created']; ?></td> </tr> <?php endforeach; ?> </table>

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  • How to find minimum of nonlinear, multivariate function using Newton's method (code not linear algeb

    - by Norman Ramsey
    I'm trying to do some parameter estimation and want to choose parameter estimates that minimize the square error in a predicted equation over about 30 variables. If the equation were linear, I would just compute the 30 partial derivatives, set them all to zero, and use a linear-equation solver. But unfortunately the equation is nonlinear and so are its derivatives. If the equation were over a single variable, I would just use Newton's method (also known as Newton-Raphson). The Web is rich in examples and code to implement Newton's method for functions of a single variable. Given that I have about 30 variables, how can I program a numeric solution to this problem using Newton's method? I have the equation in closed form and can compute the first and second derivatives, but I don't know quite how to proceed from there. I have found a large number of treatments on the web, but they quickly get into heavy matrix notation. I've found something moderately helpful on Wikipedia, but I'm having trouble translating it into code. Where I'm worried about breaking down is in the matrix algebra and matrix inversions. I can invert a matrix with a linear-equation solver but I'm worried about getting the right rows and columns, avoiding transposition errors, and so on. To be quite concrete: I want to work with tables mapping variables to their values. I can write a function of such a table that returns the square error given such a table as argument. I can also create functions that return a partial derivative with respect to any given variable. I have a reasonable starting estimate for the values in the table, so I'm not worried about convergence. I'm not sure how to write the loop that uses an estimate (table of value for each variable), the function, and a table of partial-derivative functions to produce a new estimate. That last is what I'd like help with. Any direct help or pointers to good sources will be warmly appreciated. Edit: Since I have the first and second derivatives in closed form, I would like to take advantage of them and avoid more slowly converging methods like simplex searches.

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