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  • When is it worth using a BindingSource?

    - by Justin
    I think I understand well enough what the BindingSource class does - i.e. provide a layer of indirection between a data source and a UI control. It implements the IBindingList interface and therefore also provides support for sorting. And I've used it frequently enough, without too many problems. But I'm wondering if I use it more often than I should. Perhaps an example would help. Let's say I have just a simple textbox on a form (using WinForms), and I'd like to bind that textbox to a simple property inside a class that returns a string. Is it worth using a BindingSource in this situation? Now let's say I have a grid on my form, and I'd like to bind it to a DataTable. Should I use a BindingSource now? In the latter case, I probably would not use a BindingSource, as a DataTable, from what I can gather, provides the same functionality that the BindingSource itself would. The DataTable will fire the the right events when a row is added, deleted, etc so that the grid will automatically update. But in the first case with the textbox being bound to a string, I would probably have the class that contains the string property implement INotifyPropertyChanged, so that it could fire the PropertyChanged event when the string changes. I would use a BindingSource so that it could listen to these PropertyChanged events so that it could update the textbox automatically when the string changes. How does this sound so far? I still feel like there's a gap in my understanding that's preventing me from seeing the whole picture. This has been a pretty vague question so far, so I'll try to ask some more specific questions - ideally the answers will reference the above examples or something similar... (1) Is it worth using a BindingSource in either of the above examples? (2) It seems that developers just "assume" that the DataTable class will do the right thing, in firing PropertyChanged events at the right time. How does one know if a data source is capable of doing this? Is there a particular interface that a data source should implement in order for developers to be able to assume this behaviour? (3) Does it matter what Control is being bound to, when considering whether or not to use a BindingSource? Or is it only the data source that should affect the decision? Perhaps the answer is (and this would seem logical enough): the Control needs to be intelligent enough to listen to the PropertyChanged events, otherwise a BindingSource is required. So how does one tell if the Control is capable of doing this? Again, is there a particular interface that developers can look for that the Control must implement? It is this confusion that has, in the past, led to me always using a BindingSource. But I'd like to understand better exactly when to use one, so that I do so only when necessary.

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  • Fluent NHibernate Self Referencing Many To Many

    - by Jeremy
    I have an entity called Books that can have a list of more books called RelatedBooks. The abbreviated Book entity looks something likes this: public class Book { public virtual long Id { get; private set; } public virtual IList<Book> RelatedBooks { get; set; } } Here is what the mapping looks like for this relationship HasManyToMany(x => x.RelatedBooks) .ParentKeyColumn("BookId") .ChildKeyColumn("RelatedBookId") .Table("RelatedBooks") .Cascade.SaveUpdate(); Here is a sample of the data that is then generated in the RelatedBooks table: BookId RelatedBookId 1 2 1 3 The problem happens when I Try to delete a book. If I delete the book that has an ID of 1, everything works ok and the RelatedBooks table has the two corresponding records removed. However if I try to delete the book with an ID of 3, I get the error "The DELETE statement conflicted with the REFERENCE constraint "FK5B54405174BAB605". The conflict occurred in database "Test", table "dbo.RelatedBooks", column 'RelatedBookId'". Basically what is happening is the Book cannot be deleted because the record in the RelatedBooks table that has a RelatedBookId of 3 is never deleted. How do I get that record to be deleted when I delete a book? EDIT After changing the Cascade from SaveUpdate() to All(), the same problem still exists if I try to delete the Book with an ID of 3. Also with Cascade set to All(), if delete the Book with and ID of 1, then all 3 books (ID's: 1, 2 and 3) are deleted so that won't work either. Looking at the SQL that is executed when the Book.Delete() method is called when I delete the Book with an ID of 3, it looks like the SELECT statement is looking at the wrong column (which I assume means that the SQL DELETE statment would make the same mistake, therefore never removing that record). Here is the SQL for the RelatedBook SELECT relatedboo0_.BookId as BookId3_ , relatedboo0_.RelatedBookId as RelatedB2_3_ , book1_.Id as Id14_0_ FROM RelatedBooks relatedboo0_ left outer join [Book] book1_ on relatedboo0_.RelatedBookId=book1_.Id WHERE relatedboo0_.BookId=3 The WHERE statment should look something like this for thie particular case: WHERE relatedboo0_.RelatedBookId = 3 SOLUTION Here is what I had to do to get it working for all cases Mapping: HasManyToMany(x => x.RelatedBooks) .ParentKeyColumn("BookId") .ChildKeyColumn("RelatedBookId") .Table("RelatedBooks"); Code: var book = currentSession.Get<Book>(bookId); if (book != null) { //Remove all of the Related Books book.RelatedBooks.Clear(); //Get all other books that have this book as a related book var booksWithRelated = currentSession.CreateCriteria<Book>() .CreateAlias("RelatedBooks", "br") .Add(Restrictions.Eq("br.Id", book.Id)) .List<Book>(); //Remove this book as a Related Book for all other Books foreach (var tempBook in booksWithRelated) { tempBook.RelatedBooks.Remove(book); tempBook.Save(); } //Delete the book book.Delete(); }

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  • Custom validator not invoked when using Validation Application Block through configuration

    - by Chris
    I have set up a ruleset in my configuration file which has two validators, one of which is a built-in NotNullValidator, the other of which is a custom validator. The problem is that I see the NotNullValidator hit, but not my custom validator. The custom validator is being used to validate an Entity Framework entity object. I have used the debugger to confirm the NotNull is hit (I forced a failure condition so I saw it set an invalid result), but it never steps into the custom one. I am using MVC as the web app, so I defined the ruleset in a config file at that layer, but my custom validator is defined in another project. However, I wouldn't have thought that to be a problem because when I use the Enterprise Library Configuration tool inside Visual Studio 2008 it is able to set the type properly for the custom validator. As well, I believe the custom validator is fine as it builds ok, and the config tool can reference it properly. Does anybody have any ideas what the problem could be, or even what to do/try to debug further? Here is a stripped down version of my custom validator: [ConfigurationElementType(typeof(CustomValidatorData))] public sealed class UserAccountValidator : Validator { public UserAccountValidator(NameValueCollection attributes) : base(string.Empty, "User Account") { } protected override string DefaultMessageTemplate { get { throw new NotImplementedException(); } } protected override void DoValidate(object objectToValidate, object currentTarget, string key, ValidationResults results) { if (!currentTarget.GetType().Equals(typeof(UserAccount))) { throw new Exception(); } UserAccount userAccountToValidate = (UserAccount)currentTarget; // snipped code ... this.LogValidationResult(results, "The User Account is invalid", currentTarget, key); } } Here is the XML of my ruleset in Validation.config (the NotNull rule is only there to force a failure so I could see it getting hit, and it does): <validation> <type defaultRuleset="default" assemblyName="MyProj.Entities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="MyProj.Entities.UserAccount"> <ruleset name="default"> <properties> <property name="HashedPassword"> <validator negated="true" messageTemplate="" messageTemplateResourceName="" messageTemplateResourceType="" tag="" type="Microsoft.Practices.EnterpriseLibrary.Validation.Validators.NotNullValidator, Microsoft.Practices.EnterpriseLibrary.Validation, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" name="Not Null Validator" /> </property> <property name="Property"> <validator messageTemplate="" messageTemplateResourceName="" messageTemplateResourceType="" tag="" type="MyProj.Entities.UserAccountValidator, MyProj.Entities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Custom Validator" /> </property> </properties> </ruleset> </type> </validation> And here is the stripped down version of the way I invoke the validation: var type = entity.GetType() var validator = ValidationFactory.CreateValidator(type, "default", new FileConfigurationSource("Validation.config")) var results = validator.Validate(entity) Any advice would be much appreciated! Thanks, Chris

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  • Custom property editors do not work for request parameters in Spring MVC?

    - by dvd
    Hello, I'm trying to create a multiaction web controller using Spring annotations. This controller will be responsible for adding and removing user profiles and preparing reference data for the jsp page. @Controller public class ManageProfilesController { @InitBinder public void initBinder(WebDataBinder binder) { binder.registerCustomEditor(UserAccount.class,"account", new UserAccountPropertyEditor(userManager)); binder.registerCustomEditor(Profile.class, "profile", new ProfilePropertyEditor(profileManager)); logger.info("Editors registered"); } @RequestMapping("remove") public void up( @RequestParam("account") UserAccount account, @RequestParam("profile") Profile profile) { ... } @RequestMapping("") public ModelAndView defaultView(@RequestParam("account") UserAccount account) { logger.info("Default view handling"); ModelAndView mav = new ModelAndView(); logger.info(account.getLogin()); mav.addObject("account", account); mav.addObject("profiles", profileManager.getProfiles()); mav.setViewName(view); return mav; } ... } Here is the part of my webContext.xml file: <context:component-scan base-package="ru.mirea.rea.webapp.controllers" /> <context:annotation-config/> <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="mappings"> <value> ... /home/users/manageProfiles=users.manageProfilesController </value> </property> </bean> <bean id="users.manageProfilesController" class="ru.mirea.rea.webapp.controllers.users.ManageProfilesController"> <property name="view" value="home\users\manageProfiles"/> </bean> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" /> However, when i open the mapped url, i get exception: java.lang.IllegalArgumentException: Cannot convert value of type [java.lang.String] to required type [ru.mirea.rea.model.UserAccount]: no matching editors or conversion strategy found I use spring 2.5.6 and plan to move to the Spring 3.0 in some not very distant future. However, according to this JIRA https://jira.springsource.org/browse/SPR-4182 it should be possible already in spring 2.5.1. The debug shows that the InitBinder method is correctly called. What am i doing wrong?

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  • WPF MVVM Pattern, ViewModel DataContext question

    - by orangecl4now
    I used this side to create my demo application http://windowsclient.net/learn/video.aspx?v=314683 The site was very useful in getting my started and in their example, they created a file called EmployeeRepository.cs which appears to be the source for the data. In their example, the data was hard-wired in code. So I'm trying to learn how to get the data from a data source (like a DB). In my specific case, I want to get the data from a Microsoft Access DB. (READ ONLY, So I'll only use SELECT commands). using System.Collections.Generic; using Telephone_Directory_2010.Model; namespace Telephone_Directory_2010.DataAccess { public class EmployeeRepository { readonly List<Employee> _employees; public EmployeeRepository() { if (_employees == null) { _employees = new List<Employee>(); } _employees.Add(Employee.CreateEmployee("Student One", "IT201", "Information Technology", "IT4207", "Building1", "Room650")); _employees.Add(Employee.CreateEmployee("Student Two", "IT201", "Information Technology", "IT4207", "Building1", "Room650")); _employees.Add(Employee.CreateEmployee("Student Three", "IT201", "Information Technology", "IT4207", "Building1", "Room650")); } public List<Employee> GetEmployees() { return new List<Employee>(_employees); } } } I found another example where an Access DB is used but it doesn't comply with MVVM. So I was trying to figure out how to add the DB file to the project, how to wire it up and bind it to a listbox (i'm not that far yet). Below is my modified file using System.Collections.Generic; using Telephone_Directory_2010.Model; // integrating new code with working code using Telephone_Directory_2010.telephone2010DataSetTableAdapters; using System.Windows.Data; namespace Telephone_Directory_2010.DataAccess { public class EmployeeRepository { readonly List<Employee> _employees; // start // integrating new code with working code private telephone2010DataSet.telephone2010DataTable employeeTable; private CollectionView dataView; internal CollectionView DataView { get { if (dataView == null) { dataView = (CollectionView) CollectionViewSource.GetDefaultView(this.DataContext); } return dataView; } } public EmployeeRepository() { if (_employees == null) { _employees = new List<Employee>(); } telephone2010TableAdapter employeeTableAdapter = new telephone2010TableAdapter(); employeeTable = employeeTableAdapter.GetData(); this.DataContext = employeeTable; } public List<Employee> GetEmployees() { return new List<Employee>(_employees); } } } I get the following error messages when building Error 1 'Telephone_Directory_2010.DataAccess.EmployeeRepository' does not contain a definition for 'DataContext' and no extension method 'DataContext' accepting a first argument of type 'Telephone_Directory_2010.DataAccess.EmployeeRepository' could be found (are you missing a using directive or an assembly reference?) C:\Projects\VS2010\Telephone Directory 2010\Telephone Directory 2010\DataAccess\EmployeeRepository.cs 23 90 Telephone Directory 2010

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  • Populating ComboBoxDataColumn items and values

    - by MarceloRamires
    I have a "populate combobox", and I'm so happy with it that I've even started using more comboboxes. It takes the combobox object by reference with the ID of the "value set" (or whatever you want to call it) from a table and adds the items and their respective values (which differ) and does the job. I've recently had the brilliant idea of using comboboxes in a gridview, and I was happy to notice that it worked JUST LIKE a single combobox, but populating all the comboboxes in the given column at the same time. ObjComboBox.Items.Add("yadayada"); //works just like ObjComboBoxColumn.Items.Add("blablabla"); But When I started planning how to populate these comboboxes I've noticed: There's no "Values" property in ComboBoxDataColumn. ObjComboBox.Values = whateverArray; //works, but the following doesn't ObjComboBoxColumn.Values = whateverArray; Questions: 0 - How do I populate it's values ? (I suspect it's just as simple, but uses another name) 1 - If it works just like a combobox, what's the explanation for not having this attribute ? -----[EDIT]------ So I've checked out Charles' quote, and I've figured I had to change my way of populating these bad boys. Instead of looping through the strings and inserting them one by one in the combobox, I should grab the fields I want to populate in a table, and set one column of the table as the "value", and other one as the "display". So I've done this: ObjComboBoxColumn.DataSource = DTConfig; //Double checked, guaranteed to be populated ObjComboBoxColumn.ValueMember = "Code"; ObjComboBoxColumn.DisplayMember = "Description"; But nothing happens, if I use the same object as so: ObjComboBoxColumn.Items.Add("StackOverflow"); It is added. There is no DataBind() function. It finds the two columns, and that's guaranteed ("Code" and "Description") and if I change their names to nonexistant ones it gives me an exception, so that's a good sign. -----[EDIT]------ I have a table in SQL Server that is something like code  |  text —————    1    | foo    2    | bar It's simple, and with other comboboxes (outside of gridviews) i've successfully populated looping through the rows and adding the texts: ObjComboBox.Items.Add(MyDataTable.Rows[I]["MyColumnName"].ToString()); And getting every value, adding it into an array, and setting it like: ObjComboBox.Values = MyArray; I'd like to populate my comboboxColumns just as simply as I do with comboboxes.

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  • Data denormalization and C# objects DB serialization

    - by Robert Koritnik
    I'm using a DB table with various different entities. This means that I can't have an arbitrary number of fields in it to save all kinds of different entities. I want instead save just the most important fields (dates, reference IDs - kind of foreign key to various other tables, most important text fields etc.) and an additional text field where I'd like to store more complete object data. the most obvious solution would be to use XML strings and store those. The second most obvious choice would be JSON, that usually shorter and probably also faster to serialize/deserialize... And is probably also faster. But is it really? My objects also wouldn't need to be strictly serializable, because JsonSerializer is usually able to serialize anything. Even anonymous objects, that may as well be used here. What would be the most optimal solution to solve this problem? Additional info My DB is highly normalised and I'm using Entity Framework, but for the purpose of having external super-fast fulltext search functionality I'm sacrificing a bit DB denormalisation. Just for the info I'm using SphinxSE on top of MySql. Sphinx would return row IDs that I would use to fast query my index optimised conglomerate table to get most important data from it much much faster than querying multiple tables all over my DB. My table would have columns like: RowID (auto increment) EntityID (of the actual entity - but not directly related because this would have to point to different tables) EntityType (so I would be able to get the actual entity if needed) DateAdded (record timestamp when it's been added into this table) Title Metadata (serialized data related to particular entity type) This table would be indexed with SPHINX indexer. When I would search for data using this indexer I would provide a series of EntityIDs and a limit date. Indexer would have to return a very limited paged amount of RowIDs ordered by DateAdded (descending). I would then just join these RowIDs to my table and get relevant results. So this won't actually be full text search but a filtering search. Getting RowIDs would be very fast this way and getting results back from the table would be much faster than comparing EntityIDs and DateAdded comparisons even though they would be properly indexed.

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  • Need help with implementation of the jQuery LiveUpdate routine

    - by miCRoSCoPiC_eaRthLinG
    Hey all, Has anyone worked with the LiveUpdate function (may be a bit of a misnomer) found on this page? It's not really a live search/update function, but a quick filtering mechanism for a pre-existing list, based on the pattern you enter in a text field. For easier reference, I'm pasting the entire function in here: jQuery.fn.liveUpdate = function(list){ list = jQuery(list); if ( list.length ) { var rows = list.children('li'), cache = rows.map(function(){ return this.innerHTML.toLowerCase(); }); this .keyup(filter).keyup() .parents('form').submit(function(){ return false; }); } return this; function filter(){ var term = jQuery.trim( jQuery(this).val().toLowerCase() ), scores = []; if ( !term ) { rows.show(); } else { rows.hide(); cache.each(function(i){ var score = this.score(term); if (score > 0) { scores.push([score, i]); } }); jQuery.each(scores.sort(function(a, b){return b[0] - a[0];}), function(){ jQuery(rows[ this[1] ]).show(); }); } } }; I have this list, with members as the ID. And a text field with say, qs as ID. I tried binding the function in the following manner: $( '#qs' ).liveUpdate( '#members' ); But when I do this, the function is called only ONCE when the page is loaded (I put in some console.logs in the function) but never after when text is keyed into the text field. I also tried calling the routine from the keyup() function of qs. $( '#qs' ).keyup( function() { $( this ).liveUpdate( '#members' ); }); This ends up going into infinite loops (almost) and halting with "Too much recursion" errors. So can anyone please shed some light on how I am supposed to actually implement this function? Also while you are at it, can someone kindly explain this line to me: var score = this.score(term); What I want to know is where this member method score() is coming from? I didn't find any such method built into JS or jQuery. Thanks for all the help, m^e

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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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  • Backbone.Marionette - Collection within CompositeView, which itself is nested in a CollectionView

    - by nicefinly
    *UPDATE: The problem probably involves the tour-template as I've discovered that it thinks the 'name' attribute is undefined. This leads me to think that it's not an array being passed on to the ToursView, but for some reason a string. * After studying similar questions on StackOverflow: How to handle nested CompositeView using Backbone.Marionette? How do you properly display a Backbone marionette collection view based on a model javascript array property? Nested collections with Backbone.Marionette ... and Derick Bailey's excellent blog's on this subject: http://lostechies.com/derickbailey/2012/04/05/composite-views-tree-structures-tables-and-more/ ... including the JSFiddle's: http://jsfiddle.net/derickbailey/AdWjU/ I'm still having trouble with a displaying the last node of a nested CollectionView of CompositeViews. It is the final CollectionView within each CompositeView that is causing the problem. CollectionView { CompositeView{ CollectionView {} //**<-- This is the troublemaker!** } } NOTE: I have already made a point of creating a valid Backbone.Collection given that the collection passed on to the final, child CollectionView is just a simple array. Data returned from the api to ToursList: [ { "id": "1", "name": "Venice", "theTours": "[ {'name': u'test venice'}, {'name': u'test venice 2'} ]" }, { "id": "2", "name": "Rome", "theTours": "[ {'name': u'Test rome'} ]" }, { "id": "3", "name": "Dublin", "theTours": "[ {'name': u'test dublin'}, {'name': u'test dublin 2'} ]" } ] I'm trying to nest these in a dropdown where the nav header is the 'name' (i.e. Dublin), and the subsequent li 's are the individual tour names (i.e. 'test dublin', 'test dublin2', etc.) Tour Models and Collections ToursByLoc = TastypieModel.extend({}); ToursList = TastypieCollection.extend({ model: ToursByLoc, url:'/api/v1/location/', }); Tour Views ToursView = Backbone.Marionette.ItemView.extend({ template: '#tour-template', tagName: 'li', }); ToursByLocView = Backbone.Marionette.CompositeView.extend({ template: '#toursByLoc-template', itemView: ToursView, initialize: function(){ //As per Derick Bailey's comments regarding the need to pass on a //valid Backbone.Collection to the child CollectionView //REFERENCE: http://stackoverflow.com/questions/12163118/nested-collections-with-backbone-marionette var theTours = this.model.get('theTours'); this.collection = new Backbone.Collection(theTours); }, appendHtml: function(collectionView, itemView){ collectionView.$('div').append(itemView.el); } }); ToursListView = Backbone.Marionette.CollectionView.extend({ itemView: ToursByLocView, }); Templates <script id="tour-template" type="text/template"> <%= name %> </script> <script id="toursByLoc-template" type="text/template"> <li class="nav-header"><%= name %></li> <div class="indTours"></div> <li class="divider"></li> </script>

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  • How to optimize Core Data query for full text search

    - by dk
    Can I optimize a Core Data query when searching for matching words in a text? (This question also pertains to the wisdom of custom SQL versus Core Data on an iPhone.) I'm working on a new (iPhone) app that is a handheld reference tool for a scientific database. The main interface is a standard searchable table view and I want as-you-type response as the user types new words. Words matches must be prefixes of words in the text. The text is composed of 100,000s of words. In my prototype I coded SQL directly. I created a separate "words" table containing every word in the text fields of the main entity. I indexed words and performed searches along the lines of SELECT id, * FROM textTable JOIN (SELECT DISTINCT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) ON id=textTableId LIMIT 50 This runs very fast. Using an IN would probably work just as well, i.e. SELECT * FROM textTable WHERE id IN (SELECT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) LIMIT 50 The LIMIT is crucial and allows me to display results quickly. I notify the user that there are too many to display if the limit is reached. This is kludgy. I've spent the last several days pondering the advantages of moving to Core Data, but I worry about the lack of control in the schema, indexing, and querying for an important query. Theoretically an NSPredicate of textField MATCHES '.*\bfoo.*' would just work, but I'm sure it will be slow. This sort of text search seems so common that I wonder what is the usual attack? Would you create a words entity as I did above and use a predicate of "word BEGINSWITH 'foo'"? Will that work as fast as my prototype? Will Core Data automatically create the right indexes? I can't find any explicit means of advising the persistent store about indexes. I see some nice advantages of Core Data in my iPhone app. The faulting and other memory considerations allow for efficient database retrievals for tableview queries without setting arbitrary limits. The object graph management allows me to easily traverse entities without writing lots of SQL. Migration features will be nice in the future. On the other hand, in a limited resource environment (iPhone) I worry that an automatically generated database will be bloated with metadata, unnecessary inverse relationships, inefficient attribute datatypes, etc. Should I dive in or proceed with caution?

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  • How to solve a deallocated connection in iPhone SDK 3.1.3? - Streams - CFSockets

    - by Christian
    Hi everyone, Debugging my implementation I found a memory leak issue. I know where is the issue, I tried to solve it but sadly without success. I will try to explain you, maybe someone of you can help with this. First I have two classes involved in the issue, the publish class (where publishing the service and socket configuration is done) and the connection (where the socket binding and the streams configuration is done). The main issue is in the connection via native socket. In the 'publish' class the "server" accepts a connection with a callback. The callback has the native-socket information. Then, a connection with native-socket information is created. Next, the socket binding and the streams configuration is done. When those actions are successful the instance of the connection is saved in a mutable array. Thus, the connection is established. static void AcceptCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) { Publish *rePoint = (Publish *)info; if ( type != kCFSocketAcceptCallBack) { return; } CFSocketNativeHandle nativeSocketHandle = *((CFSocketNativeHandle *)data); NSLog(@"The AcceptCallback was called, a connection request arrived to the server"); [rePoint handleNewNativeSocket:nativeSocketHandle]; } - (void)handleNewNativeSocket:(CFSocketNativeHandle)nativeSocketHandle{ Connection *connection = [[[Connection alloc] initWithNativeSocketHandle:nativeSocketHandle] autorelease]; // Create the connection if (connection == nil) { close(nativeSocketHandle); return; } NSLog(@"The connection from the server was created now try to connect"); if ( ! [connection connect]) { [connection close]; return; } [clients addObject:connection]; //save the connection trying to avoid the deallocation } The next step is receive the information from the client, thus a read-stream callback is triggered with the information of the established connection. But when the callback-handler tries to use this connection the error occurs, it says that such connection is deallocated. The issue here is that I don't know where/when the connection is deallocated and how to know it. I am using the debugger, but after some trials, I don't see more info. void myReadStreamCallBack (CFReadStreamRef stream, CFStreamEventType eventType, void *info) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; Connection *handlerEv = [[(Connection *)info retain] autorelease]; // The error -[Connection retain]: message sent to deallocated instance 0x1f5ef0 (Where 0x1f5ef0 is the reference to the established connection) [handlerEv readStreamHandleEvent:stream andEvent:eventType]; [pool drain]; } void myWriteStreamCallBack (CFWriteStreamRef stream, CFStreamEventType eventType, void *info){ NSAutoreleasePool *p = [[NSAutoreleasePool alloc] init]; Connection *handlerEv = [[(Connection *)info retain] autorelease]; //Sometimes the error also happens here, I tried without the pool, but it doesn't help neither. [handlerEv writeStreamHandleEvent:eventType]; [p drain]; } Something strange is that when I run the debugger(with breakpoints) everything goes well, the connection is not deallocated and the callbacks work fine and the server is able to receive the message. I will appreciate any hint!

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  • processing an audio wav file with C

    - by sa125
    Hi - I'm working on processing the amplitude of a wav file and scaling it by some decimal factor. I'm trying to wrap my head around how to read and re-write the file in a memory-efficient way while also trying to tackle the nuances of the language (I'm new to C). The file can be in either an 8- or 16-bit format. The way I thought of doing this is by first reading the header data into some pre-defined struct, and then processing the actual data in a loop where I'll read a chunk of data into a buffer, do whatever is needed to it, and then write it to the output. #include <stdio.h> #include <stdlib.h> typedef struct header { char chunk_id[4]; int chunk_size; char format[4]; char subchunk1_id[4]; int subchunk1_size; short int audio_format; short int num_channels; int sample_rate; int byte_rate; short int block_align; short int bits_per_sample; short int extra_param_size; char subchunk2_id[4]; int subchunk2_size; } header; typedef struct header* header_p; void scale_wav_file(char * input, float factor, int is_8bit) { FILE * infile = fopen(input, "rb"); FILE * outfile = fopen("outfile.wav", "wb"); int BUFSIZE = 4000, i, MAX_8BIT_AMP = 255, MAX_16BIT_AMP = 32678; // used for processing 8-bit file unsigned char inbuff8[BUFSIZE], outbuff8[BUFSIZE]; // used for processing 16-bit file short int inbuff16[BUFSIZE], outbuff16[BUFSIZE]; // header_p points to a header struct that contains the file's metadata fields header_p meta = (header_p)malloc(sizeof(header)); if (infile) { // read and write header data fread(meta, 1, sizeof(header), infile); fwrite(meta, 1, sizeof(meta), outfile); while (!feof(infile)) { if (is_8bit) { fread(inbuff8, 1, BUFSIZE, infile); } else { fread(inbuff16, 1, BUFSIZE, infile); } // scale amplitude for 8/16 bits for (i=0; i < BUFSIZE; ++i) { if (is_8bit) { outbuff8[i] = factor * inbuff8[i]; if ((int)outbuff8[i] > MAX_8BIT_AMP) { outbuff8[i] = MAX_8BIT_AMP; } } else { outbuff16[i] = factor * inbuff16[i]; if ((int)outbuff16[i] > MAX_16BIT_AMP) { outbuff16[i] = MAX_16BIT_AMP; } else if ((int)outbuff16[i] < -MAX_16BIT_AMP) { outbuff16[i] = -MAX_16BIT_AMP; } } } // write to output file for 8/16 bit if (is_8bit) { fwrite(outbuff8, 1, BUFSIZE, outfile); } else { fwrite(outbuff16, 1, BUFSIZE, outfile); } } } // cleanup if (infile) { fclose(infile); } if (outfile) { fclose(outfile); } if (meta) { free(meta); } } int main (int argc, char const *argv[]) { char infile[] = "file.wav"; float factor = 0.5; scale_wav_file(infile, factor, 0); return 0; } I'm getting differing file sizes at the end (by 1k or so, for a 40Mb file), and I suspect this is due to the fact that I'm writing an entire buffer to the output, even though the file may have terminated before filling the entire buffer size. Also, the output file is messed up - won't play or open - so I'm probably doing the whole thing wrong. Any tips on where I'm messing up will be great. Thanks!

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  • multi_index composite_key replace with iterator

    - by Rohit
    Is there anyway to loop through an index in a boost::multi_index and perform a replace? #include <iostream> #include <string> #include <boost/multi_index_container.hpp> #include <boost/multi_index/composite_key.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> using namespace boost::multi_index; using namespace std; struct name_record { public: name_record(string given_name_,string family_name_,string other_name_) { given_name=given_name_; family_name=family_name_; other_name=other_name_; } string given_name; string family_name; string other_name; string get_name() const { return given_name + " " + family_name + " " + other_name; } void setnew(string chg) { given_name = given_name + chg; family_name = family_name + chg; } }; struct NameIndex{}; typedef multi_index_container< name_record, indexed_by< ordered_non_unique< tag<NameIndex>, composite_key < name_record, BOOST_MULTI_INDEX_MEMBER(name_record,string, name_record::given_name), BOOST_MULTI_INDEX_MEMBER(name_record,string, name_record::family_name) > > > > name_record_set; typedef boost::multi_index::index<name_record_set,NameIndex>::type::iterator IteratorType; typedef boost::multi_index::index<name_record_set,NameIndex>::type NameIndexType; void printContainer(name_record_set & ns) { cout << endl << "PrintContainer" << endl << "-------------" << endl; IteratorType it1 = ns.begin(); IteratorType it2 = ns.end (); while (it1 != it2) { cout<<it1->get_name()<<endl; it1++; } cout << "--------------" << endl << endl; } void modifyContainer(name_record_set & ns) { cout << endl << "ModifyContainer" << endl << "-------------" << endl; IteratorType it3; IteratorType it4; NameIndexType & idx1 = ns.get<NameIndex>(); IteratorType it1 = idx1.begin(); IteratorType it2 = idx1.end(); while (it1 != it2) { cout<<it1->get_name()<<endl; name_record nr = *it1; nr.setnew("_CHG"); bool res = idx1.replace(it1,nr); cout << "result is: " << res << endl; it1++; } cout << "--------------" << endl << endl; } int main() { name_record_set ns; ns.insert( name_record("Joe","Smith","ENTRY1") ); ns.insert( name_record("Robert","Brown","ENTRY2") ); ns.insert( name_record("Robert","Nightingale","ENTRY3") ); ns.insert( name_record("Marc","Tuxedo","ENTRY4") ); printContainer (ns); modifyContainer (ns); printContainer (ns); return 0; } PrintContainer ------------- Joe Smith ENTRY1 Marc Tuxedo ENTRY4 Robert Brown ENTRY2 Robert Nightingale ENTRY3 -------------- ModifyContainer ------------- Joe Smith ENTRY1 result is: 1 Marc Tuxedo ENTRY4 result is: 1 Robert Brown ENTRY2 result is: 1 -------------- PrintContainer ------------- Joe_CHG Smith_CHG ENTRY1 Marc_CHG Tuxedo_CHG ENTRY4 Robert Nightingale ENTRY3 Robert_CHG Brown_CHG ENTRY2 --------------

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  • Performance surprise with "as" and nullable types

    - by Jon Skeet
    I'm just revising chapter 4 of C# in Depth which deals with nullable types, and I'm adding a section about using the "as" operator, which allows you to write: object o = ...; int? x = o as int?; if (x.HasValue) { ... // Use x.Value in here } I thought this was really neat, and that it could improve performance over the C# 1 equivalent, using "is" followed by a cast - after all, this way we only need to ask for dynamic type checking once, and then a simple value check. This appears not to be the case, however. I've included a sample test app below, which basically sums all the integers within an object array - but the array contains a lot of null references and string references as well as boxed integers. The benchmark measures the code you'd have to use in C# 1, the code using the "as" operator, and just for kicks a LINQ solution. To my astonishment, the C# 1 code is 20 times faster in this case - and even the LINQ code (which I'd have expected to be slower, given the iterators involved) beats the "as" code. Is the .NET implementation of isinst for nullable types just really slow? Is it the additional unbox.any that causes the problem? Is there another explanation for this? At the moment it feels like I'm going to have to include a warning against using this in performance sensitive situations... Results: Cast: 10000000 : 121 As: 10000000 : 2211 LINQ: 10000000 : 2143 Code: using System; using System.Diagnostics; using System.Linq; class Test { const int Size = 30000000; static void Main() { object[] values = new object[Size]; for (int i = 0; i < Size - 2; i += 3) { values[i] = null; values[i+1] = ""; values[i+2] = 1; } FindSumWithCast(values); FindSumWithAs(values); FindSumWithLinq(values); } static void FindSumWithCast(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { if (o is int) { int x = (int) o; sum += x; } } sw.Stop(); Console.WriteLine("Cast: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithAs(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { int? x = o as int?; if (x.HasValue) { sum += x.Value; } } sw.Stop(); Console.WriteLine("As: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithLinq(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = values.OfType<int>().Sum(); sw.Stop(); Console.WriteLine("LINQ: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } }

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  • Winforms connection strings from App.config

    - by Geo Ego
    I have a Winforms app that I am developing in C# that will serve as a frontend for a SQL Server 2005 database. I rolled the executable out to a test machine and ran it. It worked perfectly fine on the test machine up until the last round of changes that I made. However, now on the test machine, it throws the following exception immediately upon opening: System.NullReferenceException: Object reference not set to an instance of an object. at PSRD_Specs_Database_Administrat.mainMenu.mainMenu_Load(Object sender, EventArgs e) at System.Windows.Forms.Form.OnLoad(EventArgs e) at System.Windows.Forms.Form.OnCreateControl() at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible) at System.Windows.Forms.Control.CreateControl() at System.Windows.Forms.Control.WmShowWindow(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WmShowWindow(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) The only thing that I changed in this version that pertains to mainMenu_Load is the way that the connection string to the database is called. Previously, I had set a string with the connection string on every form that I needed to call it from, like: string conString = "Data Source = SHAREPOINT;Trusted_Connection = yes;" + "database = CustomerDatabase;connection timeout = 15"; As my app grew and I added forms to it, I decided to add an App.config to the project. I defined the connection string in it: <connectionStrings> <add name="conString" providerName="System.Data.SqlClient" connectionString="Data Source = SHAREPOINT;Trusted_Connection = yes;database = CustomerDatabase;connection timeout = 15" /> </connectionStrings> I then created a static string that would return the conString: public static string GetConnectionString(string conName) { string strReturn = string.Empty; if (!(string.IsNullOrEmpty(conName))) { strReturn = ConfigurationManager.ConnectionStrings[conName].ConnectionString; } else { strReturn = ConfigurationManager.ConnectionStrings["conString"].ConnectionString; } return strReturn; } I removed the conString variable and now call the connection string like so: PublicMethods.GetConnectionString("conString").ToString() It appears that this is giving me the error. I changed these instances to directly call the connection string from App.config without using GetConnectionString. For instance, in a SQLConnection: using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["conString"].ConnectionString)) This also threw the exception. However, when I went back to using the conString variable on each form, I had no issues. What I don't understand is why all three methods work fine on my development machine, while using the App.config directly or via the static string I created throw exceptions.

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  • Running 32 bit assembly code on a 64 bit Linux & 64 bit Processor : Explain the anomaly.

    - by claws
    Hello, I'm in an interesting problem.I forgot I'm using 64bit machine & OS and wrote a 32 bit assembly code. I don't know how to write 64 bit code. This is the x86 32-bit assembly code for Gnu Assembler (AT&T syntax) on Linux. //hello.S #include <asm/unistd.h> #include <syscall.h> #define STDOUT 1 .data hellostr: .ascii "hello wolrd\n"; helloend: .text .globl _start _start: movl $(SYS_write) , %eax //ssize_t write(int fd, const void *buf, size_t count); movl $(STDOUT) , %ebx movl $hellostr , %ecx movl $(helloend-hellostr) , %edx int $0x80 movl $(SYS_exit), %eax //void _exit(int status); xorl %ebx, %ebx int $0x80 ret Now, This code should run fine on a 32bit processor & 32 bit OS right? As we know 64 bit processors are backward compatible with 32 bit processors. So, that also wouldn't be a problem. The problem arises because of differences in system calls & call mechanism in 64-bit OS & 32-bit OS. I don't know why but they changed the system call numbers between 32-bit linux & 64-bit linux. asm/unistd_32.h defines: #define __NR_write 4 #define __NR_exit 1 asm/unistd_64.h defines: #define __NR_write 1 #define __NR_exit 60 Anyway using Macros instead of direct numbers is paid off. Its ensuring correct system call numbers. when I assemble & link & run the program. $cpp hello.S hello.s //pre-processor $as hello.s -o hello.o //assemble $ld hello.o // linker : converting relocatable to executable Its not printing helloworld. In gdb its showing: Program exited with code 01. I don't know how to debug in gdb. using tutorial I tried to debug it and execute instruction by instruction checking registers at each step. its always showing me "program exited with 01". It would be great if some on could show me how to debug this. (gdb) break _start Note: breakpoint -10 also set at pc 0x4000b0. Breakpoint 8 at 0x4000b0 (gdb) start Function "main" not defined. Make breakpoint pending on future shared library load? (y or [n]) y Temporary breakpoint 9 (main) pending. Starting program: /home/claws/helloworld Program exited with code 01. (gdb) info breakpoints Num Type Disp Enb Address What 8 breakpoint keep y 0x00000000004000b0 <_start> 9 breakpoint del y <PENDING> main I tried running strace. This is its output: execve("./helloworld", ["./helloworld"], [/* 39 vars */]) = 0 write(0, NULL, 12 <unfinished ... exit status 1> Explain the parameters of write(0, NULL, 12) system call in the output of strace? What exactly is happening? I want to know the reason why exactly its exiting with exitstatus=1? Can some one please show me how to debug this program using gdb? Why did they change the system call numbers? Kindly change this program appropriately so that it can run correctly on this machine. EDIT: After reading Paul R's answer. I checked my files claws@claws-desktop:~$ file ./hello.o ./hello.o: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped claws@claws-desktop:~$ file ./hello ./hello: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, not stripped All of my questions still hold true. What exactly is happening in this case? Can someone please answer my questions and provide an x86-64 version of this code?

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  • How do you handle EF Data Contexts combined with asp.net custom membership/role providers

    - by KallDrexx
    I can't seem to get my head around how to implement a custom membership provider with Entity Framework data contexts into my asp.net MVC application. I understand how to create a custom membership/role provider by itself (using this as a reference). Here's my current setup: As of now I have a repository factory interface that allows different repository factories to be created (right now I only have a factory for EF repositories and and in memory repositories). The repository factory looks like this: public class EFRepositoryFactory : IRepositoryFactory { private EntitiesContainer _entitiesContext; /// <summary> /// Constructor that generates the necessary object contexts /// </summary> public EFRepositoryFactory() { _entitiesContext = new EntitiesContainer(); } /// <summary> /// Generates a new entity framework repository for the specified entity type /// </summary> /// <typeparam name="T">Type of entity to generate a repository for </typeparam> /// <returns>Returns an EFRepository</returns> public IRepository<T> GenerateRepository<T>() where T : class { return new EFRepository<T>(_entitiesContext); } } Controllers are passed an EF repository factory via castle Windsor. The controller then creates all the service/business layer objects it requires and passes in the repository factory into it. This means that all service objects are using the same EF data contexts and I do not have to worry about objects being used in more than one data context (which of course is not allowed and causes an exception). As of right now I am trying to decide how to generate my user and authorization service layers, and have run against a design roadblock. The User/Authization service will be a central class that handles the logic for logging in, changing user details, managing roles and determining what users have access to what. The problem is, using the current methodology the asp.net mvc controllers will initialize it's own EF repository factory via Windsor and the asp.net membership/role provider will have to initialize it's own EF repository factory. This means that each part of the site will then have it's own data context. This seems to mean that if asp.net authenticates a user, that user's object will be in the membership provider's data context and thus if I try to retrieve that user object in the service layer (say to change the user's name) I will get a duplication exception. I thought of making the repository factory class a singleton, but I don't see a way for that to work with castle Windsor. How do other people handle asp.net custom providers in a MVC (or any n-tier) architecture without having object duplication issues?

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  • How to update strongly typed Html.DropDownList using Jquery

    - by Remnant
    I have a webpage with two radiobuttons and a dropdownlist as follows: <div class="sectionheader">Course <div class="dropdown"><%=Html.DropDownList("CourseSelection", Model.CourseList, new { @class = "dropdown" })%> </div> <div class="radiobuttons"><label><%=Html.RadioButton("CourseType", "Advanced", false )%> Advanced </label></div> <div class="radiobuttons"><label><%=Html.RadioButton("CourseType", "Beginner", true )%> Beginner </label></div> </div> The dropdownlist is strongly typed and populated with Model.CourseList (NB - on the first page load, 'Beginner' is the default selection and the dropdown shows the beginner course options accordingly) What I want to be able to do is to update the DropDownList based on which radiobutton is selected i.e. if 'Advanced' selected then show one list of course options in dropdown, and if 'Beginner' selected then show another list of courses. The code I would like to call sits within my Controller: public JsonResult UpdateDropDown(string courseType) { IDropDownList dropdownlistRepository = new DropDownListRepository(); IEnumerable<SelectListItem> courseList = dropdownlistRepository.GetCourseList(courseType); return Json(courseList); } Edit - Updated below to show latest position Using examples provided in jQuery in Action, I now have the following jQuery code: $('.radiobuttons input:radio').click(function() { var courseType = $(this).val(); //Get selected courseType from radiobutton var dropdownList = $(".dropdown"); //Ref for dropdownlist $.getJSON("/ByCourse/UpdateDropDown", { courseType: courseType }, function(data) { $(dropdownList).loadSelect(data); }); }); The loadSelect function is taken straight from the book and is as follows: (function($) { $.fn.emptySelect = function() { return this.each(function() { if (this.tagName == 'SELECT') this.options.length = 0; }); } $.fn.loadSelect = function(optionsDataArray) { return this.emptySelect().each(function() { if (this.tagName == 'SELECT') { var selectElement = this; $.each(optionsDataArray, function(index, optionData) { var option = new Option(optionData.Text, optionData.Value); if ($.browser.msie) { selectElement.add(option); } else { selectElement.add(option, null); } }); } }); } })(jQuery); 1 day+ later I still cannot get this to work. Assuming the jQuery code is correct then I can only think that the issue is with retrieving the actual data with $getJSON. I have verified that JsonResult UpdateDropDown does actually retrieve valid data. What am I missing? Assembly reference? (NB: I have MicrosoftAjax.js and MicrosoftMvcAjax.js in my head tags of the master page Should JsonResult be ActionResult? (I have seen both used in samples on web) Do I need to register route Controller/UpdateDropDown in Global.asax? Any further guidance would be appreciated.

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  • Would Ruby on Rails be appropriate for this Foreign Language project?

    - by Lynne Overesch-Maister
    I'm a Spanish professor & computer groupie. About 15 years ago, I authored in HyperCard a series of verb conjugation programs that are now completely out of date with respect to System OS X. I would like to redo these programs myself because I had a lot of fun doing them last time (mostly I coded while my son played in Leaps and Bounds, you know, one of those places where parents take their kids & let them run wild through the tubes...). Colleagues have mentioned using Flash, Director, and various other solutions, but I saw a presentation on RoR at our SIDLIT conference today, and was inspired. I will be parsing and comparing strings (and there are other features on top of that, but that is the main one), "adding" strings relationally indexed in some kind of database(s). It will also have to handle various foreign characters (accents, upside down question marks, etc.). On top of the main process of the program, it will have to provide a practice vs. test mode, keep track of specific answers as well as totals right/wrong, and print a report. Would this be either easier and/or more efficiently done in RoR than in other languages. I am pretty sure that it will work on a Microsoft server, right? Because I think that is where most of our stuff is. I would be programming either on a Mac or a PC, whichever you think is easier. So, in summary, is RoR the way for me to go with this project? If I have some (little) experience programming in Hypercard and C, should I be able to pick RoR up fairly quickly? What things will I need to start (I already saw something called Redhills foreign key migration plugin, which I assume would be beneficial)? I still have my old scripts from hypercard, however what I would really like to do is to combine all six of my former tense-specific programs into one larger program. I figure that it wouldn't be too hard to reference the individual tenses in some way--could that be a class? Many thanks for any help you can give me on this forum.

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  • Help with OpenSSL request using Python

    - by Ldn
    Hi i'm creating a program that has to make a request and then obtain some info. For doing that the website had done some API that i will use. There is an how-to about these API but every example is made using PHP. But my app is done using Python so i need to convert the code. here is the how-to: The request string is sealed with OpenSSL. The steps for sealing are as follows: • Random 128-bit key is created. • Random key is used to RSA-RC4 symettrically encrypt the request string. • Random key is encrypted with the public key using OpenSSL RSA asymmetrical encryption. • The encrypted request and encrypted key are each base64 encoded and placed in the appropriate fields. In PHP a full request to our API can be accomplished like so: <?php // initial request. $request = array('object' => 'Link', 'action' => 'get', 'args' => array( 'app_id' => 303612602 ) ); // encode the request in JSON $request = json_encode($request); // when you receive your profile, you will be given a public key to seal your request in. $key_pem = "-----BEGIN PUBLIC KEY----- MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALdu5C6d2sA1Lu71NNGBEbLD6DjwhFQO VLdFAJf2rOH63rG/L78lrQjwMLZOeHEHqjaiUwCr8NVTcVrebu6ylIECAwEAAQ== -----END PUBLIC KEY-----"; // load the public key $pkey = openssl_pkey_get_public($key_pem); // seal! $newrequest and $enc_keys are passed by reference. openssl_seal($request, $enc_request, $enc_keys, array($pkey)); // then wrap the request $wrapper = array( 'profile' => 'ProfileName', 'format' => 'RSA_RC4_Sealed', 'enc_key' => base64_encode($enc_keys[0]), 'request' => base64_encode($enc_request) ); // json encode the wrapper. urlencode it as well. $wrapper = urlencode(json_encode($wrapper)); // we can send the request wrapper via the cURL extension $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, 'http://api.site.com/'); curl_setopt($ch, CURLOPT_POST, 1); curl_setopt($ch, CURLOPT_POSTFIELDS, "request=$wrapper"); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); $data = curl_exec($ch); curl_close($ch); ?> Of all of that, i was able to convert "$request" and i'v also made the JSON encode. This is my code: import urllib import urllib2 import json url = 'http://api.site.com/' array = {'app_id' : "303612602"} values = { "object" : "Link", "action": "get", "args" : array } data = urllib.urlencode(values) json_data = json.dumps(data) What stop me is the sealing with OpenSSL and the publi key (that obviously i have) Using PHP OpenSSL it's so easy, but in Python i don't really know how to use it Please, help me!

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  • calling delphi dll from c#

    - by Wouter Roux
    Hi, I have a Delphi dll defined like this: TMPData = record Lastname, Firstname: array[0..40] of char; Birthday: TDateTime; Pid: array[0..16] of char; Title: array[0..20] of char; Female: Boolean; Street: array[0..40] of char; ZipCode: array[0..10] of char; City: array[0..40] of char; Phone, Fax, Department, Company: array[0..20] of char; Pn: array[0..40] of char; In: array[0..16] of char; Hi: array[0..8] of char; Account: array[0..20] of char; Valid, Status: array[0..10] of char; Country, NameAffix: array[0..20] of char; W, H: single; Bp: array[0..10] of char; SocialSecurityNumber: array[0..9] of char; State: array[0..2] of char; end; function Init(const tmpData: TMPData; var ErrorCode: integer; ResetFatalError: boolean = false): boolean; procedure GetData(out tmpData: TMPData); My current c# signatures looks like this: [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] public struct TMPData { [MarshalAs(UnmanagedType.LPStr, SizeConst = 40)] public string Lastname; [MarshalAs(UnmanagedType.LPStr, SizeConst = 40)] public string Firstname; [MarshalAs(UnmanagedType.R8)] public double Birthday; [MarshalAs(UnmanagedType.LPStr, SizeConst = 16)] public string Pid; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string Title; [MarshalAs(UnmanagedType.Bool)] public bool Female; [MarshalAs(UnmanagedType.LPStr, SizeConst = 40)] public string Street; [MarshalAs(UnmanagedType.LPStr, SizeConst = 10)] public string ZipCode; [MarshalAs(UnmanagedType.LPStr, SizeConst = 40)] public string City; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string Phone; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string Fax; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string Department; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string Company; [MarshalAs(UnmanagedType.LPStr, SizeConst = 40)] public string Pn; [MarshalAs(UnmanagedType.LPStr, SizeConst = 16)] public string In; [MarshalAs(UnmanagedType.LPStr, SizeConst = 8)] public string Hi; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string Account; [MarshalAs(UnmanagedType.LPStr, SizeConst = 10)] public string Valid; [MarshalAs(UnmanagedType.LPStr, SizeConst = 10)] public string Status; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string Country; [MarshalAs(UnmanagedType.LPStr, SizeConst = 20)] public string NameAffix; [MarshalAs(UnmanagedType.I4)] public int W; [MarshalAs(UnmanagedType.I4)] public int H; [MarshalAs(UnmanagedType.LPStr, SizeConst = 10)] public string Bp; [MarshalAs(UnmanagedType.LPStr, SizeConst = 9)] public string SocialSecurityNumber; [MarshalAs(UnmanagedType.LPStr, SizeConst = 2)] public string State; } [DllImport("MyDll.dll")] [return: MarshalAs(UnmanagedType.Bool)] public static extern bool Init(TMPData tmpData, int ErrorCode, bool ResetFatalError); [DllImport("MyDll.dll")] [return: MarshalAs(UnmanagedType.Bool)] public static extern bool GetData(out TMPData tmpData); I first call Init setting the BirthDay, LastName and FirstName. I then call GetData but the TMPData structure I get back is incorrect. The FirstName, LastName and Birthday fields are populated but the data is incorrect. Is the mapping correct? ( "array[0..40] of char" equal to "[MarshalAs(UnmanagedType.LPStr, SizeConst = 40)]" )?

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  • LINQ to XML Cloning

    - by Sir Psycho
    Can anyone explain why the original address XElement street node changes? It looks like customer1 holds a reference to the address XElement but customer2 and customer3 have taken copies. Why did the original address change? (LINQPad example) var address = new XElement ("address", new XElement ("street", "Lawley St"), new XElement ("town", "North Beach") ); var customer1 = new XElement ("customer1", address); var customer2 = new XElement ("customer2", address); var customer3 = new XElement ("customer3", address); customer1.Element ("address").Element ("street").Value = "Another St"; Console.WriteLine (customer2.Element ("address").Element ("street").Value); Console.WriteLine (); address.Dump(); Console.WriteLine (); customer1.Dump(); Console.WriteLine (); customer2.Dump(); Console.WriteLine (); customer3.Dump(); OUTPUT Lawley St <address> <street>Another St</street> <town>North Beach</town> </address> <customer1> <address> <street>Another St</street> <town>North Beach</town> </address> </customer1> <customer2> <address> <street>Lawley St</street> <town>North Beach</town> </address> </customer2> <customer3> <address> <street>Lawley St</street> <town>North Beach</town> </address> </customer3>

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  • Modelsim (XE III/Starter 6.4b) not allowing me to define a macro function

    - by montooner
    I'm working on a Xiling FPGA for a course project. Normally we use the lab computers, but I'm trying to install on my own computer. So, I'm trying to include a macro file using line: `include "Const.v" But the following macro function doesn't work. Any ideas why? `ifdef synthesis // if Synplify `define SYNPLIFY `define SYNTHESIS `define MACROSAFE `else // if not Synplify `ifdef MODELSIM `define SIMULATION `define MACROSAFE `else `define XST // synthesis translate_off // if XST then stop compiling `undef XST `define SIMULATION `define MODELSIM // synthesis translate_on // if XST then resume compiling `ifdef XST `define SYNTHESIS `define MACROSAFE `endif `endif `endif //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ // Section: Log2 Macro // Desc: A macro to take the log base 2 of any number. Useful for // calculating bitwidths. Warning, this actually calculates // log2(x-1), not log2(x). //------------------------------------------------------------------------------ `ifdef MACROSAFE `define log2(x) ((((x) > 1) ? 1 : 0) + \ (((x) > 2) ? 1 : 0) + \ (((x) > 4) ? 1 : 0) + \ (((x) > 8) ? 1 : 0) + \ (((x) > 16) ? 1 : 0) + \ (((x) > 32) ? 1 : 0) + \ (((x) > 64) ? 1 : 0) + \ (((x) > 128) ? 1 : 0) + \ (((x) > 256) ? 1 : 0) + \ (((x) > 512) ? 1 : 0) + \ (((x) > 1024) ? 1 : 0) + \ (((x) > 2048) ? 1 : 0) + \ (((x) > 4096) ? 1 : 0) + \ (((x) > 8192) ? 1 : 0) + \ (((x) > 16384) ? 1 : 0) + \ (((x) > 32768) ? 1 : 0) + \ (((x) > 65536) ? 1 : 0) + \ (((x) > 131072) ? 1 : 0) + \ (((x) > 262144) ? 1 : 0) + \ (((x) > 524288) ? 1 : 0) + \ (((x) > 1048576) ? 1 : 0) + \ (((x) > 2097152) ? 1 : 0) + \ (((x) > 4194304) ? 1 : 0) + \ (((x) > 8388608) ? 1 : 0) + \ (((x) > 16777216) ? 1 : 0) + \ (((x) > 33554432) ? 1 : 0) + \ (((x) > 67108864) ? 1 : 0) + \ (((x) > 134217728) ? 1 : 0) + \ (((x) > 268435456) ? 1 : 0) + \ (((x) > 536870912) ? 1 : 0) + \ (((x) > 1073741824) ? 1 : 0)) `endif

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  • How to make and use first object in Objective C to store sender tag

    - by dbonneville
    I started with a sample program that simply sets up a UIView with some buttons on it. Works great. I want to access the sender tag from each button and save it. My first thought was to save it to a global variable but I couldn't get it to work right. I thought the best way would be to create an object with one property and synthesize it so I can get or set it as needed. First, I created GlobalGem.h: #import <Foundation/Foundation.h> @interface GlobalGem : NSObject { int gemTag; } @property int gemTag; -(void) print; @end Then I created GlobalGem.m: #import "GlobalGem.h" @implementation GlobalGem @synthesize gemTag; -(void) print { NSLog(@"gemTag value is %i", gemTag); } @end The sample code I worked from doesn't do anything I can see in "main" where the program initializes. They just have their methods and are set up to handle IBOutlet actions. I want to use this object in the IBOutlet methods. But I don't know where to create the object. In the viewDidLoad, I tried this: GlobalGem *aGem = [[GlobalGem alloc]init]; [aGem print]; I added reference to the .h file of course. The print method works. In the nslog I get "gemTag value is 0". But now I want to use the instance aGem in some of the IBOutlet actions. For instance, if I put this same method in one of the outlet actions like this: - (IBAction)touchButton:(id)sender { [aGem print]; } ...I get a build error saying that "aGem is undeclared". Yes, I'm new to objective c and am very confused. Is the instance I created, aGem, in the viewDidLoad not accessible outside of that method? How would I create an instance of a Class that I can store a variable value that any of the IBOutlet methods can access? All the buttons need to be able to store their sender tag in the instance aGem and I'm stuck. As I mentioned earlier, I was able to write the sender tag to a global variable I declared in the UIView .h file that came with the program, but I ran into issues using it. Where am I off?

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