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• Using QT to build a WYSIWYG Editor for a Custom Markup Language

  - by Aaron

  I'm new to QT, and am trying to figure out the best means of creating a WYSIWYG editor widget for a custom markup language that displays simple text, images, and links. I need to be able to propagate changes from the WYSIWYG editor to the custom markup representation. As a concrete example of the problem domain, imagine that the custom markup might have a "player" tag which contains a player name and a team name. The markup could look like this: Last week, <player id="1234"><name>Aaron Rodgers</name><team>Packers</team></player> threw a pass. This text would display in the editor as: Last week, Aaron Rodgers of the Packers threw a pass. The player name and the team name would be editable directly within the editor in standard WYSIWYG fashion, so that my users do not have to learn any markup. Also, when the player name is moused-over, a details pop-up will appear about that player, and similarly for the team. With that long introduction, I'm trying to figure out where to start with QT. It seems that the most logical option would be the Rich Text API using a QTextDocument. This approach seems less than ideal given the limitations of a QTextDocument: I can't figure out how to capture navigation events from clicking on links. Following links on click seems to only be enabled when the QTextEdit is readonly. Custom objects that implement QTextObjectInterface are ignored in copy-and-paste operations Any HTML-based markup that is passed to it as Rich Text is retranslated into a series of span tags and lots of other junk, making it extremely difficult to propagate changes from the editor back to the original custom markup. A second option appears to be QWebKit, which allows for live editing of HTML5 markup, so I could specify a two-way translation between the custom markup and HTML5. I'm not clear on how one would propagate changes from the editor back to the original markup in real-time without re-translating the entire document on every text change. The QWebKit solutions looks like awfully bulky to me (Learning WebKit along with QT) to what should be a relatively simple problem. I have also considered implementing the WYSIWYG with a custom class using native QT containers, labels, images, and other widgets manually. This seems like the most flexible approach, and the one most likely not to run into unresolvable problems. However, I'm pretty sure that implementing all the details of a normal text editor (selecting text, font changes, cut-and-paste support, undo/redo, dragging of objects, cursor placement, etc.) will be incredibly time consuming. So, finally, my question: are there any QT gurus out there with some advice on where to start with this sort of project? BTW, I am using QT because the application is a desktop application that needs platform independence.

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• Personal Project - Next practical language/tech to learn

  - by Paul Nathan

  I'm working on a personal project doing some finance analysis. It's a totally new field for me, and I'm really having fun with it so far, plus working in the high-level language arena is a great break from my embedded systems daytime work. I have a MySQL backend on a non-local server with a pile of stock data. My task now is to do some analysis of the stocks and produce something approximating a useful result. There are a couple technical difficulties. (1) I have a lot of records. To be precise, I believe I'm near 100K records right now, and this number grows by 6.1K each weekday. I need to create a way to rummage through these fields and do data analysis - based on a given computation, go look at this other set. Fine and dandy, nothing too outre. But this means I could really use a straightforward API for talking to MySQL. (2) Ideally, it runs on OS X 10.4.11. No Windows/Linux machine at home. (3) I can use PHP, C++, Perl, etc. I even have an R installation. I'm pretty flexible with stuff, so long as it runs on OS X. (Lots of options here, pick water, H20, or dihydrogen monoxide ;-) ) (4)Lack of hassle. While I like clever and fun ways of doing things, I'm trying to get some analysis done, not spend ten hours doing installation work and scratching my head figuring out a theoretical syntax question needed to spout out "hello world". What's the question? I'd like to dig into something different than my usual PHP/C++/C toolset. I'm looking for recommendations for languages/technologies that will assist me and meet the above requirements. In particular, I've heard a lot of buzz about F# and Python on SO. I've used CLISP for small problems before, and kinda liked it. I'm seeking opinions about those in particular. edit:since I rent the DB server and have a limited amount of CPU time online, I'm trying to do the analysis on a local machine.

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• Parse and transform XML with missing elements into table structure

  - by dnlbrky

  I'm trying to parse an XML file. A simplified version of it looks like this: x <- '<grandparent><parent><child1>ABC123</child1><child2>1381956044</child2></parent><parent><child2>1397527137</child2></parent><parent><child3>4675</child3></parent><parent><child1>DEF456</child1><child3>3735</child3></parent><parent><child1/><child3>3735</child3></parent></grandparent>' library(XML) xmlRoot(xmlTreeParse(x)) ## <grandparent> ## <parent> ## <child1>ABC123</child1> ## <child2>1381956044</child2> ## </parent> ## <parent> ## <child2>1397527137</child2> ## </parent> ## <parent> ## <child3>4675</child3> ## </parent> ## <parent> ## <child1>DEF456</child1> ## <child3>3735</child3> ## </parent> ## <parent> ## <child1/> ## <child3>3735</child3> ## </parent> ## </grandparent> I'd like to transform the XML into a data.frame / data.table that looks like this: parent <- data.frame(child1=c("ABC123",NA,NA,"DEF456",NA), child2=c(1381956044, 1397527137, rep(NA, 3)), child3=c(rep(NA, 2), 4675, 3735, 3735)) parent ## child1 child2 child3 ## 1 ABC123 1381956044 NA ## 2 <NA> 1397527137 NA ## 3 <NA> NA 4675 ## 4 DEF456 NA 3735 ## 5 <NA> NA 3735 If each parent node always contained all of the possible elements ("child1", "child2", "child3", etc.), I could use xmlToList and unlist to flatten it, and then dcast to put it into a table. But the XML often has missing child elements. Here is an attempt with incorrect output: library(data.table) ## Flatten: dt <- as.data.table(unlist(xmlToList(x)), keep.rownames=T) setnames(dt, c("column", "value")) ## Add row numbers, but they're incorrect due to missing XML elements: dt[, row:=.SD[,.I], by=column][] column value row 1: parent.child1 ABC123 1 2: parent.child2 1381956044 1 3: parent.child2 1397527137 2 4: parent.child3 4675 1 5: parent.child1 DEF456 2 6: parent.child3 3735 2 7: parent.child3 3735 3 ## Reshape from long to wide, but some value are in the wrong row: dcast.data.table(dt, row~column, value.var="value", fill=NA) ## row parent.child1 parent.child2 parent.child3 ## 1: 1 ABC123 1381956044 4675 ## 2: 2 DEF456 1397527137 3735 ## 3: 3 NA NA 3735 I won't know ahead of time the names of the child elements, or the count of unique element names for children of the grandparent, so the answer should be flexible.

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• How can I easily maintain a cross-file JavaScript Library Development Environment

  - by John

  I have been developing a new JavaScript application which is rapidly growing in size. My entire JavaScript Application has been encapsulated inside a single function, in a single file, in a way like this: (function(){ var uniqueApplication = window.uniqueApplication = function(opts){ if (opts.featureOne) { this.featureOne = new featureOne(opts.featureOne); } if (opts.featureTwo) { this.featureTwo = new featureTwo(opts.featureTwo); } if (opts.featureThree) { this.featureThree = new featureThree(opts.featureThree); } }; var featureOne = function(options) { this.options = options; }; featureOne.prototype.myFeatureBehavior = function() { //Lots of Behaviors }; var featureTwo = function(options) { this.options = options; }; featureTwo.prototype.myFeatureBehavior = function() { //Lots of Behaviors }; var featureThree = function(options) { this.options = options; }; featureThree.prototype.myFeatureBehavior = function() { //Lots of Behaviors }; })(); In the same file after the anonymous function and execution I do something like this: (function(){ var instanceOfApplication = new uniqueApplication({ featureOne:"dataSource", featureTwo:"drawingCanvas", featureThree:3540 }); })(); Before uploading this software online I pass my JavaScript file, and all it's dependencies, into Google Closure Compiler, using just the default Compression, and then I have one nice JavaScript file ready to go online for production. This technique has worked marvelously for me - as it has created only one global footprint in the DOM and has given me a very flexible framework to grow each additional feature of the application. However - I am reaching the point where I'd really rather not keep this entire application inside one JavaScript file. I'd like to move from having one large uniqueApplication.js file during development to having a separate file for each feature in the application, featureOne.js - featureTwo.js - featureThree.js Once I have completed offline development testing, I would then like to use something, perhaps Google Closure Compiler, to combine all of these files together - however I want these files to all be compiled inside of that scope, as they are when I have them inside one file - and I would like for them to remain in the same scope during offline testing too. I see that Google Closure Compiler supports an argument for passing in modules but I haven't really been able to find a whole lot of information on doing something like this. Anybody have any idea how this could be accomplished - or any suggestions on a development practice for writing a single JavaScript Library across multiple files that still only leaves one footprint on the DOM?

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• M-V-VM, isn't the Model leaking into the View?

  - by BFree

  The point of M-V-VM as we all know is about speraration of concerns. In patterns like MVVM, MVC or MVP, the main purpose is to decouple the View from the Data thereby building more flexible components. I'll demonstrate first a very common scenario found in many WPF apps, and then I'll make my point: Say we have some StockQuote application that streams a bunch of quotes and displays them on screen. Typically, you'd have this: StockQuote.cs : (Model) public class StockQuote { public string Symbol { get; set; } public double Price { get; set; } } StockQuoteViewModel.cs : (ViewModel) public class StockQuoteViewModel { private ObservableCollection<StockQuote> _quotes = new ObservableCollection<StockQuote>(); public ObservableCollection<StockQuote> Quotes { get { return _quotes; } } } StockQuoteView.xaml (View) <Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:WpfApplication1" Title="Window1" Height="300" Width="300"> <Window.DataContext> <local:StockQuoteViewModel/> </Window.DataContext> <Window.Resources> <DataTemplate x:Key="listBoxDateTemplate"> <StackPanel Orientation="Horizontal"> <TextBlock Text="{Binding Symbol}"/> <TextBlock Text="{Binding Price}"/> </StackPanel> </DataTemplate> </Window.Resources> <Grid> <ListBox ItemTemplate="{StaticResource listBoxDateTemplate}" ItemsSource="{Binding Quotes}"/> </Grid> </Window> And then you'd have some kind of service that would feed the ObservableCollection with new StockQuotes. My question is this: In this type of scenario, the StockQuote is considered the Model, and we're exposing that to the View through the ViewModel's ObservableCollection. Which basically means, our View has knowledge of the Model. Doesn't that violate the whole paradigm of M-V-VM? Or am I missing something here....?

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• QT vs. Net - REAL comparisons for R.A.D. projects

  - by Pirate for Profit

  Man in all these Qt vs. .NET discussions 90% these people argue about the dumbest crap. Trying to get a real comparison chart here, because I know a little about both frameworks but I don't know everything. I believe Qt and .NET both have strengths and weaknesses. This is to make a comparison that highlights these so people can make more informed decisions before embarking on a project, in the spirit of R.A.D. Event Handling In Qt the event handling system is very simple. You just emit signals when something cool happens and then catch them in slots. ie. // run some calculations, then emit valueChanged(30, false, 20.2); and then catching it, any object can make a slot to recieve that message easily void MyObj::valueChanged(int percent, bool ok, float timeRemaining). It's easy to "block" an event or "disconnect" when needed, and works seamlessly across threads... once you get the hang of it, it just seems a lot more natural and intuitive than the way the .NET event handling is set up (you know, void valueChanged(object sender, CustomEventArgs e). And I'm not just talking about syntax, because in the end the .NET anonymous delegates are the bomb. I'm also talking about in more than just reflection (because, yes, .NET obviously has much stronger reflection capabilities). I'm talking about in the way the system feels to a human being. Qt wins hands down for the simplest yet still flexible event handling system ever i m o. Plugins and such I do love some of the ease of C# compared to C++, as well as .NET's assembly architecture, even though it leads to a bunch of .dll's (there's ways to combine everything into a single exe though). That is a big bonus for modular projects, which are a PITA to import stuff in C++ as far as RAD is concerned. Database Ease of Doing Crap Also what about datasets and database manipulations. I think .net wins here but I'm not sure. Threading/Conccurency How do you guys think of the threading? In .NET, all I've ever done is make like a list of master worker threads with locks. I like QConcurrentFramework, you don't worry about locks or anything, and with the ease of the signal slot system across threads it's nice to get notified about the progress of things. QConcurrent is the simplest threading mechanism I've ever played with. Memory Usage Also what do you think of the overall memory usage comparison. Is the .NET garbage collector pretty on the ball and quick compared to the instantaneous nature of native memory management? Or does it just let programs leak up a storm and lag the computer then clean it up when it's about to really lag? Doesn't the just-in-time compiler make native code that is pretty good, like and that only happens the first time the program is run? However, I am a n00b who doesn't know what I'm talking about, please school me on the subject.

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• GridView paging inside an UpdatePanel or PlaceHolder components

  - by John

  Hello, I'm new to ASP.NET. Im developing ASP.NET C# web form which creating GridView components dynamically and filling them using the data received from my webservice. I'm creating these GridView components programmatically in server-side (cs file)- it has to be flexible - 1 GridView and sometimes 10 GridView components. The problem occurs when I'm trying to add pagination - whenever the user clicks the "next" page, the whole page is getting refreshed because of a postBack and I'm loosing all my data and the page returns Blank/Empty. I used PlaceHolder to hold the GridView components, while searching for a solution, I found UpdatePanel as a better alternative - as far as I understand the page can be partially refreshed - which means that only the UpdatePanel has to be refreshed...but it doesn't work. The following code sample is my TEST, the UpdatePanel is the only component initiated in the client side (aspx page), the rest initiated programmatically in CS. how can I solve the issue described above? Why does the whole page is getting refreshed and I'm loosing my data? can you recommend another way? can provide me with any code sample? If I'm not rebuilding the GridView, it doesn't work... Here is my Default.aspx.cs: public partial class TestAjaxForm : System.Web.UI.Page { DataTable table; protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) bindGridView(); } public void bindGridView() { GridView gridView1 = new GridView(); gridView1.AutoGenerateColumns = true; gridView1.PageSize = 2; gridView1.AllowPaging = true; gridView1.PagerSettings.Mode = PagerButtons.Numeric; gridView1.PagerSettings.Position = PagerPosition.Bottom; gridView1.PagerSettings.PageButtonCount = 10; gridView1.PageIndexChanging += new GridViewPageEventHandler(this.GridView1_PageIndexChanging); table = new DataTable(); table.Columns.Add("FirstName"); table.Columns.Add("LastName"); DataRow row = table.NewRow(); row["FirstName"] = "John"; row["LastName"] = "Johnoson"; table.Rows.Add(row); row = table.NewRow(); row["FirstName"] = "Johnny"; row["LastName"] = "Marley"; table.Rows.Add(row); row = table.NewRow(); row["FirstName"] = "Kate"; row["LastName"] = "Li"; table.Rows.Add(row); panel.ContentTemplateContainer.Controls.Add(gridView1); gridView1.DataSource = table; gridView1.DataBind(); } protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e) { GridView gridView1 = (GridView)sender; gridView1.PageIndex = e.NewPageIndex; gridView1.DataSource = table; gridView1.DataBind(); } } Please help me, Thank you.

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• Help choosing authentication method

  - by Dima

  I need to choose an authentication method for an application installed and integrated in customers environment. There are two types of environments - windows and linux/unix. Application is user based, no web stuff, pure Java. The requirement is to authenticate users which will use my application against customer provided user base. Meaning, customer installs my app, but uses his own users to grant or deny access to my app. Typical, right? I have three options to consider and I need to pick up the one which would be a) the most flexible to cover most common modern environments and b) would take least effort while stay robust and standard. Option (1) - Authenticate locally managing user credentials in some local storage, e.g. file. Customer would then add his users to my application and it will then check the passwords. Simple, clumsy but would work. Customers would have to punch every user they want to grant access to my app using some UI we will have to provide. Lots of work for me, headache to the customer. Option (2) - Use LDAP authentication. Customers would tell my app where to look for users and I will walk their directory resolving names into user names and trying to bind with found password. This is better approach IMO, but more fragile because I will have to walk an unknown directory structure and who knows if this will be permitted everywhere. Would be harder to test since there are many LDAP implementation out there, last thing I want is drowning in this voodoo. Option(3) - Use plain Kerberos authentication. Customers would tell my app what realm (domain) and which KDC (key distribution center) to use. In ideal world these two parameters would be all I need to set while customers could use their own administration tools to configure domain and kdc. My application would simply delegate user credentials to this third party (using JAAS or Spring security) and consider success when third party is happy with them. I personally prefer #3, but not sure what surprises I might face. Would this cover windows and *nix systems entirely? Is there another option to consider?

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• How can I model the data in a multi-language data editor in WPF with MVVM?

  - by Patrick Szalapski

  Are there any good practices to follow when designing a model/ViewModel to represent data in an app that will view/edit that data in multiple languages? Our top-level class--let's call it Course--contains several collection properties, say Books and TopicsCovered, which each might have a collection property among its data. For example, the data needs to represent course1.Books.First().Title in different languages, and course1.TopicsCovered.First().Name in different languages. We want a app that can edit any of the data for one given course in any of the available languages--as well as edit non-language-specific data, perhaps the Author of a Book (i.e. course1.Books.First().Author). We are having trouble figuring out how best to set up the model to enable binding in the XAML view. For example, do we replace (in the single-language model) each String with a collection of LanguageSpecificString instances? So to get the author in the current language: course1.Books.First().Author.Where(Function(a) a.Language = CurrentLanguage).SingleOrDefault If we do that, we cannot easily bind to any value in one given language, only to the collection of language values such as in an ItemsControl. <TextBox Text={Binding Author.???} /> <!-- no way to bind to the current language author --> Do we replace the top-level Course class with a collection of language-specific Courses? So to get the author in the current language: course1.GetLanguage(CurrentLanguage).Books.First.Author If we do that, we can only easily work with one language at a time; we might want a view to show one language and let the user edit the other. <TextBox Text={Binding Author} /> <!-- good --> <TextBlock Text={Binding ??? } /> <!-- no way to bind to the other language author --> Also, that has the disadvantage of not representing language-neutral data as such; every property (such as Author) would seem to be in multiple languages. Even non-string properties would be in multiple languages. Is there an option in between those two? Is there another way that we aren't thinking of? I realize this is somewhat vague, but it would seem to be a somewhat common problem to design for. Note: This is not a question about providing a multilingual UI, but rather about actually editing multi-language data in a flexible way.

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• Advice for Architecture Design Logic for software application

  - by Prasad

  Hi, I have a framework of basic to complex set of objects/classes (C++) running into around 500. With some rules and regulations - all these objects can communicate with each other and hence can cover most of the common queries in the domain. My Dream: I want to provide these objects as icons/glyphs (as I learnt recently) on a workspace. All these objects can be dragged/dropped into the workspace. They have to communicate only through their methods(interface) and in addition to few iterative and conditional statements. All these objects are arranged finally to execute a protocol/workflow/dataflow/process. After drawing the flow, the user clicks the Execute/run button. All the user interaction should be multi-touch enabled. The best way to show my dream is : Jeff Han's Multitouch Video. consider Jeff is playing with my objects instead of the google maps. :-) it should be like playing a jigsaw puzzle. Objective: how can I achieve the following while working on this final product: a) the development should be flexible to enable provision for web services b) the development should enable easy web application development c) The development should enable client-server architecture - d) further it should also enable mouse based drag/drop desktop application like Adobe programs etc. I mean to say: I want to economize on investments. Now I list my efforts till now in design : a) Created an Editor (VB) where the user writes (manually) the object / class code b) On Run/Execute, the code is copied into a main() function and passed to interpreter. c) Catch the output and show it in the console. The interpreter can be separated to become a server and the Editor can become the client. This needs lot of standard client-server architecture work. But some how I am not comfortable in the tightness of this system. Without interpreter is there much faster and better embeddable solution to this? - other than writing a special compiler for these objects. Recently learned about AXIS-C++ can help me - looks like - a friend suggested. Is that the way to go ? Here are my questions: (pl. consider me a self taught programmer and NOT my domain) a) From the stage of C++ objects to multi-touch product, how can I make sure I will develop the parallel product/service models as well.? What should be architecture aspects I should consider ? b) What technologies are best suited for this? c) If I am thinking of moving to Cloud Computing, how difficult/ how redundant / how unnecessary my efforts will be ? d) How much time in months would it take to get the first beta ? I take the liberty to ask if any of the experts here are interested in this project, please email me: [email protected] Thank you for any help. Looking forward.

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• Arguments for moving from LINQtoSQL to Nhibernate?

  - by sah302

  Backstory: Hi all, I just spent a lot of time reading many of the LINQ vs Nhibernate threads here and on other sites. I work in a small development team of 4 people and we don't even have really any super experienced developers. We work for a small company that has a lot of technical needs but not enough developers to implement them (and hiring more is out of the question right now). Typically our projects (which individually are fairly small) have been coded separately and weren't really layered in anyway, code wasn't re-used, no class libraries, and we just use the LINQtoSQL .dbml files for our pojects, we really don't even use objects but pass around values and stuff, the only time we use objects is when inserting to a database (heck not even querying since you don't need to assign it to a type and can just bind to gridview). Despite all this as I said our company has a lot of technical needs, no one could come to us for a year and we would have plenty of work to implement requested features. Well I have decided to change that a bit first by creating class libraries and actually adding layers to our applications. I am trying to meet these guys halfway by still using LINQtoSQL as the ORM yet and still use VB as the language. However I am finding it a b***h of a time dealing with so many thing in LINQtoSQL that I found easy in Nhibernate (automatic handling of the session, criteria creation easier than expression trees, generic an dynamic querying easier etc.) So... Question: How can I convince my lead developers and other senior programmers that switching to Nhibernate is a good thing? That being in control of our domain objects is a good thing? That being able to implement interfaces is a good? I've tried exlpaining the advantages of this before but it's not understood by them because they've never programmed in a true OO & layered way. Also one of the counter arguments to this I can see is sqlMetal generates those classes automatically and therefore it saves a lot of time. I can't really counter that other than saying spending more time on infrastructure to make it more scalable and flexible is good, but they can't see how. Again, I know the features and advantages (somewhat enough I believe) of each, but I need arguments applicable to my context, hence why I provided the context. I just am not a very good arguer I guess. (Caveat: For all the LINQtoSQL lovers, I may just not be super proficient as LINQ, but I find it very cumbersome that you are required to download some extra library for dynamic queries which don't by default support guid comparisons, and I also find the way of updating entitites to be cumbersome as well in terms of data context managing, so it could just be that I suck hehe.)

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• a question about rails general practice with REST, json, and ajax

  - by Nik

  Hi all, I have this question concerning REST I think: I have read a few rest tutorials and the feeling I get from them is that each action in a restful controller tends to be lean and almost single purpose: "Index gives off a collection of a model show gives off one model edit/new a prep place for changing/create a model update/create changes and makes new model deletes removes one model" After reading all these tutorials, rest seems to be to be a means to create an interface for a model, much like active resource type of thing. the mantra seems to be "controller provides data and data only and is also pretty convention over configuration, so expect projects_path to return a bunch of projects" I can understand that, and I like the cleanliness. But here's when I run into some trouble in reality in applying these guidelines: say three models, Project with attrib title, User with attrib name, and Location with attrib address. Say in views/users/index.html.erb, I want to use Ajax to fetch and display a project in a div#project_display when the user clicks on a project element, I know that I can use views/projects/show.js.rjs like this: page.replace_html 'project_display' "#{@project.name}" where in the projects_controller.rb def show @project = Project.find(params[:id]) repsond_to do |format| format.js and other formats... end end I have no problem in doing that for a couple of years now. BUT doesn't that mean that my JS response for the project#show action is LOCkED to present data to div#project_display element and show only whatever I that rjs template says it should show? That's very limiting and doesn't sound very "interface" like. I have never used JSON before or much XML, so I thought, maybe the JS response should send back raw stuff, like JSON and somehow the page on which the ajax request was called has the instruction on what do to with these raw data. That sounds a lot more flexible, doesn't it? Because look back at that exmpale, what if in the views/locations/index.html.erb, I want to do the exact same thing except I want to put the response in div#project_goes_here and the response should be #{project.name} I know this is a trivial change but that's the point: the RJS only allows one template at a time. So I think the JSON route is the way to go, but how does the already loaded page, the one that the ajax call came from, know when or how to "look forward" to incoming data? I read that PrototypeJS has this template thing, I wouldn't mind using it with JSON, but if you can demonstrate this or other means for displaying received-from-ajax data, I am all attention. Thank You

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• Prevent SQL Injection in Dynamic column names

  - by Mr Shoubs

  I can't get away without writing some dynamic sql conditions in a part of my system (using Postgres). My question is how best to avoid SQL Injection with the method I am currently using. EDIT (Reasoning): There are many of columns in a number of tables (a number which grows (only) and is maintained elsewhere). I need a method of allowing the user to decide which (predefined) column they want to query (and if necessary apply string functions to). The query itself is far too complex for the user to write themselves, nor do they have access to the db. There are 1000's of users with varying requirements and I need to remain as flexible as possible - I shouldn't have to revisit the code unless the main query needs to change - Also, there is no way of knowing what conditions the user will need to use. I have objects (received via web service) that generates a condition (the generation method is below - it isn't perfect yet) for some large sql queries. The _FieldName is user editable (parameter name was, but it didn't need to be) and I am worried it could be an attack vector. I put double quotes (see quoted identifier) around the field name in an attempt to sanitize the string, this way it can never be a key word. I could also look up the field name against a list of fields, but it would be difficult to maintain on a timely basis. Unfortunately the user must enter the condition criteria, I am sure there must be more I can add to the sanatize method? and does quoting the column name make it safe? (my limited testing seems to think so). an example built condition would be "AND upper(brandloaded.make) like 'O%' and upper(brandloaded.make) not like 'OTHERBRAND'" ... Any help or suggestions are appreciated. Public Function GetCondition() As String Dim sb As New Text.StringBuilder 'put quote around the table name in an attempt to prevent some sql injection 'http://www.postgresql.org/docs/8.2/static/sql-syntax-lexical.html sb.AppendFormat(" {0} ""{1}"" ", _LogicOperator.ToString, _FieldName) Select Case _ConditionOperator Case ConditionOperatorOptions.Equals sb.Append(" = ") ... End Select sb.AppendFormat(" {0} ", Me.UniqueParameterName) 'for parameter Return Me.Sanitize(sb) End Function Private Function Sanitize(ByVal sb As Text.StringBuilder) As String 'compare against a similar blacklist mentioned here: http://forums.asp.net/t/1254125.aspx sb.Replace(";", "") sb.Replace("'", "") sb.Replace("\", "") sb.Replace(Chr(8), "") Return sb.ToString End Function Public ReadOnly Property UniqueParameterName() As String Get Return String.Concat(":" _UniqueIdentifier) End Get End Property

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• Design Technique: How to design a complex system for processing orders, products and units.

  - by Shyam

  Hi, Programming is fun: I learned that by trying out simple challenges, reading up some books and following some tutorials. I am able to grasp the concepts of writing with OO (I do so in Ruby), and write a bit of code myself. What bugs me though is that I feel re-inventing the wheel: I haven't followed an education or found a book (a free one that is) that explains me the why's instead of the how's, and I've learned from the A-team that it is the plan that makes it come together. So, armed with my nuby Ruby skills, I decided I wanted to program a virtual store. I figured out the following: My virtual Store will have: Products and Services Inventories Orders and Shipping Customers Now this isn't complex at all. With the help of some cool tools (CMapTools), I drew out some concepts, but quickly enough (thanks to my inferior experience in designing), my design started to bite me. My very first product-line were virtual "laptops". So, I created a class (Ruby): class Product attr_accessor :name, :price def initialize(name, price) @name = name @price = price end end which can be instantiated by doing (IRb) x = Product.new("Banana Pro", 250) Since I want my virtual customers to be able to purchase more than one product, or various types, I figured out I needed some kind of "Order" mechanism. class Order def initialize(order_no) @order_no = order_no @line_items = [] end def add_product(myproduct) @line_items << myproduct end def show_order() puts @order_no @line_items.each do |x| puts x.name.to_s + "\t" + x.price.to_s end end end that can be instantiated by doing (IRb) z = Order.new(1234) z.add_product(x) z.show_order Splendid, I have now a very simple ordering system that allows me to add products to an order. But, here comes my real question. What if I have three models of my product (economy, business, showoff)? Or have my products be composed out of separate units (bigger screen, nicer keyboard, different OS)? Surely I could make them three separate products, or add complexity to my product class, but I am looking for are best practices to design a flexible product object that can be used in the real world, to facilitate a complex system. My apologies if my grammar and my spelling are with error, as english is not my first language and I took the time to check as far I could understand and translate properly! Thank you for your answers, comments and feedback!

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• PDF Report generation

  - by IniTech

  EDIT : I completed this project using ABCpdf. For anyone interested, I love this product and their support is A+. Everything I listed as a 'Con' for the HTML - PDF solution was easily doable in ABCpdf. I've been charged with creating a data driven pdf report. After reviewing the plethora of options, I have narrowed it down to 2. I need you all to to help me decide, or offer alternatives I haven't considered. Here are the requirements: 100% Data driven Eventually PDF (a stop in HTML is fine, so long as it is converted) Can be run with multiple sets of data (the layout is always the same, the data is variable) Contains normal analysis-style copy (saved in DB with html markup) Contains tables (data for tables is generated at run-time) Header/Page # on each page Table of Contents .NET (VB or C#) Done quickly Now, because of the fact that the report is going to be generated with multiple sets of data, I don't think a stamped pdf template will work since I won't know how long or how many pages a certain piece of the report could require. So, I think my best options are: Programmatic creation using an iText-like solution. Generate in HTML and convert to PDF using a third-party application (ABCPdf is the tool I have played with so far) Both solutions have their pro's and con's. Programmatic solution: Pros: Flexible Easy page numbering/page header/table of contents Free Cons: Time consuming (to write a layer on top of iText to do what I need and keep maintainable) Since the copy is already stored in the db with html markup, I would have to parse through the data before I place it into the pdf, ensuring I don't have to break the paragraph into chunks so I can apply bold, italic, underline, etc. to specific phrases. This seems like a huge PITA, and I hope I am wrong about that assumption. HTML - PDF Pros: Easy to generate from db (no parsing necessary) Many tools for conversion Uses technology I am already familiar with Built-in "Print Preview" - not a req, but nice Cons: (Edited after project completion. All of my assumptions were incorrect and ABCpdf is awesome) 1. Almost impossible to generate page headers - Not True 2. Very difficult to generate page numbers Not True 3. Nearly impossible to generate table of contents Not True 4. (Cross-browser support isn't a con; Since its internal, I can dictate what browser to use) 5. Conversion tool quirks - may not convert exactly as rendered in browser Not True 6. Overall, I think it would be very hard to format the HTML exactly as I would want it to appear/convert to PDF. Not True That's it - I need the communitys help in deciding which way I should go. I might be wrong about some of my Pro/Con assumptions. If I am, please tell me. All thoughts and suggestions are welcome and appreciated. Thanks

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• Implementing a logging library in .NET with a database as the storage medium

  - by Dave

  I'm just starting to work on a logging library that everyone can use to keep track of any sort of system information while the user is running our application. The simplest example so far is to track Info, Warnings, and Errors. I want all plugins to be able to use this feature, but since each developer might have a different idea of what's important to report, I want to keep this as generic as possible. In the C++ world, I would normally use something like a stl::pair<string,string> to act as a key value pair structure, and have a stl::list of these to act as a "row" in the log. The log cache would then be a list<list<pair<string,string>>> (ugh!). This way, the developers can use a const string key like INFO, WARNING, ERROR to have a consistent naming for a column in the database (for SELECTing specific types of information). I'd like the database to be able to deal with any number of distinct column names. For example, John might have an INFO row with a column called USER, and Bill might have an INFO row with a column called FILENAME. I want the log viewer to be able to display all information, and if one report doesn't have a value for INFO / FILENAME, those fields should just appear blank. So one option is to use List<List<KeyValuePair<String,String>>, and the another is to have the log library consumer somehow "register" its schema, and then have the database do an ALTER TABLE to handle this situation. Yet another idea is to have a table that's just for key value pairs, with a foreign key that maps the key value pairs back to the original log entry. I obviously don't want logging to bog down the system, so I only lock the log cache to make a copy of the data (and remove the already-copied data), then a background thread will dump the information to the database. My specific questions regarding this are: Do you see any performance issues? In other words, have you ever tried something like this and found that certain things just don't work well in practice? Is there a more .NETish way to implement the key value pairs, other than List<List<KeyValuePair<String,String>>>? Even if there is a way to do #2 better, is the ALTER TABLE idea I proposed above a Bad Thing? Would you recommend multiple databases over a single one? I don't yet have an idea of how frequently the log would get written to, but we ideally would like to have lots of low level information. Perhaps there should be a DB with a fixed schema only for the low level stuff, and then another DB that's more flexible for reporting information back to users.

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• RAD Visual Web Application Creator/ Builder/ Designer for PHP

  - by inhoue

  Hi all, I want to see if any of you know a (free and open source will be ideal) tool/ app that can help build a php web application very quickly without investing too much time on writing codes, preferring drag and drop/ point and click work-flow designer for logic design (see Agile from Outsystems below). Plus, visual designer for the business logic is great since it can help a developer visualize the logic better. There are a lot of GUI builders, form builders out there, but I am looking for one app for the entire web application development process. My goal is to find an application that a team of developers can use together and use the build-in code of the app as much as possible. E.g. the app will provide a modular just for handle user login or a shopping cart; a developer just need to drag and drop the modular to the logic designer and the code will be generated. This way the functionality will be in a module and code will always be standard across developers. So if a new developer get on-board, he will just need to use the system and get up and running quickly. To explain this better: there is a lot php frameworks, e.g. cakephp, CodeIgniter, etc which I can use to help coding, but still I need to create (code) the GUI, writing quite a bit of codes. I am looking for a tool/ app that is a little more high level than those frameworks. Here is 2 examples apps I found during my google search which they have visual logic designer and gui builder in one single app. Also a single click deployment (but I need it to be php apps or at least I can deploy the (php) code to a LAMP/ WAMP server): Wavemaker: for JAVA Agile from Outsystems: for JAVA or .net (This one is really good, with work-flow drag and drop logic designer!) Talend: it is just an ETL tool, but the concept is what I want to bring up. Drag and drop, point and click logic design. Custom code can be added if it is needed, but the drag and drop process already finished the structure and most of the coding of the web app one needs to build. I want to list Adobe Flex, but it is more like a GUI designer + IDE, not exactly what I want to describe here. The drag and drop/ work-flow logic designer is a key for the app. I could go for the CMS route by learning how to extend them, but it is not that flexible for me and is a long learning curve. Anybody came across this type of app before? Or any idea of how can I find those apps? I googled them for long time, I don't see any of them for php and just few (just 2) for Java. Thanks in advance!

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• assign member based on string value

  - by Aperion

  I need start off with code because I am not sure what terminology to use. Lets say I have the following code: class Node { public: void Parse(rapidxml::xml_node<> *node) { for (rapidxml::xml_attribute<> *attr = node->first_attribute(); attr; attr = attr->next_attribute()) { std::stringstream converter; converter << attr->value(); if( !strcmp(attr->name(), "x") ) converter >> x; else if( !strcmp(attr->name(),"y") ) converter >> y; else if( !strcmp(attr->name(), "z") ) converter >> z; } } private: float x; float y; float z; }; What I can't stand is the repetition of if( !strcmp(attr-name(), "x") ) converter x; I feel that this is error prone and monotonous, but I cannot think of another way to map a string value to a member assignment. What are some other approaches one can take to avoid code such as this? The only other possible alternative I could think of was to use a hashmap, but that runs into problems with callbacks This is the best I could up with but it's not as flexible as I'd like: class Node { Node() : x(0.0f), y(0.0f), z(0.0f) { assignmentMap["x"] = &x; assignmentMap["y"] = &y; assignmentMap["z"] = &z; } public: void Parse(rapidxml::xml_node<> *node) { for (rapidxml::xml_attribute<> *attr = node->first_attribute(); attr; attr = attr->next_attribute()) { if( !attr->name() ) continue; std::stringstream converter; converter << attr->value(); converter >> *assignmentMap[attr->name()]; } } private: float x; float y; float z; std::map<std::string, float*> assignmentMap; };

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• Log4j: Issues about the FallbackErrorHandler

  - by rdogpink

  I am working on a client-server-application and wanted to implement a flexible Loggingframework, so I chose log4j, which doesn´t really evolve anymore, but it is still handy framework. Because the Logging happens along the network, i wanted a solution for the case, that the network drive isn´t available, so the Logger has to change its destination file(s). Now I wanted to use the FallbackErrorHandler (configured with a XML-File) from the Log4j-library and the implementation worked: When my network drive isn´t available, it switches to a local Logfile, so no logging should be lost. But I headded two problems since yesterday and couldn´t figure or find out, how to solve it. No return to initial Logging Configuration: When the network drive is on again and the Logger could write to the old destinations, log4j still logs at the local drive and I can´t figure out, how to notify the original (primary) Logger to start again. I also tried to attach a second Appender to the ErrorHandler, which should mirror the failed primary Logger, that it tries to write on the network destination and when the network is on again, it logs in both files, on the local and on the network drive. But unfortunately it didn´t work out, I only got a failure message that the ErrorHandler-content doesn´t fit. log4j:WARN The content of element type "errorHandler" must match "(param*,root-ref?,logger-ref*,appender-ref?)". This is the responsible code. <appender name="TraceAppender" class="org.apache.log4j.DailyRollingFileAppender"> <!-- The second appender-ref "TestAppender" leads to the error. --> <errorHandler class="org.apache.log4j.varia.FallbackErrorHandler"> <logger-ref ref="com.idoh"/> <appender-ref ref="TraceFallbackAppender"/> <appender-ref ref="TestAppender"/> </errorHandler> <param name="datePattern" value=".yyyy-MM-dd" /> <param name="file" value="logs/Trace.txt" /> <layout class="org.apache.log4j.PatternLayout"> <param name="ConversionPattern" value="%-6r %d{HH:mm:ss,SSS} [%t] %-5p - %m%n"/> </layout> </appender> So, how could I trigger log4j to reset to initial configuration or hold a second appender parallel to the "Local-Logger". My Application should work by itself and shouldn´t have to be restarted often. First Error message is swallowed: I recognized, that the first message, which leads to the switching between the primary logger and the FallbackErrorHandler (for example a logging-request to a readonly-File), is swallowed, so neither the primary logger logs it (because it can´t) nor the backup-Logger knows what it missed. So anybody else ran in this problem and could solve it? Or has any suggestions?

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• Patterns for dynamic CMS components (event driven?)

  - by CitrusTree

  Sorry my title is not great, this is my first real punt at moving 100% to OO as I've been procedural for more years than I can remember. I'm finding it hard to understand if what I'm trying to do is possible. Depending on people's thoughts on the 2 following points, I'll go down that route. The CMS I'm putting together is quote small, however focuses very much on different types of content. I could easily use Drupal which I'm very comfortable with, but I want to give myself a really good reasons to move myself into design patterns / OO-PHP 1) I have created a base 'content' class which I wish to be able to extend to handle different types of content. The base class, for example, handles HTML content, and extensions might handle XML or PDF output instead. On the other hand, at some point I may wish to extend the base class for a given project completely. I.e. if class 'content-v2' extended class 'content' for that site, any calls to that class should actually call 'content-v2' instead. Is that possible? If the code instantiates an object of type 'content' - I actually want it to instantiate one of type 'content-v2'... I can see how to do it using inheritance, but that appears to involve referring to the class explicitly, I can't see how to link the class I want it to use instead dynamically. 2) Secondly, the way I'm building this at the moment is horrible, I'm not happy with it. It feels very linear indeed - i.e. get session details get content build navigation theme page publish. To do this all the objects are called 1-by-1 which is all very static. I'd like it to be more dynamic so that I can add to it at a later date (very closely related to first question). Is there a way that instead of my orchestrator class calling all the other classes 1-by-1, then building the whole thing up at the end, that instead each of the other classes can 'listen' for specific events, then at the applicable point jump in and do their but? That way the orchestrator class would not need to know what other classes were required, and call them 1-by-1. Sorry if I've got this all twisted in my head. I'm trying to build this so it's really flexible.

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• How do you programmatically set a Style on a View?

  - by Greg

  I would like to do something like this: <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_cotent" style="@style/SubmitButtonType" /> But in code The xml approach works fine provided that SubmitButtonType is defined. Now what I assume happens is that the appt parser runs through this xml, generates an AttributeSet. That AttributeSet when passed to context/theme#obtainStyledAttributes() will have the style ref mask anything that is not written inline in this tag. Great that's fine! Now how do we do this programmatically. Button, as well as other View types, has a constructor that has the form: <Widget>(Context context, AttributeSet set, int defStyle). So I thought this would work. Button button = new Button(context, null, R.style.SubmitButtonType); However, I am finding that defStyle is badly documented as it really should be written to be a resourceId to an attribute (from R.attrs) that will be passed to obtainStyledAttributes() as the attribute resource, and not the style resource. After looking at the code, all the view implementations seem to pass 0 as the styleRef. I don't see the harm in having it passed as both the attr and the style resource (more flexible and negligible overhead) However I might be approaching this all wrong. How do you do this in code then other than by setting each individual element of the style to the specific widget you want to style (only possible by looking a the code to see what param maps to which method or set of methods). The only way I have found to do this is: <declare-styleable> <attr name="totallyAdhoc_attribute_just_for_this_case" format="reference"> </declare-styleable> <style name="MyAlreadyExistantTheme" > ... ... <item name="totallyAdhoc_attribute_just_for_this_case">@style/SubmitButtonType</item> </style> And instead of passing R.style.SubmitButtonType as defStyle, I pass the new R.attr.totallyAdhoc_attribute_just_for_this_case. Button button = new Button(context, null, R.attr.totallyAdhoc_attribute_just_for_this_case); This works but sounds way too complicated.

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• Dynamically loading modules in Python (+ threading question)

  - by morpheous

  I am writing a Python package which reads the list of modules (along with ancillary data) from a configuration file. I then want to iterate through each of the dynamically loaded modules and invoke a do_work() function in it which will spawn a new thread, so that the code runs in a separate thread. At the moment, I am importing the list of all known modules at the beginning of my main script - this is a nasty hack I feel, and is not very flexible, as well as being a maintenance pain. This is the function that spawns the threads. I will like to modify it to dynamically load the module when it is encountered. The key in the dictionary is the name of the module containing the code: def do_work(work_info): for (worker, dataset) in work_info.items(): #import the module defined by variable worker here... t = threading.Thread(target=worker.do_work, args=[dataset]) # I'll NOT dameonize since spawned children need to clean up on shutdown # Since the threads will be holding resources #t.daemon = True t.start() Question 1 When I call the function in my script (as written above), I get the following error: AttributeError: 'str' object has no attribute 'do_work' Which makes sense, since the dictionary key is a string (name of the module to be imported). When I add the statement: import worker before spawning the thread, I get the error: ImportError: No module named worker This is strange, since the variable name rather than the value it holds are being used - when I print the variable, I get the value (as I expect) whats going on? Question 2 As I mentioned in the comments section, I realize that the do_work() function written in the spawned children needs to cleanup after itself. My understanding is to write a clean_up function that is called when do_work() has completed successfully, or an unhandled exception is caught - is there anything more I need to do to ensure resources don't leak or leave the OS in an unstable state? Question 3 If I comment out the t.daemon flag statement, will the code stil run ASYNCHRONOUSLY?. The work carried out by the spawned children are pretty intensive, and I don't want to have to be waiting for one child to finish before spawning another child. BTW, I am aware that threading in Python is in reality, a kind of time sharing/slicing - thats ok Lastly is there a better (more Pythonic) way of doing what I'm trying to do?

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• Using Selenium-IDE with a rich Javascript application?

  - by Darien

  Problem At my workplace, we're trying to find the best way to create automated-tests for an almost wholly javascript-driven intranet application. Right now we're stuck trying to find a good tradeoff between: Application code in reusable and nest-able GUI components. Tests which are easily created by the testing team Tests which can be recorded once and then automated Tests which do not break after small cosmetic changes to the site XPath expressions (or other possible expressions, like jQuery selectors) naively generated from Selenium-IDE are often non-repeatable and very fragile. Conversely, having the JS code generate special unique ID values for every important DOM-element on the page... well, that is its own headache, complicated by re-usable GUI components and IDs needing to be consistent when the test is re-run. What successes have other people had with this kind of thing? How do you do automated application-level testing of a rich JS interface? Limitations We are using JavascriptMVC 2.0, hopefully 3.0 soon so that we can upgrade to jQuery 1.4.x. The test-making folks are mostly trained to use Selenium IDE to directly record things. The test leads would prefer a page-unique HTML ID on each clickable element on the page... Training the testers to write or alter special expressions (such as telling them which HTML class-names are important branching points) is a no-go. We try to make re-usable javascript components, but this means very few GUI components can treat themselves (or what they contain) as unique. Some of our components already use HTML ID values in their operation. I'd like to avoid doing this anyway, but it complicates the idea of ID-based testing. It may be possible to add custom facilities (like a locator-builder or new locator method) to the Selenium-IDE installation testers use. Almost everything that goes on occurs within a single "page load" from a conventional browser perspective, even when items are saved Current thoughts I'm considering a system where a custom locator-builder (javascript code) for Selenium-IDE will talk with our application code as the tester is recording. In this way, our application becomes partially responsible for generating a mostly-flexible expression (XPath or jQuery) for any given DOM element. While this can avoid requiring more training for testers, I worry it may be over-thinking things.

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• Passing arguments between classes - use public properties or pass a properties class as argument?

  - by devoured elysium

  So let's assume I have a class named ABC that will have a list of Point objects. I need to make some drawing logic with them. Each one of those Point objects will have a Draw() method that will be called by the ABC class. The Draw() method code will need info from ABC class. I can only see two ways to make them have this info: Having Abc class make public some properties that would allow draw() to make its decisions. Having Abc class pass to draw() a class full of properties. The properties in both cases would be the same, my question is what is preferred in this case. Maybe the second approach is more flexible? Maybe not? I don't see here a clear winner, but that sure has more to do with my inexperience than any other thing. If there are other good approaches, feel free to share them. Here are both cases: class Abc1 { public property a; public property b; public property c; ... public property z; public void method1(); ... public void methodn(); } and here is approach 2: class Abc2 { //here we make take down all properties public void method1(); ... public void methodn(); } class Abc2MethodArgs { //and we put them here. this class will be passed as argument to //Point's draw() method! public property a; public property b; public property c; ... public property z; } Also, if there are any "formal" names for these two approaches, I'd like to know them so I can better choose the tags/thread name, so it's more useful for searching purposes. That or feel free to edit them.

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• JPA - Can I create an Entity class, using an @DiscriminatorValue, that doesn't have its own table?

  - by DaveyDaveDave

  Hi - this is potentially a bit complex, so I'll do my best to describe my situation - it's also my first post here, so please forgive formatting mistakes, etc! I'm using JPA with joined inheritance and a database structure that looks like: ACTION --------- ACTION_ID ACTION_MAPPING_ID ACTION_TYPE DELIVERY_CHANNEL_ACTION -------------------------- ACTION_ID CHANNEL_ID OVERRIDE_ADDRESS_ACTION -------------------------- ACTION_ID (various fields specific to this action type) So, in plain English, I have multiple different types of action, all share an ACTION_MAPPING, which is referenced from the 'parent' ACTION table. DELIVERY_CHANNEL_ACTION and OVERRIDE_ADDRESS_ACTION both have extra, supplementary data of their own, and are mapped to ACTION with a FK. Real-world, I also have a 'suppress' action, but this doesn't have any supplementary data of its own, so it doesn't have a corresponding table - all it needs is an ACTION_MAPPING, which is stored in the ACTION table. Hopefully you're with me so far... I'm creating a new project from scratch, so am pretty flexible in what I can do, but obviously would like to get it right from the outset! My current implementation, which works, has three entities loosely defined as follows: @Entity @Table(name="ACTION") @Inheritance(strategy=InheritanceType.JOINED) @DiscriminatorValue("SUPPRESS") public class Action @Entity @Table(name="DELIVERY_CHANNEL_ACTION") @DiscriminatorValue("DELIVERY_CHANNEL") public class DeliveryChannelAction extends Action @Entity @Table(name="OVERRIDE_ADDRESS_ACTION") @DiscriminatorValue("OVERRIDE_ADDRESS") public class OverrideAddressAction extends Action That is - I have a concrete base class, Action, with a Joined inheritance strategy. DeliveryChannelAction and OverrideAddressAction both extend Action. What feels wrong here though, is that my Action class is the base class for these two actions, but also forms the concrete implementation for the suppress action. For the time being this works, but at some point more actions are likely to be added, and there's every chance that some of them will, like SUPPRESS, have no supplementary data, which will start to get difficult! So... what I would like to do, in the object model world, is to have Action be abstract, and create a SuppressAction class, which is empty apart from having a @DiscriminatorValue("SUPPRESS"). I've tried doing exactly what is described above, so, changing Action to: @Entity @Table(name="ACTION") @Inheritance(strategy=InheritanceType.JOINED) public abstract class Action and creating: @DiscriminatorValue("SUPPRESS") public class SuppressAction extends Action but no luck - it seems to work fine for DeliveryChannelAction and OverrideAddressAction, but when I try to create a SuppressAction and persist it, I get: java.lang.IllegalArgumentException: Object: com.mypackage.SuppressAction[actionId=null] is not a known entity type. at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:4147) at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:368) at com.mypackage.test.util.EntityTestUtil.createSuppressAction(EntityTestUtil.java:672) at com.mypackage.entities.ActionTest.testCRUDAction(ActionTest.java:27) which I assume is down to the fact that SuppressAction isn't registered as an entity, but I don't know how I can do that, given that it doesn't have an associated table. Any pointers, either complete answers or hints for things to Google (I'm out of ideas!), most welcome :) EDIT: to correct my stacktrace.

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