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  • Can't Set Crystal Report Selection Formula Programatically

    - by eidylon
    Hello all, first, I can't stand Crystal! Okay, that's off my chest... Now, we have an old VB6 app we maintain for a client, which uses the Crystal Automation library to programatically change the record selection formulas in a bunch of Crystal Reports 8.5 reports. There are two reports which are ALMOST identical. I had to change them recently to add another field from another table. When I added the table in to the reports though, while it added it in the visual designer, it did not add it in the FROM clause of the SQL statement. So, I manually edited the SQL statement to add in the additional join. KO, works great. If i run the reports in Crystal preview mode, they work exactly as expected. Now, the users went to test the changes from within the VB app. One of the reports works fine and dandy. The other report however, is failing to set the selection formula as expected. The code sets the selection formulas using the function PESetSelectionFormula. I verified that the string being passed in to the function as the new selection formula is correct via a step-through examination of the variables. The call to PESetSelectionFormula seems to be working okay, and is returning a value of 1, which as near as I can find anywhere indicates success. (The other report, which is working fine from code is also returning 1.) However, the report is failing with an error: Error Code: 534 - Error detected by database DLL. The code, for debugging purposes dumps out the SQL string currently being used by the report. The SQL coming out of the report is: SELECT ... FROM ... WHERE ORDER BY ... As you can see, the WHERE clause is blank, which I would imagine is why the database DLL is upchucking on this statement. I don't understand why the automation library is not setting the WHERE clause even though the call to PESetSelectionFormula is being passed a valid string and is returning success. I thought perhaps it was because I had manually edited the SQL in the report to add the table it wasn't adding, but I did the same thing in the other nearly identical report, and that one is working fine. Anyone have any ideas why PESetSelectionFormula might report success but not actually do anything? P.S. I have already tried doing a Database Verify Database from the menus, and that said the report was all up to date and did not help at all.

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  • Need help receiving ByteArray data

    - by k80sg
    Hi folks, I am trying to receive byte array data from a machine. It sends out 3 different types of data structure each with different number of fields which consist of mostly int and a few floats, and byte sizes, the first being 320 bytes, 420 for the second type and 560 for the third. When the sending program is launched, it fires all 3 types of data simultaneouly with an interval of 1 sec. Example: Sending order: Pack1 - 320 bytes 1 sec later Pack2 - 420 bytes 1 sec later Pack3 - 560 bytes 1 sec later Pack1 - 320 bytes ... .. . How do I check the incoming byte size before passing it to: byte[] handsize = new byte[bytesize]; as the data I receive are all out of order, for instance using the following the read all int: System.out.println("Reading data in int format:" + " " + datainput.readInt()); I get many different sets of values whenever I run my prog although with some valid field data but they are all over the place. I am not too sure how exactly should I do it but I tried the following and apparently my data fields are not receiving in correct sequence: BufferedInputStream bais = new BufferedInputStream(requestSocket.getInputStream()); DataInputStream datainput = new DataInputStream(bais); byte[] handsize = new byte[560]; datainput.readFully(handsize); int n = 0; int intByte[] = new int[140]; for (int i = 0; i < 140 ; i++) { System.out.println("Reading data in int format:" + " " + datainput.readInt()); intByte[n] = datainput.readInt(); n = n + 1; System.out.println("The value in array is:" + intByte[0]); System.out.println("The value in array is:" + intByte[1]); System.out.println("The value in array is:" + intByte[2]); System.out.println("The value in array is:" + intByte[3]); Also from the above code, the order of the values printed out with System.out.println("Reading data in int format:" + " " + datainput.readInt()); and System.out.println("The value in array is:" + intByte[0]); System.out.println("The value in array is:" + intByte[1]); are different. Any help will be appreciated. Thanks

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  • Does my fat-client application belong in the MVC pattern?

    - by boatingcow
    The web-based application I’m currently working on is growing arms and legs! It’s basically an administration system which helps users to keep track of bookings, user accounts, invoicing etc. It can also be accessed via a couple of different websites using a fairly crude API. The fat-client design loosely follows the MVC pattern (or perhaps MVP) with a php/MySQL backend, Front Controller, several dissimilar Page Controllers, a liberal smattering of object-oriented and procedural Models, a confusing bunch of Views and templates, some JavaScripts, CSS files and Flash objects. The programmer in me is a big fan of the principle of “Separation of Concerns” and on that note, I’m currently trying to figure out the best way to separate and combine the various concerns as the project grows and more people contribute to it. The problem we’re facing is that although JavaScript (or Flash with ActionScript) is normally written with the template, hence part of the View and decoupled from the Controller and Model, we find that it actually encompasses the entire MVC pattern... Swap an image with an onmouseover event - that’s Behaviour. Render a datagrid - we’re manipulating the View. Send the result of reordering a list via AJAX - now we’re in Control. Check a form field to see if an email address is in a valid format - we’re consulting the Model. Is it wise to let the database people write up the validation Model with jQuery? Can the php programmers write the necessary Control structures in JavaScript? Can the web designers really write a functional AJAX form for their View? Should there be a JavaScript overlord for every project? If the MVC pattern could be applied to the people instead of the code, we would end up with this: Model - the database boffins - “SELECT * FROM mind WHERE interested IS NULL” Control - pesky programmers - “class Something extends NothingAbstractClass{…}” View - traditionally the domain of the graphic/web designer - “” …and a new layer: Behaviour - interaction and feedback designer - “CSS3 is the new black…” So, we’re refactoring and I’d like to stick to best practice design, but I’m not sure how to proceed. I don’t want to reinvent the wheel, so would anyone have any hints or tips as to what pattern I should be looking at or any code samples from someone who’s already done the dirty work? As the programmer guy, how can I rewrite the app for backend and front end whilst keeping the two separate? And before you ask, yes I’ve looked at Zend, CodeIgnitor, Symfony, etc., and no, they don’t seem to cross the boundary between server logic and client logic!

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  • how can i overriding the inbound message validation with cxf?

    - by user1648330
    when i input a non-numeric content to a Integer types of field, i have got a fault mesasge 'Not a number: 0.012A'. How to do ability to in prior to the Unmarshal for schema validation and output custom error messages? I used cxf 2.6.1 and also configuration with <entry key="schema-validation-enabled" value="true" ></entry> in cxf-spring.xml. java.lang.RuntimeException: Not a number: 0.012A at com.jiemai.jmservice.handlers.ValidationEventHandler.handleEvent(ValidationEventHandler.java:19) at org.apache.cxf.jaxb.io.DataReaderImpl$WSUIDValidationHandler.handleEvent(DataReaderImpl.java:78) at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.handleEvent(UnmarshallingContext.java:655) at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.handleError(UnmarshallingContext.java:691) at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.handleError(UnmarshallingContext.java:687) at com.sun.xml.bind.v2.runtime.unmarshaller.Loader.handleParseConversionException(Loader.java:271) at com.sun.xml.bind.v2.runtime.unmarshaller.LeafPropertyLoader.text(LeafPropertyLoader.java:69) at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.text(UnmarshallingContext.java:514) at com.sun.xml.bind.v2.runtime.unmarshaller.InterningXmlVisitor.text(InterningXmlVisitor.java:93) at com.sun.xml.bind.v2.runtime.unmarshaller.StAXStreamConnector.processText(StAXStreamConnector.java:338) at com.sun.xml.bind.v2.runtime.unmarshaller.StAXStreamConnector.handleEndElement(StAXStreamConnector.java:216) at com.sun.xml.bind.v2.runtime.unmarshaller.StAXStreamConnector.bridge(StAXStreamConnector.java:185) at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:370) at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:349) at org.apache.cxf.jaxb.JAXBEncoderDecoder.doUnmarshal(JAXBEncoderDecoder.java:784) at org.apache.cxf.jaxb.JAXBEncoderDecoder.access$100(JAXBEncoderDecoder.java:97) at org.apache.cxf.jaxb.JAXBEncoderDecoder$1.run(JAXBEncoderDecoder.java:812) at java.security.AccessController.doPrivileged(Native Method) at org.apache.cxf.jaxb.JAXBEncoderDecoder.unmarshall(JAXBEncoderDecoder.java:810) at org.apache.cxf.jaxb.JAXBEncoderDecoder.unmarshall(JAXBEncoderDecoder.java:644) at org.apache.cxf.jaxb.io.DataReaderImpl.read(DataReaderImpl.java:157) at org.apache.cxf.interceptor.DocLiteralInInterceptor.handleMessage(DocLiteralInInterceptor.java:108) at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:262) at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:122) at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:211) at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:213) at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:193) at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:129) at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:187) at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:110) at javax.servlet.http.HttpServlet.service(HttpServlet.java:710) at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:166) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Unknown Source)

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  • Set default form textfield value (webbrowser control)

    - by Khou
    Hi I would like my application to load a webpage and set default the form textfield value a predefine value. Requirements: -The application is a windows form, it is to use the web browser control, to load a web page. -Textfield values are define by within the application. -When textfield on the webpage matches the applications predefined elements, the predefine fixed value is set and can not be changed by the end user. Example If my application defines element "FirstName" equal to value "John", the text field for value for element "FirstName" will always equal "John" and this value can not be changed by the end user. Below is html/javascript code to perform this functionality, now how do I implement this in a windows form? (without having to modify the loaded webpage source code (if possible). HTML <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <head> <title>page title</title> <script script type="text/javascript" src="demo1.js"></script> </head> <body onload="def(document.someform, 'name', 'my default name value');"> <h2 style="color: #8e9182">test form title</h2> <form name="someform" id="someform_frm" action="#"> <table cellspacing="1"> <tr><td><label for="name">NameX: </label></td><td><input type="text" size="30" maxlength="155" name="name" onchange="def(document.someform, 'name', 'my default name value');"></td></tr> <tr><td><label for="name2">NameY: </label></td><td><input type="text" size="30" maxlength="155" name="name2"></td></tr> <tr><td colspan="2"><input type="button" name="submit" value="Submit" onclick="showFormData(this.form);" ></td></table> </form> </body> </html> JAVASCRIPT function def(oForm, element_name, def_txt) { oForm.elements[element_name].value = def_txt; }

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  • Managing a difficult manager

    - by griegs
    I have a situation here at work. We are redeveloping our basic architecture across the entire company. Currently we have the following hierarchy; SQL Database <= Stored Procs not allowed. nHibernate Classes to convert nHibernate into our own objects Web Service <= for all external and [internal] calls. Class to take objects from Web Service and back into our own objects and then… Normal nTier application architecture such as Data Transformation Layer, Business layer etc. Within the database, when we are writing a hierarchy of objects to the database, say for example; Order Person Details Address Product Other We need to serialise the object and save it, in its entirety, to an image field in a table. No attempt has been made to store the objects in their own tables so that we can do useful stuff like report on it. This is an architecture that was implemented [way] before I started and as you can probably appreciate, is a complete nightmare not to mention slow as a wet weekend. We’re not even allowed to have stored procs within SQL server because in my boss’s last job they had a hundred or so and he had a problem identifying them all so therefore all stored procs are the devil. Now the same person that developed the above architecture has developed the new one. It came as no surprise that he’s essentially used the same framework only now it’s using DotNet 3.5 with interfaces and generics. We still have to go through web services, still need to serialise (everything), still not allowed to use stored procs etc. In fact, we’re only barely able to bang two rocks together here. He says to us that the framework is open for discussion but when you discuss it, unless you approve of his design, you are told flatly “No”. He simply won’t listen to any other suggestions. Even when you show him demo applications of his proposed architecture v’s yours and he can see the speed difference, he still won’t take that on board. So I guess my question is, and I know others have experienced the same things out there, how do I get through to someone like this? How do you convince someone to ditch Web Services for internal calls and applications? How do you demonstrate, and make it stick, that stored procs are a better way to go than ad-hoc sql statements? This is killing me. I don’t want to repeat the mistakes of the past and I certainly don’t want to write code that I know is going to be slow and cumbersome. Help!

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  • From a 3D modeler to an iPhone app - what are best practices?

    - by bonkey
    I am quite new in 3D programming on iPhone and I would like to ask for hints about organizing a work between designers and programmers on that platform. Most of all: what kind of tools, libraries or plugins cooperate the best on both sides. Although I consider the question as looking for general best-practices advice I would like to find a solution for my current situation which I describe further, too. I've already done some research and found following libraries: SIO2 Khronos OpenGL ES 1.x SDK for PowerVR MBX Unity3D Oolong Game Engine I've checked modellers or plugins to them giving output formats readable by those tools: obj2opengl Wavefront OBJ to plain header file converter Blender with SIO2 exporter iphonewavefrontloader Cheetah3D PVRGeoPOD for 3DS / Maya Unfortunately I still have no clear vision how to combine any of that tools to get a desinger's work in an application. I look for a way of getting it in the most possible complete way: models, lights, scenes, textures, maybe some simple animations (but rather no game-like physics), but I still got nothing. And here comes my situation: I would like to find right way to present few (but quite complicated) models from a single scene. The designers mostly use 3DS Max 9, sometimes 10 (which partly prevents using PVRGeoPOD) and are rather reluctant to switch to something else but if there's no other choice I suppose it would be possible. The basic rule I've already found in some places "use Wavefront OBJ" not always works. I haven't got any acceptable results with production files, actually. The only things worked fine were some mere examples. Some of my models did imported incomplete, sometimes exporters hung or generated enormous files not really useful on an iPhone, sometimes enabling textures (with GL_TEXTURE_2D) just crashed an app. I know it might be a problem with too complicated models or my mistakes coming from inexeperience but I am not able to find any guidelines for that process to have streamlined cooperation with designers. I am even willing to write some things from scratch in pure OpenGL-ES if it's necessary, but I would like to avoid what might be avoided and get the most from the model files. The best would be the effect I saw on some SIO2 tutorials: export, build & go. But at that moment I've got only "import, wrong", "import, where are textures?", "import, that almost looks fine, export, hang" and so on... Is it really so much frustrating or I am just missed something obvious? Can anybody share his/her experience in that field and tell what kind of software uses for "making things happen"?

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

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

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  • Windows forms application blocks after station lock

    - by Silviu
    We're having a serious issue at work. We've discovered that after the station where the client was running is locked/unlocked the client is blocked. No repaint. So the UI thread is blocked with something. Looking at the callstack of the UI thread (thread 0) using windbg we see that a UserPreferenceChanged event gets raised. It is marshalled through a WindowsFormsSynchronizationContext using it's controlToSend field to the UI. It gets blocked by a call to the marshalling control. The method called is MarshaledInvoke it builds a ThreadMethodEntry entry = new ThreadMethodEntry(caller, method, args, synchronous, executionContext); This entry is supposed to do the magic. The call is a synchronous call and because of that (still in the MarshaledInvoke of the Control class) the wait call is reached: if (!entry.IsCompleted) { this.WaitForWaitHandle(entry.AsyncWaitHandle); } The last thing that i can see on the stack is the WaitOne called on the previously mentioned AsyncWaitHandle. This is very annoying because having just the callstack of the runtime and not one of our methods being invoked we cannot really point to a bug in our code. I might be wrong, but I'm guessing that the marshaling control is not "marshaling" to the ui thread. But another one...i don't really know which one because the other threads are being used by us and are blocked...maybe this is the issue. But none of the other threads are running a message loop. This is very annoying. We had some issues in the past with marshaling controls to the right ui thread. That is because the first form that is constructed is a splash form. Which is not the main form. We used to use the main form to marshal call to the ui thread. But from time to time some calls would go to a non ui thread and some grids would broke with a big red X on them. I fixed this by creating a specific class: public class WindowsFormsSynchronizer { private static readonly WindowsFormsSynchronizationContext = new WindowsFormsSynchronizationContext(); //Methods are following that would build the same interface of the synchronization context. } This class gets build as one of the first objects in the first form being constructed. We've noticed some other strange thing. Looking at the heap there are 7 WindowsFormsSynchronizationContext objects. 6 of these have the same instance of controlToSend, and the other one has some different instance of controlToSend. This last one is the one that should marshal the calls to the UI. I don't have any other idea...maybe some of you guys had this same issue?

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  • Delphi: how to set the length of a RTTI-accessed dynamic array using DynArraySetLength?

    - by conciliator
    I'd like to set the length of a dynamic array, as suggested in this post. I have two classes TMyClass and the related TChildClass defined as TChildClass = class private FField1: string; FField2: string; end; TMyClass = class private FField1: TChildClass; FField2: Array of TChildClass; end; The array augmentation is implemented as var RContext: TRttiContext; RType: TRttiType; Val: TValue; // Contains the TMyClass instance RField: TRttiField; // A field in the TMyClass instance RElementType: TRttiType; // The kind of elements in the dyn array DynArr: TRttiDynamicArrayType; Value: TValue; // Holding an instance as referenced by an array element ArrPointer: Pointer; ArrValue: TValue; ArrLength: LongInt; i: integer; begin RContext := TRTTIContext.Create; try RType := RContext.GetType(TMyClass.ClassInfo); Val := RType.GetMethod('Create').Invoke(RType.AsInstance.MetaclassType, []); RField := RType.GetField('FField2'); if (RField.FieldType is TRttiDynamicArrayType) then begin DynArr := (RField.FieldType as TRttiDynamicArrayType); RElementType := DynArr.ElementType; // Set the new length of the array ArrValue := RField.GetValue(Val.AsObject); ArrLength := 3; // Three seems like a nice number ArrPointer := ArrValue.GetReferenceToRawData; DynArraySetLength(ArrPointer, ArrValue.TypeInfo, 1, @ArrLength); { TODO : Fix 'Index out of bounds' } WriteLn(ArrValue.IsArray, ' ', ArrValue.GetArrayLength); if RElementType.IsInstance then begin for i := 0 to ArrLength - 1 do begin Value := RElementType.GetMethod('Create').Invoke(RElementType.AsInstance.MetaclassType, []); ArrValue.SetArrayElement(i, Value); // This is just a test, so let's clean up immediatly Value.Free; end; end; end; ReadLn; Val.AsObject.Free; finally RContext.Free; end; end. Being new to D2010 RTTI, I suspected the error could depend on getting ArrValue from the class instance, but the subsequent WriteLn prints "TRUE", so I've ruled that out. Disappointingly, however, the same WriteLn reports that the size of ArrValue is 0, which is confirmed by the "Index out of bounds"-exception I get when trying to set any of the elements in the array (through ArrValue.SetArrayElement(i, Value);). Do anyone know what I'm doing wrong here? (Or perhaps there is a better way to do this?) TIA!

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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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  • ASP MVC 2: Error with dropdownlist on POST

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

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  • How to use multiple flatpages models in a django app?

    - by the_drow
    I have multiple models that can be converted to flatpages but have to have some extra information (For example I have an about us page but I also have a blog). However I understand that there must be only one flatpages model since the middleware only returns the flatpages instance and does not resolve the child models. What do I have to do? EDIT: It seems I need to change the views. Here's the current code: from django.contrib.flatpages.models import FlatPage from django.template import loader, RequestContext from django.shortcuts import get_object_or_404 from django.http import HttpResponse, HttpResponseRedirect from django.conf import settings from django.core.xheaders import populate_xheaders from django.utils.safestring import mark_safe from django.views.decorators.csrf import csrf_protect DEFAULT_TEMPLATE = 'flatpages/default.html' # This view is called from FlatpageFallbackMiddleware.process_response # when a 404 is raised, which often means CsrfViewMiddleware.process_view # has not been called even if CsrfViewMiddleware is installed. So we need # to use @csrf_protect, in case the template needs {% csrf_token %}. # However, we can't just wrap this view; if no matching flatpage exists, # or a redirect is required for authentication, the 404 needs to be returned # without any CSRF checks. Therefore, we only # CSRF protect the internal implementation. def flatpage(request, url): """ Public interface to the flat page view. Models: `flatpages.flatpages` Templates: Uses the template defined by the ``template_name`` field, or `flatpages/default.html` if template_name is not defined. Context: flatpage `flatpages.flatpages` object """ if not url.endswith('/') and settings.APPEND_SLASH: return HttpResponseRedirect("%s/" % request.path) if not url.startswith('/'): url = "/" + url # Here instead of getting the flat page it needs to find if it has a page with a child model. f = get_object_or_404(FlatPage, url__exact=url, sites__id__exact=settings.SITE_ID) return render_flatpage(request, f) @csrf_protect def render_flatpage(request, f): """ Internal interface to the flat page view. """ # If registration is required for accessing this page, and the user isn't # logged in, redirect to the login page. if f.registration_required and not request.user.is_authenticated(): from django.contrib.auth.views import redirect_to_login return redirect_to_login(request.path) if f.template_name: t = loader.select_template((f.template_name, DEFAULT_TEMPLATE)) else: t = loader.get_template(DEFAULT_TEMPLATE) # To avoid having to always use the "|safe" filter in flatpage templates, # mark the title and content as already safe (since they are raw HTML # content in the first place). f.title = mark_safe(f.title) f.content = mark_safe(f.content) # Here I need to be able to configure what I am passing in the context c = RequestContext(request, { 'flatpage': f, }) response = HttpResponse(t.render(c)) populate_xheaders(request, response, FlatPage, f.id) return response

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  • please explain NHibernate HiLo

    - by Ben
    I'm struggling to get my head round how the HiLo generator works in NHibernate. I've read the explanation here which made things a little clearer. My understanding is that each SessionFactory retrieves the high value from the database. This improves performance because we have access to IDs without hitting the database. The explanation from the above link also states: For instance, supposing you have a "high" sequence with a current value of 35, and the "low" number is in the range 0-1023. Then the client can increment the sequence to 36 (for other clients to be able to generate keys while it's using 35) and know that keys 35/0, 35/1, 35/2, 35/3... 35/1023 are all available. How does this work in a web application as don't I only have one SessionFactory and therefore one hi value. Does this mean that in a disconnected application you can end up with duplicate (low) ids in your entity table? In my tests I used these settings: <id name="Id" unsaved-value="0"> <generator class="hilo"/> </id> I ran a test to save 100 objects. The IDs in my table went from 32768 - 32868. The next hi value was incremented to 2. Then I ran my test again and the Ids were in the range 65536 - 65636. First off, why start at 32768 and not 1, and secondly why the jump from 32868 to 65536? Now I know that my surrogate keys shouldn't have any meaning but we do use them in our application. Why can't I just have them increment nicely like a SQL Server identity field would. Finally can someone give me an explanation of how the max_lo parameter works? Is this the maximum number of low values (entity ids in my head) that can be created against the high value? This is one topic in NHibernate that I have struggled to find documentation for. I read the entire NHibernate in action book and it still doesn't go into how this works in any detail. Thanks Ben

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  • How to limit JTextArea max Rows and Coloums?

    - by Billbo bug
    I am using JTextArea in JScrollPane I want to limit the maximum number of lines possible and the maximum chars in each line. I need that the string will be exactly like on the screen, each line will end with '\n' (if there another line after it) and the user will be able to insert only X lines and Y chars in each line. I tried to limit the lines but i don't know exactly how many lines do i have because of the line wrapping, The line wrapping is starting new line visualy on the screen(because of the width of the JTextArea) but in the string of the component it is really the same line with no '\n' to indicate new line. I do not have an idea how to limit the max chars in each line while typing. There are 2 stages: The typing of the string- keep that the user will not be able to type more then X lines and Y chars in each line. (even if the line wrap only visualy or the user typed '/n') Insert the string to the DB- after cliking 'OK' convert the string that every line will end with "/n" even if the user did not typed it and the line was wrapped only visualy. There are few problems if i will count the chars in the line and insert '/n' in the end of the line, thats why i decided to do it in two stages. In the first stage ehile the user is typing i would rather only limit it visualy and force line wrpping or something similar. Only in the second stage when i save string i will add the '/n' even if the user did not typed it in the end of the lines! Does anyone have an idea? I know that i will have to use DocumentFilter OR StyledDocument. Here is sample code that limit only the lines to 3:(but not the chars in row to 19) private JTextArea textArea ; textArea = new JTextArea(3,19); textArea .setLineWrap(true); textArea .setDocument(new LimitedStyledDocument(3)); JScrollPane scrollPane = new JScrollPane(textArea public class LimitedStyledDocument extends DefaultStyledDocument /** Field maxCharacters */ int maxLines; public LimitedStyledDocument(int maxLines) { maxCharacters = maxLines; } public void insertString(int offs, String str, AttributeSet attribute) throws BadLocationException { Element root = this.getDefaultRootElement(); int lineCount = getLineCount(str); if (lineCount + root.getElementCount() <= maxLines){ super.insertString(offs, str, attribute); } else { Toolkit.getDefaultToolkit().beep(); } } /** * get Line Count * * @param str * @return the count of '\n' in the String */ private int getLineCount(String str){ String tempStr = new String(str); int index; int lineCount = 0; while (tempStr.length() > 0){ index = tempStr.indexOf("\n"); if(index != -1){ lineCount++; tempStr = tempStr.substring(index+1); } else{ break; } } return lineCount; } }

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  • How to use imported css styles in GWT correctly

    - by Eduard Wirch
    Imagine you created the following simple widget with UiBinder: <!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent"> <ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder" xmlns:g="urn:import:com.google.gwt.user.client.ui"> <ui:style type="my.package.Widget1.Widget1Style"> .childWidgetStyle { border-width: 1px; border-style: dotted; } </ui:style> <g:TextArea styleName="{style.childWidgetStyle}"/> </ui:UiBinder> package my.package; // some imports here public class Widget1 extends Composite { private static Widget1UiBinder uiBinder = GWT.create(Widget1UiBinder.class); interface Widget1UiBinder extends UiBinder<Widget, Widget1> { } public interface Widget1Style extends CssResource { String childWidgetStyle(); } @UiField TextArea textArea; public Widget1(String text) { initWidget(uiBinder.createAndBindUi(this)); textArea.setText(text); } } Than you use this simple widget in another (parent) widget you created: <!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent"> <ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder" xmlns:g="urn:import:com.google.gwt.user.client.ui"> <ui:style> .parentWidgetStyle .childWidgetStyle { margin-bottom: 10px; } </ui:style> <g:VerticalPanel ui:field="listPanel" addStyleNames="{style.parentWidgetStyle}" /> </ui:UiBinder> package my.package; // imports go here public class ParentWidget extends Composite { private static ParentWidgetUiBinder uiBinder = GWT.create(ParentWidgetUiBinder.class); interface ParentWidgetUiBinder extends UiBinder<Widget, ParentWidget> { } @UiField VerticalPanel listPanel; public ParentWidget(final String... texts) { initWidget(uiBinder.createAndBindUi(this)); for (final String text : texts) { final Widget1 entry = new Widget1(text); listPanel.add(entry); } } } What you want to achieve is to get some margin between the Widget1 entries in the list using css. But this won't work. Because GWT will obfuscate the css names. And the obfuscated name for .childWidgetStyle in ParentWidget will be different from the .childWidgetStyle in Widget1. The resulting css will look similar to this: .G1unc9fbE { border-style:dotted; border-width:1px; } .G1unc9fbBB .G1unc9fDa { margin-bottom:10px; } So the margin setting wont apply. How do I do this correctly?

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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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  • NSCollectionView draws nothing

    - by PCWiz
    I'm trying to set up an NSCollectionView (I have done this successfully in the past, but for some reason it fails this time). I have a model class called "TestModel", and it has an NSString property that just returns a string (just for testing purposes right now). I then have an NSMutableArray property declaration in my main app delegate class, and to this array I add instances of the TestModel object. I then have an Array Controller that has its Content Array bound the app delegate's NSMutableArray. I can confirm that everything up to here is working fine; NSLogging: [[[arrayController arrangedObjects] objectAtIndex:0] teststring] worked fine. I then have all the appropriate bindings for the collection view set up, (itemPrototype and content), and for the Collection View Item (view). I then have a text field in the collection item view that is bound to Collection View Item.representedObject.teststring. However NOTHING displays in the collection view when I start the app, just a blank white screen. What am I missing? UPDATE: Here is the code I use (requested by wil shipley): // App delegate class @interface AppController : NSObject { NSMutableArray *objectArray; } @property (readwrite, retain) NSMutableArray *objectArray; @end @implementation AppController @synthesize objectArray; - (id)init { if (self = [super init]) { objectArray = [[NSMutableArray alloc] init]; } return self; } - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { TestModel *test = [[[TestModel alloc] initWithString:@"somerandomstring"] autorelease]; if (test) [objectArray addObject:test]; } @end // The model class (TestModel) @interface TestModel : NSObject { NSString *teststring; } @property (readwrite, retain) NSString *teststring; - (id)initWithString:(NSString*)customString; @end @implementation TestModel @synthesize teststring; - (id)initWithString:(NSString*)customString { [self setTeststring:customString]; } - (void)dealloc { [teststring release]; } @end And then like I said the content array of the Array Controller is bound to this "objectArray", and the Content of the NSCollectionView is bound to Array Controller.arrangedObjects. I can verify that the Array Controller has the objects in it by NSLogging [arrayController arrangedObjects], and it returns the correct object. Its just that nothing displays in the NSCollectionView. UPDATE 2: If I log [collectionView content] I get nothing: 2009-10-21 08:02:42.385 CollViewTest[743:a0f] ( ) The problem is probably there. UPDATE 3: As requested here is the Xcode project: http://www.mediafire.com/?mjgdzgjjfzw Its a menubar app, so it has no window. When you build and run the app you'll see a menubar item that says "test", this opens the view that contains the NSCollectionView. Thanks

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  • CellTable + AsyncListViewAdapter<T> + SimplePager<T>, stuck with 'loading' bar when paging

    - by Jaroslav Záruba
    Hi I'm trying to make CellTable, AsyncListViewAdapter<T> and SimplePager<T> working together. I managed to display my data, but whenever I click either "go to start" or "go to end" button I get that 'loading' indicator which stays there till the end of days. (And AsyncListViewAdapter<T>.onRangeChanged doesn't even get called this time.) I went through the code-snippets in this thread, but I can't see nothing suspicions in what I've been doing. Is there some obvious answer to a rookie mistake? I shrinked my variable names, hopefully it won't wrap too much. protected class MyAsyncAdapter extends AsyncListViewAdapter<DTO> { @Override protected void onRangeChanged(ListView<DTO> v) { // doesn't get called on go2start/go2end :( Range r = v.getRange(); fetchData(r.getStart(), r.getLength()); } } private void addTable() { // table: CellTable<DTO> table = new CellTable<DTO>(10); table.addColumn(new Column<DTO, String>(new TextCell()) { @Override public String getValue(DTO namespace) { return namespace.getName(); } }, "Name"); // pager: SimplePager<DTO> pager = new SimplePager<DTO>(table); table.setPager(pager); adapter = new MyAsyncAdapter(); adapter.addView(table); // does not make any difference: // adapter.updateDataSize(0, false); // adapter.updateDataSize(10, true); VerticalPanel vPanel = new VerticalPanel(); vPanel.add(table); vPanel.add(pager); RootLayoutPanel.get().add(vPanel); } // success-handler of my fetching AsyncCallback @Override public void onSuccess(List<DTO> data) { // AsyncCallback<List<DTO>> has start field adapter.updateViewData(start, data.size(), data); if(data.size() < length) adapter.updateDataSize(start + data.size(), true); } Regards J. Záruba

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  • Java Nimbus LAF with transparent text fields

    - by Software Monkey
    I have an application that uses disabled JTextFields in several places which are intended to be transparent - allowing the background to show through instead of the text field's normal background. When running the new Nimbus LAF these fields are opaque (despite setting setOpaque(false)), and my UI is broken. It's as if the LAF is ignoring the opaque property. Setting a background color explicitly is both difficult in several places, and less than optimal due to background images actually doesn't work - it still paints it's LAF default background over the top, leaving a border-like appearance (the splash screen below has the background explicitly set to match the image). Any ideas on how I can get Nimbus to not paint the background for a JTextField? Note: I need a JTextField, rather than a JLabel, because I need the thread-safe setText(), and wrapping capability. Note: My fallback position is to continue using the system LAF, but Nimbus does look substantially better. See example images below. Conclusions The surprise at this behavior is due to a misinterpretation of what setOpaque() is meant to do - from the Nimbus bug report: This is a problem the the orginal design of Swing and how it has been confusing for years. The issue is setOpaque(false) has had a side effect in exiting LAFs which is that of hiding the background which is not really what it is ment for. It is ment to say that the component my have transparent parts and swing should paint the parent component behind it. It's unfortunate that the Nimbus components also appear not to honor setBackground(null) which would otherwise be the recommended way to stop the background painting. Setting a fully transparent background seems unintuitive to me. In my opinion, setOpaque()/isOpaque() is a faulty public API choice which should have been only: public boolean isFullyOpaque(); I say this, because isOpaque()==true is a contract with Swing that the component subclass will take responsibility for painting it's entire background - which means the parent can skip painting that region if it wants (which is an important performance enhancement). Something external cannot directly change this contract (legitimately), whose fulfillment may be coded into the component. So the opacity of the component should not have been settable using setOpaque(). Instead something like setBackground(null) should cause many components to "no long have a background" and therefore become not fully opaque. By way of example, in an ideal world most components should have an isOpaque() that looks like this: public boolean isOpaque() { return (background!=null); }

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  • Using OpenID as the only authentication method

    - by iconiK
    I have read the other questions and they mostly talk about the security of doing so. That's not entirely my concern, mostly because the website is question is a browser-based game. However, the larger issue is the user - not every user is literate enough to understand OpenID. Sure RPX makes this pretty easy, which is what I'll use, but what if the user does not have an account at Google or Facebook or whatever, or does not trust the system to log in with an existing account? They'd have to get an account at another provide - I'm sure most will know how to do it, let alone be bothered to do it. There is also the problem of how to manage it in the application. A user might want to use multiple identities with a single account, so it's not as simple as username + password to deal with. How do I store the OpenID identities of a user in the database? Using OpenID gives me a benefit too: RPX can provide extensive profile information, so I can just prefill the profile form and ask the user to edit as required. I currently have this: UserID Email ------ --------------- 86000 [email protected] 86001 [email protected] UserOpenID OpenID ---------- ------ 86000 16733 86001 16839 86002 19361 OpenID Provider Identifier ------ -------- ---------------- 16733 Yahoo https:\\me.yahoo.com\bob#d36bd 16839 Yahoo https:\\me.yahoo.com\bigbobby#x75af 19361 Yahoo https:\\me.yahoo.com\alice#c19fd Is that the right way to store OpenID identifiers in the database? How would I match the identifier RPX gave me with one in the database to log in the user (if the identifier is known). So here are concrete questions: How would I make it accessible to users not having an OpenID or not wanting to use one? (security concerns over say, logging in with their Google account for example) How do I store the identifier in the database? (I'm not sure if the tables above are right) What measures do I need to take in order to prevent someone from logging in as another user and happily doing anything with their account? (as I understand RPX sends the identifier via HTTP, so what anyone would have to do is to just somehow grab it then enter it in the "OpenID" field) What else do I need to be aware of when using OpenID?

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  • Can LINQ-to-SQL omit unspecified columns on insert so a database default value is used?

    - by Todd Ropog
    I have a non-nullable database column which has a default value set. When inserting a row, sometimes a value is specified for the column, sometimes one is not. This works fine in TSQL when the column is omitted. For example, given the following table: CREATE TABLE [dbo].[Table1]( [id] [int] IDENTITY(1,1) NOT NULL, [col1] [nvarchar](50) NOT NULL, [col2] [nvarchar](50) NULL, CONSTRAINT [PK_Table1] PRIMARY KEY CLUSTERED ([id] ASC) ) GO ALTER TABLE [dbo].[Table1] ADD CONSTRAINT [DF_Table1_col1] DEFAULT ('DB default') FOR [col1] The following two statements will work: INSERT INTO Table1 (col1, col2) VALUES ('test value', '') INSERT INTO Table1 (col2) VALUES ('') In the second statement, the default value is used for col1. The problem I have is when using LINQ-to-SQL (L2S) with a table like this. I want to produce the same behavior, but I can't figure out how to make L2S do that. I want to be able to run the following code and have the first row get the value I specify and the second row get the default value from the database: var context = new DataClasses1DataContext(); var row1 = new Table1 { col1 = "test value", col2 = "" }; context.Table1s.InsertOnSubmit(row1); context.SubmitChanges(); var row2 = new Table1 { col2 = "" }; context.Table1s.InsertOnSubmit(row2); context.SubmitChanges(); If the Auto Generated Value property of col1 is False, the first row is created as desired, but the second row fails with a null error on col1. If Auto Generated Value is True, both rows are created with the default value from the database. I've tried various combinations of Auto Generated Value, Auto-Sync and Nullable, but nothing I've tried gives the behavior I want. L2S does not omit the column from the insert statement when no value is specified. Instead it does something like this: INSERT INTO Table1 (col1, col2) VALUES (null, '') ...which of course causes a null error on col1. Is there some way to get L2S to omit a column from the insert statement if no value is given? Or is there some other way to get the behavior I want? I need the default value at the database level because not all row inserts are done via L2S, and in some cases the default value is a little more complex than a hard coded value (e.g. creating the default based on another field) so I'd rather avoid duplicating that logic.

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  • Non RBAC User Roles and Permissions System: a role with properties

    - by micha12
    We are currently designing a User Roles and Permissions System in our web application (ASP.NET), and it seems that we have several cases that do no fit within the classical Role-Based Access Control (RBAC). I will post several questions, each devoted to a particular case. This is my second question (the first question is here: http://stackoverflow.com/questions/2839797/non-rbac-user-roles-and-permissions-system-checking-the-users-city). We have the following case: we need to implement a Manager role in our web application. However, a Manager can belong to one or several companies (within a big group of companies for which we are creating this web app). Say, there can be “Manager of companies A and B”, “Manager of company C”, etc. Depending on the companies that the Manager belongs, he has access to certain operations: for example, he can communicate with clients only of those companies that he belongs to. That is, “Manager of companies A and B” can only have contacts with clients of companies A and B, and not with those of company C. He can also view clients’ details pages of companies A and B and not of C, etc. It seems that this case falls within the RBAC. However, this is not really the case. We will need to create a ManagerRole class that will have a Companies property – that is, this will not be just a role as a collection of permissions (like in the classical RBAC), but a role with properties! This was just one example of a role having properties. There will be others: for example, an Administrator role that will also belong to a number of companies and will also have other custom properties. This means that we will a hierarchy or roles classes: class Role – base class class ManagerRole : Role List Companies class AdministratorRole : Role List Companies Other properties We investigated pure RBAC and its implementation in several systems, and found no systems featuring a hierarchy or roles, each having custom properties. In RBAC, roles are just collections of permissions. We could model our cases using permission with properties, like ManagerPermission, AdministratorPermission, but this has a lot of drawbacks, the main being that we will not be able to assign a role like “Manager of Companies A and B” to a user directly, but will have to create a role containing a ManagerPermission for companies A and B… Moreover, a "Manager" seems to be rather a "role" (position in the company) rather than a "permission" from the linguistic point of view. Would be grateful for any ideas on this subject, as well as any experience in this field! Thank you.

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  • How to represent different entities that have identical behavior?

    - by Dominik
    I have several different entities in my domain model (animal species, let's say), which have a few properties each. The entities are readonly (they do not change state during the application lifetime) and they have identical behavior (the differ only by the values of properties). How to implement such entities in code? Unsuccessful attempts: Enums I tried an enum like this: enum Animals { Frog, Duck, Otter, Fish } And other pieces of code would switch on the enum. However, this leads to ugly switching code, scattering the logic around and problems with comboboxes. There's no pretty way to list all possible Animals. Serialization works great though. Subclasses I also thought about where each animal type is a subclass of a common base abstract class. The implementation of Swim() is the same for all Animals, though, so it makes little sense and serializability is a big issue now. Since we represent an animal type (species, if you will), there should be one instance of the subclass per application, which is hard and weird to maintain when we use serialization. public abstract class AnimalBase { string Name { get; set; } // user-readable double Weight { get; set; } Habitat Habitat { get; set; } public void Swim(); { /* swim implementation; the same for all animals but depends uses the value of Weight */ } } public class Otter: AnimalBase{ public Otter() { Name = "Otter"; Weight = 10; Habitat = "North America"; } } // ... and so on Just plain awful. Static fields This blog post gave me and idea for a solution where each option is a statically defined field inside the type, like this: public class Animal { public static readonly Animal Otter = new Animal { Name="Otter", Weight = 10, Habitat = "North America"} // the rest of the animals... public string Name { get; set; } // user-readable public double Weight { get; set; } public Habitat Habitat { get; set; } public void Swim(); } That would be great: you can use it like enums (AnimalType = Animal.Otter), you can easily add a static list of all defined animals, you have a sensible place where to implement Swim(). Immutability can be achieved by making property setters protected. There is a major problem, though: it breaks serializability. A serialized Animal would have to save all its properties and upon deserialization it would create a new instance of Animal, which is something I'd like to avoid. Is there an easy way to make the third attempt work? Any more suggestions for implementing such a model?

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  • Servlet, JSP, JavaBeans and HTML form

    - by dedalo
    Hi, I'm working on a servlet that makes a connection to a database gets the information of one of the tables ans sends this information to a jsp file. This file will print on the brower the information table, adding radio buttons that allows us to choose one of the rows. The servlet looks like this: List<InfoBean> items = new ArrayList<InfoBean>(); if (!conexion.isClosed()){ Statement st = (Statement) conexion.createStatement(); ResultSet rs = st.executeQuery("select * from lista_audio" ); while (rs.next()) {items.add(getRow(rs));} conexion.close();} req.getSession().setAttribute("items", items); In the JSP file I can print a table with the information, adding radio buttons that the user will use to choose 1 row and send the selected info to a servlet using a form I can add: < form action="administ" method=get enctype=multipart/form-data> < table> < table border=\"1\">< tr>< th>Title< /th>< th>Author< /th>< th>Album< /th>< /tr> < c:forEach items="${items}" var="item"> < tr>< td><input type="radio" name="SongInfo" value=${item.title}> < td>${item.title}< /td> < td>${item.author}< /td> < td>${item.album}< /td>< /tr> < /c:forEach> < /table> In the field 'value' I should be able to send to the servlet the information stored in ${item.title}. When I set value = ${item.title} and title is, for example "The bodyguard", in the servlet the information I can retrieve is just "The". It looks like it sends the characters located before the first white space of the string. How could I get the whole string? Thanks

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