Search Results

Search found 15115 results on 605 pages for 'state pattern'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 103/605 | < Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >

  • Foreign key reference to a two-column primary key

    - by Adam Ernst
    One of my tables has a two-column primary key: CREATE TABLE tournament ( state CHAR(2) NOT NULL, year INT NOT NULL, etc..., PRIMARY KEY(state, year) ); I want a reference to the tournament table from another table, but I want this reference to be nullable. Here's how I might do it, imagining that a winner doesn't necessarily have a tournament: CREATE TABLE winner ( name VARCHAR NOT NULL, state CHAR(2) NULL, year INT NULL ); If state is null but year is not, or vice-versa, the table would be inconsistent. I believe the following FOREIGN KEY constraint fixes it: ALTER TABLE winner ADD CONSTRAINT FOREIGN KEY fk (name, state) REFERENCES tournament (name, state); Is this the proper way of enforcing consistency? Is this schema properly normalized?

    Read the article

  • How can we implement change notification propagation for WPF and SL in the MVVM pattern?

    - by Firoso
    Here's an example scenario targetting MVVM WPF/SL development: View data binds to view model Property "Target" "Target" exposes a field of an object called "data" that exists in the local application model, called "Original" when "Original" changes, it should raise notification to the view model and then propogate that change notification to the View. Here are the solutions I've come up with, but I don't like any of them all that much. I'm looking for other ideas, by the time we come up with something rock solid I'm certain Microsoft will have released .NET 5 with WPF/SL extensions for better tools for MVVM development. For now the question is, "What have you done to solve this problem and how has it worked out for you?" Option 1. Proposal: Attach a handler to data's PropertyChanged event that watches for string values of properties it cares about that might have changed, and raises the appropriate notification. Why I don't like it: Changes don't bubble naturally, objects must be explicitly watched, if data changes to a new source, events must be un-registered/registered. Why I kind of like it: I get explicit control over propogation of changes, and I don't have to use any types that belong at a higher level of the application such as dependancy properties. Option 2. Proposal: Attach a handler to data's PropertyChanged event that re-raises the event across all properties using the name property name. Why I don't like it: This is essentially the same as option 1, but less intelligent, and forces me to never change my property names, as they have to be the same as the property names on data Why I kind of like it: It's very easy to set up and I don't have to think about it... Then again if I try to think, and change names to things that make sense, I shoot myself in the foot, and then I have to think about it! Option 3. Proposal: Inherit my view model from dependancy object, and notify binding sources of changes directly. Why I don't like it: I'm not even 100% sure dependancy properties/objects can DO this, it was just a thought to look into. Also I don't personally feel that WPF/SL types like Dep Obj belong at the view model level. Why I kind of like it: IF it has the capability that I'm seeking then it's a good answer! minus that pesky layering issue. Option 4. Proposal: Use a consistant agent messaging system based off of Task Parallels DataFlow Library to propogate everything through linked pipelining. Why I don't like it: I've never tried this, and somehow I think it will be lacking, plus it requires me to think about my code completely differently all the way around. Why I kind of like it: It has the possiblity of allowing me to do some VERY fun manipulations with a push based data model and using ActionBlocks as validation AND setters to then privately change view model properties and explicitly control PropertyChanged notifications.

    Read the article

  • Update table.column with another table.column with common joined column

    - by Matt
    Hit a speed bump, trying to update some column values in my table from another table. This is what is supposed to happen when everything works Correct all the city, state entries in tblWADonations by creating an update statement that moves the zip city from the joined city/state zip field to the tblWADonations city state TBL NAME | COLUMN NAMES tblZipcodes with zip,city,State tblWADonations with zip,oldcity,oldstate This is what I have so far: UPDATE tblWADonations SET oldCity = tblZipCodes.city, oldState = tblZipCodes.state FROM tblWADonations INNER JOIN tblZipCodes ON tblWADonations.zip = tblZipCodes.zip Where oldCity <> tblZipcodes.city; There seems to be easy ways to do this online but I am overlooking something. Tried this by hand and in editor this is what it kicks back. Msg 8152, Level 16, State 2, Line 1 String or binary data would be truncated. The statement has been terminated. Please include a sql statement or where I need to make the edit so I can mark this post as a reference in my favorites. Thanks!

    Read the article

  • How can I print lines that match a pattern in Perl?

    - by kivien
    Assuming the file.txt having just one sentence per line as follows:- John Depp is a great guy. He is very inteligent. He can do anything. Come and meet John Depp. The perl code is as follows:- open ( FILE, "file.txt" ) || die "can't open file!"; @lines = <FILE>; close (FILE); $string = "John Depp"; foreach $line (@lines) { if ($line =~ $string) { print "$line"; } } The output is going to be first and fourth line. I want to make it working for the file having random line breaks rather than one English sentence per line. I mean it should also work for the following:- John Depp is a great guy. He is very inteligent. He can do anything. Come and meet John Depp. The output should be first and fourth sentence. Any ideas please?

    Read the article

  • What's the best Communication Pattern for EJB3-based applications?

    - by Hank
    I'm starting a JEE project that needs to be strongly scalable. So far, the concept was: several Message Driven Beans, responsible for different parts of the architecture each MDB has a Session Bean injected, handling the business logic a couple of Entity Beans, providing access to the persistence layer communication between the different parts of the architecture via Request/Reply concept via JMS messages: MDB receives msg containing activity request uses its session bean to execute necessary business logic returns response object in msg to original requester The idea was that by de-coupling parts of the architecture from each other via the message bus, there is no limit to the scalability. Simply start more components - as long as they are connected to the same bus, we can grow and grow. Unfortunately, we're having massive problems with the request-reply concept. Transaction Mgmt seems to be in our way plenty. It seams that session beans are not supposed to consume messages?! Reading http://blogs.sun.com/fkieviet/entry/request_reply_from_an_ejb and http://forums.sun.com/message.jspa?messageID=10338789, I get the feeling that people actually recommend against the request/reply concept for EJBs. If that is the case, how do you communicate between your EJBs? (Remember, scalability is what I'm after) Details of my current setup: MDB 1 'TestController', uses (local) SLSB 1 'TestService' for business logic TestController.onMessage() makes TestService send a message to queue XYZ and requests a reply TestService uses Bean Managed Transactions TestService establishes a connection & session to the JMS broker via a joint connection factory upon initialization (@PostConstruct) TestService commits the transaction after sending, then begins another transaction and waits 10 sec for the response Message gets to MDB 2 'LocationController', which uses (local) SLSB 2 'LocationService' for business logic LocationController.onMessage() makes LocationService send a message back to the requested JMSReplyTo queue Same BMT concept, same @PostConstruct concept all use the same connection factory to access the broker Problem: The first message gets send (by SLSB 1) and received (by MDB 2) ok. The sending of the returning message (by SLSB 2) is fine as well. However, SLSB 1 never receives anything - it just times out. I tried without the messageSelector, no change, still no receiving message. Is it not ok to consume message by a session bean? SLSB 1 - TestService.java @Resource(name = "jms/mvs.MVSControllerFactory") private javax.jms.ConnectionFactory connectionFactory; @PostConstruct public void initialize() { try { jmsConnection = connectionFactory.createConnection(); session = jmsConnection.createSession(false, Session.AUTO_ACKNOWLEDGE); System.out.println("Connection to JMS Provider established"); } catch (Exception e) { } } public Serializable sendMessageWithResponse(Destination reqDest, Destination respDest, Serializable request) { Serializable response = null; try { utx.begin(); Random rand = new Random(); String correlationId = rand.nextLong() + "-" + (new Date()).getTime(); // prepare the sending message object ObjectMessage reqMsg = session.createObjectMessage(); reqMsg.setObject(request); reqMsg.setJMSReplyTo(respDest); reqMsg.setJMSCorrelationID(correlationId); // prepare the publishers and subscribers MessageProducer producer = session.createProducer(reqDest); // send the message producer.send(reqMsg); System.out.println("Request Message has been sent!"); utx.commit(); // need to start second transaction, otherwise the first msg never gets sent utx.begin(); MessageConsumer consumer = session.createConsumer(respDest, "JMSCorrelationID = '" + correlationId + "'"); jmsConnection.start(); ObjectMessage respMsg = (ObjectMessage) consumer.receive(10000L); utx.commit(); if (respMsg != null) { response = respMsg.getObject(); System.out.println("Response Message has been received!"); } else { // timeout waiting for response System.out.println("Timeout waiting for response!"); } } catch (Exception e) { } return response; } SLSB 2 - LocationService.Java (only the reply method, rest is same as above) public boolean reply(Message origMsg, Serializable o) { boolean rc = false; try { // check if we have necessary correlationID and replyTo destination if (!origMsg.getJMSCorrelationID().equals("") && (origMsg.getJMSReplyTo() != null)) { // prepare the payload utx.begin(); ObjectMessage msg = session.createObjectMessage(); msg.setObject(o); // make it a response msg.setJMSCorrelationID(origMsg.getJMSCorrelationID()); Destination dest = origMsg.getJMSReplyTo(); // send it MessageProducer producer = session.createProducer(dest); producer.send(msg); producer.close(); System.out.println("Reply Message has been sent"); utx.commit(); rc = true; } } catch (Exception e) {} return rc; } sun-resources.xml <admin-object-resource enabled="true" jndi-name="jms/mvs.LocationControllerRequest" res-type="javax.jms.Queue" res-adapter="jmsra"> <property name="Name" value="mvs.LocationControllerRequestQueue"/> </admin-object-resource> <admin-object-resource enabled="true" jndi-name="jms/mvs.LocationControllerResponse" res-type="javax.jms.Queue" res-adapter="jmsra"> <property name="Name" value="mvs.LocationControllerResponseQueue"/> </admin-object-resource> <connector-connection-pool name="jms/mvs.MVSControllerFactoryPool" connection-definition-name="javax.jms.QueueConnectionFactory" resource-adapter-name="jmsra"/> <connector-resource enabled="true" jndi-name="jms/mvs.MVSControllerFactory" pool-name="jms/mvs.MVSControllerFactoryPool" />

    Read the article

  • Invalid view state exception in asp.net. do you know any solution?

    - by mmtemporary
    this problem make me crazy! i have asp.net website it raise periodically this error (in IE8): System.Web.HttpException: Invalid viewstate. at System.Web.UI.Page.DecryptStringWithIV(String s, IVType ivType) at System.Web.Handlers.AssemblyResourceLoader.System.Web.IHttpHandler .ProcessRequest(HttpContext context) ,... or (in IE6) System.FormatException: Invalid length for a Base-64 char array. at System.Convert.FromBase64String(String s) at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) or (in IE7) System.FormatException: Invalid character in a Base-64 string. at System.Convert.FromBase64String(String s) at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) i set enableViewStateMac in web.config to false and defined machinekey in my web.config and defined UTF-8 encoding for every page but i received this errors. do you have any solution? best regards

    Read the article

  • where to set wait cursor in long operation in MVP pattern?

    - by Benny
    For a long operation that will be executed in presenter, where to set the wait cursor? in View? the view shouldn't know too much about business logic, it is passive. in presenter? seems odd in presenter to call UI code. add method to View interface, like SetWait(bool), and call it in presenter? So what do you think?

    Read the article

  • Wrappers/law of demeter seems to be an anti-pattern...

    - by Robert Fraser
    I've been reading up on this "Law of Demeter" thing, and it (and pure "wrapper" classes in general) seem to generally be anti patterns. Consider an implementation class: class Foo { void doSomething() { /* whatever */ } } Now consider two different implementations of another class: class Bar1 { private static Foo _foo = new Foo(); public static Foo getFoo() { return _foo; } } class Bar2 { private static Foo _foo = new Foo(); public static void doSomething() { _foo.doSomething(); } } And the ways to call said methods: callingMethod() { Bar1.getFoo().doSomething(); // Version 1 Bar2.doSomething(); // Version 2 } At first blush, version 1 seems a bit simpler, and follows the "rule of Demeter", hide Foo's implementation, etc, etc. But this ties any changes in Foo to Bar. For example, if a parameter is added to doSomething, then we have: class Foo { void doSomething(int x) { /* whatever */ } } class Bar1 { private static Foo _foo = new Foo(); public static Foo getFoo() { return _foo; } } class Bar2 { private static Foo _foo = new Foo(); public static void doSomething(int x) { _foo.doSomething(x); } } callingMethod() { Bar1.getFoo().doSomething(5); // Version 1 Bar2.doSomething(5); // Version 2 } In both versions, Foo and callingMethod need to be changed, but in Version 2, Bar also needs to be changed. Can someone explain the advantage of having a wrapper/facade (with the exception of adapters or wrapping an external API or exposing an internal one).

    Read the article

  • mysql true row merge... not just a union

    - by panofish
    What is the mysql I need to achieve the result below given these 2 tables: table1: +----+-------+ | id | name | +----+-------+ | 1 | alan | | 2 | bob | | 3 | dave | +----+-------+ table2: +----+---------+ | id | state | +----+---------+ | 2 | MI | | 3 | WV | | 4 | FL | +----+---------+ I want to create a temporary view that looks like this desired result: +----+---------+---------+ | id | name | state | +----+---------+---------+ | 1 | alan | | | 2 | bob | MI | | 3 | dave | WV | | 4 | | FL | +----+---------+---------+ I tried a mysql union but the following result is not what I want. create view table3 as (select id,name,"" as state from table1) union (select id,"" as name,state from table2) table3 union result: +----+---------+---------+ | id | name | state | +----+---------+---------+ | 1 | alan | | | 2 | bob | | | 3 | dave | | | 2 | | MI | | 3 | | WV | | 4 | | FL | +----+---------+---------+ First suggestion results: SELECT * FROM table1 LEFT OUTER JOIN table2 USING (id) UNION SELECT * FROM table1 RIGHT OUTER JOIN table2 USING (id) +----+---------+---------+ | id | name | state | +----+---------+---------+ | 1 | alan | | | 2 | bob | MI | | 3 | dave | WV | | 2 | MI | bob | | 3 | WV | dave | | 4 | FL | | +----+---------+---------+

    Read the article

  • How to use Page Object pattern with Cucumber and Webrat / Selenium?

    - by Will Sargent
    I'm looking at a cucumber test suite that is somewhat brittle right now; many small steps, and no knowledge of the page itself. I'd like to factor out the logic involved in the step definitions inside a series of Selenium PageObjects. As seen here. However, because I'm using Webrat and not Selenium, everything has to go through the Webrat model. So I cannot do class MyPage < Selenium::WebPage end because that adds a direct dependency. So I have to route everything through Webrat while still maintaining the Selenium Page object goodness. No documentation on this that I can see: if someone has anything on Webrat + PageModel I'd love to see it.

    Read the article

  • how to: re-assemble machine generated classes from xsd files to their original nested state.

    - by Paul Connolly
    Hi everyone, I'm working in Visual Studio 2008 using c#. Let's say I have 2 xsd files e.g "Envelope.xsd" and "Body.xsd" I create 2 sets of classes by running xsd.exe, creating something like "Envelope.cs" and "Body.cs", so far so good. I can't figure out how to link the two classes to serialize (using XmlSerializer) into the proper nested xml, i.e: I want: <Envelope><DocumentTitle>Title</DocumentTitle><Body>Body Info</Body></Envelope> But I get: <Envelope><DocumentTitle>Title</DocumentTitle></Envelope><Body>Body Info</Body> Could someone perhaps show me how the two .cs classes should look to enable XmlSerializer to runt the desired nested result? Thanks a million Paul

    Read the article

  • Can you find a pattern to sync files knowing only dates and filenames?

    - by Robert MacLean
    Imagine if you will a operating system that had the following methods for files Create File: Creates (writes) a new file to disk. Calling this if a file exists causes a fault. Update File: Updates an existing file. Call this if a file doesn't exist causes a fault. Read File: Reads data from a file. Enumerate files: Gets all files in a folder. Files themselves in this operating system only have the following meta data: Created Time: The original date and time the file was created, by the Create File method. Modified Time: The date and time the file was last modified by the Update File method. If the file has never been modified, this will equal the Create Time. You have been given the task of writing an application which will sync the files between two directories (lets call them bill and ted) on a machine. However it is not that simple, the client has required that The application never faults (see methods above). That while the application is running the users can add and update files and those will be sync'd next time the application runs. Files can be added to either the ted or bill directories. File names cannot be altered. The application will perform one sync per time it is run. The application must be almost entirely in memory, in other words you cannot create a log of filenames and write that to disk and then check that the next time. The exception to point 6 is that you can store date and times between runs. Each date/time is associated with a key labeled A through J (so you have 10 to use) so you can compare keys between runs. There is no way to catch exceptions in the application. Answer will be accepted based on the following conditions: First answer to meet all requirements will be accepted. If there is no way to meet all requirements, the answer which ensures the smallest amount of missed changes per sync will be accepted. A bounty will be created (100 points) as soon as possible for the prize. The winner will be selected one day before the bounty ends. Please ask questions in the comments and I will gladly update and refine the question on those.

    Read the article

  • Optimizing mathematics on arrays of floats in Ada 95 with GNAT

    - by mat_geek
    Consider the bellow code. This code is supposed to be processing data at a fixed rate, in one second batches, It is part of an overal system and can't take up too much time. When running over 100 lots of 1 seconds worth of data the program takes 35 seconds (or 35%), executing this function in a loop. The test loop is timed specifically with Ada.RealTime. The data is pregenerated so the majority of the execution time is definatetly in this loop. How do I improce the code to get the processing time down to a minimum? The code will be running on an Intel Pentium-M which is a P3 with SSE2. package FF is new Ada.Numerics.Generic_Elementary_Functions(Float); N : constant Integer := 820; type A is array(1 .. N) of Float; type A3 is array(1 .. 3) of A; procedure F(state : in out A3; result : out A3; l : in A; r : in A) is s : Float; t : Float; begin for i in 1 .. N loop t := l(i) + r(i); t := t / 2.0; state(1)(i) := t; state(2)(i) := t * 0.25 + state(2)(i) * 0.75; state(3)(i) := t * 1.0 /64.0 + state(2)(i) * 63.0 /64.0; for r in 1 .. 3 loop s := state(r)(i); t := FF."**"(s, 6.0) + 14.0; if t > MAX then t := MAX; elsif t < MIN then t := MIN; end if; result(r)(i) := FF.Log(t, 2.0); end loop; end loop; end; psuedocode for testing create two arrays of 80 random A3 arrays, called ls and rs; init the state and result A3 array record the realtime time now, called last for i in 1 .. 100 loop for j in 1 .. 80 loop F(state, result, ls(j), rs(j)); end loop; end loop; record the realtime time now, called curr output the duration between curr and last

    Read the article

  • How do I check if a user is authenticated with NickServ using POE::Component::IRC::State in Perl?

    - by Troy
    I'm trying to test whether a user is registered on FreeNode. nick_info() doesn't seem to return information about this, so I want to use $irc-yield(whois = $nick); and then grab the irc_whois event's reply. The problem is that I want to wait until this event is fired, so I created a global variable $whois_result and wrote a sub like this: sub whois { my $nick = $_[0]; $whois_result = 0; $irc->yield(whois => $nick); while($whois_result == 0) { } return $whois_result; } with the irc_whois handler looking like: sub on_whois { $whois_result = $_[ARG0]; print "DEBUG: irc_whois fired.\n"; } Unfortunately, the event can't fire while the loop is running so this hangs. I'm sure there's a better way to do this, but I'm not familiar enough with this kind of programming to know. Any help would be greatly appreciated.

    Read the article

  • Enterprise library Validation block and rulesets

    - by user102533
    I am using Rulesets on a type that looks like this: public class Salary { public decimal HourlyRate { get; set; } [ValidHours] //Custom validator public int NumHours { get; set; } [VerifyValidState(Ruleset="State")] //Custom validator with ruleset public string State { get; set; } } Due to business requirements, I'd need to first validate the ruleset "State" and then validate the entire business entity public void Save() { ValidationResults results = Validation.Validate(salary, "State"); //Check for validity //Now run the validation for ALL rules including State ruleset ValidationResults results2 = Validation.Validate(salary); //Does not run the ruleset marked with "State" } How do I accomplish what I am trying to do?

    Read the article

  • Undefined Behavior and Sequence Points Reloaded

    - by Nawaz
    Consider this topic a sequel of the following topic: Previous Installment Undefined Behavior and Sequence Points Let's revisit this funny and convoluted expression (the italicized phrases are taken from the above topic *smile* ): i += ++i; We say this invokes undefined-behavior. I presume that when say this, we implicitly assume that type of i is one of built-in types. So my question is: what if the type of i is a user-defined type? Say it's type is Index which is defined later in this post (see below). Would it still invoke undefined-behavior? If yes, why? Is it not equivalent to writing i.operator+=(i.operator ++()); or even syntactically simpler i.add(i.inc());? Or, do they too invoke undefined-behavior? If no, why not? After all, the object i gets modified twice between consecutive sequence points. Please recall the rule of thumb : an expression can modify an object's value only once between consecutive "sequence points. And if i += ++i is an expression, then it must invoke undefined-behavior. If so, then it's equivalents i.operator+=(i.operator ++()); and i.add(i.inc()); must also invoke undefined-behavior which seems to be untrue! (as far as I understand) Or, i += ++i is not an expression to begin with? If so, then what is it and what is the definition of expression? If it's an expression, and at the same time, it's behavior is also well-defined, then it implies that number of sequence points associated with an expression somehow depends on the type of operands involved in the expression. Am I correct (even partly)? By the way, how about this expression? a[++i] = i; //taken from the previous topic. but here type of `i` is Index. class Index { int state; public: Index(int s) : state(s) {} Index& operator++() { state++; return *this; } Index& operator+=(const Index & index) { state+= index.state; return *this; } operator int() { return state; } Index & add(const Index & index) { state += index.state; return *this; } Index & inc() { state++; return *this; } };

    Read the article

  • .htaccess with public folder

    - by ninumedia
    I have a directory structure with the following on localhost: http://localhost/testing/ A directory structure exists inside of testing as follows: /testing/public /testing/public/index.php /testing/public/img /testing/public/css ..etc for the js and swf directories A .htaccess file is inside the testing folder and the contents are as follows: Options +FollowSymLinks RewriteEngine on RewriteBase /testing/ RewriteRule ^public$ public/ [R,QSA] RewriteRule ^public/$ public/index.php?state=public [L,QSA] RewriteRule ^stackoverflow$ stackoverflow/ [R,QSA] RewriteRule ^stackoverflow/$ public/index.php?state=stackoverflow[L,QSA] I am using PHP and inside of the /testing/public/index.php file I wanted to test that the $_GET['state'] is indeed saving the variable. When I try to test out: http://localhost/testing/public $_GET['state'] is not found at all BUT http://localhost/testing/stackoverflow does indeed echo out that $_GET['state'] equals 'stackoverflow'. What am I missing here??? Why is it that I cannot get the state=public in the first link? Thanks for the help!

    Read the article

  • Is it possible in AvalonDock to programatically change DockableContent state to floating?

    - by Marqus
    In my application I'm loading windows from 'plugins', so my app doesn't know them until runtime. I'm creating DockableContent for each plugin and sets it's Content to Control returned by plugin. Each plugin tells, if it's window should be initially docked or floating, user can change it later. So I have an instance of DockableContent and I want to change it to FloatingWindow programatically. Changing content.DockableStyle to DockableStyle.Floating isn't enough, what else I have to do?

    Read the article

  • How do I get the collection of Model State Errors in ASP.NET MVC?

    - by Ryan Montgomery
    How do I get the collection of errors in a view? I don't want to use the Html Helper Validation Summary or Validation Message. Instead I want to check for errors and if any display them in specific format. Also on the input controls I want to check for a specific property error and add a class to the input. P.S. I'm using the Spark View Engine but the idea should be the same. So I figured I could do something like... <if condition="${ModelState.Errors.Count > 0}"> DispalyErrorSummary() </if> ....and also... <input type="text" value="${Model.Name}" class="?{ModelState.Errors["Name"] != string.empty} error" /> .... Or something like that. UPDATE My final solution looked like this: <input type="text" value="${ViewData.Model.Name}" class="text error?{!ViewData.ModelState.IsValid && ViewData.ModelState["Name"].Errors.Count() > 0}" id="Name" name="Name" /> This only adds the error css class if this property has an error.

    Read the article

  • What is the basic pattern for using (N)Hibernate?

    - by Vilx-
    I'm creating a simple Windows Forms application with NHibernate and I'm a bit confused about how I'm supposed to use it. To quote the manual: ISession (NHibernate.ISession) A single-threaded, short-lived object representing a conversation between the application and the persistent store. Wraps an ADO.NET connection. Factory for ITransaction. Holds a mandatory (first-level) cache of persistent objects, used when navigating the object graph or looking up objects by identifier. Now, suppose I have the following scenario: I have a simple classifier which is a MSSQL table with two columns - ID (auto_increment) and Name (nvarchar). To edit this classifier I create a form which contains a single gridview and two buttons - OK and Cancel. The user can nearly directly edit the table in the gridview, and when he hits OK the changes he made are persisted to the DB (or if he hits cancel, nothing happens). Now, I have several questions about how to organize this: What should the lifetime of my ISession be? Should I create a single ISession for my whole application; an ISession for each of my forms (the application is single-threaded MDI); or an ISession for every DB operation/transaction? Does NHibernate offer some kind of built-in dirty tracking or must I do this myself? The manual mentions something like it here and there but does not go into details. How is this done? Is there not a huge overhead? Is it somehow tied with the cache(s) that NHibernate has? What are these caches for? Are they not specific to a single ISession? That is, if I use a seperate ISession for every transaction, won't it break the dirty tracking? How does the built-in dirty tracking detect deleted objects?

    Read the article

  • C# Reflection - Casting private Object field

    - by alhazen
    I have the following classes: public class MyEventArgs : EventArgs { public object State; public MyEventArgs (object state) { this.State = state; } } public class MyClass { // ... public List<string> ErrorMessages { get { return errorMessages; } } } When I raise my event, I set 'State' of the MyEventArgs object to an object of type MyClass. I'm trying to retrieve ErrorMessages by reflection in my event handler: public static void OnEventEnded(object sender, EventArgs args) { Type type = args.GetType(); FieldInfo stateInfo = type.GetField("State"); PropertyInfo errorMessagesInfo = stateInfo.FieldType.GetProperty("ErrorMessages"); object errorMessages = errorMessagesInfo.GetValue(null, null); } But this returns errorMessagesInfo as null (even though stateInfo is not null). Is it possible to retrieve ErrorMessages ? Thank you

    Read the article

  • Spring webflow 1.0 - Downloading a file

    - by Dave
    I am using spring webflow 1.0. I am uploading a csv file, parsing it, and displying results before proceeding. The user has an option to download a csv file that contains the records that did not pass validation. When I click the link in a JSP to download this file, webflow invokes a form Action. The form action writes out a file via getting the output stream off the response: HttpServletResponse response = ((ServletExternalContext) context.getExternalContext()).getResponse(); I do not want to leave the jsp I'm currently on. I just want to download the file. In other words, I do not want to transition to another state. I just want to serve the dynamically rendered file. Everything works (I don't leave the page, and I download the file), but I'm getting the following error in my console: _pEncydKfggPHJo8=org.springframework.webflow.engine.NoMatchingTransitionException: No transition was matched on the event(s) signaled by the [1] action(s) that executed in this action state 'downloadErrorReportAction' of flow 'myFlow'; transitions must be defined to handle action result outcomes -- possible flow configuration error? Note: the eventIds signaled were: 'array<String>[[null]]', while the supported set of transitional criteria for this action state is 'array<TransitionCriteria>[[empty]]' at org.springframework.webflow.engine.ActionState.doEnter(ActionState.java:187) at org.springframework.webflow.engine.State.enter(State.java:191) at org.springframework.webflow.engine.Transition.execute(Transition.java:212) at org.springframework.webflow.engine.TransitionableState.onEvent(TransitionableState.java:107) at org.springframework.webflow.engine.Flow.onEvent(Flow.java:534) Truncated. see log file for complete stacktrace Here is the relevant portion of my webflow config. <view-state id="showUploadResults" view="UploadResults3.0"> <render-actions> <action bean="UploadResultsAction" method="transitionToWebflow"/> <action bean="UploadResultsAction" method="setupData"/> </render-actions> <transition on="submit" to="proceed"/> <transition on="downloadErrorReport" to="downloadErrorReportAction"/> </view-state> <action-state id="downloadErrorReportAction"> <action bean="UploadResultsAction" method="downloadErrorReport" name="downloadErrorReport"/> </action-state>

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >