Search Results

Search found 12089 results on 484 pages for 'rule of three'.

Page 346/484 | < Previous Page | 342 343 344 345 346 347 348 349 350 351 352 353  | Next Page >

• Website often sticks, but clicking the link again everything loads fine

  - by Dave

  Hi I have a website, which normally is very fast, however in the last week or two we're run into a problem whereby randomly if you click a link the browser will just sit there with the throbber spinning but the page doesn't appear to load If you click the link again it then responds straight away This doesn't seem to be limited to Chrome, Firefox or IE as we've tried all with all having same problems The site is build in ASP and connects to a MySQL database and runs on a dedicated windows 2003 server The firewalls were changed in the data centre recently to pixies but I've not been able to reproduce the problem outside of the office Within the office, we have 11 people (only 7 today and still experiencing problems) connected to a 7MB ADSL connection with Eclipse I have made some changes to the network in the office, namely wiring 4 desks back to the main 24 port switch rather than to small 5 port which then linked on to the 24 port switch... however we were having problems before this was done, and I did this to try and rule out an issue with the switch We have a backup ADSL connection, so I may try switching to that, or switching to a different router, but do you think this is a likely issue? Failing that, what else would you check? Thanks, sorry for length! Dave

  Read the article

• XSLT Built-in Template Rules for attributes

  - by Martin Smith

  I'm sure that this is an extremely basic question but here goes anyway! I have read that the built in template rule for text and attribute nodes in XSLT is <xsl:template match="text()|@*"> <xsl:value-of select="."/> </xsl:template> However for the source document <?xml version="1.0"?> <booker> <award> <author blah="test">Aravind Adiga</author> <title>The White Tiger</title> <year>2008</year> </award> </booker> And XSLT <?xml version="1.0" encoding="utf-8"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output method="text"/> </xsl:stylesheet> I get the following output applying the transform in Visual Studio. Can someone please explain why I don't see "test" in the output? Aravind Adiga The White Tiger 2008

  Read the article

• Problem with python urllib

  - by mudder

  I'm getting an error when ever I try to pull down a web page with urllib.urlopen. I've disabled windows firewall and my AV so its not that. I can access the pages in my browser. I even reinstalled python to rule out it being a broken urllib. Any help would be greatly appreciated. >>> import urllib >>> h = urllib.urlopen("http://www.google.com").read() Traceback (most recent call last): File "<pyshell#1>", line 1, in <module> h = urllib.urlopen("http://www.google.com").read() File "C:\Python26\lib\urllib.py", line 86, in urlopen return opener.open(url) File "C:\Python26\lib\urllib.py", line 205, in open return getattr(self, name)(url) File "C:\Python26\lib\urllib.py", line 344, in open_http h.endheaders() File "C:\Python26\lib\httplib.py", line 904, in endheaders self._send_output() File "C:\Python26\lib\httplib.py", line 776, in _send_output self.send(msg) File "C:\Python26\lib\httplib.py", line 735, in send self.connect() File "C:\Python26\lib\httplib.py", line 716, in connect self.timeout) File "C:\Python26\lib\socket.py", line 514, in create_connection raise error, msg IOError: [Errno socket error] [Errno 10061] No connection could be made because the target machine actively refused it >>>

  Read the article

• Converting FoxPro Date type to SQL Server 2005 DateTime using SSIS

  - by Avrom

  Hi, When using SSIS in SQL Server 2005 to convert a FoxPro database to a SQL Server database, if the given FoxPro database has a date type, SSIS assumes it is an integer type. The only way to convert it to a dateTime type is to manually select this type. However, that is not practical to do for over 100 tables. Thus, I have been using a workaround in which I use DTS on SQL Server 2000 which converts it to a smallDateTime, then make a backup, then a restore into SQL Server 2005. This workaround is starting to be a little annoying. So, my question is: Is there anyway to setup SSIS so that whenever it encounters a date type to automatically assume it should be converted to a dateTime in SQL Server and apply that rule across the board? Update To be specific, if I use the import/export wizard in SSIS, I get the following error: Column information for the source and the destination data could not be retrieved, or the data types of source columns were not mapped correctly to those available on the destination provider. Followed by a list of a given table's date columns. If I manually set each one to a dateTime, it imports fine. But I do not wish to do this for a hundred tables.

  Read the article

• MVVM pattern: ViewModel updates after Model server roundtrip

  - by Pavel Savara

  I have stateless services and anemic domain objects on server side. Model between server and client is POCO DTO. The client should become MVVM. The model could be graph of about 100 instances of 20 different classes. The client editor contains diverse tab-pages all of them live-connected to model/viewmodel. My problem is how to propagate changes after server round-trip nice way. It's quite easy to propagate changes from ViewModel to DTO. For way back it would be possible to throw away old DTO and replace it whole with new one, but it will cause lot of redrawing for lists/DataTemplates. I could gather the server side changes and transmit them to client side. But the names of fields changed would be domain/DTO specific, not ViewModel specific. And the mapping seems nontrivial to me. If I should do it imperative way after round-trip, it would break SOC/modularity of viewModels. I'm thinking about some kind of mapping rule engine, something like automappper or emit mapper. But it solves just very plain use-cases. I don't see how it would map/propagate/convert adding items to list or removal. How to identify instances in collections so it could merge values to existing instances. As well it should propagate validation/error info. Maybe I should implement INotifyPropertyChanged on DTO and try to replay server side events on it ? And then bind ViewModel to it ? Would binding solve the problems with collection merges nice way ? Is EventAgregator from PRISM useful for that ? Is there any event record-replay component ? Is there better client side pattern for architecture with server side logic ?

  Read the article

• Can I serialize an object if I didn't write the class used to instantiate that object?

  - by Richard77

  Hello, I've a simple class [Serializable] public class MyClass { public String FirstName { get; set: } public String LastName { get; set: } //Bellow is what I would like to do //But, it's not working //I get an exception ContactDataContext db = new ContactDataContext(); public void Save() { Contact contact = new Contact(); contact.FirstName = FirstName; contact.LastName = LastName; db.Contacts.InsertOnSubmit(contact); db.SubmitChanges(); } } I wanted to attach a Save method to the class so that I could call it on each object. When I introduced the above statement which contains ContactDataContext, I got the following error "In assembly ... PublicKeyToken=null' is not marked as serializable" It's clear that the DataContext class is generated by the framework (). I checked and did not see where that class was marked serialize. What can I do to overcome that? What's the rule when I'm not the author of a class? Just go ahead and mark the DataContext class as serializable, and pretend that everything will work? Thanks for helping

  Read the article

• Python Post Upload JPEG to Server?

  - by iJames

  It seems like this answer has been provided a bunch of times but in all of it, I'm still getting errors from the server and I'm sure it has to do with my code. I've tried HTTP, and HTTPConnection from httplib and both create quite different terminal outputs in terms of formatting/encoding so I'm not sure where the problem lies. Does anything stand out here? Or is there just a better way? Pieced together from an ancient article because I really needed to understand the basis of creating the post: http://code.activestate.com/recipes/146306-http-client-to-post-using-multipartform-data/ Note, the jpeg is supposed to be "unformatted". The pseudocode: boundary = "somerandomsetofchars" BOUNDARY = '--' + boundary CRLF = '\r\n' fields = [('aspecialkey','thevalueofthekey')] files = [('Image.Data','mypicture.jpg','/users/home/me/mypicture.jpg')] bodylines = [] for (key, value) in fields: bodylines.append(BOUNDARY) bodylines.append('Content-Disposition: form-data; name="%s"' % key) bodylines.append('') bodylines.append(value) for (key, filename, fileloc) in files: bodylines.append(BOUNDARY) bodylines.append('Content-Disposition: form-data; name="%s"; filename="%s"' % (key, filename)) bodylines.append('Content-Type: %s' % self.get_content_type(fileloc)) bodylines.append('') bodylines.append(open(fileloc,'r').read()) bodylines.append(BOUNDARY + '--') bodylines.append('') #print bodylines content_type = 'multipart/form-data; boundary=%s' % BOUNDARY body = CRLF.join(bodylines) #conn = httplib.HTTP("www.ahost.com") # In both this and below, the file part was garbling the rest of the body?!? conn = httplib.HTTPConnection("www.ahost.com") conn.putrequest('POST', "/myuploadlocation/uploadimage") headers = { 'content-length': str(len(body)), 'Content-Type' : content_type, 'User-Agent' : 'myagent' } for headerkey in headers: conn.putheader(headerkey, headers[headerkey]) conn.endheaders() conn.send(body) response = conn.getresponse() result = response.read() responseheaders = response.getheaders() It's interesting in that the real code I've implemented seems to work and is getting back valid responses, but the problem it it's telling me that it can't find the image data. Maybe this is particular to the server, but I'm just trying to rule out that I'm not doing some thing exceptionally stupid here. Or perhaps there's other methodologies for doing this more efficiently. I've not tried poster yet because I want to make sure I'm formatting the POST correctly first. I figure I can upgrade to poster after it's working yes?

  Read the article

• How can I build the Boost.Python example on Ubuntu 9.10?

  - by Gatlin

  I am using Ubuntu 9.10 beta, whose repositories contain boost 1.38. I would like to build the hello-world example. I followed the instructions here (http://www.boost.org/doc/libs/1%5F40%5F0/libs/python/doc/tutorial/doc/html/python/hello.html), found the example project, and issued the "bjam" command. I have installed bjam and boost-build. I get the following output: Jamroot:18: in modules.load rule python-extension unknown in module Jamfile</usr/share/doc/libboost1.38-doc/examples/libs/python/example>. /usr/share/boost-build/build/project.jam:312: in load-jamfile /usr/share/boost-build/build/project.jam:68: in load /usr/share/boost-build/build/project.jam:170: in project.find /usr/share/boost-build/build-system.jam:248: in load /usr/share/boost-build/kernel/modules.jam:261: in import /usr/share/boost-build/kernel/bootstrap.jam:132: in boost-build /usr/share/doc/libboost1.38-doc/examples/libs/python/example/boost-build.jam:7: in module scope I do not know enough about Boost (this is an exploratory exercise for myself) to understand why the python-extension macro in the included Jamroot is not valid. I am running this example from the install directory, so I have not altered the Jamroot's use-project setting. As a side question, if I were to just willy-nilly start a project in an arbitrary directory, how would I write my jamroot?

  Read the article

• XSD any element

  - by ofer shwartz

  HI! I'm trying to create a list that some of the elements are defined and some are not, without priority to order. I tried it this way, with an any element: <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:complexType name="object" mixed="true"> <xs:choice> <xs:element name="value" minOccurs="1" maxOccurs="1"> <xs:simpleType> <xs:restriction base="xs:integer"> <xs:enumeration value="1"/> </xs:restriction> </xs:simpleType> </xs:element> <xs:any namespace="##any" processContents="skip"/> </xs:choice> </xs:complexType> <xs:element name="object" type="object"/> </xs:schema> And it tells me this error: :0:0: error: complex type 'object' violates the unique particle attribution rule in its components 'value' and '##any' Can someone help me out solve the problem? Ofer

  Read the article

• @WebServices as @Stateless session bean in ejb jar

  - by kislo_metal

  Hi! Scenario: Creating some web service as @Stateless bean, package it as ejb jar. Result - can`t access to wsdl file. Goal: I want to use @WebServices as @Stateless session using ejb jar packaging with accessible wsdl file form web. Web service: @Stateless @WebService(serviceName = "ws.isp.SecurityService", wsdlLocation = "META-INF/wsdl/SecurityService.wsdl") public class SecurityService{ @EJB private Kerberos factory; @EJB private UsersServiceBean uService; public SecurityService() { } @WebMethod @WebResult(name = "SimpleResponse") public SimpleResponse LogOut( @WebParam(name = "sessionUUID", targetNamespace = "https://secure.co.ua/ws/") String sessionUUID ) { SimpleResponse resp = new SimpleResponse(); try{ factory.removeSession(sessionUUID); resp.setError(WSErrorCodes.SUCCESS); }catch (Exception e){ e.printStackTrace(); resp.setError(WSErrorCodes.UNRELOSVED_ERROR); } return resp; } @WebMethod public MySession logIn( @WebParam(name = "username", targetNamespace = "https://secure.co.ua/ws/") String username, @WebParam(name = "password", targetNamespace = "https://secure.co.ua/ws/") String password){ MySession result = new MySession(); try { UserSession us = factory.creatSession(uService.getUser(username, password).getId()); result.setSessionID(us.getSessionUUID().toString()); result.setError(WSErrorCodes.SUCCESS); } catch (NullPointerException e){ e.printStackTrace(); result.setError(WSErrorCodes.UNRELOSVED_USER); } catch (Exception e){ e.printStackTrace(); result.setError(WSErrorCodes.UNRELOSVED_ERROR); } return result; } } In this case I getting Invalid wsdl request http://192.168.44.48:8181/ws.isp.SecurityService/SecurityService when I try to access to wsdl and if do not use description of wsdlLocation I getting blank page. Web service as it self working good. Q1: what is the rule of describing wsdl file location for web services as stateless in ejb jar. Q2: is it possible to generate wsdl file during maven packaging ? Q3: how to generate wsdl file for web service where we have such annotation as @Stateless and @EJB (currently I can generate it only by commenting those annotations) environment: mave 2, ejb 3.1, glassfish v3, jax-ws 2.x Thank you!

  Read the article

• SSIS - Bulk Update at Database Field Level

  - by Adam

  Hello, Here's our mission: Receive files from clients. Each file contains anywhere from 1 to 1,000,000 records. Records are loaded to a staging area and business-rule validation is applied. Valid records are then pumped into an OLTP database in a batch fashion, with the following rules: If record does not exist (we have a key, so this isn't an issue), create it. If record exists, optionally update each database field. The decision is made based on one of 3 factors...I don't believe it's important what those factors are. Our main problem is finding an efficient method of optionally updating the data at a field level. This is applicable across ~12 different database tables, with anywhere from 10 to 150 fields in each table (original DB design leaves much to be desired, but it is what it is). Our first attempt has been to introduce a table that mirrors the staging environment (1 field in staging for each system field) and contains a masking flag. The value of the masking flag represents the 3 factors. We've then put an UPDATE similar to... UPDATE OLTPTable1 SET Field1 = CASE WHEN Mask.Field1 = 0 THEN Staging.Field1 WHEN Mask.Field1 = 1 THEN COALESCE( Staging.Field1 , OLTPTable1.Field1 ) WHEN Mask.Field1 = 2 THEN COALESCE( OLTPTable1.Field1 , Staging.Field1 ) ... As you can imagine, the performance is rather horrendous. Has anyone tackled a similar requirement? We're a MS shop using a Windows Service to launch SSIS packages that handle the data processing. Unfortunately, we're pretty much novices at this stuff.

  Read the article

• Is MVVM killing silverlight development?

  - by DeanMc

  This is a question I have had rattling around in my head for some time. I had a chat with a guy the other night who told me he would not be using the navigational framework because he could not figure out how it works with MVVM. As much as I tried to explain that patterns should be taken with a pinch of salt he would not listen. My point is this, patterns are great when they solve some problem. Sometimes only part of the pattern solves a particular problem while the other parts of it cause different problems. The goal of any developer is to build a solid application using a combination of patterns know how and foresight. I feel MVVM is becoming the one pattern to rule them all. As it is not directly supported by .Net some fancy business is needed to make it work. I feel that people are missing the point of the pattern, which is loosely coupled, testable code and instead jumping through hoops and missing out on great experiences trying to follow MVVM to the letter. MVVM is great but I wish it came with a warning or disclaimer for newbies as my fear is people will shy away from silverlight development for fear of being smacked with the mvvm stick. EDIT: Can I just add as an edit, I use and agree with MVVM as a pattern I know when it is and isn't feasible in my projects. My issue is with the encompassing nature it is taking, as if it HAS to be used as part of development. It is being used as an integral feature and not a pattern, which it is.

  Read the article

• URL rewriting to a common end point

  - by sunil

  I want to create an asp.net white-label site http://whitelabel.com, that could be styled for each of our clients according to their specific needs. So for example, client abc would see the site in their corporate colours and be accessed through their specific url http://abc.com. Likewise client xyz would see the site in their own styling and url http://xyz.com. Typing either url, in effect, takes the user to http://whitelabel.com where the styling is applied, and the client's url structure is retained. I was thinking of URL rewriting using URLRewriter.Net (http://urlrewriter.net/), or similar, mapping the incoming address to a client id and applying the theme accordingly. So, a url rewrite rule may be something like <rewrite url="http//abc.com/(.+)" to="~/$1?id=1" /> <rewrite url="http//xyz.com/(.+)" to="~/$1?id=2" /> I could then read the id, map it to the client, and with a bit of jiggery-pokery, apply the correct theme. I was wondering if: this is the right approach ? I've overlooked something ? there is a better way to do this ? Any suggestions would be appreciated.

  Read the article

• howto distinguish composition and self-typing use-cases

  - by ayvango

  Scala has two instruments for expressing object composition: original self-type concept and well known trivial composition. I'm curios what situations I should use which in. There are obvious differences in their applicability. Self-type requires you to use traits. Object composition allows you to change extensions on run-time with var declaration. Leaving technical details behind I can figure two indicators to help with classification of use cases. If some object used as combinator for a complex structure such as tree or just have several similar typed parts (1 car to 4 wheels relation) than it should use composition. There is extreme opposite use case. Lets assume one trait become too big to clearly observe it and it got split. It is quite natural that you should use self-types for this case. That rules are not absolute. You may do extra work to convert code between this techniques. e.g. you may replace 4 wheels composition with self-typing over Product4. You may use Cake[T <: MyType] {part : MyType} instead of Cake { this : MyType => } for cake pattern dependencies. But both cases seem counterintuitive and give you extra work. There are plenty of boundary use cases although. One-to-one relations is very hard to decide with. Is there any simple rule to decide what kind of technique is preferable? self-type makes you classes abstract, composition makes your code verbose. self-type gives your problems with blending namespaces and also gives you extra typing for free (you got not just a cocktail of two elements but gasoline-motor oil cocktail known as a petrol bomb). How can I choose between them? What hints are there? Update: Let us discuss the following example: Adapter pattern. What benefits it has with both selt-typing and composition approaches?

  Read the article

• Help regarding Android NDK

  - by Siva Kumar

  I am a beginner in using Android NDK. I am using Eclipse and I installed cygwin to build the c file to generate the .so file But while building the c file in cygwin I am always getting the error make: ***No rule to make target 'file.c' ... .Stop I tried building different C codes but for every file it says the same error .. Here is the source code: public class ndktest extends Activity { static { System.loadLibrary("ndkt"); } private native void helloLog(String logThis); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); helloLog("this is to test log file"); } } file.c void Java_com_ndktest_helloLog(JNIEnv * env, jobject this, jstring logThis) { jboolean isCopy; const char * szLogThis = (*env)->GetStringUTFChars(env, logThis, &isCopy); (*env)->ReleaseStringUTFChars(env, logThis, szLogThis); } And here is my Android.mk LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_LDLIBS := -llog LOCAL_MODULE := ndkt LOCAL_SRC_FILES := file.c include $(BUILD_SHARED_LIBRARY) I searched for the solution for the cause of error ... but nothing works for me. Can anyone tell me where I am making the mistake ? Thanks, Siva Kumar

  Read the article

• Enums, Constructor overloads with similar conversions.

  - by David Thornley

  Why does VisualC++ (2008) get confused 'C2666: 2 overloads have similar conversions' when I specify an enum as the second parameter, but not when I define a bool type? Shouldn't type matching already rule out the second constructor because it is of a 'basic_string' type? #include <string> using namespace std; enum EMyEnum { mbOne, mbTwo }; class test { public: #if 1 // 0 = COMPILE_OK, 1 = COMPILE_FAIL test(basic_string<char> myString, EMyEnum myBool2) { } test(bool myBool, bool myBool2) { } #else test(basic_string<char> myString, bool myBool2) { } test(bool myBool, bool myBool2) { } #endif }; void testme() { test("test", mbOne); } I can work around this by specifying a reference 'ie. basic_string &myString' but not if it is 'const basic_string &myString'. Also calling explicitly via "test((basic_string)"test", mbOne);" also works. I suspect this has something to do with every expression/type being resolved to a bool via an inherent '!=0'. Curious for comments all the same :)

  Read the article

• Why do mozilla and webkit prepend -moz- and -webkit- to CSS3 rules?

  - by egarcia

  CSS3 rules bring lots of interesting features. Take border-radius, for example. The standard says that if you write this rule: div.rounded-corners { border-radius: 5px; } I should get a 5px border radius. But neither mozilla nor webkit implement this. However, they implement the same thing, with the same parameters, with a different name (-moz-border-radius and -webkit-border-radius, respectively). In order to satisfy as many browsers as possible, you end up with this: div.rounded-corners { border-radius: 5px; -moz-border-radius: 5px; -webkit-border-radius: 5px; } I can see two obvious disadvantages: Copy-paste code. This has obvious risks that I will not discuss here. The W3C CSS validator will not validate these rules. At the same time, I don't see any obvious advantages. I believe that the people behind mozilla and webkit are more intelligent than myself. There must be some good reasons to have things structured this way. It's just that I can't see them. So, I must ask you people: why is this?

  Read the article

• POST xml to php with apache2

  - by Berry

  I'm working on an application that receives XML data via POST, processes it with a PHP script, and returns an XML response. I'm getting the XML with this PHP code: $requestStr = file_get_contents('php://input'); $requests = simplexml_load_string($requestStr); which works fine on the Linux-based product hardware using nginx as the server. However, for testing I'd like to be able to run it on my MacBook Pro, so I can avoid the "build image, install on product, reboot product, wait, test change" loop while I do targeted development on this XML processor. I enabled "web sharing" which starts up Apache, added a rewrite rule to point a convenient URI at my development source directory and used curl to send a request to my PHP script thus: curl -H "Content-Type:text/xml" -d @request.xml http://localhost/test/path/testscript "testscript" is handled by the PHP script fine, but when it goes to read "php:://input" I get nothing -- the empty string. Anyone have a clue why this would work under Linux with nginx and not under MacOS with Apache? I've googled and searched stackoverlow.com to no avail. Thanks for any answers. UPDATE: I've discovered that at least in this configuration, reading from php://stdin will work fine, while php://input will not. Who knew?

  Read the article

• Is saving to database just to get an ID a bad hack?

  - by Narsil

  I hope the title is not too confusing. I am trying to make folders with linq-to-sql objects' IDs. Actually I have to create folders before I should save them. I will use them to keep user uploaded files. As you can see I have to create the folder with the FileID before I can save it there. So I just save a record which will be edited or maybe deleted File newFile = new File(); ...//add some values to fields so they don't throw rule violations db.AddFile(newFile); db.Save(); System.IO.Directory.CreateDirectory("..Uploads/"+newFile.FileId.ToString()); After that I will have to edit some fields and save again. Of course user might stop upload and I would have to delete it. I know I can write a stored procedure to get the next available FileID but some other upload happening at the same time would get the same number. So they would write in same directory which is a thing I don't want. Should I go on with this, would there be some problems? Can you think of a better way?

  Read the article

• MSI Installer start auto-repair when service starts

  - by Josh Clark

  I have a WiX based MSI that installs a service and some shortcuts (and lots of other files that don't). The shortcut is created as described in the WiX docs with a registry key under HKCU as the key file. This is an all users install, but to get past ICE38, this registry key has to be under the current user. When the service starts (it runs under the SYSTEM account) it notices that that registry key isn't valid (at least of that user) and runs the install again to "repair". In the Event Log I get MsiInstaller Events 1001 and 1004 showing that "The resource 'HKEY_CURRENT_USER\SOFTWARE\MyInstaller\Foo' does not exist." This isn't surprising since the SYSTEM user wouldn't have this key. I turned on system wide MSI logging and the auto-repair created its log file in the C:\Windows\Temp folder rather than a specific user's TEMP folder which seems to imply the current user was SYSTEM (plus the log file shows the "Calling process" to be my service). Is there something I can do to disable the auto-repair functionality? Am I doing something wrong or breaking some MSI rule? Any hints on where to look next?

  Read the article

• Are finalizers ever allowed to call other managed classes' methods?

  - by romkyns

  I used to be pretty sure the answer is "no", as explained in Overriding the Finalize method and Object.Finalize documentation. However, while randomly browsing through FileStream in Reflector, I found that it can actually call just such a method from a finalizer: private SafeFileHandle _handle; ~FileStream() { if (this._handle != null) { this.Dispose(false); } } protected override void Dispose(bool disposing) { try { ... } finally { if ((this._handle != null) && !this._handle.IsClosed) // <=== HERE { this._handle.Dispose(); // <=== AND HERE } [...] } } I started wondering whether this will always work due to the exact way in which it's written, and hence whether the "do not touch managed classes from finalizers" is just a guideline that can be broken given a good reason and the necessary knowledge to do it right. I dug a bit deeper and found out that the worst that can happen when the "rule" is broken is that the managed object being accessed had already been finalized, or may be getting finalized in parallel on a separate thread. So if the SafeFileHandle's finalizer didn't do anything that would cause a subsequent call to Dispose fail then the above should be fine... right? Question: so there might after all be situations in which a method on another managed class may be called reliably from a finalizer? I've always believed this to be false, but this code suggests that it's possible and that there can be good enough reasons to do it. Bonus: Observe that the SafeFileHandle will not even know it's being called from a finalizer, since this is just a normal call to Dispose(). The base class, SafeHandle, actually has two private methods, InternalDispose and InternalFinalize, and in this case InternalDispose will be called. Isn't this a problem? Why not?...

  Read the article

• How do you refactor a large messy codebase?

  - by Ricket

  I have a big mess of code. Admittedly, I wrote it myself - a year ago. It's not well commented but it's not very complicated either, so I can understand it -- just not well enough to know where to start as far as refactoring it. I violated every rule that I have read about over the past year. There are classes with multiple responsibilities, there are indirect accesses (I forget the technical term - something like foo.bar.doSomething()), and like I said it is not well commented. On top of that, it's the beginnings of a game, so the graphics is coupled with the data, or the places where I tried to decouple graphics and data, I made the data public in order for the graphics to be able to access the data it needs... It's a huge mess! Where do I start? How would you start on something like this? My current approach is to take variables and switch them to private and then refactor the pieces that break, but that doesn't seem to be enough. Please suggest other strategies for wading through this mess and turning it into something clean so that I can continue where I left off!

  Read the article

• Nested parsers in happy / infinite loop?

  - by McManiaC

  I'm trying to write a parser for a simple markup language with happy. Currently, I'm having some issues with infinit loops and nested elements. My markup language basicly consists of two elements, one for "normal" text and one for bold/emphasized text. data Markup = MarkupText String | MarkupEmph [Markup] For example, a text like Foo *bar* should get parsed as [MarkupText "Foo ", MarkupEmph [MarkupText "bar"]]. Lexing of that example works fine, but the parsing it results in an infinite loop - and I can't see why. This is my current approach: -- The main parser: Parsing a list of "Markup" Markups :: { [Markup] } : Markups Markup { $1 ++ [$2] } | Markup { [$1] } -- One single markup element Markup :: { Markup } : '*' Markups1 '*' { MarkupEmph $2 } | Markup1 { $1 } -- The nested list inside *..* Markups1 :: { [Markup] } : Markups1 Markup1 { $1 ++ [$2] } | Markup1 { [$1] } -- Markup which is always available: Markup1 :: { Markup } : String { MarkupText $1 } What's wrong with that approach? How could the be resolved? Update: Sorry. Lexing wasn't working as expected. The infinit loop was inside the lexer. Sorry. :) Update 2: On request, I'm using this as lexer: lexer :: String -> [Token] lexer [] = [] lexer str@(c:cs) | c == '*' = TokenSymbol "*" : lexer cs -- ...more rules... | otherwise = TokenString val : lexer rest where (val, rest) = span isValidChar str isValidChar = (/= '*') The infinit recursion occured because I had lexer str instead of lexer cs in that first rule for '*'. Didn't see it because my actual code was a bit more complex. :)

  Read the article

• wpf & validation application block > message localization > messageTemplateResource Name&Type

  - by Shaboboo

  I'm trying to write validation rules for my data objects in a WPF application. I'm writing them in the configuration file, and so far they are working fine. I'm stumped on how to localize the messages using messageTemplateResourceName and messageTemplateResourceType. What I know is that the strings can be writen in a resource file, given a name and referenced by that name. I get the idea, but i haven't been able to make this work. <ruleset name="Rule Set"> <properties> <property name="StringValue"> <validator lowerBound="0" lowerBoundType="Ignore" upperBound="25" upperBoundType="Inclusive" negated="false" messageTemplate="" messageTemplateResourceName="msg1" messageTemplateResourceType="Resources" tag="" type="Microsoft.Practices.EnterpriseLibrary.Validation.Validators.StringLengthValidator, Microsoft.Practices.EnterpriseLibrary.Validation" name="String Length Validator" /> </property> </properties> </ruleset> Where is the resource file and what value do I pass to messageTemplateResourceType? I have tried writing the messages in the shell project's resource file but no sucess trying to retrieve the value. I only get the default built-in message. I've tried messageTemplateResourceType="typeof(Resources)" messageTemplateResourceType="Resources" messageTemplateResourceType="Resources.resx" messageTemplateResourceType="typeof(Shell)" messageTemplateResourceType="Shell" messageTemplateResourceType="Shell, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" I've also tried adding a new resource file in the shell project, and adding a resource file to the data object's library. I'm all out of ideas Does anyone have any suggestions? I'm not even married to the idea of resource files, so if there are other ways to localize these messages I'd love to know! thanks

  Read the article

• Binary Search Tree for specific intent

  - by Luís Guilherme

  We all know there are plenty of self-balancing binary search trees (BST), being the most famous the Red-Black and the AVL. It might be useful to take a look at AA-trees and scapegoat trees too. I want to do deletions insertions and searches, like any other BST. However, it will be common to delete all values in a given range, or deleting whole subtrees. So: I want to insert, search, remove values in O(log n) (balanced tree). I would like to delete a subtree, keeping the whole tree balanced, in O(log n) (worst-case or amortized) It might be useful to delete several values in a row, before balancing the tree I will most often insert 2 values at once, however this is not a rule (just a tip in case there is a tree data structure that takes this into account) Is there a variant of AVL or RB that helps me on this? Scapegoat-trees look more like this, but would also need some changes, anyone who has got experience on them can share some thougts? More precisely, which balancing procedure and/or removal procedure would help me keep this actions time-efficient?

  Read the article

< Previous Page | 342 343 344 345 346 347 348 349 350 351 352 353  | Next Page >