Search Results

Search found 55766 results on 2231 pages for 'error handling'.

Page 151/2231 | < Previous Page | 147 148 149 150 151 152 153 154 155 156 157 158  | Next Page >

• Capturing USB Plug/Unplug events in Firemonkey

  - by radsdau

  [RAD Studio XE3 / C++] I have a FMX project running in Windows only at this stage, but I need to detect events when USB devices are connected and disconnected. I have a similar VCL app that can do this fine, but the Application-HookMainWindow is not exposed in FMX (only VCL). Is there an elegant way to handle this? Or do I have to hack some VCL stuff into my FMX app to make that work? I'd imagine I have to abstract it so I can support other platforms down the track. For the meantime though I need to get the Windows solution working. If the 'VCL hack' thing is required, how would I reference the vcl::Forms::Application from within my Fmx app? Cheers.

  Read the article

• Does Delphi really handle dynamic classes better than static?

  - by John

  Hello, I was told more than once that Delphi handles dynamic classes better than static.Thereby using the following: type Tsomeclass=class(TObject) private procedure proc1; public someint:integer; procedure proc2; end; var someclass:TSomeclass; implementation ... initialization someclass:=TSomeclass.Create; finalization someclass.Free; rather than type Tsomeclass=class private class procedure proc1; public var someint:integer; class procedure proc2; end; 90% of the classes in the project I'm working on have and need only one instance.Do I really have to use the first way for using those classes? Is it better optimized,handled by Delphi? Sorry,I have no arguments to backup this hypothesis,but I want an expert's opinion. Thanks in advance!

  Read the article

• What do programs see when ZFS can't deliver uncorrupted data?

  - by Jay Kominek

  Say my program attempts a read of a byte in a file on a ZFS filesystem. ZFS can locate a copy of the necessary block, but cannot locate any copy with a valid checksum (they're all corrupted, or the only disks present have corrupted copies). What does my program see, in terms of the return value from the read, and the byte it tried to read? And is there a way to influence the behavior (under Solaris, or any other ZFS-implementing OS), that is, force failure, or force success, with potentially corrupt data?

  Read the article

• django handling file uploads - target different than media folder

  - by Tom Tom

  Hi, I want to enable the user to upload media which will not be saved in the media folder. When I use the following line of code data will be uploaded to media/upload/logo . logo_img = models.FileField(upload_to='upload/logo', blank=True) I'm wondering how I can change this behaviour. I would try to write a custom FileField and a view that serves the data based on the database entries. I do not want to place the data the user uploads to the media folder, since it is no public data. Is this approach correct? Are there solutions out there which do exactly what I want and I would reinvent the wheel with implementing this by myself? Would appreciate any help!

  Read the article

• How do I implement a fibonacci sequence in java using try/catch logic?

  - by Lars Flyger

  I know how to do it using simple recursion, but in order to complete this particular assignment I need to be able to accumulate on the stack and throw an exception that holds the answer in it. So far I have: public static int fibo(int index) { int sum = 0; try { fibo_aux(index, 1, 1); } catch (IntegerException me) { sum = me.getIntValue(); } return sum; } fibo_aux is supposed to throw an IntegerException (which holds the value of the answer that is retireved via getIntValue) and accumulates the answer on the stack, but so far I can't figure it out. Can anyone help?

  Read the article

• How can I dynamically inject code into event handlers in Delphi?

  - by mjustin

  For debugging / performance tests I would like to dynamically add logging code to all event handlers of components of a given type. For example, for all Dataset components located ona TDatamodule, I would like to add some code for the BeforeOpen and the AfterOpen event to store the start and end time and send a line to a logger with the elapsed time in the AfterOpen event. I would prefer to do this dynamically (no component subclassing), so that I can add this to all existing datamodules and forms with minimal effort only when needed. Iterating all components and filtering by their type is easy, but for the components which already have event handlers assigned, I need a way to store the existing event handlers, and assign a new modified event handler which first does the logging and then will invoke the original code which was already present. Is there a design pattern which can be applied, or even some example code which shows how to implement this in Delphi?

  Read the article

• Is it okay to use try catch inside finally?

  - by Hiral Lakdavala

  Hi, I am using a buffered writer and my code, closes the writer in the finally block. My code is like this. ........... BufferedWriter theBufferedWriter = null; try{ theBufferedWriter =..... .... ...... ..... } catch (IOException anException) { .... } finally { try { theBufferedWriter.close(); } catch (IOException anException) { anException.printStackTrace(); } } I have to use the try catch inside the clean up code in finally as theBufferedWriter might also throw an IOException. I do not want to throw this exception to the calling methos. Is it a good practice to use a try catch in finally? If not what is the alternative? Please suggest. Regards, Hiral

  Read the article

• GWT removeHandler on first event notification

  - by Keith

  I want to remove a GWT event handler the first time I receive an event. I also want to avoid polluting my class with tracking registration objects that aren't really necessary. I currently have it coded as: final HandlerRegistration[] registrationRef = new HandlerRegistration[1]; registrationRef[0] = dialog.addFooHandler(new FooHandler() { public void onFoo(FooEvent event) { HandlerRegistration removeMe = registrationRef[0]; if(removeMe != null) { removeMe.removeHandler(); } // do stuff here } }); but the use of registrationRef makes the code less readable. Is there a better way to do this without adding variables to my class?

  Read the article

• Customizing error handling of JAXB unmarshall process

  - by ekeren

  Assuming I have a schema that describes a root element class Root that contains a List<Entry> where the Entry class has a required field name. Here is how it looks in code: @XmlRootElement class Root{ @XmlElement(name="entry") public List<Entry> entries = Lists.newArrayList(); } @XmlRootElement class Entry{ @XmlElement(name="name",required=true) public String name; } If I supply the following XML for unmarshalling: <root> <entry> <name>ekeren</name> </entry> <entry> </entry> </root> I have a problem because the second entry does not contain a name. So unmarshall produces null. Is there a way to customize JAXB to unmarshall a Root object that will only contain the "good" entry?

  Read the article

• OOP - Handling Automated Instances of a Class - PHP

  - by dscher

  This is a topic that, as a beginner to PHP and programming, sort of perplexes me. I'm building a stockmarket website and want users to add their own stocks. I can clearly see the benefit of having each stock be a class instance with all the methods of a class. What I am stumped on is the best way to give that instance a name when I instantiate it. If I have: class Stock() { ....doing stuff..... } what is the best way to give my instances of it a name. Obviously I can write: $newStock = new Stock(); $newStock.getPrice(); or whatever, but if a user adds a stock via the app, where can the name of that instance come from? I guess that there is little harm in always creating a new child with $newStock = new Stock() and then storing that to the DB which leads me to my next question! What would be the best way to retrieve 20 user stocks(for example) into instances of class Stock()? Do I need to instantiate 20 new instances of class Stock() every time the user logs in or is there something I'm missing? I hope someone answers this and more important hope a bunch of people answer this and it somehow helps someone else who is having a hard time wrapping their head around what probably leads to a really elegant solution. Thanks guys!

  Read the article

• Handling Datetime with decimal '2010-02-14 20:18:58.313000000'

  - by AaronLS

  In SQL Server I have some textual data in varchar fields I am trying to convert to datetime's. The funny thing is this data at some point was in a datetime field, exported to flat file, and now I am reimporting it. The problem is it is in this format 2010-02-14 20:18:58.313000000 and the conversion to datetime fails. I have no idea how it ended up like this when it was originally extracted from a datetime column. Basically a table was exported to a flat file by someone else. The original table was lost. I am reimporting back from the flatfile. I could just drop the decimal but this would be like throwing out some of the data. I'd like to maintain as much precision as possible. How can I import this data from the varchar column back into a datetime column and preserve as much accuracy as possible?

  Read the article

• Delphi : Handling the fact that Strings are not Objects

  - by awmross

  I am trying to write a function that takes any TList and returns a String representation of all the elements of the TList. I tried a function like so function ListToString(list:TList<TObject>):String; This works fine, except you can't pass a TList to it. E2010 Incompatible types: 'TList<System.TObject>' and 'TList<System.string>' In Delphi, a String is not an Object. To solve this, I've written a second function: function StringListToString(list:TList<string>):String; Is this the only solution? Are there other ways to treat a String as more 'object-like'? In a similar vein, I also wanted to write an 'equals' function to compare two TLists. Again I run into the same problem function AreListsEqual(list1:TList<TObject>; list2:TList<TObject>):boolean; Is there any way to write this function (perhaps using generics?) so it can also handle a TList? Are there any other tricks or 'best practises' I should know about when trying to create code that handles both Strings and Objects? Or do I just create two versions of every function? Can generics help? I am from a Java background but now work in Delphi. It seems they are lately adding a lot of things to Delphi from the Java world (or perhaps the C# world, which copied them from Java). Like adding equals() and hashcode() to TObject, and creating a generic Collections framework etc. I'm wondering if these additions are very practical if you can't use Strings with them.

  Read the article

• Handling undo and edit flag on window with several model objects

  - by Rui Pacheco

  Hi, I've a window that will hold several instances of a model object, listed in a table. The model object is updated using a text view. What is the best way to keep the edit flag and undo manager in synch with the content of the different model objects? I'm thinking creating an instance of the undo manager on the model object and manually set the undo manager for the text view every time the user choses a new model object. Does the undo manager also handle the edited flag?

  Read the article

• Handling Google clientLogin Captcha Example

  - by Yan Cheng CHEOK

  I have a desktop application. I try to perform authentication using http://code.google.com/apis/accounts/docs/AuthForInstalledApps.html However, whenever I get a Captcha challenge, I use a HTTP GET request (I test using web browser) to get the image to present to user. https://www.google.com/accounts/Captcha?ctoken=Y-DrsDJRiWNOP3gR7fq0PAq4Yxvi3UXewu7P7jgAKjk0eZKQ358nbh27-JZ3-nlzXvfKOD3JvZNXwmlRunyz8jPKzqmkOLw2LYb3ZWjg-tE%3A0gMUFttsSH7QwganSJd1aw However, I always get the images : Sorry, we are unable to handle your request at this time. Please try again later. Any idea what I had did wrong? Thanks!

  Read the article

• How can I dynamically inject code to event handlers in Delphi?

  - by mjustin

  For debugging / performance tests I would like to dynamically add logging code to all event handlers of components of a given type. For example, for all Dataset components located ona TDatamodule, I would like to add some code for the BeforeOpen and the AfterOpen event to store the start and end time and send a line to a logger with the elapsed time in the AfterOpen event. I would prefer to do this dynamically (no component subclassing), so that I can add this to all existing datamodules and forms with minimal effort only when needed. Iterating all components and filtering by their type is easy, but for the components which already have event handlers assigned, I need a way to store the existing event handlers, and assign a new modified event handler which first does the logging and then will invoke the original code which was already present. Is there a design pattern which can be applied, or even some example code which shows how to implement this in Delphi?

  Read the article

• Very weird C file-handling anomaly

  - by KáGé

  Hello, I got a very weird issue that I cant figure out in my school project, which is the simulation of a simple filesystem in a human-readable textfile. Unfortunately I don't yet have enough time to translate the comments in my code or make it less gibberish, so if you are bothered by that, you don't have to help, I understand. See the code HERE. Now in drive.h, at line 574 is this part: i = getline(); #ifdef DEBUG printf("Free space in all found at %d.\n\n", i); if(drive.disk != NULL){ printf("Disk OK\n\n"); } #endif //write in data state = seekline(i); Before this it finds place for the allocation database entry in the ALL sector (see the "image files" in the mounts folder, this issue was tested on mount_30.efs-dbf), then gets the line with i = getline() fine (getline is in lglobal.h, line 39), but after that any file manipulation (in this case seekline's fseek, but if I comment that out, then the first fprintf after that) crashes the program straight away. I think the file gets somehow corrupted (though the Disk OK message appears) but can't figure out how. I've tried putting i = getline(); into comment, but it didn't make any difference. I've also tried asking at local programming forums but they didn't really help either. The last few lines of the output before it crashes: Dir written. (drive.h line 562) Seekline entered: 268 (called at drive.h line 564) Getline entered. (called at drive.h line 574) Line got: 268. Free space in all found at 268. (drive.h line 576) Seekline entered: 268 (called at drive.h line 582, note that this exact call was run successfully less than 20 lines back. This one should set the pointer to the beginning of the line it is currently in) After this it crashes. Does anyone has any idea of what causes this and how could I fix it? Thank you.

  Read the article

• Drupal SQL injection attacks prevention and apostrophe handling in Forms

  - by jini

  in typical PHP applications I used to use mysql_real_escape_string before I did SQL inserts. However I am unable to do that in Drupal so would need some assistance. And without any sort of function like that, user input with apostrophes is breaking my code. Please suggest. Thank You My SQL is as follows: $sql = "INSERT INTO some_table (field1, field2) VALUES ('$field1', '$field2')"; db_query($sql);

  Read the article

• Handling learning curve for new developers

  - by pete the pagan-gerbil

  Our company likes to hire new developers, with no experience. We have a core set of skills that we try to get them up to speed with, like ASP.NET and WinForms - to teach basic programming, the .NET languages, and the things they'll need to maintain and write. We also try and mentor them through early projects, so they can learn from someone more experienced. Recently, we've been seeing the benefits of new frameworks like MVC and ideas like Unit Testing and TDD (by extension, dependancy injection and IoC), and we'd like to start using these in the team. However, this increases the time that a junior would have before they can get started on a new project - because doing something like unit tests wrong could cause major headaches months or years later in maintenance, especially if we believe unit tests to be comprehensive. How do you handle the huge amount of things that a junior will need to take on, acknowledging that the business wants them working independantly as soon as possible? Is it acceptable to tell them not to unit test till a while after they are independant (and give them small, simpler projects in the meantime) before taking them to 'level 2' of the core skills?

  Read the article

• Regexp for handling recursive arguments

  - by Matt

  Hi all, I'm a regexp novice, so I'm wondering what the regexp for the following: function {function arg1, arg2}, arg3 I'm looking to be able to just select the top-level arguments: {function arg1, arg2} & arg3 Ideally the response would be using preg_match in PHP, but almost any regexp would work fine. Thanks! Matt

  Read the article

• bad performance from too many caught errors?

  - by Christopher Klein

  I have a large project in C# (.NET 2.0) which contains very large chunks of code generated by SubSonic. Is a try-catch like this causing a horrible performance hit? for (int x = 0; x < identifiers.Count; x++) {decimal target = 0; try { target = Convert.ToDecimal(assets[x + identifiers.Count * 2]); // target % } catch { targetEmpty = true; }} What is happening is if the given field that is being passed in is not something that can be converted to a decimal it sets a flag which is then used further along in the record to determine something else. The problem is that the application is literally throwing 10s of thousands of exceptions as I am parsing through 30k records. The process as a whole takes almost 10 minutes for everything and my overall task is to improve that time some and this seemed like easy hanging fruit if its a bad design idea. Any thoughts would be helpful (be kind, its been a miserable day) thanks, Chris

  Read the article

• JPA Entity Manager resource handling

  - by chiragshahkapadia

  Every time I call JPA method its creating entity and binding query. My persistence properties are: <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect"/> <property name="hibernate.cache.provider_class" value="net.sf.ehcache.hibernate.SingletonEhCacheProvider"/> <property name="hibernate.cache.use_second_level_cache" value="true"/> <property name="hibernate.cache.use_query_cache" value="true"/> And I am creating entity manager the way shown below: emf = Persistence.createEntityManagerFactory("pu"); em = emf.createEntityManager(); em = Persistence.createEntityManagerFactory("pu").createEntityManager(); Is there any nice way to manage entity manager resource instead create new every time or any property can set in persistence. Remember it's JPA. See below binding log every time : 15:35:15,527 INFO [AnnotationBinder] Binding entity from annotated class: * 15:35:15,527 INFO [QueryBinder] Binding Named query: * = * 15:35:15,527 INFO [QueryBinder] Binding Named query: * = * 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [EntityBinder] Bind entity com.* on table * 15:35:15,542 INFO [HibernateSearchEventListenerRegister] Unable to find org.hibernate.search.event.FullTextIndexEventListener on the classpath. Hibernate Search is not enabled. 15:35:15,542 INFO [NamingHelper] JNDI InitialContext properties:{} 15:35:15,542 INFO [DatasourceConnectionProvider] Using datasource: 15:35:15,542 INFO [SettingsFactory] RDBMS: and Real Application Testing options 15:35:15,542 INFO [SettingsFactory] JDBC driver: Oracle JDBC driver, version: 9.2.0.1.0 15:35:15,542 INFO [Dialect] Using dialect: org.hibernate.dialect.Oracle10gDialect 15:35:15,542 INFO [TransactionFactoryFactory] Transaction strategy: org.hibernate.transaction.JDBCTransactionFactory 15:35:15,542 INFO [TransactionManagerLookupFactory] No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recomm ended) 15:35:15,542 INFO [SettingsFactory] Automatic flush during beforeCompletion(): disabled 15:35:15,542 INFO [SettingsFactory] Automatic session close at end of transaction: disabled 15:35:15,542 INFO [SettingsFactory] JDBC batch size: 15 15:35:15,542 INFO [SettingsFactory] JDBC batch updates for versioned data: disabled 15:35:15,542 INFO [SettingsFactory] Scrollable result sets: enabled 15:35:15,542 INFO [SettingsFactory] JDBC3 getGeneratedKeys(): disabled 15:35:15,542 INFO [SettingsFactory] Connection release mode: auto 15:35:15,542 INFO [SettingsFactory] Default batch fetch size: 1 15:35:15,542 INFO [SettingsFactory] Generate SQL with comments: disabled 15:35:15,542 INFO [SettingsFactory] Order SQL updates by primary key: disabled 15:35:15,542 INFO [SettingsFactory] Order SQL inserts for batching: disabled 15:35:15,542 INFO [SettingsFactory] Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory 15:35:15,542 INFO [ASTQueryTranslatorFactory] Using ASTQueryTranslatorFactory 15:35:15,542 INFO [SettingsFactory] Query language substitutions: {} 15:35:15,542 INFO [SettingsFactory] JPA-QL strict compliance: enabled 15:35:15,542 INFO [SettingsFactory] Second-level cache: enabled 15:35:15,542 INFO [SettingsFactory] Query cache: enabled 15:35:15,542 INFO [SettingsFactory] Cache region factory : org.hibernate.cache.impl.bridge.RegionFactoryCacheProviderBridge 15:35:15,542 INFO [RegionFactoryCacheProviderBridge] Cache provider: net.sf.ehcache.hibernate.SingletonEhCacheProvider 15:35:15,542 INFO [SettingsFactory] Optimize cache for minimal puts: disabled 15:35:15,542 INFO [SettingsFactory] Structured second-level cache entries: disabled 15:35:15,542 INFO [SettingsFactory] Query cache factory: org.hibernate.cache.StandardQueryCacheFactory 15:35:15,542 INFO [SettingsFactory] Statistics: disabled 15:35:15,542 INFO [SettingsFactory] Deleted entity synthetic identifier rollback: disabled 15:35:15,542 INFO [SettingsFactory] Default entity-mode: pojo 15:35:15,542 INFO [SettingsFactory] Named query checking : enabled 15:35:15,542 INFO [SessionFactoryImpl] building session factory 15:35:15,542 INFO [SessionFactoryObjectFactory] Not binding factory to JNDI, no JNDI name configured 15:35:15,542 INFO [UpdateTimestampsCache] starting update timestamps cache at region: org.hibernate.cache.UpdateTimestampsCache 15:35:15,542 INFO [StandardQueryCache] starting query cache at region: org.hibernate.cache.StandardQueryCache

  Read the article

• Handling duplicate nodes in XML

  - by JYelton

  Scenario: I am parsing values from an XML file using C# and have the following method: private static string GetXMLNodeValue(XmlNode basenode, string strNodePath) { if (basenode.SelectSingleNode(strNodePath) != null) return (basenode.SelectSingleNode(strNodePath).InnerText); else return String.Empty; } To get a particular value from the XML file, I generally pass the root node and a path like "parentnode/item" I recently ran into an issue where two nodes at the same document level share the same name. Question: What is the best way to get the values for duplicate-named nodes distinctly? My thought was to load all values matching the node name into an array and then using the array index to refer to them. I'm not sure how to implement that, though. (I'm not well-versed in XML navigation.)

  Read the article

• How to name an event handler of a private variable in Vb.Net following FxCop rules and Vb.Net standa

  - by SoMoS

  Hello, On one side, in Vb.Net when you add an event handler to an object the created method is named: <NameOfTheObject>_<NameOfTheMethod>. As I like to have consistent syntax I always follow this rule when creating event handlers by hand. On the other side when I create private variables I prefix them with m_ as this is a common thing used by the community, in C# people use to put _ at the beginning of a variable but this is no CLS compliant. At the end, when I create event handlers for events raised by private variables I end with Subs like m_myVariable_MyEvent. Code Analysis (Fx Cop) is complainig about this way of naming because the method does not start with uppercase and because the _, so the question is: What naming standards do you follow when creating event handlers by hand that follow the Fxcop rules if any? Thanks in advance.

  Read the article

• Should the PHP community start using more discriptive Exceptions?

  - by fireeyedboy

  I work with Zend Framework a lot and I just took a peek at Kohana, and it strikes me as odd that this is a typical scenario in these frameworks: throw Some_Componenents_Exception( 'invalid argument' ); Where I believe this wouldn't be mouch more useful: throw Some_Components_InvalidArgumentException( 'whatever discription' ); Because it is easier to catch. I suspect, but immediately admit it's prejudiced, that the former practice is common in the PHP community. Should we, the PHP community, start using these descriptive types of expections more?

  Read the article

• Client Web Browser Behavior When Handling 301 Redirect

  - by Jon Swanson

  The RFC seems to suggest that the client should permanently cache the response: http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html 10.3.2 301 Moved Permanently The requested resource has been assigned a new permanent URI and any future references to this resource SHOULD use one of the returned URIs. Clients with link editing capabilities ought to automatically re-link references to the Request-URI to one or more of the new references returned by the server, where possible. This response is cacheable unless indicated otherwise. The new permanent URI SHOULD be given by the Location field in the response. Unless the request method was HEAD, the entity of the response SHOULD contain a short hypertext note with a hyperlink to the new URI(s). If the 301 status code is received in response to a request other than GET or HEAD, the user agent MUST NOT automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued. Note: When automatically redirecting a POST request after receiving a 301 status code, some existing HTTP/1.0 user agents will erroneously change it into a GET request. I'm having a hard time finding concrete browser documentation for any major browser that states how they handle these. I've started digging through the source code of firefox, but quickly got lost. Is the following scenario true for which (if any) browsers, and is there definitive documentation for either Firefox or IE that states as much?: First Time Around: 1.1: User enters link to site A, or clicks on a link directed at Site A 1.2: Browser interprets link at Site A, first time, no cache. Sends GET to Site A. 1.2: Site A responds with 301 Redirect to Site B 1.3: Browser sends GET to Site B. Any Subsequent Times Around: 2.2: User clicks on a link directed at Site A 2.2: Browser sees that, due to a past 301 redirect, Site A should now be Site B. 2.3: Without initiating any request whatsoever at Site A, browser initiates GET at Site B.

  Read the article

< Previous Page | 147 148 149 150 151 152 153 154 155 156 157 158  | Next Page >