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Mono on OS X Compatible with MSVC 2010 peers?

- by Chris

I'm to begin .NET development at work but have the option of using MonoDevelop/Mono on OS X instead of MSVC 2010 on Windows and would prefer it because of my familiarity with OS X. We are likely going to use a number of popular frameworks, such as NHibernate and Castle DI - my question to those of you familiar with .NET development and Mono: will I be at much of a disadvantage? Are there strong incompatibilities or, with some "paper cuts", the two systems are roughly compatible? Again, my colleagues will be using MSVC 2010 and we intend on working on the same codebases together. Thanks for any insight you can give to this .NET newbie. EDIT: I should note I'll primarily be doing development with MVC 2, which I understand does work with Mono, and will have some leeward in choosing frameworks, i.e. I can avoid highly incompatible frameworks.

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How to enforce lazy loading of entities on certain conditions

- by Samuel

We have an JPA @Entity class (say User) which has a @ManyToOne reference (say Address) loaded using the EAGER option which in turn loads it's own @ManyToOne fields (say Country) in a EAGER fashion. We use the EntityQuery interface to count the list of User's based on a search criteria, during such a load all the @ManyToOne fields which have been marked as EAGER get loaded. But in order to perform a EntityQuery.resultCount(), I actually don't need to load the @ManyToOne fields. Is there a way to prevent loading of the EAGER fields in such cases so that we can avoid the unnecessary joins?

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Appending target="_blank" to links in an iframe without using <body onload>

- by CincauHangus

I'm trying to change the links in an iframe to load in a new window instead of the iframe itself. Currently I use this code in head: $(document).ready(function() { var oIFrame = document.getElementById("iframeID"); var oDoc = (oIFrame.contentWindow || oIFrame.contentDocument); if(oDoc.document) oDoc = oDoc.document; var links = oDoc.getElementsByTagName("a"); for(var i=0; i<links.length; i++) { links[i].target="_blank"; } }); However, the code above is triggered before the iframe is fully loaded with its contents. I know this code would work if it's triggered in the body onload attribute, but I'd like to avoid that method and implement it in a function or a file instead.

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Library for Dataflow in C

- by msutherl

How can I do dataflow (pipes and filters, stream processing, flow based) in C? And not with UNIX pipes. I recently came across stream.py. Streams are iterables with a pipelining mechanism to enable data-flow programming and easy parallelization. The idea is to take the output of a function that turns an iterable into another iterable and plug that as the input of another such function. While you can already do this using function composition, this package provides an elegant notation for it by overloading the operator. I would like to duplicate a simple version of this kind of functionality in C. I particularly like the overloading of the operator to avoid function composition mess. Wikipedia points to this hint from a Usenet post in 1990. Why C? Because I would like to be able to do this on microcontrollers and in C extensions for other high level languages (Max, Pd*, Python). * (ironic given that Max and Pd were written, in C, specifically for this purpose – I'm looking for something barebones)

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Is SHA sufficient for checking file duplication? (sha1_file in PHP)

- by wag2639

Suppose you wanted to make a file hosting site for people to upload their files and send a link to their friends to retrieve it later and you want to insure files are duplicated where we store them, is PHP's sha1_file good enough for the task? Is there any reason to not use md5_file instead? For the frontend, it'll be obscured using the original file name store in a database but some additional concerns would be if this would reveal anything about the original poster. Does a file inherit any meta information with it like last modified or who posted it or is this stuff based in the file system? Also, is using a salt frivolous since security in regards of rainbow table attack mean nothing to this and the hash could later be used as a checksum? One last thing, scalability? initially, it's only going to be used for small files a couple of megs big but eventually... Edit 1: The point of the hash is primarily to avoid file duplication, not to create obscurity.

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The underlying connection was closed when using a WSDL web service

- by joshlrogers

I am trying to consume this WSDL service: Transit Time Service I successfully connect and get a response the first time but on subsequent calls I receive the exception: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server. I overrode the GetWebRequest in the reference.cs file as such: protected override System.Net.WebRequest GetWebRequest(Uri uri) { HttpWebRequest webRequest = (HttpWebRequest)base.GetWebRequest(uri); webRequest.KeepAlive = false; return webRequest; } This hasn't yielded any improvement. I am at a loss as to what options I have now, does anyone have any other ideas that I could try so that I may avoid this error? Thanks in advance! Josh

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Regex to catch all files but those starting with "."

- by tmslnz

In a directory with mixed content such as: .afile .anotherfile bfile.file bnotherfile.file .afolder/ .anotherfolder/ bfolder/ bnotherfolder/ How would you catch everything but the files (not dirs) starting with .? I have tried with a negative lookahead ^(?!\.).+? but it doesn't seem to work right. Please note that I would like to avoid doing it by excluding the . by using [a-zA-Z< plus all other possible chars minus the dot >] Any suggestions?

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Why isn't it possible to update an ObservableCollection from a different thread?

- by MainMa

In a multi-threaded WPF application, it is not possible to update an ObservableCollection from a thread other than WPF window thread. I know there are workarounds, so my question is not how to avoid the "This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread" exception. My question is, why there is such an exception? Why wasn't it possible to allow collection updates from any thread? Personally, I don't see any reason to block UI update when ObservableCollection is changed from other threads. If two threads (including parallel ones) are accessing the same object, one listening for changes of object properties through events, the other one doing changes, it will always work, at least if locks are used properly. So, what are the reasons?

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Java Instance of: Supertypes and Subtypes seem to be equal? How to test exactly for Type?

- by jens

I need to test, if an instance is exactly of a given type. But it seems that instanceof returns true also if the subtype is tested for the supertype (case 3). I never knew this before and I am quite surprised. Am I doing something wrong here? How do I exactly test for a given type? //.. class DataSourceEmailAttachment extends EmailAttachment //... EmailAttachment emailAttachment = new EmailAttachment(); DataSourceEmailAttachment emailAttachmentDS = new DataSourceEmailAttachment(); if (emailAttachment instanceof EmailAttachment){ System.out.println(" 1"); } if (emailAttachment instanceof DataSourceEmailAttachment){ System.out.println(" 2"); } if (emailAttachmentDS instanceof EmailAttachment){ System.out.println(" 3 "); } if (emailAttachmentDS instanceof DataSourceEmailAttachment){ System.out.println(" 4"); } RESULT: 1 3 4 I want to avoid case 3, I only want "exact matches" (case 1 and 4) how do I test for them?

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Hashing a python function to regenerate output when the function is modified

- by Seth Johnson

I have a python function that has a deterministic result. It takes a long time to run and generates a large output: def time_consuming_function(): # lots_of_computing_time to come up with the_result return the_result I modify time_consuming_function from time to time, but I would like to avoid having it run again while it's unchanged. [time_consuming_function only depends on functions that are immutable for the purposes considered here; i.e. it might have functions from Python libraries but not from other pieces of my code that I'd change.] The solution that suggests itself to me is to cache the output and also cache some "hash" of the function. If the hash changes, the function will have been modified, and we have to re-generate the output. Is this possible or ridiculous? Updated: based on the answers, it looks like what I want to do is to "memoize" time_consuming_function, except instead of (or in addition to) arguments passed into an invariant function, I want to account for a function that itself will change.

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How to have NHibernate persist a String.Empty property value as NULL

- by Todd

I have a fairly simple class that I want to save to SQL Server via NHibernate (w/ Fluent mappings). The class is made up mostly of optional string fields. My problem is I default the class fields to string.empty to avoid NullRefExceptions and when NHibernate saves the row to the database each column contains an empty string instead of null. Question: Is there a way for me to get NHibernate to automatically save null when the string property is an empty string? Or do I need to litter my code with if (string.empty) checks?

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Check if iOS app is live in app store

- by MSK

Is it possible somehow to code like below in iOS app ? if(app is live in app store) { //Do something } else { //Do other thing } I wanted to avoid cases where our QE/Dev team is using app for testing. Is there a way I can detect how app code is signed (Developer/Adhoc/Distribution) to check ? Even if it is possible, it will not eliminate cases when Apple is using our app for testing as part of review. We recorded many downloads of our content by Apple before our app goes live in App store.

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Jquery UI autocomplete header

- by Kanaka

I have a jQuery UI autocomplete (with custom styling) where I added an header. You can see it at work here: http://jsfiddle.net/fbonomi/wJWGV/ the header is added like this: function cComboboxOpen( event) { var s='.... header .....'; $("ul.ui-autocomplete[style*='block']").prepend(s); } it works, and it keeps the column-like form I need (the real data will also be in columns) BUT, I would like to have the header NOT scrolling away when you have a long, scrollable list (e.g if you type "a" in the list) I have seen another very similar question here: jQuery UI Autocomplete with fixed header But it hasn't been answered, and in its current form it does not work properly (the header is "fixed" even when one scrolls the page, for example) How can I avoid the header to scroll away?

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Snapshot on, still deadlocks, ROWLOCK

- by Patto

I turned snapshot isolation on in my database using the following code ALTER DATABASE MyDatabase SET ALLOW_SNAPSHOT_ISOLATION ON ALTER DATABASE MyDatabase SET READ_COMMITTED_SNAPSHOT ON and got rid off lots of deadlocks. But my database still produces deadlocks, when I need to run a script every hour to clean up 100,000+ rows. Is there a way I can avoid deadlocks in my cleanup script, do I need to set ROWLOCK specifically in that query? Is there a way to increase the number of row level locks that a database uses? How are locks promoted? From row level to page level to table level? My delete script is rather simple: delete statvalue from statValue, (select dateadd(minute,-60, getdate()) as cutoff_date) cd where temporaryStat = 1 and entrydate < cutoff_date Right now I am looking for quick solution, but a long term solution would be even nicer. Thanks a lot, Patrikc

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How to put Custom View above built in views in Android?

- by Lord.F

Hi All, I am developing a small app for Android. I am creating my own view. I am planning to design the layout to be: <LinearLayout> <MyView> <Button><Button> </LinearLayout> But when I run my program, my custom view will cover the whole screen. Is there anyway to avoid this? I have already tried to add android:layout_width, layout_height to be wrap_content, fill_partent, but no luck.

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deleting a large number of rows from a table

- by Azeem

We have a requirement to delete rows in the order of millions from multiple tables as a batch job (note that we are not deleting all the rows, we are deleting based on a timestamp stored in an indexed column). Obviously a normal DELETE takes forever (because of logging, referential constraint checking etc.). I know in the LUW world, we have ALTER TABLE NOT LOGGED INITIALLY but I can't seem to find the an equivalent SQL statement for DB2 v8 z/OS. Any one has any ideas on how to do this really fast? Also, any ideas on how to avoid the referential checks when deleting the rows? Please let me know.

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Doing a lot of input validation in VB.NET

- by Andy

I have a form set up where users can enter their booking for a room at my college. I want to validate the user input to avoid SQL injection (my program uses a MS Access database) and also stop numbers and synbols in their name, etc. I can do the validation fine, but there is to be a lot of validation and then methods executed only if all validation tests come back as true. I did have something like this: If txtName.Text = "" Then frmBookErr.SetError(txtName, "Name field cannot be left blank.") fail = 1 Else frmBookErr.SetError(txtName, "") fail = 0 End If And then check the fail variable, but it obviously gets overridden later in the form if one of the validation tests come back as true. Can anyone provide some input into this? Thanks.

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How do you compose DataTemplates / link to a child datatemplate in WPF?

- by Gishu

Here's the problem. Given a large/intricate datatemplate A, which has 3 sections - General, Properties, Misc. Imagine 3 grids for each. Now I need to reuse the Properties section of the above Datatemplate in another place. Reasons: To avoid redundancy + ensure that further updates to the datatemplate are applied identically to all usages. So I guess what I am asking for is an ability to slot in a link to a child DataTemplate in a parent Datatemplate. What's the best way to go about this ? I found one way to do this.. but I'm not sure if its the right way or the best.. Posting it as an answer below so that it can be rated.

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Redirect to prevent dup submission...but then you loose existing data

- by coffeeaddict

Here's the scenario User is on your checkout.aspx page Somewhere in the process, when clicking the pay button, you redirect the user to an intermediate page (before the confirmation page) to do some other logic. That intermediate page performs whatever logic based on a querystring flag you sent with the redirect from the checkout page This intermediate page also serves as an error page. So if any logic in the intermediatePage.aspx.cs fails I'm setting a message to be displayed on this page to the user If I refresh, that querystring value is still in the url..hence when it hits my Page_Load again, then the server-side logic is called & run again and I don't want this to happen The avoid this behavior/problem, the logical next step is to do a redirect back to the same page if they refresh (not sure how you'd catch that) to get rid of that querystring But when you redirect back to the same page your error message is gone, lost in the redirect therefore you end up showing them the same page but all values for the error message are now gone I do not want to solve this with Javascript either. I am not sure the best way to handle this.

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jQuery - Animate function

- by Arun Kumar

I have a piece of code shown below: $(".tagArea li").mouseover(function(){ $(this).animate({ borderWidth: "2px" }, 1000 ); }); $(".tagArea li").mouseout(function () { $(this).animate({ borderWidth: "1px" }, 1000 ); }); When I try to hover it on a particular list item, it properly animates but doesn't stop doing just once. It keeps doing 2 or 3 times. How to avoid this, I 've tried many a times but no positive result occurs to me. Kindly help.

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SVN - ignoring files already in repository

- by Alex

I have a configuration file in my project which needs to be in the repository (so new developers get it when they checkout the project). Each developer might change some values in the file locally - these changes should not be committed and I don't want them showing in the synchronization menu (I'm using eclipse and subversive if it matters). Note that I can't just set the svn:ignore property since it only works on files that aren't under version control - but I do want to keep a base version of the file in the repository. How can I avoid the file showing in synchronization without deleting it from repository? EDIT: A better description - what I actually need is to be able to set a "read-only" property on the config file, so it can't be changed in the repository as long as the property is on. Do you know anything like this? Thanks

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Iterate attributes and IBOutlets of a UIViewController

- by Espuz

I've a generic UIViewController on my app. All the UIViewController on the app inherits from this generic one. I'm trying to automate the deallocation and releasing of attributes and IBOutlets as properties. I'm doing the first (attributes) on dealloc method and the second (IBOutlets as properties) on viewDidUnload. - (void) dealloc { [_att1 release]; _att1 = nil; [_att2 release]; _att2 = nil; // ... } - (void) viewDidUnload { self.att1 = nil; // att1 is an IBOutlet self.att2 = nil; // att2 is an IBOutlet // ... } Is there any way to iterate all my attributes and IBOutlets to simplify this operations? I want to avoid do it for each outlet and attribute and delegate it to the generic UIViewController. Thanks.

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c# .net framework subtracting time-span from date

- by smkngspcmn

I want to subtract a time-span from a date-time object. Date is 1983/5/1 13:0:0 (y/m/d-h:m:s) Time span is 2/4/28-2:51:0 (y/m/d-h:m:s) I can use the native DateTime and TimeSpan objects to do this, after converting years and months of the time-span to days (assuming a 30 day month and a ~364 day year). new DateTime(1981,5,1,13,0,0).Subtract(new TimeSpan(878,13,51,0)); With this i get the result: {12/4/1978 11:09:00 PM} But this is not exactly what i expected. If i do this manually (assuming a 30 day month) i get 1981/0/3-10:9:0 This is pretty close to what i'm after except i shouldn't get 0 for month and year should be 1980. So can someone please show me how i can do this manually and avoid getting a 0 month value? Also why do i get a completely different value when i use native classes?

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When designing an event, is it a good idea to prevent listeners from being added twice?

- by Matt

I am creating an event-based API where a user can subscribe to an event by adding listener objects (as is common in Java or C#). When the event is raised, all subscribed listeners are invoked with the event information. I initially decided to prevent adding an event listener more than once. If a listener is added that already exists in the listener collection, it is not added again. However, after thinking about it some more, it doesn't seem that most event-based structures actually prevent this. Was my initial instinct wrong? I'm not sure which way to go here. I guess I thought that preventing addition of an existing listener would help to avoid a common programming error. Then again, it could also hide a bug that would lead to code being run multiple times when it shouldn't.

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JSF navigation on commandbutton

- by Nitesh Panchal

Hello, I want to conditionally navigate to some page. If some condition is true i want to navigate to some other page else i want to remain on the same page. I have something like :- <h:commandButton action="#{bean.navigate}"/> in bean.navigate i have something like :- public String navigate(){ if(value <= 0) return "helloWorld"; else return ""; } But if i return "", error is thrown and in h:messages message is appended that page not found etc. How do i avoid this error?

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