Search Results

Search found 9026 results on 362 pages for 'vs extensibility'.

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 113/362 | < Previous Page | 109 110 111 112 113 114 115 116 117 118 119 120  | Next Page >

  • NSNotifications vs delegate for multiple instances of same protocol

    - by Brent Traut
    I could use some architectural advice. I've run into the following problem a few times now and I've never found a truly elegant way to solve it. The issue, described at the highest level possible:I have a parent class that would like to act as the delegate for multiple children (all using the same protocol), but when the children call methods on the parent, the parent no longer knows which child is making the call. I would like to use loose coupling (delegates/protocols or notifications) rather than direct calls. I don't need multiple handlers, so notifications seem like they might be overkill. To illustrate the problem, let me try a super-simplified example: I start with a parent view controller (and corresponding view). I create three child views and insert each of them into the parent view. I would like the parent view controller to be notified whenever the user touches one of the children. There are a few options to notify the parent: Define a protocol. The parent implements the protocol and sets itself as the delegate to each of the children. When the user touches a child view, its view controller calls its delegate (the parent). In this case, the parent is notified that a view is touched, but it doesn't know which one. Not good enough. Same as #1, but define the methods in the protocol to also pass some sort of identifier. When the child tells its delegate that it was touched, it also passes a pointer to itself. This way, the parent know exactly which view was touched. It just seems really strange for an object to pass a reference to itself. Use NSNotifications. The parent defines a separate method for each of the three children and then subscribes to the "viewWasTouched" notification for each of the three children as the notification sender. The children don't need to attach themselves to the user dictionary, but they do need to send the notification with a pointer to themselves as the scope. Same as #4, but rather than using separate methods, the parent could just use one with a switch case or other branching along with the notification's sender to determine which path to take. Create multiple man-in-the-middle classes that act as the delegates to the child views and then call methods on the parent either with a pointer to the child or with some other differentiating factor. This approach doesn't seem scalable. Are any of these approaches considered best practice? I can't say for sure, but it feels like I'm missing something more obvious/elegant.

    Read the article

  • C++ STL Map vs Vector speed

    - by sub
    In the interpreter for my experimental programming language I have a symbol table. Each symbol consists of a name and a value (the value can be e.g.: of type string, int, function, etc.). At first I represented the table with a vector and iterated through the symbols checking if the given symbol name fitted. Then I though using a map, in my case map<string,symbol>, would be better than iterating through the vector all the time but: It's a bit hard to explain this part but I'll try. If a variable is retrieved the first time in a program in my language, of course its position in the symbol table has to be found (using vector now). If I would iterate through the vector every time the line gets executed (think of a loop), it would be terribly slow (as it currently is, nearly as slow as microsoft's batch). So I could use a map to retrieve the variable: SymbolTable[ myVar.Name ] But think of the following: If the variable, still using vector, is found the first time, I can store its exact integer position in the vector with it. That means: The next time it is needed, my interpreter knows that it has been "cached" and doesn't search the symbol table for it but does something like SymbolTable.at( myVar.CachedPosition ). Now my (rather hard?) question: Should I use a vector for the symbol table together with caching the position of the variable in the vector? Should I rather use a map? Why? How fast is the [] operator? Should I use something completely different?

    Read the article

  • Domain object validation vs view model validation

    - by Brendan Vogt
    I am using ASP.NET MVC 3 and I am using FluentValidation to validate my view models. I am just a little concerned that I might not be on the correct track. As far as what I know, model validation should be done on the domain object. Now with MVC you might have multiple view models that are similar that needs validation. What happens if a property from a domain object occurs in more than one view model? Now you are validating the same property twice, and they might not even be in sync. So if I have a User domain object then I would like to do validation on this object. Now what happens if I have UserAViewModel and UserBViewModel, so now it is multiple validations that needs to be done. The scenario above is just an example, so please don't critise on it.

    Read the article

  • C++ Array vs vector

    - by blue_river
    when using C++ vector, time spent is 718 milliseconds, while when I use Array, time is almost 0 milliseconds. Why so much performance difference? int _tmain(int argc, _TCHAR* argv[]) { const int size = 10000; clock_t start, end; start = clock(); vector<int> v(size*size); for(int i = 0; i < size; i++) { for(int j = 0; j < size; j++) { v[i*size+j] = 1; } } end = clock(); cout<< (end - start) <<" milliseconds."<<endl; // 718 milliseconds int f = 0; start = clock(); int arr[size*size]; for(int i = 0; i < size; i++) { for(int j = 0; j < size; j++) { arr[i*size+j] = 1; } } end = clock(); cout<< ( end - start) <<" milliseconds."<<endl; // 0 milliseconds return 0; }

    Read the article

  • Category VS logger tags in jboss-log4j.xml

    - by Vladimir Bezugliy
    What should we use in jboss-log4j.xml in order to turn on/off traces for our product - "category" or "logger" tag? By default JBoss uses "category" in jboss-log4j.xml. But as far as I know "category" is deprecated and "logger" should be used instead. Why JBoss uses deprecated "category" tag in a new product?

    Read the article

  • Sesion timout vs Form Authentication timeout

    - by Costa
    Hi What is the difference between a abandon Session and a cookie timeout, what if the session is abandon and the cookie is still alive, is that can lead to a problem? <sessionState timeout="1" /> <authentication mode="Forms"> <forms loginUrl="login.aspx" timeout="1" /> </authentication> Thanks

    Read the article

  • ModelName(django.contrib.auth.models.User) vs ModelName(models.Model)

    - by amr.negm
    I am developing a django project. I created some apps, some of those are related to User model, for instance, I have a feeds app that handles user feeds, and another app that deals with extra user data like age, contacts, and friends. for each of these, I created a table that should be connected to the User model, which I using for storing and authenticating users. I found two ways to deal with this issue. One, is through extending User model to be like this: ModelName(User): friends = models.ManyToMany('self') ..... Two, is through adding a foreign key to the new table like this: ModelName(models.Model): user = models.ForeignKey(User, unique=True) friends = friends = models.ManyToMany('self') ...... I can't decide which to use in which case. in other words, what are the core differences between both?

    Read the article

  • Sbyte[] vs byte[][] using methods

    - by blgnklc
    It is written byte[][] getImagesForFields(java.lang.String[] fieldnames) Gets an array of images for the given fields. On the other hand, as long as I use the method in the web application project built on asp.net 2.o using c#; the provided web method declared above, returns sbyte; Have a look my code below; formClearanceService.openSession(imageServiceUser); formClearanceService.prepareInstance(formId); byte[][] fieldImagesList = formClearanceService.getImagesForFields(fieldNames); formClearanceService.closeSession(); thus I get the following error: Cannot implicitly convert type 'sbyte[]' to 'byte[][]' So now, 1- should I ask the web service provider what is going on? or 2- any other way that can use the sbyte as I was suppose to use byte[][] like following using: byte[] ssss = fieldImagesList [0]..

    Read the article

  • iPhone SDK development obj-C vs interface builder

    - by Amy
    I'm new to the iOS platform. I'm not clear on the purpose of the interface builder. It looks like I can avoid using it entirely and just write all the code in objective c. am I right? is there anything that IB can do but obj-c cannot? It reminds me of visual basic 6.

    Read the article

  • Zend Framework: Controller Plugins vs Action Helpers

    - by Laimoncijus
    Could someone give few tips and/or examples how Controller Plugins and Action Helpers are different? Are there situations where particular task could be accomplished with one but not another? For me they both look more or less the same and I'm often having trouble having to decide when to use what... Are there any big differences?

    Read the article

  • Warning vs. error

    - by Samuel
    I had an annoying issue, getting a "Possible loss of precision" error when compiling my Java program on BlueJ (But from what i read this isn't connected to a specific IDE). I was surprised by the fact that the compiler told me there is a possible loss of precision and wouldnt let me compile/run the program. Why is this an error and not a warning saying you might loose precision here, if you don't want that change your code? The program runs just fine when i drop the float values, it wouldn't matter since there is no point (e.g [143.08, 475.015]) on my screen. On the other hand when i loop through an ArrayList and in this loop i have an if clause removing elements from the ArrayList it runs fine, just throws an error and doesn't display the ArrayList [used for drawing circles] for a fraction of a second. This appears to me as a severe error but doesn't cause (hardly) any troubles, while i wouldn't want to have such a thing in my code at all. What's the boundary?

    Read the article

  • Ruby proc vs lambda in initialize()

    - by Jimmy Chu
    I found out this morning that proc.new works in a class initialize method, but not lambda. Concretely, I mean: class TestClass attr_reader :proc, :lambda def initialize @proc = Proc.new {puts "Hello from Proc"} @lambda = lambda {puts "Hello from lambda"} end end c = TestClass.new c.proc.call c.lambda.call In the above case, the result will be: Hello from Proc test.rb:14:in `<main>': undefined method `call' for nil:NilClass (NoMethodError) Why is that? Thanks!

    Read the article

  • JSF (and friends) tags vs. traditional html tags

    - by H3wh0s33ks
    So this question came up today and I didn't have a specific or scientific answer. What are the costs associated with using jsf (or tomahawk, faclets, etc., etc.) tags in place of traditional html tags. My gut reaction is that you should use jsf tags in situations where you need the additional functionality they provide, and use traditional tags when you don't. Also I feel like jsf tags would require more resources (since the server has to take them and rerender them as html anyways) than html. Does anybody know what the cost actually is (as far as time and memory)? Also useful information is what is the convention that is in use, pure jsf or a mixture of the two?

    Read the article

  • Java BufferedReader behavior in CSV vs TXT file

    - by Gabriel
    If i try to read a CSV file called csv_file.csv. The problem is that when i read lines with BufferedReader.readLine() it skips the first line with months. But when i rename the file to csv_file.txt it reads it allright and it's not skipping the first line. Is there an undocumented "feature" of BufferedReader that i'm not aware? Example of file: Months, SEP2010, OCT2010, NOV2010 col1, col2, col3, col4, col5 aaa,,sdf,"12,456",bla bla bla, xsaffadfafda and so on, and so on, "10,00", xxx, xxx The code: FileInputStream stream = new FileInputStream(UploadSupport.TEMPORARY_FILES_PATH+fileName); BufferedReader br = new BufferedReader(new InputStreamReader(stream, "UTF-8")); String line = br.readLine(); String months[] = line.split(","); while ((line=br.readLine())!=null) { /*parse other lines*/ }

    Read the article

  • F# ref-mutable vars vs object fields

    - by rwallace
    I'm writing a parser in F#, and it needs to be as fast as possible (I'm hoping to parse a 100 MB file in less than a minute). As normal, it uses mutable variables to store the next available character and the next available token (i.e. both the lexer and the parser proper use one unit of lookahead). My current partial implementation uses local variables for these. Since closure variables can't be mutable (anyone know the reason for this?) I've declared them as ref: let rec read file includepath = let c = ref ' ' let k = ref NONE let sb = new StringBuilder() use stream = File.OpenText file let readc() = c := stream.Read() |> char // etc I assume this has some overhead (not much, I know, but I'm trying for maximum speed here), and it's a little inelegant. The most obvious alternative would be to create a parser class object and have the mutable variables be fields in it. Does anyone know which is likely to be faster? Is there any consensus on which is considered better/more idiomatic style? Is there another option I'm missing?

    Read the article

  • Improving Javascript Load Times - Concatenation vs Many + Cache

    - by El Yobo
    I'm wondering which of the following is going to result in better performance for a page which loads a large amount of javascript (jQuery + jQuery UI + various other javascript files). I have gone through most of the YSlow and Google Page Speed stuff, but am left wondering about a particular detail. A key thing for me here is that the site I'm working on is not on the public net; it's a business to business platform where almost all users are repeat visitors (and therefore with caches of the data, which is something that YSlow assumes will not be the case for a large number of visitors). First up, the standard approach recommended by tools such as YSlow is to concatenate it, compress it, and serve it up in a single file loaded at the end of your page. This approach sounds reasonably effective, but I think that a key part of the reasoning here is to improve performance for users without cached data. The system I currently have is something like this * All javascript files are compressed and loaded at the bottom of the page * All javascript files have far future cache expiration dates, so will remain (for most users) in the cache for a long time * Pages only load the javascript files that they require, rather than loading one monolithic file, most of which will not be required Now, my understanding is that, if the cache expiration date for a javascript file has not been reached, then the cached version is used immediately; there is no HTTP request sent at to the server at all. If this is correct, I would assume that having multiple tags is not causing any performance penalty, as I'm still not having any additional requests on most pages (recalling from above that almost all users have populated caches). In addition to this, not loading the JS means that the browser doesn't have to interpret or execute all this additional code which it isn't going to need; as a B2B application, most of our users are unfortunately stuck with IE6 and its painfully slow JS engine. Another benefit is that, when code changes, only the affected files need to be fetched again, rather than the whole set (granted, it would only need to be fetched once, so this is not so much of a benefit). I'm also looking at using LabJS to allow for parallel loading of the JS when it's not cached. So, what do people think is a better approach? In a similar vein, what do you think about a similar approach to CSS - is monolithic better?

    Read the article

  • Looping differences in Ruby using Range vs. Times

    - by jbjuly
    I'm trying to solve a Project Euler problem using Ruby, I used 4 different looping methods, the for-loop, times, range and upto method, however the for-loop and times method only produces the expected answer, while the range and upto method does not. I'm assuming that they are somewhat the same, but I found out it's not. Can someone please explain the differences between these methods? Here's the looping structure I used # for-loop method for n in 0..1 puts n end 0 1 => 0..1 # times method 2.times do |n| puts n end 0 1 => 2 # range method (0..1).each do |n| puts n end 0 1 => 0..1 # upto method 0.upto(1) do |n| puts n end 0 1 => 0

    Read the article

  • String comparison in Python: is vs. ==

    - by Coquelicot
    I noticed a Python script I was writing was acting squirrelly, and traced it to an infinite loop, where the loop condition was "while line is not ''". Running through it in the debugger, it turned out that line was in fact ''. When I changed it to != rather than 'is not', it worked fine. I did some searching, and found this question, the top answer to which seemed to be just what I needed. Except the answer it gave was counter to my experience. Specifically, the answerer wrote: For all built-in Python objects (like strings, lists, dicts, functions, etc.), if x is y, then x==y is also True. I double-checked the type of the variable, and it was in fact of type str (not unicode or something). Is his answer just wrong, or is there something else afoot? Also, is it generally considered better to just use '==' by default, even when comparing int or Boolean values? I've always liked to use 'is' because I find it more aesthetically pleasing and pythonic (which is how I fell into this trap...), but I wonder if it's intended to just be reserved for when you care about finding two objects with the same id.

    Read the article

  • Physical Cores vs Virtual Cores in Parallelism

    - by Code Curiosity
    When it comes to virtualization, I have been deliberating on the relationship between the physical cores and the virtual cores, especially in how it effects applications employing parallelism. For example, in a VM scenario, if there are less physical cores than there are virtual cores, if that's possible, what's the effect or limits placed on the application's parallel processing? I'm asking, because in my environment, it's not disclosed as to what the physical architecture is. Is there still much advantage to parallelizing if the application lives on a dual core VM hosted on a single core physical machine?

    Read the article

  • Table Naming Dilemma: Singular vs. Plural Names

    - by ProfK
    Convention has it that table names should be the singular of the entity that they store attributes of. I dislike any T-SQL that requires square brackets around names, but I have renamed a Users table to the singular, forever sentencing those using the table to sometimes have to use brackets. My gut feel is that it is more correct to stay with the singular, but my gut feel is also that brackets indicate undesirables like column names with spaces in them etc. Should I stay, or should I go?

    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 | 109 110 111 112 113 114 115 116 117 118 119 120  | Next Page >