Search Results

Search found 15206 results on 609 pages for 'identity map pattern'.

Page 421/609 | < Previous Page | 417 418 419 420 421 422 423 424 425 426 427 428  | Next Page >

• Managing Data Prefetching and Dependencies with .NET Typed Datasets

  - by Derek Morrison

  I'm using .NET typed datasets on a project, and I often get into situations where I prefetch data from several tables into a dataset and then pass that dataset to several methods for processing. It seems cleaner to let each method decide exactly which data it needs and then load the data itself. However, several of the methods work with the same data, and I want the performance benefit of loading data in the beginning only once. My problem is that I don't know of a good way or pattern to use for managing dependencies (I want to be sure I load all the data that I'm going to need for each class/method that will use the dataset). Currently, I just end up looking through the code for the various classes that will use the dataset to make sure I'm loading everything appropriately. What are good approaches or patterns to use in this situation? Am I doing something fundamentally wrong? Although I'm using typed datasets, this seems like it would be a common situation where prefetching data is used. Thanks!

  Read the article

• Break a string into parts, returning all characters

  - by Benjamin

  I want to break a string according to the following rules: all consecutive alpha-numeric chars, plus the dot (.) must be treated as one part all other consecutive chars must be treated as one part consecutive combinations of 1 and 2 must be treated as different parts no whitespace must be returned For example this string: Method(hierarchy.of.properties) = ? Should return this array: Array ( [0] => Method [1] => ( [2] => hierarchy.of.properties [3] => ) [4] => = [5] => ? ) I was unsuccessful with preg_split(), as AFAIK it cannot treat the pattern as an element to be returned. Any idea for a simple way to do this?

  Read the article

• CommandManager "cannot resolve symbol"

  - by Budda

  After adding "RelayCommand" class (that uses CommandManager class) into my Silverlight App I've got an error: The name 'CommandManager' does not exist in the current context This class is a member of System.Windows.Input namespace that is in PresentationCore.dll assembly. The problem is that I can't add this dll into my app... I am having a strange assumption: this class (CommmandManager) can't be used in the Silverlight. Am I right? How can I implement MVVM-pattern (http://msdn.microsoft.com/en-us/magazine/dd419663.aspx)? Thanks.

  Read the article

• General approach for posting business logic status messages to UI?

  - by generalt

  Hello all. I have been struggling with this question for awhile now, and I haven't reached a conclusion. I'm not typically a UI programmer, so forgive the noobishness. I'm writing a typical application with a UI layer (WPF) and a business layer. I want to post status messages to the UI from the business layer (perhaps deep within the business layer), but I don't want the business layer to have any knowledge of the UI. Is there a generally accepted pattern for this? I was thinking to have a message queue of some sort to which the business layer posts status messages, and have the view model of the UI subscribe to that queue and intercept messages from the queue and route them to the UI. Is that a good approach? Is there somewhere else I should start? Thank you.

  Read the article

• How to check for undefined or null variable in javascript

  - by Thomas Wanner

  We are frequently using the following code pattern in our javascript code if(typeof(some_variable) != 'undefined' && some_variable != null) { // do something with some_variable } and I'm wondering whether there is a less verbose way of checking that has the same effect. According to some forums and literature saying simply if(some_variable) { // do something with some_variable } should have the same effect. Unfortunately, Firebug evaluates such a statement as error on runtime when some_variable is undefined, whereas the first one is just fine for him. Is this only an (unwanted) behavior of Firebug or is there really some difference between those two ways ?

  Read the article

• How to grab the lines AFTER a matched line in python

  - by toofly

  Hi All, I am an amateur using Python on and off for some time now. Sorry if this is a silly question, but I was wondering if anyone knew an easy way to grab a bunch of lines if the format in the input file is like this: " Heading 1 Line 1 Line 2 Line 3 Heading 2 Line 1 Line 2 Line 3 " I won't know how many lines are after each heading, but I want to grab them all. All I know is the name, or a regular expression pattern for the heading. The only way I know to read a file is the "for line in file:" way, but I don't know how to grab the lines AFTER the line I'm currently on. Hope this makes sense, and thanks for the help!

  Read the article

• How to properly match the following message id format in a case statement

  - by hsatterwhite

  I'm trying to get this regex pattern working in a case statement to match a particular type of ID, which could be passed to the script. I need to match the exact number of alphanumeric characters with the dashes to differentiate this message id from anything else, which may be passed to this bash script. An example of the message id format: c7c3e910-c9d2-71e1-0999-0aec446b0000 #!/bin/bash until [ -z "$1" ] do case "$1" in "") echo "No value passed" ;; [a-z0-9]\{8\}-[a-z0-9]\{4\}-[a-z0-9]\{4\}-[a-z0-9]\{4\}-[a-z0-9]\{12\}) echo "Found message ID: $1" ;; *) echo "Server $1" ;; esac shift done

  Read the article

• Cancelling Two Way Data Binding In Silverlight

  - by DaveB

  I have an ObervableCollection of data items. This collection is bound to a ListBox. When the user selects a item from the listbox and clicks the Edit button a UserControl with the details of that item is displayed with the various properties bound to text boxes. Each binding mode is set for TwoWay. On this details UserControl, I would like to implement 2 buttons, OK and Cancel. This would be consistent with UIs in Windows. This application is using the Model-View_ViewModel pattern. Here is my question: 1) How can I implement the Cancel button when all the changes have already been committed?

  Read the article

• trying to prune down a list of files

  - by romunov

  I have a list of files and I'm trying to extract all layer1_*.grd files. Is there a way of doing this in one grep expression? lof <- c("layer1_1.grd", "layer1_1.gri", "layer1_2.grd", "layer1_2.gri", "layer1_3.grd", "layer1_3.gri", "layer1_4.grd", "layer1_4.gri", "layer1_5.grd", "layer1_5.gri", "layer2_1.grd", "layer2_1.gri", "layer2_2.grd", "layer2_2.gri", "layer2_3.grd", "layer2_3.gri", "layer2_4.grd", "layer2_4.gri", "layer2_5.grd", "layer2_5.gri", "layer3_1.grd", "layer3_1.gri", "layer3_2.grd", "layer3_2.gri", "layer3_3.grd", "layer3_3.gri", "layer3_4.grd", "layer3_4.gri", "layer3_5.grd", "layer3_5.gri", "layer4_1.grd", "layer4_1.gri", "layer4_2.grd", "layer4_2.gri", "layer4_3.grd", "layer4_3.gri", "layer4_4.grd", "layer4_4.gri", "layer4_5.grd", "layer4_5.gri" I tried doing this in two steps: list.of.files <- list.files(pattern = c("1_")) list.of.files <- list.of.files[grep(".grd", list.of.files)] Can someone enlighten me how to do this with grep in one step? I naively tried passing list() and c() to the grep but, as you can imagine, it doesn't work. list.of.files <- list.files() list.of.files <- list.of.files[grep(list("1_", ".grd"), list.of.files)]

  Read the article

• Project Euler #163 understanding

  - by Paul

  I spent quite a long time searching for a solution to this problem. I drew tons of cross-hatched triangles, counted the triangles in simple cases, and searched for some sort of pattern. Unfortunately, I hit the wall. I'm pretty sure my programming/math skills did not meet the prereq for this problem. So I found a solution online in order to gain access to the forums. I didn't understand most of the methods at all, and some just seemed too complicated. Can anyone give me an understanding of this problem? One of the methods, found here: http://www.math.uni-bielefeld.de/~sillke/SEQUENCES/grid-triangles (Problem C) allowed for a single function to be used. How did they come up with that solution? At this point, I'd really just like to understand some of the concepts behind this interesting problem. I know looking up the solution was not part of the Euler spirit, but I'm fairly sure I would not have solved this problem anyhow.

  Read the article

• In c++ is there any Events/delegates/interfaces/notifications! anything?

  - by Bach

  Say i have these classes ViewA and ViewB In objective C using the delegate pattern I could do @protocol ViewBDelegate{ - (void) doSomething(); } then in ViewB interface: id<ViewBDelegate> delegate; then in ViewA implementation i set the delegate: viewB.delegate = self; and now I can call in doSomething from viewB onto any that unknown type delegate. [delegate doSomething]; "C++ How to Program" has been the worse read an can't find simple examples that demonstrates basic design patterns. What i'm looking for in C++ is: events ActionScript and java either delegates or notifications in Objective C anything that allows class A, Class B and Class C to know that ClassX didSomething()!!! thanks

  Read the article

• A faster alternative to Pandas `isin` function

  - by user3576212

  I have a very large data frame df that looks like: ID Value1 Value2 1345 3.2 332 1355 2.2 32 2346 1.0 11 3456 8.9 322 And I have a list that contains a subset of IDs ID_list. I need to have a subset of df for the ID contained in ID_list. Currently, I am using df_sub=df[df.ID.isin(ID_list)] to do it. But it takes a lot time. IDs contained in ID_list doesn't have any pattern, so it's not within certain range. (And I need to apply the same operation to many similar dataframes. I was wondering if there is any faster way to do this. Will it help a lot if make ID as the index? Thanks!

  Read the article

• Behavior with primitive data types' value out of range & C99's PRI* macros

  - by Yktula

  Say we have an 8-bit unsigned integer n (UINT8_MAX=255); what is the behavior of the compiler for n=256? Where can I find a table of default behavior when the value of a data type is out of range for different data types? Is there a pattern to how they behave when set out of range? #include <stdio.h> #include <inttypes.h> uint8_t n = UINT8_MAX; int main() { printf("%hhu ",n++); printf("%hhu",n); return 0; } Compiling with gcc -std=c99 -Wall *.c, this prints: 255 0 Also, is it acceptable to use C99's PRI* macros? How are they named?

  Read the article

• ColdFusion - pass regex backreference to function call

  - by stubotnik

  Hi, I'm using ColdFusion's reReplace() function for regular expression pattern replacement. I'd like to use a function call for the replacement string, and pass a matched backreference to it. Something like this: <cfset s = "STARTDATE_2010-05-07 00:05:00.0_ENDDATE" /> <cfset s = reReplace(s, "STARTDATE_([\s-.:0-9]*)_ENDDATE", dateAdd("h", 1, "\1")) /> But that fails because "The value of parameter 3, which is currently \1, must be a class java.util.Date value." Is there any other way to achieve this? Thanks, Stu

  Read the article

• asynchronous calls in asp.net

  - by lockedscope

  in this sample, two threads created; a worker thread created by BeginInvoke and an I/O completion thread created by SendAsync method. but another author in his UnsafeQueueNativeOverlapped example, don't recommend this. i want to use SendAsync or ...Async in an asp.net page and i want to use PageAsyncTask. however, its BeginEventHandler requires AsyncResult to be returned which SendAsync does not return. afaik, event based async pattern is the most recommended way so how could we call SendAsync or any ...Async methods without creating two threads and hurting the performance?

  Read the article

• tutorials/books to create a plugin/module/library?

  - by fayer

  i wonder if there are tutorials/books explaining how you create a library/plugin/module for other to implement? libraries/frameworks like solr, doctrine, codeigniter etc. cause it seems that they follow the same pattern. having one "bootstrap" file to load configurations, other classes and so on. i aim to understand the basics, so i can create a such library. cause at the moment i want to code an address book that other can use. just include a bootstrap file and they are ready to use my classes (like Doctrine). recommendations of sources to learn these things of stuff? you experienced guys, how did you learn it? thanks.

  Read the article

• In .NET, what thread will Events be handled in?

  - by Ben

  I have attempted to implement a producer/consumer pattern in c#. I have a consumer thread that monitors a shared queue, and a producer thread that places items onto the shared queue. The producer thread is subscribed to receive data...that is, it has an event handler, and just sits around and waits for an OnData event to fire (the data is being sent from a 3rd party api). When it gets the data, it sticks it on the queue so the consumer can handle it. When the OnData event does fire in the producer, I had expected it to be handled by my producer thread. But that doesn't seem to be what is happening. The OnData event seems as if it's being handled on a new thread instead! Is this how .net always works...events are handled on their own thread? Can I control what thread will handle events when they're raised? What if hundreds of events are raised near-simultaneously...would each have its own thread?

  Read the article

• Model View Presenter plus ASP.NET Web Service; where does the asmx live?

  - by Dirk

  I've been slowly transitioning from a traditional web forms architecture to the MVP pattern (Passive View). So far, it's been fairly easy to implement b/c the views I've dealt with have all employed a classic PostBack model. However, I've come across my first view that will refresh portions of itself via web services. I can't grok where the web service should live (Presenter I think) or how to expose that asmx end point to my View while still maintaining the clean separation of concerns/testability that MVP affords me. I've searched far and wide for some examples on how this might be implemented and have come up with nothing. Please help!

  Read the article

• How do you make your Java application memory efficient?

  - by Boune

  How do you optimize the heap size usage of an application that has a lot (millions) of long-lived objects? (big cache, loading lots of records from a db) Use the right data type Avoid java.lang.String to represent other data types Avoid duplicated objects Use enums if the values are known in advance Use object pools String.intern() (good idea?) Load/keep only the objects you need I am looking for general programming or Java specific answers. No funky compiler switch. Edit: Optimize the memory representation of a POJO that can appear millions of times in the heap. Use cases Load a huge csv file in memory (converted into POJOs) Use hibernate to retrieve million of records from a database Resume of answers: Use flyweight pattern Copy on write Instead of loading 10M objects with 3 properties, is it more efficient to have 3 arrays (or other data structure) of size 10M? (Could be a pain to manipulate data but if you are really short on memory...)

  Read the article

• Grep for multiple patterns over multiple files

  - by prelic

  I've been googling around, and I can't find the answer I'm looking for. Say I have a file, text1.txt, in directory mydir whose contents are: one two and another called text2.txt, also in mydir, whose contents are: two three four I'm trying to get a list of files (for a given directory) which contain all (not any) patterns I search for. In the example I provided, I'm looking for output somewhere along the lines of: ./text1.txt or ./text1.txt:one ./text1.txt:two The only things I've been able to find are concerning matching any patterns in a file, or matching multiple patterns in a single file (which I tried extending to a whole directory, but received grep usage errors). Any help is much appreciated. Edit-Things I've tried grep "pattern1" < ./* | grep "pattern2" ./* "ambiguous redirect" grep 'pattern1'|'pattern2' ./* returns files that match either pattern

  Read the article

• Using Remote Web Server to Initialize iPhone App

  - by Chris_K

  My iPhone app relies on a vendor's XML feed to provide data. But that feed is not locked down. The vendor could change the format of the XML at any time, although so far they've promised not to. Since I might want to tell my app to use a different URL for its data source, I'd like to set up a single "Command Central" Web page, on my own server, to direct the app to the correct data source. In other words, each time my app starts, in the background and unseen by the user, it would visit "http://www.myserver.com/iphoneapp_data_sources.xml" to retrieve the URL for retrieving data from my vendor. That way, if my vendor suddenly changes the exact URL or the XML feed that the app needs, I can update that Web page and ensure that all installations of the app are using the correct XML feed. Does anyone have any advice or examples showing this kind of approach? It seems as if this must be a common problem, but so far I haven't found a well-established design pattern that fits it.

  Read the article

• Regular expression: who's greedier?

  - by polygenelubricants

  My primary concern is with the Java flavor, but I'd also appreciate information regarding others. Let's say you have a subpattern like this: (.*)(.*) Not very useful as is, but let's say these two capture groups (say, \1 and \2) are part of a bigger pattern that matches with backreferences to these groups, etc. So both are greedy, in that they try to capture as much as possible, only taking less when they have to. My question is: who's greedier? Does \1 get first priority, giving \2 its share only if it has to? What about: (.*)(.*)(.*) Let's assume that \1 does get first priority. Let's say it got too greedy, and then spit out a character. Who gets it first? Is it always \2 or can it be \3? Let's assume it's \2 that gets \1's rejection. If this still doesn't work, who spits out now? Does \2 spit to \3, or does \1 spit out another to \2 first?

  Read the article

• Remove objects from different environments

  - by Fred

  I have an R script file that executes a second R script via: source("../scripts/second_file.R") That second file has the following lines: myfiles <- list.files(".",pattern = "*.csv") ... rm(myfiles) When I run the master R file I get: > source("../scripts/second_file.R") Error in file.remove(myfiles) : object 'myfiles' not found and the program aborts. I think this has something to do with the environment. I looked at ?rm() pages but less than illuminating. I figure I have to give it a position argument, but not sure which.

  Read the article

• PHP: Loop through text file and isolate lines which a specific "starting point"

  - by Mestika

  Hi everyone, I’m trying to reduce some editing time within some textfiles where there approximately are 10.000 lines of text, but I only need around 200 or some. The text file relies on a almost specific pattern but it deviates from time to time but my “focus” in order to select the right line to keep is, that the line always starts with: z3455 and then have a variable afterwards, e.g.: z3455 http://url.com/data1/data1.1/data1.3/ (342kb) I have an algorithm to capture the URL and its content but now I need some way to loop through the text file, deleting all lines except does that starts with z3455 and then “push” them together so they are listed underneath each other. I’ve tried different approaches for this in PHP but can’t seem to find a correct function. I can “isolate” a specific line number but when it deviates I can’t use this approach fully. I hope that someone can help me, either by providing the code or knocking me in the right direction to how I’ll solve this problem. Thanks in advance Sincerely - Mestika

  Read the article

• Reusability, testability, code complexity reduction and showing-off-ability programming importance

  - by Andrew Florko

  There are lots of programming and architecture patterns. Patterns allow to make code cleaner, reusable, more testable & at last (but not at least) to feel the follower a real cool developer. How do you rank these considerations for you? What does affect you most when you decide to apply pattern? I wonder how many times code reusability (especially for MVP, MVC patterns) was important? For example DAL library often shared between projects (it's reusable) but how often controllers/views (abstracted via interfaces) are reused?

  Read the article

< Previous Page | 417 418 419 420 421 422 423 424 425 426 427 428  | Next Page >