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  • How to avoid injecting dependencies into an object so that it can pass them on?

    - by Pheter
    I am interested in applying dependency injection to my current project, which makes use of the MVC pattern. My controllers will call the models and therefore will need to inject the dependencies into the models. To do this, the controller must have the dependencies (such as a database object) in the first place. The controller doesn't need to make use of some of these dependencies (such as the database object), so I feel that it shouldn't be given this dependency. However, it has to have these dependencies if it is to inject them into the model objects. How can I avoid having dependencies injected into an object just so that it can pass them on? Doing so feels wrong and can result in many dependencies being injected into an object. Edit: I am using PHP.

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  • RegEx, matching if not containing...

    - by Tommy Jakobsen
    I've been trying to figure out how to write this regular expression. It is to be used for ISAPI_Rewrite, a module for IIS 6, for doing URL rewriting. I want the url /hg/<parameter> to be mathed, so it can be rewrited to /hg/hgwebdir.cgi/<parameter>. I've matched it using ^/hg/(.*). My problem is, if the URL /hg/hgwebdir.cgi/<parameter> is used, the regex should NOT match. Using the above regex with this URL, will rewrite to /hg/hgwebdig.cgi/hgwebdig.cgi/<parameter> which is not correct. Can you help me create the matching pattern?

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  • Where does form processing logic belong in a MVC web application?

    - by AdamTheHutt
    In a web-based application that uses the Model-View-Controller design pattern, the logic relating to processing form submissions seems to belong somewhere in between the Model layer and the Controller layer. This is especially true in the case of a complex form (i.e. where form processing goes well beyond simple CRUD operations). What's the best way to conceptualize this? Are forms simply a kind of glue between models and controllers? Or does form logic belong squarely in the M or C camp? EDIT: I understand the basic flow of information in an MVC application (see chills42's answer for a summary). My question is where the form processing logic belongs - in the controller, in the model, or somewhere else?

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  • Why are events and commands in MVVM so unsupported by WPF / Visual Studio?

    - by Edward Tanguay
    When creating an WPF application with the MVVM pattern, it seems I have to gather the necessary tools myself to even begin the most rudimentary event handling, e.g. AttachedBehaviors I get from here DelegateCommands I get from here Now I'm looking for some way to handle the ItemSelected event in a ComboBox and am getting suggestions of tricks and workarounds to do this (using a XAML trigger or have other elements bound to the selected item, etc.). Ok, I can go down this road, but it seems to be reinventing the wheel. It would be nice to just have an ItemSelected command that I can handle in my ViewModel. Am I missing some set of standard tools or is everyone doing MVVM with WPF basically building and putting together their own collection of tools just so they can do the simplest plumbing tasks with events and commands, things that take only a couple lines in code-behind with a Click="eventHandler"?

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  • Recursive Syntax in Oslo

    - by Kevin Lawrence
    I'm writing my first DSL with Oslo and I am having a problem with a recursive syntax definition. The input has sections which can contain questions or other sections recursively (composite pattern) like this: Section: A Question: 1 Question: 2 Section: B Question: 1 End End My definition for a Section looks like this syntax Section = "Section:" id:Text body:(SectionBody)* "End Section"; Which works (but doesn't handle recursive sections) if I define SectionBody like this syntax SectionBody = (Question); but doesn't work with a recursive definition like this syntax SectionBody = (Question | Section); What am I missing?

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  • Catch all exceptions in Scala 2.8 RC1

    - by Michel Krämer
    I have the following dummy Scala code in the file test.scala: class Transaction { def begin() {} def commit() {} def rollback() {} } object Test extends Application { def doSomething() {} val t = new Transaction() t.begin() try { doSomething() t.commit() } catch { case _ => t.rollback() } } If I compile this on Scala 2.8 RC1 with scalac -Xstrict-warnings test.scala I'll get the following warning: test.scala:16: warning: catch clause swallows everything: not advised. case _ => t.rollback() ^ one warning found So, if catch-all expressions are not advised, how am I supposed to implement such a pattern instead? And apart from that why are such expressions not advised anyhow?

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  • arbitrary typed data in django model

    - by Dmitry Shevchenko
    I have a model, say, Item. I want to store arbitrary amount of attributes on it, like title, description, release_date. And i want them to be not just strings but have python type, so string, boolean, datetime etc. What are my options here? EAV pattern with separate name-value table won't work because of the same DB type across all values. JSONField can probably help, but it doesn't know about datetime, for example. Also i was looking at PickeField, it fits perfectly, but i'm a bit concerned about performance.

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  • FlexUnit - howto check label text

    - by Maik
    I am trying to automatically verify certain conventions, such as label/table column header text (Sentence Case, use of colons, etc). It would be nice if there was a way in FlexUnit, or other means, to Iterate over all views in the app Get all titles, labels, column headers Run some pattern checks and fail where needed. Does anyone have a suggestion on what the best way would be to achieve that? I suppose I could do this on a code level on the MXML files, but it would be nicer if it could be integrated into the overall unit test suits. Thanks for any suggestions

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  • How to generate a lower frequency version of a signal in Matlab?

    - by estourodepilha.com
    With a sine input, I tried to modify it's frequency cutting some lower frequencies in the spectrum, shifting the main frequency towards zero. As the signal is not fftshifted I tried to do that by eliminating some samples at the begin and at the end of the fft vector: interval = 1; samplingFrequency = 44100; signalFrequency = 440; sampleDuration = 1 / samplingFrequency; timespan = 1 : sampleDuration : (1 + interval); original = sin(2 * pi * signalFrequency * timespan); fourierTransform = fft(original); frequencyCut = 10; %% Hertz frequencyCut = floor(frequencyCut * (length(pattern) / samplingFrequency) / 4); %% Samples maxFrequency = length(fourierTransform) - (2 * frequencyCut); signal = ifft(fourierTransform(frequencyCut + 1:maxFrequency), 'symmetric'); But it didn't work as expected. I also tried to remove the center part of the spectrum, but it wielded a higher frequency sine wave too. How to make it right?

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  • What is stopping data flow with .NET 3.5 asynchronous System.Net.Sockets.Socket?

    - by TonyG
    I have a .NET 3.5 client/server socket interface using the asynchronous methods. The client connects to the server and the connection should remain open until the app terminates. The protocol consists of the following pattern: send stx receive ack send data1 receive ack send data2 (repeat 5-6 while more data) receive ack send etx So a single transaction with two datablocks as above would consist of 4 sends from the client. After sending etx the client simply waits for more data to send out, then begins the next transmission with stx. I do not want to break the connection between individual exchanges or after each stx/data/etx payload. Right now, after connection, the client can send the first stx, and get a single ack, but I can't put more data onto the wire after that. Neither side disconnects, the socket is still intact. The client code is seriously abbreviated as follows - I'm following the pattern commonly available in online code samples. private void SendReceive(string data) { // ... SocketAsyncEventArgs completeArgs; completeArgs.Completed += new EventHandler<SocketAsyncEventArgs>(OnSend); clientSocket.SendAsync(completeArgs); // two AutoResetEvents, one for send, one for receive if ( !AutoResetEvent.WaitAll(autoSendReceiveEvents , -1) ) Log("failed"); else Log("success"); // ... } private void OnSend( object sender , SocketAsyncEventArgs e ) { // ... Socket s = e.UserToken as Socket; byte[] receiveBuffer = new byte[ 4096 ]; e.SetBuffer(receiveBuffer , 0 , receiveBuffer.Length); e.Completed += new EventHandler<SocketAsyncEventArgs>(OnReceive); s.ReceiveAsync(e); // ... } private void OnReceive( object sender , SocketAsyncEventArgs e ) {} // ... if ( e.BytesTransferred > 0 ) { Int32 bytesTransferred = e.BytesTransferred; String received = Encoding.ASCII.GetString(e.Buffer , e.Offset , bytesTransferred); dataReceived += received; } autoSendReceiveEvents[ SendOperation ].Set(); // could be moved elsewhere autoSendReceiveEvents[ ReceiveOperation ].Set(); // releases mutexes } The code on the server is very similar except that it receives first and then sends a response - the server is not doing anything (that I can tell) to modify the connection after it sends a response. The problem is that the second time I hit SendReceive in the client, the connection is already in a weird state. Do I need to do something in the client to preserve the SocketAsyncEventArgs, and re-use the same object for the lifetime of the socket/connection? I'm not sure which eventargs object should hang around during the life of the connection or a given exchange. Do I need to do something, or Not do something in the server to ensure it continues to Receive data? The server setup and response processing looks like this: void Start() { // ... listenSocket.Bind(...); listenSocket.Listen(0); StartAccept(null); // note accept as soon as we start. OK? mutex.WaitOne(); } void StartAccept(SocketAsyncEventArgs acceptEventArg) { if ( acceptEventArg == null ) { acceptEventArg = new SocketAsyncEventArgs(); acceptEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(OnAcceptCompleted); } Boolean willRaiseEvent = this.listenSocket.AcceptAsync(acceptEventArg); if ( !willRaiseEvent ) ProcessAccept(acceptEventArg); // ... } private void OnAcceptCompleted( object sender , SocketAsyncEventArgs e ) { ProcessAccept(e); } private void ProcessAccept( SocketAsyncEventArgs e ) { // ... SocketAsyncEventArgs readEventArgs = new SocketAsyncEventArgs(); readEventArgs.SetBuffer(dataBuffer , 0 , Int16.MaxValue); readEventArgs.Completed += new EventHandler<SocketAsyncEventArgs>(OnIOCompleted); readEventArgs.UserToken = e.AcceptSocket; dataReceived = ""; // note server is degraded for single client/thread use // As soon as the client is connected, post a receive to the connection. Boolean willRaiseEvent = e.AcceptSocket.ReceiveAsync(readEventArgs); if ( !willRaiseEvent ) this.ProcessReceive(readEventArgs); // Accept the next connection request. this.StartAccept(e); } private void OnIOCompleted( object sender , SocketAsyncEventArgs e ) { // switch ( e.LastOperation ) case SocketAsyncOperation.Receive: ProcessReceive(e); // similar to client code // operate on dataReceived here case SocketAsyncOperation.Send: ProcessSend(e); // similar to client code } // execute this when a data has been processed into a response (ack, etc) private SendResponseToClient(string response) { // create buffer with response // currentEventArgs has class scope and is re-used currentEventArgs.SetBuffer(sendBuffer , 0 , sendBuffer.Length); Boolean willRaiseEvent = currentClient.SendAsync(currentEventArgs); if ( !willRaiseEvent ) ProcessSend(currentEventArgs); } A .NET trace shows the following when sending ABC\r\n: Socket#7588182::SendAsync() Socket#7588182::SendAsync(True#1) Data from Socket#7588182::FinishOperation(SendAsync) 00000000 : 41 42 43 0D 0A Socket#7588182::ReceiveAsync() Exiting Socket#7588182::ReceiveAsync() - True#1 And it stops there. It looks just like the first send from the client but the server shows no activity. I think that could be info overload for now but I'll be happy to provide more details as required. Thanks!

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  • How to re-use a thread in Java ?

    - by David
    I am a building a console Sudoku Solver where the main objective is raw speed. I now have a ManagerThread that starts WorkerThreads to compute the neibhbors of each cell. So one WorkerThread is started for each cell right now. How can I re-use an existing thread that has completed its work? The Thread Pool Pattern seems to be the solution, but I don't understand what to do to prevent the thread from dying once its job has been completed. ps : I do not expect to gain much performance for this particular task, just want to experiment how multi-threading works before applying it to the more complex parts of the code. Thanks

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  • Model-Controller cyclic reference/design problem

    - by jasamer
    I have a CoreData entity X, and controllers for this entity, XController. Now there's another entity, XGroup, containing a collection of X entities, and a XGroupController. Now the problem is that XGroupController needs to interact with XController, and it would be nice to just pass XGroupController a XGroup to observe, and then get the XControllers from the X entities. So the question is: is it a good idea to store a (weak, to avoid retain cycles) reference to a controller in an entity? It just feels a bit "wrong". Is there another design pattern for this?

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  • Ideas for multiplatform encrypted java mobile storage system

    - by Fernando Miguélez
    Objective I am currently designing the API for a multiplatform storage system that would offer same interface and capabilities accross following supported mobile Java Platforms: J2ME. Minimum configuration/profile CLDC 1.1/MIDP 2.0 with support for some necessary JSRs (JSR-75 for file storage). Android. No minimum platform version decided yet, but rather likely could be API level 7. Blackberry. It would use the same base source of J2ME but taking advantage of some advaced capabilities of the platform. No minimum configuration decided yet (maybe 4.6 because of 64 KB limitation for RMS on 4.5). Basically the API would sport three kind of stores: Files. These would allow standard directory/file manipulation (read/write through streams, create, mkdir, etc.). Preferences. It is a special store that handles properties accessed through keys (Similar to plain old java properties file but supporting some improvements such as different value data types such as SharedPreferences on Android platform) Local Message Queues. This store would offer basic message queue functionality. Considerations Inspired on JSR-75, all types of stores would be accessed in an uniform way by means of an URL following RFC 1738 conventions, but with custom defined prefixes (i.e. "file://" for files, "prefs://" for preferences or "queue://" for message queues). The address would refer to a virtual location that would be mapped to a physical storage object by each mobile platform implementation. Only files would allow hierarchical storage (folders) and access to external extorage memory cards (by means of a unit name, the same way as in JSR-75, but that would not change regardless of underlying platform). The other types would only support flat storage. The system should also support a secure version of all basic types. The user would indicate it by prefixing "s" to the URL (i.e. "sfile://" instead of "file://"). The API would only require one PIN (introduced only once) to access any kind of secure object types. Implementation issues For the implementation of both plaintext and encrypted stores, I would use the functionality available on the underlying platforms: Files. These are available on all platforms (J2ME only with JSR-75, but it is mandatory for our needs). The abstract File to actual File mapping is straight except for addressing issues. RMS. This type of store available on J2ME (and Blackberry) platforms is convenient for Preferences and maybe Message Queues (though depending on performance or size requirements these could be implemented by means of normal files). SharedPreferences. This type of storage, only available on Android, would match Preferences needs. SQLite databases. This could be used for message queues on Android (and maybe Blackberry). When it comes to encryption some requirements should be met: To ease the implementation it will be carried out on read/write operations basis on streams (for files), RMS Records, SharedPreferences key-value pairs, SQLite database columns. Every underlying storage object should use the same encryption key. Handling of encrypted stores should be the same as the unencrypted counterpart. The only difference (from the user point of view) accessing an encrypted store would be the addressing. The user PIN provides access to any secure storage object, but the change of it would not require to decrypt/re-encrypt all the encrypted data. Cryptographic capabilities of underlying platform should be used whenever it is possible, so we would use: J2ME: SATSA-CRYPTO if it is available (not mandatory) or lightweight BoncyCastle cryptographic framework for J2ME. Blackberry: RIM Cryptographic API or BouncyCastle Android: JCE with integraced cryptographic provider (BouncyCastle?) Doubts Having reached this point I was struck by some doubts about what solution would be more convenient, taking into account the limitation of the plataforms. These are some of my doubts: Encryption Algorithm for data. Would AES-128 be strong and fast enough? What alternatives for such scenario would you suggest? Encryption Mode. I have read about the weakness of ECB encryption versus CBC, but in this case the first would have the advantage of random access to blocks, which is interesting for seek functionality on files. What type of encryption mode would you choose instead? Is stream encryption suitable for this case? Key generation. There could be one key generated for each storage object (file, RMS RecordStore, etc.) or just use one for all the objects of the same type. The first seems "safer", though it would require some extra space on device. In your opinion what would the trade-offs of each? Key storage. For this case using a standard JKS (or PKCS#12) KeyStore file could be suited to store encryption keys, but I could also define a smaller structure (encryption-transformation / key data / checksum) that could be attached to each storage store (i.e. using addition files with the same name and special extension for plain files or embedded inside other types of objects such as RMS Record Stores). What approach would you prefer? And when it comes to using a standard KeyStore with multiple-key generation (given this is your preference), would it be better to use a record-store per storage object or just a global KeyStore keeping all keys (i.e. using the URL identifier of abstract storage object as alias)? Master key. The use of a master key seems obvious. This key should be protected by user PIN (introduced only once) and would allow access to the rest of encryption keys (they would be encrypted by means of this master key). Changing the PIN would only require to reencrypt this key and not all the encrypted data. Where would you keep it taking into account that if this got lost all data would be no further accesible? What further considerations should I take into account? Platform cryptography support. Do SATSA-CRYPTO-enabled J2ME phones really take advantage of some dedicated hardware acceleration (or other advantage I have not foreseen) and would this approach be prefered (whenever possible) over just BouncyCastle implementation? For the same reason is RIM Cryptographic API worth the license cost over BouncyCastle? Any comments, critics, further considerations or different approaches are welcome.

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  • xml regular expression/regex OR operator

    - by Naz Haque
    Hi am trying to use a regeX to read through my document to identify currency types whether they're $,£ or a €. The regex I've created doesn't seem to work, somebody please advise me what it should be. I'd really appreciate the help: The regEX I've created ("\$|£|€]")is in a simpleType within my XSD file used for validating a document. The code is show after the colon, please note to display on stackoverflow I've had to remove the open/close tags (<): xs:simpleType name="currencyType" xs:restriction base="utf8-string" xs:length value="1" / xs:pattern value="[\$|£|€]"/ /xs:restriction /xs:simpleType

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  • Map Reduce Frameworks/Infrastructure

    - by Johannes Rudolph
    Map Reduce is a pattern that seems to get a lot of traction lately and I start to see it manifest in one of my projects that is focused on an event processing pipeline (iPhone Accelerometer and GPS data). I needed to built a lot of infrastructure for this project, in fact it overweighs the logic code interacting with it by 2x. Some of the components I built where EventProcessors (with in- and output plus buffering, timing etc.), multiplexers and aggregators. This leads me to my question what the "common" required infrastrucutre for map reduce is. Since I am working with .Net a lot I can see map reduce infrastructure built into the Framework and language constructs. Functional languages support this paradigm per se. It seems every language can be used with map reduce, some have better support than others, others again are built around that concept (e.g. Go). And there are Frameworks like Apache Hadoop to support map reduce.

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  • Will this Java regex return a single result or multiple

    - by Blankman
    If my HTML is: <tr><td>....</td><hr></tr> <tr><td>....</td><hr></tr> <tr><td>....</td><hr></tr> <tr><td>....</td><hr></tr> <tr><td>....</td><hr></tr> <tr><td>....</td><hr></tr> If my regex is: Patterp p = Pattern.compile("<tr>(.*)<hr></tr>"); Should this get 1 result or all the individual rows? Is there a way to force it to get all the rows and not just the entire html from the top <tr> to the last instance of <hr></tr> ?

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  • Need Help Customizing a Grammar Checking Replace Rule in Java

    - by user567785
    Hello, I am currently adding the Khmer (Cambodian) language to LanguageTool, an opensource grammar checker for OpenOffice (http://www.languagetool.org). I don't know enough Java to customize one of the scripts and wanted to make a request here asking if anyone would be willing to customize it for me (I can put link to your website at http://www.sbbic.org/lang/en-us/volunteer/ if you help). Here is the script that needs customization KhmerWordCoherencyRule.java: /* LanguageTool, a natural language style checker * Copyright (C) 2005 Daniel Naber (http://www.danielnaber.de) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 * USA */ package de.danielnaber.languagetool.rules.km; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.ResourceBundle; import de.danielnaber.languagetool.AnalyzedSentence; import de.danielnaber.languagetool.AnalyzedToken; import de.danielnaber.languagetool.AnalyzedTokenReadings; import de.danielnaber.languagetool.JLanguageTool; import de.danielnaber.languagetool.tools.StringTools; import de.danielnaber.languagetool.rules.Category; import de.danielnaber.languagetool.rules.RuleMatch; /** * A Khmer rule that matches words or phrases which should not be used and suggests * correct ones instead. Loads the relevant words from * <code>rules/km/coherency.txt</code>, where km is a code of the language. * * @author Andriy Rysin */ public abstract class KhmerWordCoherencyRule extends KhmerRule { private static final String FILE_ENCODING = "utf-8"; private Map<String, String> wrongWords; // e.g. "????? -> "?????" private static final String FILE_NAME = "/km/coherency.txt"; public abstract String getFileName(); public String getEncoding() { return FILE_ENCODING; } /** * Indicates if the rule is case-sensitive. Default value is <code>true</code>. * @return true if the rule is case-sensitive, false otherwise. */ //in Khmer there is no case public boolean isCaseSensitive() { return false; } /** * @return the locale used for case conversion when {@link #isCaseSensitive()} is set to <code>false</code>. */ public Locale getLocale() { return Locale.getDefault(); } public KhmerWordCoherencyRule(final ResourceBundle messages) throws IOException { if (messages != null) { super.setCategory(new Category(messages.getString("category_misc"))); } wrongWords = loadWords(JLanguageTool.getDataBroker().getFromRulesDirAsStream(getFileName())); } public String getId() { return "KM_WORD_COHERENCY"; } public String getDescription() { return "Checks for wrong words/phrases"; } public String getSuggestion() { return " does not match your previous spelling of the word, use "; } public String getShort() { return "Use a consistant spelling throughout"; } public final RuleMatch[] match(final AnalyzedSentence text) { final List<RuleMatch> ruleMatches = new ArrayList<RuleMatch>(); final AnalyzedTokenReadings[] tokens = text.getTokensWithoutWhitespace(); for (int i = 1; i < tokens.length; i++) { final String token = tokens[i].getToken(); final String origToken = token; final String replacement = isCaseSensitive()?wrongWords.get(token):wrongWords.get(token.toLowerCase(getLocale())); if (replacement != null) { final String msg = token + getSuggestion() + replacement; final int pos = tokens[i].getStartPos(); final RuleMatch potentialRuleMatch = new RuleMatch(this, pos, pos + origToken.length(), msg, getShort()); if (!isCaseSensitive() && StringTools.startsWithUppercase(token)) { potentialRuleMatch.setSuggestedReplacement(StringTools.uppercaseFirstChar(replacement)); } else { potentialRuleMatch.setSuggestedReplacement(replacement); } ruleMatches.add(potentialRuleMatch); } } return toRuleMatchArray(ruleMatches); } private Map<String, String> loadWords(final InputStream file) throws IOException { final Map<String, String> map = new HashMap<String, String>(); InputStreamReader isr = null; BufferedReader br = null; try { isr = new InputStreamReader(file, getEncoding()); br = new BufferedReader(isr); String line; while ((line = br.readLine()) != null) { line = line.trim(); if (line.length() < 1) { continue; } if (line.charAt(0) == '#') { // ignore comments continue; } final String[] parts = line.split(";"); if (parts.length != 2) { throw new IOException("Format error in file " + JLanguageTool.getDataBroker().getFromRulesDirAsUrl(getFileName()) + ", line: " + line); } map.put(parts[0], parts[1]); } } finally { if (br != null) { br.close(); } if (isr != null) { isr.close(); } } return map; } public void reset() { } } Here is what I need the SimpleReplaceRule.java to do: 1 - Be able to have more than two spelling variations in the coherency.txt file (right now it can only be Word1;Word2). 2 - Find the first use of ANY of the spelling variations in a document that are found in coherency.txt and then make sure only that spelling is used throughout the document (ex. in the coherency.txt I have Word1;Word2;Word3 then in my document on the first line I write Word2. then on next line I write Word1 and Word 3 - then the grammar checker will flag Word1 and Word3 saying that I should use the spelling "Word2" instead...etc.). If anyone can help I would be grateful! Thanks for your time, Nathan

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  • Designing a state machine in C++

    - by skyeagle
    I have a little problem that involves modelling a state machine. I have managed to do a little bit of knowledge engineering and 'reverse engineer' a set of primitive deterministic rules that determine state as well as state transitions. I would like to know what the best practises are regarding: How to rigorously test my states and state transitions to make sure that the system cannot end up in an undeetermined state. How to enforce state transition requirements (for example, it should be impossible to go directly from stateFoo to StateFooBar, i.e. to embue each state with 'knowlege' about the states it can transition to. Ideally, I would like to use clean, pattern based design, with templates wherever possible. I do need somewhere to start though and I would be grateful for any pointers (no pun intended), that are sent my way.

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  • What are some good design patterns for CRUD?

    - by Extrakun
    I am working with a number of data entities which can be created, read, updated and deleted, and I find myself writing more or less the same code for them. For example, I need to sometimes output data as JSON, and sometimes in a table format. I am finding myself writing 2 different types of view to export the data to. Also, the creation of those entities within DB usually differs just by the SQL statements and the input parameters. I am thinking of creating a strategy pattern to represent different 'contexts'. For example, the read() method of an AJAX context will be to return the data as JSON. However, I wonder if others have deal with this problem beforehand and will like to know what design patterns are usually use for CRUD operations.

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  • Saving data to server with user accounts.

    - by AKRamkumar
    Ok, so for an app I am making, I want the user to be able to save data online. On my website, I will provide a web server with tables of UserName/Password/SaveData. How can I do this without crashing the server load? How can I guarantee security ? Is there a Design Pattern for this?Is there a better way of doing this? This is going to be a free application, available to the public and I would like for their settings to be available, no matter the computer they are using. Is there a better way of doing this? I am using MEF for plugins so is there a way I can save plugin data as well?

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  • How can I avoid properties being reset at design-time in tightly bound user controls?

    - by David Anderson
    I have UserControl 'A' with a label, and this property: /// <summary> /// Gets or Sets the text of the control /// </summary> [ Browsable(true), EditorBrowsable(EditorBrowsableState.Always), Category("Appearance") ] public override string Text { get { return uxLabel.Text; } set { uxLabel.Text = value; } } I then have UserControl 'B' which has UserControl 'A' on it, and I set the Text Property to "My Example Label" in the designer. Then, I have my MainForm, which has UserControl 'B' on it. Each time I do a build or run, the Text property of UserControl 'A' is reset to its default value. I suppose this is because since I am doing a rebuild, it rebuilds both UserControl 'A' and 'B', thus causing the problem. How can I go about a better approach to design pattern to avoid this type of behavior when working with tightly bound controls and forms in a application?

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  • Usage of WCF RIA Services, where the datasource isn't a classical (relational) database

    - by Kottan
    I want (have) to write a Silverlight and (or) ASP.NET based webapplication with SAP in the backend (in other words, the datasource is no classical database) . The usage of Silverlight and ASP.NET is a precondition. Is it possible to use the WCF RIA Services (and Silverlight) where the data-source are RFCs from SAP ? Makes this sense ? If yes, how the pattern/architecture could be shortly described ? Or should I take other architectures into considerations (usage of plain WCF services, WCF data services,...) ?

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  • how to implement IOC without a global static service (non-service locator solution)?

    - by Michel
    Hi, we want to use Unity for IOC. All i've seen is the implementation that there is one global static service which holds a reference to the Unity container, which registers all interface/class combinations and every class asks that object: give me an implementation for Ithis or IThat. Frequently i see a response that this pattern is not good because it leads to a dependency from ALL classes to this service. But what i don't see often, is: what is the alternative way? Michel EDIT: found out that the global static service is called the service locator, added that to the title.

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  • How to properly update a feature branch from trunk?

    - by Pavel Radzivilovsky
    SVN book says: ...Another way of thinking about this pattern is that your weekly sync of trunk to branch is analogous to running svn update in a working copy, while the final merge step is analogous to running svn commit from a working copy I find this approach very unpractical in large developments, for several reasons, mostly related to reintegration step. From SVN v1.5, merging is done rev-by-rev. Cherry-picking the areas to be merged would cause us to resolve the trunk-branch conflicts twice (one when merging trunk revisions to the FB, and once more when merging back). Repository size: trunk changes might be significant for a large code base, and copying the differences files (unlike SVN copy) from trunk elsewhere may be a significant overhead. Instead, we do what we call "re-branching". In this case, when a significant chunk of trunk changes is needed, a new feature branch is opened from current trunk, and the merge is always downward (Feature branches - trunk - stable branches). This does not go along SVN book guidelines and developers see it as extra pain. How do you handle this situation?

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  • .ics Calendar File - Parsing Date Time - What is the time format?

    - by Josh
    I am coding in php, attempting to get the start\end dates and times for events. I am utilizing the following RegEx for parsing out the information: $pattern='/(?P<StartDate>[0-9]{8})T(?P<StartTime>[0-9]{6}) .+(?P<EndDate>[0-9]{8})T(?P<EndTime>[0-9]{6})/'; The sample event entry is here: BEGIN:VEVENT UID:34b09fd7-8e6e-4d56-86b0-445745b89d93 ORGANIZER;CN=*********:mailto:********* DTSTART;TZID="(GMT-06.00) Central Time (US & Canada)":20100413T130000 DTEND;TZID="(GMT-06.00) Central Time (US & Canada)":20100413T160000 STATUS:CONFIRMED CLASS:PRIVATE X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY TRANSP:OPAQUE X-MICROSOFT-DISALLOW-COUNTER:TRUE DTSTAMP:20100414T140711Z SEQUENCE:0 END:VEVENT 20100413T130000 and 20100413T160000 are the start and end points. The dates are straight forward, however how do I interpret the time part? This event starts at one and ends at four.

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