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  • Can I use loops in repeater? Is it recommended?

    - by iTayb
    My datasource has an Rating dataItem contains an integer from 0 to 5. I'd like to print stars accordignly. I'm trying to do it within Repeater control: <b>Rating:</b> <% for (int j = 1; j <= DataBinder.Eval(Container.DataItem, "Rating"); j++) { %> <img src="App_Pics/fullstar.png" /> <% } for (int j = 1; j <= 5 - DataBinder.Eval(Container.DataItem, "Rating"); j++) { %> <img src="App_Pics/emptystar.png" /> <%} %> I get the error The name 'Container' does not exist in the current context. It is weird, because when I used <%# DataBinder.Eval(Container.DataItem, "Name")%> a line before, it worked great. Is it clever to include loops in my aspx page? I think it's not very convenient. What's my alternatives? What's that # means? Thank you very much.

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  • JTextField vs JComboBox behaviour in JTable

    - by Ash
    Okay, this is a hard one to explain but I'll try my best. I have a JTextField and a JComboBox in a JTable, whose getCellEditor method has been overriden as follows: public TableCellEditor getCellEditor( int row, int column ) { if ( column == 3 ) { // m_table is the JTable if ( m_table.getSelectedRowCount() == 1 ) { JComboBox choices = new JComboBox(); choices.setEditable( true ); choices.addItem( new String( "item 1" ) ); return new DefaultCellEditor( choices ); } return super.getCellEditor( row, column ); } Here are the behavioral differences (NOTE that from this point on, when I say JTextField or JComboBox, I mean the CELL in the JTable containing either component): When I click once on a JTextField, the cell is highlighted. Double clicking brings up the caret and I can input text. Whereas, with a JComboBox, single clicking brings up the caret to input text, as well as the combo drop down button. When I tab or use the arrow keys to navigate to a JTextField and then start typing, the characters I type automatically get entered into the cell. Whereas, when I navigate to a JComboBox the same way and then start typing, nothing happens apart from the combo drop down button appearing. None of the characters I type get entered unless I hit F2 first. So here's my question: What do I need to do have JComboBoxes behave exactly like JTextFields in the two instances described above? Please do not ask why I'm doing what I'm doing or suggest alternatives (it's the way it is and I need to do it this way) and yes, I've read the API for all components in question....the problem is, it's a swing API. Thanks in advance, Ash

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  • List<object>.RemoveAll - How to create an appropriate Predicate

    - by CJM
    This is a bit of noob question - I'm still fairly new to C# and generics and completely new to predicates, delegates and lamda expressions... I have a class 'Enquiries' which contains a generic list of another class called 'Vehicles'. I'm building up the code to add/edit/delete Vehicles from the parent Enquiry. And at the moment, I'm specifically looking at deletions. From what I've read so far, it appears that I can use Vehicles.RemoveAll() to delete an item with a particular VehicleID or all items with a particular EnquiryID. My problem is understanding how to feed .RemoveAll the right predicate - the examples I have seen are too simplistic (or perhaps I am too simplistic given my lack of knowledge of predicates, delegates and lambda expressions). So if I had a List<Of Vehicle> Vehicles where each Vehicle had an EnquiryID, how would I use Vehicles.RemoveAll() to remove all vehicles for a given EnquiryID? I understand there are several approaches to this so I'd be keen to hear the differences between approaches - as much as I need to get something working, this is also a learning exercise. As an supplementary question, is a Generic list the best repository for these objects? My first inclination was towards a Collection, but it appears I am out of date. Certainly Generics seem to be preferred, but I'm curious as to other alternatives. Thanks

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  • C# reference collection for storing reference types

    - by ivo s
    I like to implement a collection (something like List<T>) which would hold all my objects that I have created in the entire life span of my application as if its an array of pointers in C++. The idea is that when my process starts I can use a central factory to create all objects and then periodically validate/invalidate their state. Basically I want to make sure that my process only deals with valid instances and I don't re-fetch information I already fetched from the database. So all my objects will basically be in one place - my collection. A cool thing I can do with this is avoid database calls to get data from the database if I already got it (even if I updated it after retrieval its still up-to-date if of course some other process didn't update it but that a different concern). I don't want to be calling new Customer("James Thomas"); again if I initted James Thomas already sometime in the past. Currently I will end up with multiple copies of the same object across the appdomain - some out of sync other in sync and even though I deal with this using timestamp field on the MSSQL server I'd like to keep only one copy per customer in my appdomain (if possible process would be better). I can't use regular collections like List or ArrayList for example because I cannot pass parameters by their real local reference to the their existing Add() methods where I'm creating them using ref so that's not to good I think. So how can this be implemented/can it be implemented at all ? A 'linked list' type of class with all methods working with ref & out params is what I'm thinking now but it may get ugly pretty quickly. Is there another way to implement such collection like RefList<T>.Add(ref T obj)? So bottom line is: I don't want re-create an object if I've already created it before during the entire application life unless I decide to re-create it explicitly (maybe its out-of-date or something so I have to fetch it again from the db). Is there alternatives maybe ?

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  • Javascript Object.Watch for all browsers?

    - by SeanW
    Hey all, I was looking for an easy way to monitor an object or variable for changes, and I found Object.Watch that's supported in Mozilla browsers, but not IE. So I started searching around to see if anyone had written some sort of equivalent. About the only thing I've found has been a jQuery plugin (http://plugins.jquery.com/files/jquery-watch.js.txt), but I'm not sure if that's the best way to go. I certainly use jQuery in most of my projects, so I'm not worried about the jQuery aspect... Anyway, the question: can someone show me a working example of that jQuery plugin? I'm having problems making it work... Or, does anyone know of any better alternatives that would work cross browser? Thanks! Update after answers: Thanks everyone for the responses! I tried out the code posted here: http://webreflection.blogspot.com/2009/01/internet-explorer-object-watch.html But I couldn't seem to make it work with IE. The code below works fine in FireFox, but does nothing in IE. In Firefox, each time watcher.status is changed, the document.write in watcher.watch is called and you can see the output on the page. In IE, that doesn't happen, but I can see that watcher.status is updating the value, because the last document.write shows the correct value (in both IE and FF). But, if the callback function isn't called, then that's kind of pointless... :) Am I missing something? var options = {'status': 'no status'}, watcher = createWatcher(options); watcher.watch("status", function(prop, oldValue, newValue) { document.write("old: " + oldValue + ", new: " + newValue + "<br>"); return newValue; }); watcher.status = 'asdf'; watcher.status = '1234'; document.write(watcher.status + "<br>");

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  • Does a VCL OrgChart component with decent features exists? Is there a viable alternative?

    - by user193655
    I am using DevExpress OrgChart component that is still maintained but not developed since 2003 (fortunately bugs are fixed, but nothing more). Honestly this component, even if it starts to look too old still suffices my requirements except for 2 things: 1) it doesn't support at all the staff feature, for understanding what I mean see this image (where the items in staff are Administration, Communication, IT, Special Projects). 2) it arranges the items without optimizing the space, for example if there are 3 items at top level, and only the second item has 2 childs, the top items items are drawn more distantly, because of the 2 childs, there is no an option for "shirinking" the diagram. Of course the component misses tons of the features one would expect from an OrgChart tool, but in my case Those 2, and expecially (1) are important, the rest is lack of eye-candy. I look for VCL components, but if (as I fear, since I never found it) such component doesn't exist) I can see the following alternatives: i) using Hydra with .net winforms components ii) using ActiveX components. Between the 2 I would prefer ActiveX because of the .NET deployment hell (what I like about Delphi is that you ship the exe to the customer witn Win2k and it works). Anyway I never used an activeX control and I don't know which are the deployment issues, but I fear I will lose the opportunity of replacing an exe and upgrading the software. iii) hire a delphi component develoeper that can customize the DevEx component by adding feature (1) and maybe (2). I am stuck.

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  • Help understanding .NET delegates, events, and eventhandlers

    - by Seth Spearman
    Hello, In the last couple of days I asked a couple of questions about delegates HERE and HERE. I confess...I don't really understand delegates. And I REALLY REALLY REALLY want to understand and master them. (I can define them--type safe function pointers--but since I have little experience with C type languages it is not really helpful.) Can anyone recommend some online resource(s) that will explain delegates in a way that presumes nothing? This is one of those moments where I suspect that VB actually handicaps me because it does some wiring for me behind the scenes. The ideal resource would just explain what delegates are, without reference to anything else like (events and eventhandlers), would show me how all everything is wired up, explain (as I just learned) that delegates are types and what makes them unique as a type (perhaps using a little ildasm magic)). That foundation would then expand to explain how delegates are related to events and eventhandlers which would need a pretty good explanation in there own right. Finally this resource could tie it all together using real examples and explain what wiring DOES happen automatically by the compiler, how to use them, etc. And, oh yeah, when you should and should not use delegates, in other words, downsides and alternatives to using delegates. What say ye? Can any of you point me to resource(s) that can help me begin my journey to mastery? EDIT One last thing. The ideal resource will explain how you can and cannot use delegates in an interface declaration. That is something that really tripped me up. Thanks for your help. Seth

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  • Patterns for non-layered applications

    - by Paul Stovell
    In Patterns of Enterprise Application Architecture, Martin Fowler writes: This book is thus about how you decompose an enterprise application into layers and how those layers work together. Most nontrivial enterprise applications use a layered architecture of some form, but in some situations other approaches, such as pipes and filters, are valuable. I don't go into those situations, focussing instead on the context of a layered architecture because it's the most widely useful. What patterns exist for building non-layered applications/parts of an application? Take a statistical modelling engine for a financial institution. There might be a layer for data access, but I expect that most of the code would be in a single layer. Would you still expect to see Gang of Four patterns in such a layer? How about a domain model? Would you use OO at all, or would it be purely functional? The quote mentions pipes and filters as alternate models to layers. I can easily imagine a such an engine using pipes as a way to break down the data processing. What other patterns exist? Are there common patterns for areas like task scheduling, results aggregation, or work distribution? What are some alternatives to MapReduce?

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  • ant ftp task "Could not date test remote file"

    - by avok00
    Hi guys! I am using Ant ftp task to deploy my project files to a remote app server. Ant is not able to detect the date of the remote file and it re-uploads all files every time. When I start Ant in debug mode it says: [ftp] checking date for mailer.war [ftp] Could not date test remote file: mailer.war assuming out of date. The remote server is MS FTP (Windows Vista version) Ant version is 1.8.2; I use commons-net-2.2 and jakarta-oro-2.0.8 (could not find newer version) My ant task looks like this <!-- Deploy new and changed files --> <target name="deploy" depends="package" description="Deploy new and changed files"> <ftp server="localhost" userid="" password="" action="send" depends="yes" passive="true" systemTypeKey="WINDOWS" serverTimeZoneConfig="Europe/Sofia" defaultDateFormatConfig="MMM dd yyyy" recentDateFormatConfig="MMM dd HH:mm" binary="true" retriesAllowed="3" verbose="true"> <fileset dir="${webapp.artefacts.path}"/> </ftp> </target> I read an article here: Ant:The definitive guide that says I need a version of jakarta oro AFTER 2.0.8 to talk to MS FTP servers, but I was not able to find such version. Jakarta oro site - http://jakarta.apache.org/oro/ says the oro project is retired as of 2010, but their latest distribution is from 2003! Please, can anyone help me with this? Any solution or any alternatives to the Ant ftp task? Thanks!

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  • Should I persist images on EBS or S3?

    - by javanes
    I am migrating my Java,Tomcat, Mysql server to AWS EC2. I have already attached EBS volume for storing MySql data. In my web application people may upload images. So I should persist them. There are 2 alternatives in my mind: Save uploaded images to EBS volume. Use the S3 service. The followings are my notes, please be skeptic about them, as my expertise is not on servers, but software development. EBS plus: S3 storage is more expensive. (0.15 $/Gb 0.1$/Gb) S3 plus: Serving statics from EBS may influence my web server's performance negatively. Is this true? Does Serving images affect server performance notably? For S3 my server will not be responsible for serving statics. S3 plus: Serving statics from EBS may result I/O cost, probably it will be minor. EBS plus: People say EBS is faster. S3 plus: People say S3 is more safe for persistence. EBS plus: No need to learn API, it is straight forward to save the images to EBS volume. Namely I can not decide, will be happy if you guide. Thanks

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  • How can I find out if two arguments are instances of the same, but unknown class?

    - by Ingmar
    Let us say we have a method which accepts two arguments o1 and o2 of type Object and returns a boolean value. I want this method to return true only when the arguments are instances of the same class, e.g.: foo(new Integer(4),new Integer(5)); Should return true, however: foo(new SomeClass(), new SubtypeSomeClass()); should return false and also: foo(new Integer(3),"zoo"); should return false. I believe one way is to compare the fully qualified class names: public boolean foo(Object o1, Object o2){ Class<? extends Object> c1 = o1.getClass(); Class<? extends Object> c2 = o2.getClass(); if(c1.getName().equals(c2.getName()){ return true;} return false; } An alternative conditional statement would be : if (c1.isAssignableFrom(c2) && c2.isAssignableFrom(c1)){ return true; } The latter alternative is rather slow. Are there other alternatives to this problem?

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  • How can "today's date" be varied for unit testing purposes?

    - by ck
    I use VS2008 targetting .NET 2.0 Framework, and, just in case, no I can't change this :) I have a DateCalculator class. Its method GetNextExpirationDate attempts to determine the next expiration, internally using DateTime.Today as a baseline date. As I was writing unit tests, I realized that I wanted to test GetNextExpirationDate for different 'today' dates. What's the best way to do this? Here are some alternatives I've considered: Expose a property/overloaded method with argument baselineDate and only use it from the unit test. In actual client code, disregard the property/overloaded method in favour of the method that defaults baselineDate to DateTime.Today. I'm reluctant to do this as it makes the public interface of the DateCalculator class awkward. Create a protected field called baselineDate that is internally set to DateTime.Today. When testing, derive a DateCalculatorForTesting from DateCalculator and set baslineDate via the constructor. It keeps the public interface clean, but still isn't great - baselineDate was made protected and a derived class is required, both solely for testing. Use extension methods. I tried this after adding the ExtensionAttribute, then realized it wouldn't work because extension methods can't access private/protected variables. I initially thought this was really quite an elegant solution. :( I'd be interested in hearing what others think.

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  • Managing large binary files with git

    - by pi
    Hi there. I am looking for opinions of how to handle large binary files on which my source code (web application) is dependent. We are currently discussing several alternatives: Copy the binary files by hand. Pro: Not sure. Contra: I am strongly against this, as it increases the likelihood of errors when setting up a new site/migrating the old one. Builds up another hurdle to take. Manage them all with git. Pro: Removes the possibility to 'forget' to copy a important file Contra: Bloats the repository and decreases flexibility to manage the code-base and checkouts/clones/etc will take quite a while. Separate repositories. Pro: Checking out/cloning the source code is fast as ever, and the images are properly archived in their own repository. Contra: Removes the simpleness of having the one and only git repository on the project. Surely introduces some other things I haven't thought about. What are your experiences/thoughts regarding this? Also: Does anybody have experience with multiple git repositories and managing them in one project? Update: The files are images for a program which generates PDFs with those files in it. The files will not change very often(as in years) but are very relevant to a program. The program will not work without the files. Update2: I found a really nice screencast on using git-submodule at GitCasts.

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  • General Address Parser for Freeform Text

    - by Daemonic
    We have a program that displays map data (think Google Maps, but with much more interactivity and custom layers for our clients). We allow navigation via a set of combo boxes that prefill certain fields with a bunch of data (ie: Country: Canada, the Province field is filled in. Select Ontario, and a list of Counties/Regions is filled in. Select a county/region, and a city is filled in, etc...). While this guarantees accurate addresses, it's a pain for the users if they don't know where a street address or a city are located (ie, which county/region is kitchener in?). So we are looking at trying to do an address parser with a freeform text field. The user could enter something like this (similar to Google Maps, Bing Maps, etc...): 22 Main St, Kitchener, On And we could compartmentalize it into sections and do lookups on the data and get to the point they are looking for (or suggest alternatives). The problem with this is that how do we properly compartmentalize information? How do we break up the sections and find possible matches? I'm guessing we wouldn't be guaranteed that the user would enter data in a format we always expected (obviously). A follow up to this would be how to present the data if we don't find an exact match (or find multiple exact matches... two cities with the same street name in different counties, for example). We have a ton of data available in the mapping data (mapinfo tab format mostly). So we can do quick scans of street names, cities, states, etc. But I'm not sure about the best way to go about approaching this problem. Sure, using Google Maps would be nice, bue most of our clients are in closed in networks where outside access is not usually allowed and most aren't willing to rely on google maps (since it doesn't contain as much information as they need, such as custom map layers). They could, obviously, go to google and get the proper location then move to our software, but this would time consuming and speed of the process can be quite important.

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  • Determining the color of a pixel in a bitmap using C# in a WPF app

    - by DanM
    The only way I found so far is System.Drawing.Bitmap.GetPixel(), but Microsoft has warnings for System.Drawing that are making me wonder if this is the "old way" to do it. Are there any alternatives? Here's what Microsoft says about the System.Drawing namespace. I also noticed that the System.Drawing assembly was not automatically added to the references when I created a new WPF project. System.Drawing Namespace The System.Drawing namespace provides access to GDI+ basic graphics functionality. More advanced functionality is provided in the System.Drawing.Drawing2D, System.Drawing.Imaging, and System.Drawing.Text namespaces. The Graphics class provides methods for drawing to the display device. Classes such as Rectangle and Point encapsulate GDI+ primitives. The Pen class is used to draw lines and curves, while classes derived from the abstract class Brush are used to fill the interiors of shapes. Caution Classes within the System.Drawing namespace are not supported for use within a Windows or ASP.NET service. Attempting to use these classes from within one of these application types may produce unexpected problems, such as diminished service performance and run-time exceptions. - http://msdn.microsoft.com/en-us/library/system.drawing.aspx

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  • maven and unit testing - combining maven surefire plugin AND testNG eclipse plugin

    - by lisak
    Hey, could you please share your way of unit testing in eclipse ? Are you using surefire plugin, m2eclipse & maven, or only testNG eclipse plugin ? Do you combine these alternatives ? I'm using testNG + maven surefire-plugin and I had been using the testNG eclipse plugin a year ago so that I could see the results in testNG view. Then I started using Maven, but when I do "maven test phase" using m2eclipse, there is only console output and surefire reports that I can check in browser and to choose what test suite, test, or test method can be set up only via testng.xml. On the other hand, if you use only surefire plugin and you have some specific settings regarding classpath etc., that you rely on, then running tests via testNG eclipse plugin doesn't have to be compatible with your code. Using surefire plugin, the classpath is different - target/test-classes and target/classes - than using testNG plugin, that is using the project classpath. How do you go about what I was just talking about? Is it possible to synchronize "maven test" using m2eclipse and surefire plugin WITH testNG eclipse plugin and view ? EDITED: I'm also wondering, why the Maven project ("Java build path") output folder is target/classes for src/main and src/test whereas surefire plugin makes two locations target/test-classes and target/classes Thank you very much for your your opinions.

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  • How to preserve order of temp table rows when inner joined with another table?

    - by Triynko
    Does an SQL Server "join" preserve any kind of row order consistently (i.e. that of the left table or that of the right table)? Psuedocode: create table #p (personid bigint); foreach (id in personid_list) insert into #p (personid) values (id) select id from users inner join #p on users.personid = #p.id Suppose I have a list of IDs that correspond to person entries. Each of those IDs may correspond to zero or more user accounts (since each person can have multiple accounts). To quickly select columns from the users table, I populate a temp table with person ids, then inner join it with the users table. I'm looking for an efficient way to ensure that the order of the results in the join matches the order of the ids as they were inserted into the temp table, so that the user list that's returned is in the same order as the person list as it was entered. I've considered the following alternatives: using "#p inner join users", in case the left table's order is preserved using "#p left join users where id is not null", in case a left join preserves order and the inner join doesn't using "create table (rownum int, personid bigint)", inserting an incrementing row number as the temp table is populated, so the results can be ordered by rownum in the join using an SQL Server equivalent of the "order by order of [tablename]" clause available in DB2 I'm currently using option 3, and it works... but I hate the idea of using an order by clause for something that's already ordered. I just don't know if the temp table preserves the order in which the rows were inserted or how the join operates and what order the results come out in.

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  • Get Function Pointer to function in a shared library I didn't directly load

    - by bdk
    My Linux application (A) links against a Third Party shared Library (B) which I don't have source code to. This library makes use of another third party shared library that I don't have source code to (C). I believe that (B) uses dlopen to access (C) instead of directly linking. My reasoning for this is that 'ldd' on (B) does not show (C) and objdump -X (B) shows references to dlopen/dlclose/dlsym. My requirement is that I need to in my code for (A) get a function pointer to a function foo() located in (C). Normally I'd use dlsym for this, but I need to pass it the handle returned from dlopen which I don't have since (B) does not expose this. - For the larger context: I need to modify the function in (C) such that everytime it calls its helper function bar() (also located in (C)), it also calls a function with the same signature located in (A) with the same parameters (Basically inject my code into the codepath of (C) foo()-bar(). I believe I've found a way to accomplish this using gdb, but in order to port my gdb command list, but I'm stuck on the step of getting the function pointer. I'm also open to alternatives to accomplish the same task rather than the exact problem as stated above Edit: After writing this I realized I can probably just do another dlopen on the file in my code and the symbols returned via dlsym on that handle should be the same as received via the original dlopen, If I'm reading the dlopen man page correctly. However I'm still interested in advice or assistance with the my larger context, If theres a better way to go about this

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  • Simplest distributed persistent key/value store that supports primary key range queries

    - by StaxMan
    I am looking for a properly distributed (i.e. not just sharded) and persisted (not bounded by available memory on single node, or cluster of nodes) key/value ("nosql") store that does support range queries by primary key. So far closest such system is Cassandra, which does above. However, it adds support for other features that are not essential for me. So while I like it (and will consider using it of course), I am trying to figure out if there might be other mature projects that implement what I need. Specifically, for me the only aspect of value I need is to access it as a blob. For key, however, I need range queries (as in, access values ordered, limited by start and/or end values). While values can have structures, there is no need to use that structure for anything on server side (can do client-side data binding, flexible value/content types etc). For added bonus, Cassandra style storage (journaled, all sequential writes) seems quite optimal for my use case. To help filter out answers, I have investigated some alternatives within general domain like: Voldemort (key/value, but no ordering) and CouchDB (just sharded, more batch-oriented); and am aware of systems that are not quite distributed while otherwise qualifying (bdb variants, tokyo cabinet itself (not sure if Tyrant might qualify), redis (in-memory store only)).

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  • Shall this Regex do what I expect from it, that is, matching against "A1:B10,C3,D4:E1000"?

    - by Will Marcouiller
    I'm currently writing a library where I wish to allow the user to be able to specify spreadsheet cell(s) under four possible alternatives: A single cell: "A1"; Multiple contiguous cells: "A1:B10" Multiple separate cells: "A1,B6,I60,AA2" A mix of 2 and 3: "B2:B12,C13:C18,D4,E11000" Then, to validate whether the input respects these formats, I intended to use a regular expression to match against. I have consulted this article on Wikipedia: Regular Expression (Wikipedia) And I also found this related SO question: regex matching alpha character followed by 4 alphanumerics. Based on the information provided within the above-linked articles, I would try with this Regex: Default Readonly Property Cells(ByVal cellsAddresses As String) As ReadOnlyDictionary(Of String, ICell) Get Dim validAddresses As Regex = New Regex("A-Za-z0-9:,A-Za-z0-9") If (Not validAddresses.IsMatch(cellsAddresses)) then _ Throw New FormatException("cellsAddresses") // Proceed with getting the cells from the Interop here... End Get End Property Questions 1. Is my regular expression correct? If not, please help me understand what expression I could use. 2. What exception is more likely to be the more meaningful between a FormatException and an InvalidExpressionException? I hesitate here, since it is related to the format under which the property expect the cells to be input, aside, I'm using an (regular) expression to match against. Thank you kindly for your help and support! =)

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  • Change classes instantiated with loadNibNamed

    - by Nick H247
    I am trying to change the class of objects created with a nib with the iPhone SDK. The reason for this is; i dont know until runtime what the class is that i want the nib object to be (though they will have the same UIView based super class), and i dont want to create a different nib for every eventuality - as the .nib will be the same for each, apart from the class of one object. I have been successful, with a couple of methods, but either have some knock on effects or am unsure of how safe the methods I have used are: Method 1: Override alloc, on the super class and set a c variable to the class I require: + (id) alloc { if (theClassIWant) { id object = [theClassIWant allocWithZone:NSDefaultMallocZone()]; theClassIWant = nil; return object; } return [BaseClass allocWithZone:NSDefaultMallocZone()]; } this works well, and i assume is 'reasonably' safe, though if I alloc a subclass myself (without setting 'theClassIWant') - an object of the base class is created. I also dont really like the idea of overriding alloc... Method 2: use object_setClass(self,theClassIWant) in initWithCoder (before calling initWithCoder on the super class): - (id) initWithCoder:(NSCoder *)aDecoder { if (theClassIWant) { // the framework doesn't like this: //[self release]; //self = [theClassIWant alloc]; // whoa now! object_setClass(self,theClassIWant); theClassIWant = nil; return [self initWithCoder:aDecoder]; } if (self = [super initWithCoder:aDecoder]) { ... this also works well, but not all the subclasses are necessarily going to be the same size as the super class, so this could be very unsafe! To combat this i tried releasing and re-allocing to the correct type within initWithCoder, but i got the following error from the framework: "This coder requires that replaced objects be returned from initWithCoder:" dont quite get what this means! i am replacing an object in initWithCoder... Any comments on the validity of these methods, or suggestions of improvements or alternatives welcome!

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  • Suggested (simple) approach for drawing large numbers of visual elements in WPF?

    - by Ender
    I'm writing an interface that features a large (~50000px width) "canvas"-type area that is used to display a lot of data in a fairly novel way. This involves lots of lines, rectangles, and text. The user can scroll around to explore the entire canvas. At the moment I'm just using a standard Canvas panel with various Shapes placed on it. This is nice and easy to do: construct a shape, assign some coordinates, and attach it to the Canvas. Unfortunately, it's pretty slow (to construct the children, not to do the actual rendering). I've looked into some alternatives, it's a bit intimidating. I don't need anything fancy - just the ability to efficiently construct and place objects in a coordinate plane. If all I get are lines, colored rectangles, and text, I'll be happy. Do I need Geometry instances inside of Geometry Groups inside of GeometryDrawings inside of some Panel container? Note: I'd like to include text and graphics (i.e. colored rectangles) in the same space, if possible.

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  • Precision of Interval for PL/SQL Function value

    - by Gary
    Generally, when you specify a function the scale/precision/size of the return datatype is undefined. For example, you say FUNCTION show_price RETURN NUMBER or FUNCTION show_name RETURN VARCHAR2. You are not allowed to have FUNCTION show_price RETURN NUMBER(10,2) or FUNCTION show_name RETURN VARCHAR2(20), and the function return value is unrestricted. This is documented functionality. Now, I get an precision error (ORA-01873) if I push 9999 hours (about 400 days) into the following. The limit is because the default days precision is 2 DECLARE v_int INTERVAL DAY (4) TO SECOND(0); FUNCTION hhmm_to_interval return INTERVAL DAY TO SECOND IS v_hhmm INTERVAL DAY (4) TO SECOND(0); BEGIN v_hhmm := to_dsinterval('PT9999H'); RETURN v_hhmm; -- END hhmm_to_interval; BEGIN v_int := hhmm_to_interval; end; / and it won't allow the precision to be specified directly as part of the datatype returned by the function. DECLARE v_int INTERVAL DAY (4) TO SECOND(0); FUNCTION hhmm_to_interval return INTERVAL DAY (4) TO SECOND IS v_hhmm INTERVAL DAY (4) TO SECOND(0); BEGIN v_hhmm := to_dsinterval('PT9999H'); RETURN v_hhmm; -- END hhmm_to_interval; BEGIN v_int := hhmm_to_interval; end; / I can use a SUBTYPE DECLARE subtype t_int is INTERVAL DAY (4) TO SECOND(0); v_int INTERVAL DAY (4) TO SECOND(0); FUNCTION hhmm_to_interval return t_int IS v_hhmm INTERVAL DAY (4) TO SECOND(0); BEGIN v_hhmm := to_dsinterval('PT9999H'); RETURN v_hhmm; -- END hhmm_to_interval; BEGIN v_int := hhmm_to_interval; end; / Any drawbacks to the subtype approach ? Any alternatives (eg some place to change a default precision) ? Working with 10gR2.

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  • What is the preferred way in C++ for converting a builtin type (int) to bool?

    - by Martin
    When programming with Visual C++, I think every developer is used to see the warning warning C4800: 'BOOL' : forcing value to bool 'true' or 'false' from time to time. The reason obviously is that BOOL is defined as int and directly assigning any of the built-in numerical types to bool is considered a bad idea. So my question is now, given any built-in numerical type (int, short, ...) that is to be interpreted as a boolean value, what is the/your preferred way of actually storing that value into a variable of type bool? Note: While mixing BOOL and bool is probably a bad idea, I think the problem will inevitably pop up whether on Windows or somewhere else, so I think this question is neither Visual-C++ nor Windows specific. Given int nBoolean; I prefer this style: bool b = nBoolean?true:false; The following might be alternatives: bool b = !!nBoolean; bool b = (nBoolean != 0); Is there a generally preferred way? Rationale? I should add: Since I only work with Visual-C++ I cannot really say if this is a VC++ specific question or if the same problem pops up with other compilers. So it would be interesting to specifically hear from g++ or users how they handle the int-bool case. Regarding Standard C++: As David Thornley notes in a comment, the C++ Standard does not require this behavior. In fact it seems to explicitly allow this, so one might consider this a VC++ weirdness. To quote the N3029 draft (which is what I have around atm.): 4.12 Boolean conversions [conv.bool] A prvalue of arithmetic, unscoped enumeration, pointer, or pointer to member type can be converted to a prvalue of type bool. A zero value, null pointer value, or null member pointer value is converted to false; any other value is converted to true. (...)

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  • Existing Calendar Software for Web Service?

    - by OverClocked
    I'd like to offer users of my web platform calendars, and also offer group calendar and public calendar features. I know of Google Calendar API, of course, but that would require all my users to have Google accounts (although, I guess the question is who does not these days). I am wondering if there are any other alternatives? I can write my own, but this has gotten to have been done thousands of times already! I am looking not so much at the front end; we'd probably going to re-skin the UI anyways. But I want a solution that has good backend support for storing events and recurring events, and maintaining multiple calendars. Ideally, the engine would also support things like shared event between different calendars, syncing with other calendars, etc. Sad thing is that this does seem like Google Calendar would cover it, but asking all the users to have to have google accounts may not be realistic. Especially since we'd also want to create group calendars, and I am not sure under who's google account that'd be, and if that'd even be covered under their terms of use. Your thoughts? Thanks.

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