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  • Exclude subdirectory from rewrite rule in web.config

    - by Clog
    This question comes up often, but I can only find solutions for PHP, Apache, htaccess etc but not for web.config I would like my pages to return in HTTP not HTTPS, except for forms within certain subdirectories. I have created the following web.config file, but how do I exclude a subdirectory called forms. <configuration> <system.webServer> <rewrite> <rules> <rule name="Force all to HTTP" stopProcessing="true"> <match url="(.*)" /> <conditions> <add input="{HTTPS}" pattern="on" ignoreCase="true" /> </conditions> <action type="Redirect" redirectType="Found" url="http://www.mysite.com/{R:1}" /> </rule> </rules> </rewrite> </system.webServer> </configuration> Many thanks all you clever clogs.

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  • Creating sublines on Joomla menu items

    - by ploughansen
    In my toplevel menu items, I would like to make a subline for each item. I don't think it's possible to do by default, byt YooTheme has done it in many of their templates. The menu output look like this <div class="moduletable_menu"> <ul id="mainmenu" class="menu"> <li class="active item1" id="current"> <a href="URL_HIDDEN"> <span>Services</span> </a> </li> </ul> This basically outputs a one line menu item like so: Services What I would like to do is have a menu item like this: Services Service x, Service y, Service z For reference, have a look at the main menu on the YooTheme demo page. The way YooTheme does this, is using two pipes (||) as a linebreak, so in the Joomla backend you type "Services||Service x, Service y, Service z" as the menu title, and then there must be some fancy javascript that breaks this title into two spans, ready to be styled using css. Does anyone know of an easy way to code this? Please note that I am looking to build this feature into a custom template (ie. non-yootheme). Also note that I am not using MooTools, but Jquery instead.

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  • How strict should I be in the "do the simplest thing that could possible work" while doing TDD

    - by Support - multilanguage SO
    For TDD you have to Create a test that fail Do the simplest thing that could possible work to pass the test Add more variants of the test and repeat Refactor when a pattern emerge With this approach you're supposing to cover all the cases ( that comes to my mind at least) but I'm wonder if am I being too strict here and if it is possible to "think ahead" some scenarios instead of simple discover them. For instance, I'm processing a file and if it doesn't conform to a certain format I am to throw an InvalidFormatException So my first test was: @Test void testFormat(){ // empty doesn't do anything... processor.validate("empty.txt"); try { processor.validate("invalid.txt"); assert false: "Should have thrown InvalidFormatException"; } catch( InvalidFormatException ife ) { assert "Invalid format".equals( ife.getMessage() ); } } I run it and it fails because it doesn't throw an exception. So the next thing that comes to my mind is: "Do the simplest thing that could possible work", so I : public void validate( String fileName ) throws InvalidFormatException { if(fileName.equals("invalid.txt") { throw new InvalidFormatException("Invalid format"); } } Doh!! ( although the real code is a bit more complicated, I found my self doing something like this several times ) I know that I have to eventually add another file name and other test that would make this approach impractical and that would force me to refactor to something that makes sense ( which if I understood correctly is the point of TDD, to discover the patterns the usage unveils ) but: Q: am I taking too literal the "Do the simplest thing..." stuff?

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  • Regular Expression with Names and Emails

    - by Nina
    I am having a problem with regular expressions at the moment. What I'm trying to do is that for each line through the iteration, it checks for this type of pattern: Lastname, Firstname If it finds the name, then it will take the first letter of the first name, and the first six letters of the lastname and form it as an email. I have the following: $checklast = "[A-z],"; $checkfirst = "[A-z]"; if (ereg($checklast, $parts[1])||ereg($checkfirst, $parts[2])){ $first = preg_replace($checkfirst, $checkfirst{1,1}, $parts[2]); print "<a href='mailto:[email protected];'> $parts[$i] </a>"; } This one obviously broke the code. But I was initially attempting to find only the first letter of the firstname and then after that the first six letters of the lastname followed by the @email.com This didn't work out too well. I'm not sure what to do at this point. Any help is much appreciated.

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  • Do I need to write a trigger for such a simple constraint?

    - by Paul Hanbury
    I really had a hard time knowing what words to put into the title of my question, as I am not especially sure if there is a database pattern related to my problem. I will try to simplify matters as much as possible to get directly to the heart of the issue. Suppose I have some tables. The first one is a list of widget types: create table widget_types ( widget_type_id number(7,0) primary key, description varchar2(50) ); The next one contains icons: create table icons ( icon_id number(7,0) primary key, picture blob ); Even though the users get to select their preferred widget, there is a predefined subset of widgets that they can choose from for each widget type. create table icon_associations ( widget_type_id number(7,0) references widget_types, icon_id number(7,0) references icons, primary key (widget_type_id, icon_id) ); create table icon_prefs ( user_id number(7,0) references users, widget_type_id number(7,0), icon_id number(7,0), primary key (user_id, widget_type_id), foreign key (widget_type_id, icon_id) references icon_associations ); Pretty simple so far. Let us now assume that if we are displaying an icon to a user who has not set up his preferences, we choose one of the appropriate images associated with the current widget. I'd like to specify the preferred icon to display in such a case, and here's where I run into my problem: alter table icon_associations add ( is_preferred char(1) check( is_preferred in ('y','n') ) ) ; I do not see how I can enforce that for each widget_type there is one, and only one, row having is_preferred set to 'y'. I know that in MySQL, I am able to write a subquery in my check constraint to quickly resolve this issue. This is not possible with Oracle. Is my mistake that this column has no business being in the icon_associations table? If not where should it go? Is this a case where, in Oracle, the constraint can only be handled with a trigger? I ask only because I'd like to go the constraint route if at all possible. Thanks so much for your help, Paul

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  • Entity Framework POCO objects

    - by Dan
    I'm struggling with understanding Entity Framework and POCO objects. Here's what I'm trying to achieve. 1) Separate the DAL from the Business Layer by having my business layer use an interface to my DAL. Maybe use Unity to create my context. 2) Use Entity Framework inside my DAL. I have a Domain model with objects that reside in my business layer. I also have a database full of tables that doesn't really represent my domain model. I setup Entity Framework and generated POCO objects by using the ADO.NET POCO Generator extension. This gave me an object for each table in my database. Now I want to be able to say context.GetAll<User>(); and have it return a list of my User objects. The User object is in my business layer. Is that possible? Does that make sense or am I totally off and should start over? I'm guessing I need to use the repository pattern to achieve this, but I'm not sure. Can anyone help?

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  • Why does this Haskell code produce the "infinite type" error?

    - by Charlie Flowers
    I am new to Haskell and facing a "cannot construct infinite type" error that I cannot make sense of. In fact, beyond that, I have not been able to find a good explanation of what this error even means, so if you could go beyond my basic question and explain the "infinite type" error, I'd really appreciate it. Here's the code: intersperse :: a -> [[a]] -> [a] -- intersperse '*' ["foo","bar","baz","quux"] -- should produce the following: -- "foo*bar*baz*quux" -- intersperse -99 [ [1,2,3],[4,5,6],[7,8,9]] -- should produce the following: -- [1,2,3,-99,4,5,6,-99,7,8,9] intersperse _ [] = [] intersperse _ [x] = x intersperse s (x:y:xs) = x:s:y:intersperse s xs And here's the error trying to load it into the interpreter: Prelude :load ./chapter.3.ending.real.world.haskell.exercises.hs [1 of 1] Compiling Main ( chapter.3.ending.real.world.haskell.exercises.hs, interpreted ) chapter.3.ending.real.world.haskell.exercises.hs:147:0: Occurs check: cannot construct the infinite type: a = [a] When generalising the type(s) for `intersperse' Failed, modules loaded: none. Thanks. EDIT: Thanks to the responses, I have corrected the code and I also have a general guideline for dealing with the "infinite type" error in Haskell: Corrected code intersperse _ [] = [] intersperse _ [x] = x intersperse s (x:xs) = x ++ s:intersperse s xs What the problem was: My type signature states that the second parameter to intersperse is a list of lists. Therefore, when I pattern matched against "s (x:y:xs)", x and y became lists. And yet I was treating x and y as elements, not lists. Guideline for dealing with the "infinite type" error: Most of the time, when you get this error, you have forgotten the types of the various variables you're dealing with, and you have attempted to use a variable as if it were some other type than what it is. Look carefully at what type everything is versus how you're using it, and this will usually uncover the problem.

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  • How should I handle expected errors? eg. "username already exists"

    - by Pheter
    I am struggling to understand how I should design the error handling parts of my code. I recently asked a similar question about how I should go about returning server error codes to the user, eg. 404 errors. I learnt that I should handle the error from within the current part of the application; seem's simple enough. However, what should I do when I can't handle the error from the current link in the chain? For example, I may have a class that is used to manage authentication. One of it's methods could be createUser($username, $password). Within that function, I need to determine if the username already exists. If this is true, how should I alert the calling code about this? Returning null instead of a user object is one way. But how do I then know what caused the error? How should I handle errors in such a way that calling code can easily find out what caused the error? Is there a design pattern commonly used for this kind of situation?

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  • How to face observable object containing an observable field

    - by iseek
    Hello, I need a hint concerning MVC and Observer-Pattern. For example a model contains the classes "Address" and "Person". The Address class contains the fields street:String, zipcode:String, location:String. Whereas the Person class contains the fields name:String, firstName:String, address:Address. My approach so far looks something like this: Both, Address and Person are observable. If one of their setters is being called, I validate whether the current value and new value differ. Only in this case an update event is fired. The event contains the source, the name of the changed field, the old and the new value. The class for the view contains text fields to display and edit the information of a person: name, firstname, street, zipcode, location. It knows the Person model and is an subscribed observer for the person. So it gets the update events from the person object. My questions concerns the address field from type Address in the person class, since an address is observable on its own. If the view gets an update event from person when a new address has been set, I can update all of the address related fields in the view. But what if a field of the address changes? Should the view also register for update events from the address? Any hints about common design approaches would be appreciated. Greetings.

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  • How do I resize table view after resizing it's footer?

    - by Pedro
    I have a UITableView with header & footer added with code following the pattern shown in Apple's recipes example so the code for the footer is... if (tableFooterView == nil) { [[NSBundle mainBundle] loadNibNamed:@"DetailFooterView" owner:self options:nil]; self.tableView.tableFooterView = tableFooterView; } The footer NIB contains nothing more than a UITextView & I set text & resize with... CGSize size = [footerText sizeWithFont:[footerTextView font] constrainedToSize:CGSizeMake(304.0, 500.0)]; CGRect frame = CGRectMake(8.0, 0.0, size.width, size.height + 24.0); footerTextView.frame = frame; footerTextView.text = footerText; [tableFooterView sizeToFit]; That all works however I can't get the UITableView to resize around the resized footer. If I set the original size of the footer for any possible text I have a big whitespace in most cases. If I set it smaller then I can push the view up to see the whole text but it bounces back on release. I've tried [[self view] sizeToFit]; but that doesn't work. Can anyone fill me in? Cheers & TIA, Pedro :)

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  • JSR-299 (CDI) configuration at runtime

    - by nsn
    I need to configure different @Alternatives, @Decorators and @Injectors for different runtime environments (think testing, staging and production servers). Right now I use maven to create three wars, and the only difference between those wars are in the beans.xml files. Is there a better way to do this? I do have @Alternative @Stereotypes for the different environments, but even then I need to alter beans.xml, and they don't work for @Decorators (or do they?) Is it somehow possible to instruct CDI to ignore the values in beans.xml and use a custom configuration source? Because then I could for example read a system property or other environment variable. The application exclusively runs in containers that use Weld, so a weld-specific solution would be ok. I already tried to google this but can't seem to find good search terms, and I asked the Weld-Users-Forums, but to no avail. Someone over there suggested to write my own custom extension, but I can't find any API to actually change the container configuration at runtime. I think it would be possible to have some sort of @ApplicationScoped configuration bean and inject that into all @Decorators which could then decide themselves whether they should be active or not and then in order to configure @Alternatives write @Produces methods for every interface with multiple implementations and inject the config bean there too. But this seems to me like a lot of unnecessary work to essentially duplicate functionality already present in CDI?

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  • How to get multiple html() strings in jQuery

    - by Bryan
    I'm pretty new to jQuery... so far I'm impressed. But I encountered a situation today that is giving me trouble. I want to use .html() to get some raw text and use that in a selector, but that function only returns the first element. In the following structure, how can I get ALL of the "toggle_containerLG" divs to show when I click on the trigger "Some Header"? <h6 class="trigger active">Some Header</h6> <ul> <li><a href="#" class="trigger">Title One</a></li> <li><a href="#" class="trigger">Title Two</a></li> <li><a href="#" class="trigger">Title Three</a></li> </ul> <div class="toggle_containerLG" id='Title_One'></div> <!-- show these! --> <div class="toggle_containerLG" id='Title_Two'></div> <div class="toggle_containerLG" id='Title_Three'></div> <div class="toggle_containerLG" id='Title_Four'></div> <!-- not this one! --> I can't use $(".toggle_containerLG") because there are others I don't want to expand... I just want the ones listed under "Some Header". Seems like there should be an easy way to do it... and I'm just missing it because I don't know jQuery very well.

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  • What Test Environment Setup do Committers Use in the Ruby Community?

    - by viatropos
    Today I am going to get as far as I can setting up my testing environment and workflow. I'm looking for practical advice on how to setup the test environment from you guys who are very passionate and versed in Ruby Testing. By the end of the day (6am PST?) I would like to be able to: Type one 1-command to run test suites for ANY project I find on Github. Run autotest for ANY Github project so I can fork and make TESTABLE contributions. Build gems from the ground up with Autotest and Shoulda. For one reason or another, I hardly ever run tests for projects I clone from Github. The major reason is because unless they're using RSpec and have a Rake task to run the tests, I don't see the common pattern behind it all. I have built 3 or 4 gems writing tests with RSpec, and while I find the DSL fun, it's less than ideal because it just adds another layer/language of methods I have to learn and remember. So I'm going with Shoulda. But this isn't a question about which testing framework to choose. So the questions are: What is your, the SO reader and Github project committer, test environment setup using autotest so that whenever you git clone a gem, you can run the tests and autotest-develop them if desired? What are the guys who are writing the Paperclip Tests and Authlogic Tests doing? What is their setup? Thanks for the insight. Looking for answers that will make me a more effective tester.

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  • Testing When Correctness is Poorly Defined?

    - by dsimcha
    I generally try to use unit tests for any code that has easily defined correct behavior given some reasonably small, well-defined set of inputs. This works quite well for catching bugs, and I do it all the time in my personal library of generic functions. However, a lot of the code I write is data mining code that basically looks for significant patterns in large datasets. Correct behavior in this case is often not well defined and depends on a lot of different inputs in ways that are not easy for a human to predict (i.e. the math can't reasonably be done by hand, which is why I'm using a computer to solve the problem in the first place). These inputs can be very complex, to the point where coming up with a reasonable test case is near impossible. Identifying the edge cases that are worth testing is extremely difficult. Sometimes the algorithm isn't even deterministic. Usually, I do the best I can by using asserts for sanity checks and creating a small toy test case with a known pattern and informally seeing if the answer at least "looks reasonable", without it necessarily being objectively correct. Is there any better way to test these kinds of cases?

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  • How to start matching and saving matched from exact point in a text

    - by yuliya
    I have a text and I write a parser for it using regular expressions and perl. I can match what I need with two empty lines (I use regexp), because there is a pattern that allows recognize blocks of text after two empty lines. But the problem is that the whole text has Introduction part and some text in the end I do not need. Here is a code which matches text when it finds two empty lines #!/usr/bin/perl use strict; use warnings; my $file = 'first'; open(my $fh, '<', $file); my $empty = 0; my $block_num = 1; open(OUT, '>', $block_num . '.txt'); while (my $line = <$fh>) { chomp ($line); if ($line =~ /^\s*$/) { $empty++; } elsif ($empty == 2) { close(OUT); open(OUT, '>', ++$block_num . '.txt'); $empty = 0; } else { $empty = 0;} print OUT "$line\n"; } close(OUT); This is example of the text I need (it's really small :)) this is file example I think that I need to iterate over the text till the moment it will find the word LOREM IPSUM with regexps this kind "/^LOREM IPSUM/", because it is the point from which needed text starts(and save the text in one file when i reach the word). And I need to finish iterating over the text when INDEX word is fount or save the text in separate file. How could I implement it. Should I use next function to proceed with lines or what? BR, Yuliya

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  • How to specify multiple values in where with AR query interface in rails3

    - by wkhatch
    Per section 2.2 of rails guide on Active Record query interface here: which seems to indicate that I can pass a string specifying the condition(s), then an array of values that should be substituted at some point while the arel is being built. So I've got a statement that generates my conditions string, which can be a varying number of attributes chained together with either AND or OR between them, and I pass in an array as the second arg to the where method, and I get: ActiveRecord::PreparedStatementInvalid: wrong number of bind variables (1 for 5) which leads me to believe I'm doing this incorrectly. However, I'm not finding anything on how to do it correctly. To restate the problem another way, I need to pass in a string to the where method such as "table.attribute = ? AND table.attribute1 = ? OR table.attribute1 = ?" with an unknown number of these conditions anded or ored together, and then pass something, what I thought would be an array as the second argument that would be used to substitute the values in the first argument conditions string. Is this the correct approach, or, I'm just missing some other huge concept somewhere and I'm coming at this all wrong? I'd think that somehow, this has to be possible, short of just generating a raw sql string.

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  • ZEND - Creating custom routes without overwriting the default ones

    - by Pedro Cordeiro
    I'm trying to create something that looks like facebook's profile URL (http://facebook.com/username). So, at first I tried something like that: $router->addRoute( 'eventName', new Zend_Controller_Router_Route( '/:eventName', array( 'module' => 'default', 'controller' => 'event', 'action' => 'detail' ) ) ); I kept getting the following error: Fatal error: Uncaught exception 'Zend_Controller_Router_Exception' with message 'eventName is not specified' in /var/desenvolvimento/padroes/zf/ZendFramework-1.12.0/library/Zend/Controller/Plugin/Broker.php on line 336 Not only I was unable to make that piece of code work, all my default routes were (obviously) overwritten. So I have, for example, stuff like "mydomain.com/admin", that was now returning the same error (as it fell in the same pattern as /:eventName). What I need to do is to create this custom route, without overwriting the default ones and actually working (dûh). I have already checked the online docs and a lot (A LOT) of stuff on google, but I didn't find anything related to the error I'm getting or how to not overwrite the default routes. I'd appreciate anything that could point me the right direction. Thanks.

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  • How can I use a meter-style progress bar?

    - by Yadyn
    In Vista/7, the Windows Explorer shell window makes use of a special kind of static progress bar to display hard drive space. With default styles, this bar is blue colored and non-animated. It also turns red colored when it gets close to being full (low disk space). Using messaging, I can tell the Windows Forms ProgressBar control to update its state to Paused and Error (yellow and red colored, respectively), which works fine, but these are still specific to progress. In the Windows User Experience Guidelines, it specifically points out this "meter" variant of the Progress Bar: This pattern isn't a progress bar, but it is implemented using the progress bar control. Meters have a distinct look to differentiate them from true progress bars. They say it "is implemented using the progress bar control", so... how? What message could I send to the control to have it behave this way? I've seen that you can send messages for setting the bar color, but the documentation says these calls are ignored when visual styles are enabled. Nothing else in the Windows API documentation for raw ProgressBar controls seemed to suggest a way to do this. Am I just stuck making a custom drawn bar? I'd really like to utilize the OS whenever possible so that the application will appear consistent throughout different OS versions. I realize that pre-Vista versions probably won't support this, though. I'm looking for a Windows Forms solution, but I wonder if it is even exposed at all via Win32 API.

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  • Mysql count and sum from two diferent tables

    - by Agent_x
    Hi all, i have a problem with some querys in php and mysql: I have 2 diferent tables with one field in common: table 1 id | hits | num_g | cats | usr_id |active 1 | 10 | 11 | 1 | 53 | 1 2 | 13 | 16 | 3 | 53 | 1 1 | 10 | 22 | 1 | 22 | 1 1 | 10 | 21 | 3 | 22 | 1 1 | 2 | 6 | 2 | 11 | 1 1 | 11 | 1 | 1 | 11 | 1 table 2 id | usr_id | points 1 | 53 | 300 Now i use this statement to sum just the total from the table 1 every id count + 1 too SELECT usr_id, COUNT( id ) + SUM( num_g + hits ) AS tot_h FROM table1 WHERE usr_id!='0' GROUP BY usr_id ASC LIMIT 0 , 15 and i get the total for each usr_id usr_id| tot_h | 53 | 50 22 | 63 11 | 20 until here all is ok, now i have a second table with extra points (table2) I try this: SELECT usr_id, COUNT( id ) + SUM( num_g + hits ) + (SELECT points FROM table2 WHERE usr_id != '0' ) AS tot_h FROM table1 WHERE usr_id != '0' GROUP BY usr_id ASC LIMIT 0 , 15 but it seems to sum the 300 extra points to all users: usr_id| tot_h | 53 | 350 22 | 363 11 | 320 Now how i can get the total like the first try but + the secon table in one statement? because now i have just one entry in the second table but i can be more there. thanks for all the help. =============================================================================== hi thomas thanks for your reply, i think is in the right direction, but im getting weirds results, like usr_id | tot_h 22 | NULL <== i think the null its because that usr_id as no value in the table2 53 | 1033 Its like the second user is getting all the the values. then i try this one: SELECT table1.usr_id, COUNT( table1.id ) + SUM( table1.num_g + table1.hits + table2.points ) AS tot_h FROM table1 LEFT JOIN table2 ON table2.usr_id = table1.usr_id WHERE table1.usr_id != '0' AND table2.usr_id = table1.usr_id GROUP BY table1.usr_id ASC Same result i just get the sum of all values and not by each user, i need something like this result: usr_id | tot_h 53 | 53 <==== plus 300 points on table1 22 | 56 <==== plus 100 points on table2 /////////the result i need //////////// usr_id | tot_h 53 | 353 <==== plus 300 points on table2 22 | 156 <==== plus 100 points on table2 I think the structure need to be something like this Pseudo statements ;) from table1 count all id to get the number of record where the usr_id are then sum hits + num_g and from table2 select the extra points where the usr_id are the same as table1 and get teh result: usr_id | tot_h 53 | 353 22 | 156

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  • VB.net/Excel- "Backwards" tab index For Each iteration with textboxes.

    - by MSD
    Hi there, I have a form with 3 textboxes and 1 button. textbox1 has tab index 0, and it's text = 1 textbox2 has tab index 1, and it's text = 2 textbox3 has tab index 2, and it's text = 3 I want to iterate thru the textboxes and place their values into cells so that... range("A1").value = txtbox1.text (ie: A1 = "1") range("A2").value = txtbox2.text (ie: A2 = "2") range("A3").value = txtbox3.text (ie: A3 = "3") but what I am getting is... range("A1").value = txtbox1.text (ie: A1 = "3") range("A2").value = txtbox2.text (ie: A2 = "2") range("A3").value = txtbox3.text (ie: A3 = "1") I have tried reversing the tab index for the text boxes, but it doesn't change the "backwards iteration". Is there something I can do to change this so that the loop runs from lowest tab index to highest? Thanks! Public Class Form1 Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim objExcel As New Microsoft.Office.Interop.Excel.Application 'Declaring the object. objExcel.Visible = True 'Setting Excel to visible. Dim cntrl As Control With objExcel .Workbooks.Add() 'Adding a workbook. .Range("A1").Select() 'Selecting cell A1. End With 'Form contains 3 text boxes, with one number in each (1,2,3), and one button to fire the code in this sub. For Each cntrl In Me.Controls 'For every control on the form... If TypeOf (cntrl) Is TextBox Then 'If the control is a textbox, then... With objExcel .ActiveCell.Value = cntrl.Text 'place the control's text in the active cell and... .ActiveCell.Offset(1, 0).Activate() 'offset down one row. End With End If 'If the control is not a textbox (if it's the button), do nothing. Next 'Go to the next control. objExcel = Nothing 'Release the object. GC.Collect() 'Clean up. End Sub End Class

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  • Appropriate uses of Monad `fail` vs. MonadPlus `mzero`

    - by jberryman
    This is a question that has come up several times for me in the design code, especially libraries. There seems to be some interest in it so I thought it might make a good community wiki. The fail method in Monad is considered by some to be a wart; a somewhat arbitrary addition to the class that does not come from the original category theory. But of course in the current state of things, many Monad types have logical and useful fail instances. The MonadPlus class is a sub-class of Monad that provides an mzero method which logically encapsulates the idea of failure in a monad. So a library designer who wants to write some monadic code that does some sort of failure handling can choose to make his code use the fail method in Monad or restrict his code to the MonadPlus class, just so that he can feel good about using mzero, even though he doesn't care about the monoidal combining mplus operation at all. Some discussions on this subject are in this wiki page about proposals to reform the MonadPlus class. So I guess I have one specific question: What monad instances, if any, have a natural fail method, but cannot be instances of MonadPlus because they have no logical implementation for mplus? But I'm mostly interested in a discussion about this subject. Thanks! EDIT: One final thought occured to me. I recently learned (even though it's right there in the docs for fail) that monadic "do" notation is desugared in such a way that pattern match failures, as in (x:xs) <- return [] call the monad's fail. It seems like the language designers must have been strongly influenced by the prospect of some automatic failure handling built in to haskell's syntax in their inclusion of fail in Monad.

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  • Focus-dependent text change for TextBoxes in WPF

    - by Simon
    Hey there. I'm writing an application in WPF using the MVVM-pattern and will really often use TextBoxes. I don't want to use labels for the user to know user what the text box is for, i.e. I don't want something like this: <TextBlock> Name: </TextBlock> <TextBox /> Instead, I would like the TextBox to contain its own label. Statically, you would express it like this: <TextBox>Name</TextBox> If the cursor is displayed in the textbox, i.e. the TextBox gains focus, I want the description text to disappear. If the TextBox is left empty and it loses the focus, the description text should be shown again. It's similar to the search textbox of StackOverflow or the one of Firefox. (please tell me if your not sure what I mean). One TextBox's label may change at runtime, dependending on e.g. a ComboBox's selected element or a value in my ViewModel. (It's like in Firefox's search TextBox, if you select google from the search engins' menu, the TextBox's label changes to "Google", if you select "Yahoo" its set to "Yahoo"). Thus I want to be able to bind the label's content. Consider that I may already have a Binding on the Text-Property of the TextBox. How can implement such a behaviour and make it reusable for any of my TextBox's? Code is welcome but not needed; a description of what to do is enough. Thank you in advance.

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  • MSI install sequence - run DB scripts before services start

    - by marc_s
    Folks, we're running into some sequencing troubles with our MSI install. As part of our app, we install a bunch of services and allow the user to pick whether to start them right away or later. When they start right away, they seem to start too early in the install sequence - before our database manager had a chance to update the database. Right now, our custom action to run the database updater looks like this - it's being run after "InstallFinalize" - very late in the process. <InstallExecuteSequence> <RemoveExistingProducts After='InstallInitialize' /> <Custom Action='RunDbUpdateManagerAction' After='InstallFinalize'> DbUpdateManager=3</Custom> </InstallExecuteSequence> What would be the more appropriate step to run after or before, to make sure the DB scripts are executed before any of the installed services start up? Is there a "BeforeServiceStart" step? EDIT: Just defining the "Before='StartServices'" attribute on the tag didn't solve my problem. I am assuming the issue is this: the custom action has an "inner text", which represents a condition, and this condition is: "&DbUpdateManager=3". From what I can deduce from trial & error, this probably means "the DbUpdateManager feature must be published". Now, trouble is: "PublishFeature" comes way at the end in the install sequence, just before "InstallFinalize", and definitely AFTER InstallServices / StartServices. So when I specify the "Before=StartServices" requirement, the condition "DbUpdateManager feature must be published" isn't true yet, so the DbUpdateManager doesn't get executed :-( I tried removing the condition - in that case, my DbUpdateManager sometimes doesn't execute at all, sometimes more than once - no real clear pattern as to what happens when..... Any more ideas?? Is there a way I could check for a condition "the DbUpdateManager feature is installed" which would be true after the "InstallFiles" step?? Marc

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  • Should frontend and backend be handled by different controllers?

    - by DR
    In my previous learning projects I always used a single controller, but now I wonder if that is good practice or even always possible. In all RESTful Rails tutorials the controllers have a show, an edit and an index view. If an authorized user is logged on, the edit view becomes available and the index view shows additional data manipulation controls, like a delete button or a link to the edit view. Now I have a Rails application which falls exactly into this pattern, but the index view is not reusable: The normal user sees a flashy index page with lots of pictures, complex layout, no Javascript requirement, ... The Admin user index has a completly different minimalistic design, jQuery table and lots of additional data, ... Now I'm not sure how to handle this case. I can think of the following: Single controller, single view: The view is split into two large blocks/partials using an if statement. Single controller, two views: index and index_admin. Two different controllers: BookController and BookAdminController None of these solutions seems perfect, but for now I'm inclined to use the 3rd option. What's the preferred way to do this?

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  • Refactoring an ASP.NET 2.0 app to be more "modern"

    - by Wayne M
    This is a hypothetical scenario. Let's say you've just been hired at a company with a small development team. The company uses an internal CRM/ERP type system written in .NET 2.0 to manage all of it's day to day things (let's simplify and say customer accounts and records). The app was written a couple of years ago when .NET 2.0 was just out and uses the following architectural designs: Webforms Data layer is a thin wrapper around SqlCommand that calls stored procedures Rudimentary DTO-style business objects that are populated via the sprocs A "business logic" layer that acts as a gateway between the webform and database (i.e. code behind calls that layer) Let's say that as there are more changes and requirements added to the application, you start to feel that the old architecture is showing its age, and changes are increasingly more difficult to make. How would you go about introducing refactoring steps to A) Modernize the app (i.e. proper separation of concerns) and B) Make sure that the app can readily adapt to change in the organization? IMO the changes would involve: Introduce an ORM like Linq to Sql and get rid of the sprocs for CRUD Assuming that you can't just throw out Webforms, introduce the M-V-P pattern to the forms Make sure the gateway classes conform to SRP and the other SOLID principles. Change the logic that is re-used to be web service methods instead of having to reuse code What are your thoughts? Again this is a totally hypothetical scenario that many of us have faced in the past, or may end up facing.

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