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• What is the correct way to implement a massive hierarchical, geographical search for news?

  - by Philip Brocoum

  The company I work for is in the business of sending press releases. We want to make it possible for interested parties to search for press releases based on a number of criteria, the most important being location. For example, someone might search for all news sent to New York City, Massachusetts, or ZIP code 89134, sent from a governmental institution, under the topic of "traffic". Or whatever. The problem is, we've sent, literally, hundreds of thousands of press releases. Searching is slow and complex. For example, a press release sent to Queens, NY should show up in the search I mentioned above even though it wasn't specifically sent to New York City, because Queens is a subset of New York City. We may also want to implement "and" and "or" and negation and text search to the query to create complex searches. These searches also have to be fast enough to function as dynamic RSS feeds. I really don't know anything about search theory, or how it's properly done. The way we are getting by right now is using a data mart to store the locations the releases were sent to in a single table. However, because of the subset thing mentioned above, the data mart is gigantic with millions of rows. And we haven't even implemented cities yet, and there are about 50,000 cities in the United States, which will exponentially increase the size of the data mart by so much I'm afraid it just won't work anymore. Anyway, I realize this is not a simple question and there won't be a "do this" answer. However, I'm hoping one of you can point me in the right direction where I can learn about how massive searches are done? Because I really know nothing about it. And such a search engine is turning out to be incredibly difficult to make. Thanks! I know there must be a way because if Google can search the entire internet we must be able to search our own database :-)

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• Pitfalls and practical Use-Cases: Toplink, Hibernate, Eclipse Link, Ibatis ...

  - by Martin K.

  I worked a lot with Hibernate as my JPA implementation. In most cases it works fine! But I have also seen a lot of pitfalls: Remoting with persisted Objects is difficult, because Hibernate replaces the Java collections with its own collection implementation. So the every client must have the Hibernate .jar libraries. You have to take care on LazyLoading exceptions etc. One way to get around this problem is the use of webservices. Dirty checking is done against the Database without any lock. "Delayed SQL", causes that the data access isn't ACID compliant. (Lost data...) Implict Updates So we don't know if an object is modified or not (commit causes updates). Are there similar issues with Toplink, Eclipse Link and Ibatis? When should I use them? Have they a similar performance? Are there reasons to choose Eclipse Link/Toplink... over Hibernate?

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• Automatically release resources RAII-style in Perl

  - by Philip Potter

  Say I have a resource (e.g. a filehandle or network socket) which has to be freed: open my $fh, "<", "filename" or die "Couldn't open filename: $!"; process($fh); close $fh or die "Couldn't close filename: $!"; Suppose that process might die. Then the code block exits early, and $fh doesn't get closed. I could explicitly check for errors: open my $fh, "<", "filename" or die "Couldn't open filename: $!"; eval {process($fh)}; my $saved_error = $@; close $fh or die "Couldn't close filename: $!"; die $saved_error if $saved_error; but this kind of code is notoriously difficult to get right, and only gets more complicated when you add more resources. In C++ I would use RAII to create an object which owns the resource, and whose destructor would free it. That way, I don't have to remember to free the resource, and resource cleanup happens correctly as soon as the RAII object goes out of scope - even if an exception is thrown. Unfortunately in Perl a DESTROY method is unsuitable for this purpose as there are no guarantees for when it will be called. Is there a Perlish way to ensure resources are automatically freed like this even in the presence of exceptions? Or is explicit error checking the only option?

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• Proper way to validate model in ASP.NET MVC 2 and ViewModel apporach

  - by adrin

  I am writing an ASP.NET MVC 2 application using NHibernate and repository pattern. I have an assembly that contains my model (business entities), moreover in my web project I want to use flattened objects (possibly with additional properties/logic) as ViewModels. These VMs contain UI-specific metadata (eg. DisplayAttribute used by Html.LabelFor() method). The problem is that I don't know how to implement validation so that I don't repeat myself throughout various tiers (specifically validation rules are written once in Model and propagated to ViewModel). I am using DataAnnotations on my ViewModel but this means no validation rules are imposed on the Model itself. One approach I am considering is deriving ViewModel objects from business entities adding new properties/overriding old ones, thus preserving validation metadata between the two however this is an ugly workaround. I have seen Automapper project which helps to map properties, but I am not sure if it can handle ASP.NET MVC 2 validation metadata properly. Is it difficult to use custom validation framework in asp.net mvc 2? Do you have any patterns that help to preserve DRY in regard to validation?

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• Capture *all* display-characters in JavaScript?

  - by Jean-Charles

  I was given an unusual request recently that I'm having the most difficult time addressing that involves capturing all display-characters when typed into a text box. The set up is as follows: I have a text box that has a maxlength of 10 characters. When the user attempts to type more than 10 characters, I need to notify the user that they're typing beyond the character count limit. The simplest solution would be to specify a maxlength of 11, test the length on every keyup, and truncate back down to 10 characters but this solution seems a bit kludgy. What I'd prefer to do is capture the character before keyup and, depending on whether or not it is a display-character, present the notification to the user and prevent the default action. A white-list would be challenging since we handle a lot of international data. I've played around with every combination of keydown, keypress, and keyup, reading event.keyCode, event.charCode, and event.which, but I can't find a single combination that works across all browsers. The best I could manage is the following that works properly in =IE6, Chrome5, FF3.6, but fails in Opera: NOTE: The following code utilizes jQuery. $(function(){ $('#textbox').keypress(function(e){ var $this = $(this); var key = ('undefined'==typeof e.which?e.keyCode:e.which); if ($this.val().length==($this.attr('maxlength')||10)) { switch(key){ case 13: //return case 9: //tab case 27: //escape case 8: //backspace case 0: //other non-alphanumeric break; default: alert('no - '+e.charCode+' - '+e.which+' - '+e.keyCode); return false; }; } }); }); I'll grant that what I'm doing is likely over-engineering the solution but now that I'm invested in it, I'd like to know of a solution. Thanks for your help!

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• Behavior of retained propertie while holder is retained

  - by Aurélien Vallée

  Hello everyone, I am a beginner ObjectiveC programmer, coming from the C++ world. I find it very difficult to understand the memory management offered by NSObject :/ Say I have the following class: @interface User : NSObject { NSString* name; } @property (nonatomic,retain) NSString* name; - (id) initWithName: (NSString*) theName; - (void) release; @end @implementation User @synthetise name - (id) initWithName: (NSString*) theName { if ( self = [super init] ) { [self setName:theName]; } return self; } - (void) release { [name release]; [super release]; } @end No considering the following code, I can't understand the retain count results: NSString* name = [[NSString alloc] initWithCString:/*C string from sqlite3*/]; // (1) name retainCount = 1 User* user = [[User alloc] initWithName:name]; // (2) name retainCount = 2 [whateverMutableArray addObject:user]; // (3) name retainCount = 2 [user release]; // (4) name retainCount = 1 [name release]; // (5) name retainCount = 0 At (4), the retain count of name decreased from 2 to 1. But that's not correct, there is still the instance of user inside the array that points to name ! The retain count of a variable should only decrease when the retain count of a referring variable is 0, that is, when it is dealloced, not released.

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• Explaining the need to avoid horizontal scroll

  - by Bradley Herman

  I need help explaining to my boss why her design is poor on a client's website. She has no knowledge of the web, and it can be difficult as a web developer working with a woman who is a graphic designer (not even a web designer really). On a current site she has designed, an image bar "needs" to be ~1200px according to her, though it isn't necessary with the content. A quick sketch to illustrate what's going on: As you see, the banner spills out past the 960px of the content and as wide as 1200px. This creates a horizontal scroll when all the content is viewable within the 960px wide viewport. I need to make this an <img and not a CSS background because it's a jQuery slideshow that fades from image to image. I think this is a big problem because a lot of people are going to get a horizontal scroll bar imposed in their browser when they're still able to see all the relevant content. She thinks no one will notice and it'll be fine; I think it's very bad practice and confusing to the end user. How do I explain the problem to her?

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• Find first item inside angular brackets after occurrence of other item, using RegEx, in C#

  - by Mihaela

  I have an xml-like text, in which I would like to find the item that occurs in the first occurrence of a certain pattern: typically: ... <PropertyGroup><name>true</name></PropertyGroup><PropertyGroup>.... .... Could also be ... <PropertyGroup> <name> true</name> </PropertyGroup> ... <PropertyGroup> ... In the above, I need to extract the "name". My initial assumption was that all occurrences were to be in one line, and I wrote my code using string properties, but it is very difficult o take in consideration every possibility, and only RegEx can save me. I just don't know how to write it... I Have started with something like this: Regex regex = new Regex("(?<=<PropertyGroup>#)<+"); Match matches = regex.Matches(Text)[0]; MessageBox.Show(matches.ToString()); I think this finds the first item after a <PropertyGroup>, but I don't know how to make it get the item within the angular brackets... (which may be after one or more newlines, and/or spaces). I know that there are utilities for parsing xml, but I am looking for something simple to insert in a c# program Can someone please help me ? Thank you very much.

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• Mercurial Hg Clone fails on C# project with GUID

  - by AnneTheAgile

  UPDATE: In trying to replicate this problem one more time to answer your questions I could not! I can only conclude that my initial setup of Mercurial was problematic and/or possibly I was trying to checkin a build that failed compilation before the checkin. Sigh! Thank you so very much for your help. I gave credit for the help on how to do a script. I need to try that for general purposes. hi all, I hope you can help me :). I am trying to see if Mercurial would be a good DCVS for my project at work, and I'm surely a newbie to many things. We have a fairly large codebase in C# (Dotnet3.0 not 3.5 , WindowsXP) and it utilizes the GUID feature. I confess to know little about how or why we use the GUID, but I do know that I cannot touch it. So, when I try hg clone, it fails unless I change the GUID in the cloned directory (ie create new GUID in Visual Studio and then paste that new GUID to replace the old one). To me, this completely defeats the purpose and utility of quick easy clones. It also makes difficult all the many workflows that require multiple clones. Is there a workaround, or is there something I'm doing wrong? How can I simplify and/or remove this problem? Would Bazaar make this easier? Thank you!

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• Why is iPdb not displaying STOUT after my input?

  - by BryanWheelock

  I can't figure out why ipdb is not displaying stout properly. I'm trying to debug why a test is failing and so I attempt to use ipdb debugger. For some reason my Input seems to be accepted, but the STOUT is not displayed until I (c)ontinue. Is this something broken in ipdb? It makes it very difficult to debug a program. Below is an example ipdb session, notice how I attempt to display the values of the attributes with: user.is_authenticated() user_profile.reputation user.is_superuser The results are not displayed until 'begin captured stdout ' In [13]: !python manage.py test Creating test database... < SNIP remove loading tables nosetests ...E.. /Users/Bryan/work/APP/forum/auth.py(93)can_retag_questions() 92 import ipdb; ipdb.set_trace() ---> 93 return user.is_authenticated() and ( 94 RETAG_OTHER_QUESTIONS <= user_profile.reputation < EDIT_OTHER_POSTS or user.is_authenticated() user_profile.reputation user.is_superuser c F /Users/Bryan/work/APP/forum/auth.py(93)can_retag_questions() 92 import ipdb; ipdb.set_trace() ---> 93 return user.is_authenticated() and ( 94 RETAG_OTHER_QUESTIONS <= user_profile.reputation < EDIT_OTHER_POSTS or c .....EE...... FAIL: test_can_retag_questions (APP.forum.tests.test_views.AuthorizationFunctionsTestCase) Traceback (most recent call last): File "/Users/Bryan/work/APP/../APP/forum/tests/test_views.py", line 71, in test_can_retag_questions self.assertTrue(auth.can_retag_questions(user)) AssertionError: -------------------- begin captured stdout << --------------------- ipdb True ipdb 4001 ipdb False ipdb --------------------- end captured stdout << ---------------------- Ran 20 tests in 78.032s FAILED (errors=3, failures=1) Destroying test database... In [14]: Here is the actual test I'm trying to run: def can_retag_questions(user): """Determines if a User can retag Questions.""" user_profile = user.get_profile() import ipdb; ipdb.set_trace() return user.is_authenticated() and ( RETAG_OTHER_QUESTIONS <= user_profile.reputation < EDIT_OTHER_POSTS or user.is_superuser) I've also tried to use pdb, but that doesn't display anything. I see my test progress .... , and then nothing and not responsive to keyboard input. Is this a problem with readline?

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• dynamic check_box using field_for in rails

  - by Craig Whitley

  I have a many-to-many relationship with a link box, and I want to pull those models together into one form so I can update from the same page. I'm really struggling with getting the check_box to even show all the elements of my array - I've scoured the net and been working on this literally all day, and I'm finding it difficult to apply the information I'm reading to my problem. I'm also extremely new to RoR and I've been following a bit of an outdated video tutorial (pre 2.0) so apologies for my code. So far, I've got it to output only one key pair in the array (the last one) - although outside the form, the code used in the tutorial works exactly how it should. Thats of little use though! Host is the model for which the main form is for, and Billing is the outside model that I'm trying to add to the form. This is the code that works outside of the form from the tutorial: <% for billing in @billings -%> <%= check_box_tag('billing_title[]', billing.id, @host.billings.collect {|obj| obj.id}.include?(billing.id))%> <%= billing.title %><br /> <% end -%> I just need to know how to make it work inside the form. This is the aforementioned code that only retrieves the last array keypair after looping through them: <% f.fields_for :billings do |obj| %><br /> <%= check_box_tag('billing_title[]', billing.id, @billings.collect {|obj| obj.id}.include?(billing.id))%> <%= billing.title %><br /> <% end %> The debug(@billings) : --- - !ruby/object:Billing attributes: title: Every Month id: "1" attributes_cache: {} - !ruby/object:Billing attributes: title: 12 Months id: "2" attributes_cache: {} - !ruby/object:Billing attributes: title: 6 Months id: "5" attributes_cache: {} Any help really appreciated.

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• PHP (A few questions) OO, refactoring, eclipse

  - by jax

  I am using PHP in eclipse. It works ok, I can connect to my remote site, there is colour coding of code elements and some code hints. I realise this may be too long to answer all questions, if you have a good answer for one part, answering just that is ok. Firstly General Coding I have found that it is easy to loose track of included files and their variables. For example if there was a database $cursor it is difficult to remember or even know that it was declared in the included file (this becomes much worse the more files you include). How are people dealing with this? How are people documenting their code - in particular the required GET and POST data? Secondly OO Development: Should I be going full OO in my development. Currently I have a functions library which I can include and have separated each "task" into a separate file. It is a bit nasty but it works. If I go OO how do I structure the directories in PHP, java uses packages - what about php? How should I name my files, should I use all lower case with _ for spaces "hello_world.php"? Should I name classes with Uppercase like Java "HelloWorld.php"? Is there a different naming convention for Classes and regular function files? Thirdly Refactoring I must say this is a real pain. If I change the name of a variable in one place I have to go through whole document and each file that included this file and change the name their too. Of course, errors everywhere is what results. How are people dealing with this problem? In Java if you change the name in one place it changes everywhere. Are there any plugins to improve php refactoring? I am using the official PHP version of Eclipse from their website. thanks

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• Playing a .TS file on iOS

  - by Jonathan Grynspan

  We're working with some hardware that produces files in the .TS format, and we'd like to play them on an iOS device. (The files are internally consistent with what iOS supports--MPEG-4 video, AAC audio.) We've been investigating three options so far: Roll our own integrated HTTP Live Streaming server and serve up a faux M3U8 playlist from within the app. This... doesn't seem to want to play nice, and we've had mixed luck actually getting the .TS files to play on devices. Unwrap the MPEG-4 and AAC data from the TS file and re-wrap it as MP4. This, I'm told, is exceedingly difficult to do, and I haven't found anything useful online that could shed light on how to do it. We've got code in the pipeline to do it but it won't be ready until long after we need it. If we could do it, I could easily subclass NSURLProtocol and have it working within a matter of hours minutes. Use FFmpeg to implement option #2. FFmpeg seems like a possible solution but it isn't configured to build for iOS and I don't have the background to get it working (whereas the rest of our engineers don't have the Apple background needed.) I think #2 is our best bet, but as I don't know the ins and outs of MPEG-2 TS and MPEG-4, I don't have the ability to put it together myself. Does anybody have any insight into this problem? Perhaps some experience playing local TS files on iOS, or some tips on converting from TS to MP4?

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• What version control system is best designed to *prevent* concurrent editing?

  - by Fred Hamilton

  We've been using CVS (with TortoiseCVS interface) for years for both source control and wide-ranging document control (including binaries such as Word, Excel, Framemaker, test data, simulation results, etc.). Unlike typical version control systems, 99% of the time we want to prevent concurrent editing - when a user starts editing a file, the pre-edit version of the file becomes read only to everyone else. Many of the people who will be using this are not programmers or even that computer savvy, so we're also looking for a system that let's people simply add documents to the repository, check out and edit a document (unless someone else is currently editing it), and check it back in with a minimum of fuss. We've gotten this to work reasonably well with CVS + TortoiseCVS, but we're now considering Subversion and Mercurial (and open to others if they're a better fit) for their better version tracking, so I was wondering which one supported locking files most transparently. For example, we'd like exclusive locking enabled as the default, and we want to make it as difficult as possible for someone to accidentally start editing a file that someone else has checked out. For example when someone checks out a file for editing, it checks with the master database first even if they have not recently updated their sandbox. Maybe it even won't let a user check out a document if it's off the network and can't check in with the mothership.

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• Producer/consumer system using database (MySql), is this feasible?

  - by johnrl

  Hi all. I need to use something to coordinate my system with several consumers/producers each running on different machines with different operating systems. I have been researching on using MySql to do this, but it seems ridiculously difficult. My requirements are simple: I want to be able to add or remove consumers/producers at any time and thus they should not depend on each other at all. Naturally a database would separate the two nicely. I have been looking at Q4M message queuing plugin for MySql but it seems complicated to use: I have to recompile it every time I upgrade MySql (can this really be true?) because when I try to install it on Ubuntu 9.10 with MySql 5.1.37 it says "Can't open shared library 'libqueue_engine.so' (errno: 0 API version for STORAGE ENGINE plugin is too different)". There is no precompiled version for MySql 5.1.37 apparently. Also what if I want to run MySql on my windows machine, then I can't rely on this plugin as it only seems to run on Linux and OSX?? I really need some input on how to construct my system best possible.

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• Ruby on Rails: how to get error messages from a child resource displayed?

  - by randombits

  I'm having a difficult time understanding how to get Rails to show explicitly the error messages that a child resource is failing on when I render an XML template. Hypothetically, I have the following classes: class School < ActiveRecord::Base has_many :students validates_associated :students end class Student < ActiveRecord::Base belongs_to :school validates_format_of :email, :with => /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i, :message => "You must supply a valid email" end Now, in the controller, let's say we want to build a trivial API to allow us to add a new School with a student in it (again, I said, it's a terrible example, but plays its role for the purpose of the question) class SchoolsController < ApplicationController def create @school = School.new @student = school.students.build @student.email = "bad@email" respond_to do |format| if @school.save # some code else format.xml { render :xml => @school.errors, :status => :unprocessable_entity } end end end end Now the validation is working just fine, things die because the email doesn't match the regex that's set in the validates_format_of method in the Student class. However the output I get is the following: <?xml version="1.0" encoding="UTF-8"?> <errors> <error>Students is invalid</error> </errors> I want the more meaningful error message that I set above with validates_format_of to show up. Meaning, I want it to say: <error>You must supply a valid email</error> What am I doing wrong for that not to show up?

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• Q on Python serialization/deserialization

  - by neil

  What chances do I have to instantiate, keep and serialize/deserialize to/from binary data Python classes reflecting this pattern (adopted from RFC 2246 [TLS]): enum { apple, orange } VariantTag; struct { uint16 number; opaque string<0..10>; /* variable length */ } V1; struct { uint32 number; opaque string[10]; /* fixed length */ } V2; struct { select (VariantTag) { /* value of selector is implicit */ case apple: V1; /* VariantBody, tag = apple */ case orange: V2; /* VariantBody, tag = orange */ } variant_body; /* optional label on variant */ } VariantRecord; Basically I would have to define a (variant) class VariantRecord, which varies depending on the value of VariantTag. That's not that difficult. The challenge is to find a most generic way to build a class, which serializes/deserializes to and from a byte stream... Pickle, Google protocol buffer, marshal is all not an option. I made little success with having an explicit "def serialize" in my class, but I'm not very happy with it, because it's not generic enough. I hope I could express the problem. My current solution in case VariantTag = apple would look like this, but I don't like it too much import binascii import struct class VariantRecord(object): def __init__(self, number, opaque): self.number = number self.opaque = opaque def serialize(self): out = struct.pack('>HB%ds' % len(self.opaque), self.number, len(self.opaque), self.opaque) return out v = VariantRecord(10, 'Hello') print binascii.hexlify(v.serialize()) >> 000a0548656c6c6f Regards

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• Load Images in WPF application

  - by LLS

  I am not familiar with WPF, and I just feel quite confusing. I am trying to create a little computer game, and there are elements I want to display dynamically. I use Image class and add the images to a canvas. But I'm not sure whether it's a good practice. I feel that adding controls to canvas seem to be a little wired. And I'm a little concerned about the performance, because I may need many images. The real problem is, I can't load the images from the image files. I see an example in a text book like this (XMAL): <Image Panel.ZIndex="0" Margin="0,0,0,0" Name ="image1"> <Image.Source> <BitmapImage UriSource="Bell.gif" /> </Image.Source> </Image> Where Bell.gif is added into the project. And I tried to copy this in code to create an image. new Image { Source = new BitmapImage(new Uri("Blockade.bmp"))} But I got invalid Uri exception. After some search in the Internet, I found that loading resources dynamically seems to be difficult. Can I load the files added to the project dynamically? If I use absolute path then it's OK. But I can't expect every computer will put the files in the same location. Can I use relative path? I tried new Image { Source = new BitmapImage(new Uri(@"Pictures\Blank Land.bmp", UriKind.Relative)) } But it doesn't work. (The image is blank) Thanks.

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• Holding value in collection

  - by Amit Ranjan

  I have a application which is on timesheet. I have total of 54 columns out of which 10 columns are visible rest invisible. First 3 columns are Project, MileStone and Classes. Rest are Sun- Sat work hrs. Now I have a column named 'taskid' as SunTaskID,MonTaskID and so on till SatTaskID for holding each days taskid. Now on the selection of SunHrs (Sunday's Work Hrs), i retrieve that days taskid and on the basis of task id i retrieve attachments which is displayed under a listbox. Now the problem is that since a day can have multiple attachments and a user can attach multiple attachments at time. He can enter values from grid to. Grid cells are editable. I am using BindingList(of TaskClass) in VB.Net for binding grid. I have total 54 properties n my task class. So i want to what property do i need to hod each days attachment and in what way. Earlier I tried Dictionary. But i was not aware of its usage as a property so i gave. Then prepared a separate class for attachment but, it was difficult to synchronize the existing attachments with taskid...

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• Workflow UI Integration - is WF a good approach?

  - by AJ

  Somewhat similar to this question, except we haven't decided that we're going with WF yet. I'm working on designing a system that requires a series of decisions and activities on a "work object," so I naturally began to consider workflow, specifically WF. What I'm wondering is if WF is a good solution for a situation like the following (oversimplified for this question) case (please forgive bad ascii art): __________________ | Gather some info | | (web page) | |__________________| | | / \ / \ / \ / \ / cond \ \ 1 / \ / \ / \ / \ / | | ______________|_______________ | | | | | ______|______ ______|________ / do some / | Get more info | / process / | (web page) | /____________/ |_______________| | | / \ / \ / \ / cond. \ \ 2 / \ / \ / \ / | | |__________________ | | | | _____|_____ _____|_____ / some / / another / / process / / process / /__________/ /__________/ The part I'm struggling with is the get more info (web page) step and what happens subsequent, which would mean a halt in the execution of the workflow runtime. I'm aware that this is possible, but I'm not sure that WF is the best approach for this type of code, as the user interaction may be required at many different points through the entire workflow, and the workflow will drive what data entry screens are needed. We are using a WinForms/ASP.NET web forms package for UI, which is homegrown and difficult to push deployments on, so something like SharePoint integration is out of the question. Our back-end is DB2, and the workflow code (whether it's in WF or otherwise) will need to interact with that as well. I guess the bottom line is, should we look into using WF for this, or would we be better served just coding it ourselves? Can WF easily integrate data entry screens to capture information that can be used further on in the workflow?

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• Atomic Instructions and Variable Update visibility

  - by dsimcha

  On most common platforms (the most important being x86; I understand that some platforms have extremely difficult memory models that provide almost no guarantees useful for multithreading, but I don't care about rare counter-examples), is the following code safe? Thread 1: someVariable = doStuff(); atomicSet(stuffDoneFlag, 1); Thread 2: while(!atomicRead(stuffDoneFlag)) {} // Wait for stuffDoneFlag to be set. doMoreStuff(someVariable); Assuming standard, reasonable implementations of atomic ops: Is Thread 1's assignment to someVariable guaranteed to complete before atomicSet() is called? Is Thread 2 guaranteed to see the assignment to someVariable before calling doMoreStuff() provided it reads stuffDoneFlag atomically? Edits: The implementation of atomic ops I'm using contains the x86 LOCK instruction in each operation, if that helps. Assume stuffDoneFlag is properly cleared somehow. How isn't important. This is a very simplified example. I created it this way so that you wouldn't have to understand the whole context of the problem to answer it. I know it's not efficient.

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• Is there any way to combine transparency and "ajax usability" with HTML templates

  - by Sam

  I'm using HTML_Template_Flexy in PHP but the question should apply to any language or template library. I am outputting a list of relatively complex objects. In the beginning I just iterated over a list of the objects and called a toHtml method on them. When I was about to have my layout designer look over the template I noticed that it was too opaque and that he would have ended up looking through and/or editing many additional php source files to see what really gets generated by the toHtml method. So I extracted most of the HTML strings in the php classes up to the template which made for one clear file where you can see the whole page structure at once. However this causes problems when you want to add an object to the list using javascript. Then I have to keep the old toHtml method and maintain both the main template and the html strings at the same time, so I can output just the HTML for a new object that should be added to the page. So I'm back to the idea of using smaller templates for the objects that make up the page, but I was wondering if there was some easy way of having my cake and eating it too by having one template that shows the whole page but also the mini-templates for smaller objects on the page. Edit: Yes, updating the page is not a problem at all. My concern is with having both maintainability and transparency of the template files. If I have one single template for the whole page, then I must maintain mini-templates of the objects that are shown on the page. If I just have the mini-templates and include them from the higher-level template it becomes more difficult to look at the top-level html and imagine what the end result will look like.

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• PHP: If no Results - Split the Searchrequest and Try to find Parts of the Search

  - by elmaso

  Hello, i want to split the searchrequest into parts, if there's nothing to find. example: "nelly furtado ft. jimmy jones" - no results - try to find with nelly, furtado, jimmy or jones.. i have an api url.. thats the difficult part.. i show you some of the actually snippets: $query = urlencode (strip_tags ($_GET[search])); and $found = '0'; if ($source == 'all') { if (!($res = @get_url ('http://api.example.com/?key=' . $API . '&phrase=' . $query . ' . '&sort=' . $sort))) { exit ('<error>Cannot get requested information.</error>'); ; } how can i put a else request in this snippet, like if nothing found take the first word, or the second word, is this possible? or maybe you can tell me were i can read stuff about this function? thank you!!

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• What programming hack from your past are you most ashamed of?

  - by LeopardSkinPillBoxHat

  We've all been there (usually when we are young and inexperienced). Fixing it properly is too difficult, too risky or too time-consuming. So you go down the hack path. Which hack from your past are you most ashamed of, and why? I'm talking about the ones where you would be really embarrassed if someone could attribute the hack to you (quite easily if you are using revision control software). One hack per answer please. Mine was shortly after I started in my first job. I was working on a legacy C system, and there was this strange defect where a screen view failed to update properly under certain circumstances. I wasn't familiar with how to use the debugger at this time, so I added traces into the code to figure out what was going on. Then I realised that the defect didn't occur anymore with the traces in the code. I slowly backed out the traces one-by-one, until I realised that only a single trace was required to make the problem go away. My logic now would tell me that I was dealing with some sort of race-condition or timing related issue that the trace just "hid under the rug". But I checked in the code with the following line, and all was well: printf(""); Which hacks are you ashamed of?

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• Behavior of retained property while holder is retained

  - by Aurélien Vallée

  Hello everyone, I am a beginner ObjectiveC programmer, coming from the C++ world. I find it very difficult to understand the memory management offered by NSObject :/ Say I have the following class: @interface User : NSObject { NSString* name; } @property (nonatomic,retain) NSString* name; - (id) initWithName: (NSString*) theName; - (void) release; @end @implementation User @synthesize name - (id) initWithName: (NSString*) theName { if ( self = [super init] ) { [self setName:theName]; } return self; } - (void) release { [name release]; [super release]; } @end No considering the following code, I can't understand the retain count results: NSString* name = [[NSString alloc] initWithCString:/*C string from sqlite3*/]; // (1) name retainCount = 1 User* user = [[User alloc] initWithName:name]; // (2) name retainCount = 2 [whateverMutableArray addObject:user]; // (3) name retainCount = 2 [user release]; // (4) name retainCount = 1 [name release]; // (5) name retainCount = 0 At (4), the retain count of name decreased from 2 to 1. But that's not correct, there is still the instance of user inside the array that points to name ! The retain count of a variable should only decrease when the retain count of a referring variable is 0, that is, when it is dealloced, not released.

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