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  • GAE python database object design for simple list of values

    - by Joey
    I'm really new to database object design so please forgive any weirdness in my question. Basically, I am use Google AppEngine (Python) and contructing an object to track user info. One of these pieces of data is 40 Achievement scores. Do I make a list of ints in the User object for this? Or do I make a separate entity with my user id, the achievement index (0-39) and the score and then do a query to grab these 40 items every time I want to get the user data in total? The latter approach seems more object oriented to me, and certainly better if I extend it to have more than just scores for these 40 achievements. However, considering that I might not extend it, should I even consider just doing a simple list of 40 ints in my user data? I would then forgo doing a query, getting the sorted list of achievements, reading the score from each one just to process a response etc. Is doing this latter approach just such a common practice and hand-waved as not even worth batting an eyelash at in terms of thinking it might be more costly or complex processing wise?

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  • Subselecting with MDX

    - by Vince
    Greetings stack overflow community. I've recently started building an OLAP cube in SSAS2008 and have gotten stuck. I would be grateful if someone could at least point me towards the right direction. Situation: Two fact tables, same cube. FactCalls holds information about calls made by subscribers, FactTopups holds topup data. Both tables have numerous common dimensions one of them being the Subscriber dimension. FactCalls             FactTopups SubscriberKey      SubscriberKey CallDuration         DateKey CallCost               Topup Value ... What I am trying to achieve is to be able to build FactCalls reports based on distinct subscribers that have topped up their accounts within the last 7 days. What I am basically looking for an MDX equivalent to SQL's: select * from FactCalls where SubscriberKey in ( select distinct SubscriberKey from FactTopups where ... ); I've tried creating a degenerate dimension for both tables containing SubscriberKey and doing: Exist( [Calls Degenerate].[Subscriber Key].Children, [Topups Degenerate].[Subscriber Key].Children ) Without success. Kind regards, Vince

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  • iPhone Landscape FAQ and Solutions

    - by Johannes Rudolph
    There has been a lot of confusion and a set of corresponding set of questions here on SO how iPhone applications with proper handling for Landscape/Portrait mode autorotation can be implemented. It is especially difficult to implement such an application when starting in landscape mode is desired. The most common observed effect are scrambled layouts and areas of the screen where touches are no longer recognized. A simple search for questions tagged iphone and landscape reveals these issues, which occur under certain scenarios: Landscape only iPhone app with multiple nibs: App started in Landscape mode, view from first nib is rendered fine, everything view loaded from a different nib is not displayed correctly. Iphone Landscape mode switching to Portraite mode on loading new controller: Self explanatory iPhone: In landscape-only, after first addSubview, UITableViewController doesn’t rotate properly: Same issue as above. iPhone Landscape-Only Utility-Template Application: Layout errors, controller does not seem to recognize the view should be rotated but displays a clipped portrait view in landscape mode, causing half of the screen to stay blank. presentModalViewController in landscape after portrait viewController: Modal views are not correctly rendered either. A set of different solutions have been presented, some of them including completely custom animation via CoreGraphics, while others build on the observation that the first view controller loaded from the main nib is always displayed correct. I have spent a significant amount of time investigating this issue and finally found a solution that is not only a partial solution but should work under all these circumstances. It is my intend with this CW post to provide sort of a FAQ for others having issues with UIViewControllers in Landscape mode. Please provide feedback and help improve the quality of this Post by incorporating any related observations. Feel free to edit and post other/better answers if you know of any.

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  • Why do people hate SQL cursors so much?

    - by Steven A. Lowe
    I can understand wanting to avoid having to use a cursor due to the overhead and inconvenience, but it looks like there's some serious cursor-phobia-mania going on where people are going to great lengths to avoid having to use one for example, one question asked how to do something obviously trivial with a cursor and the accepted answer proposed using a common table expression (CTE) recursive query with a recursive custom function, even though this limits the number of rows that could be processed to 32 (due to recursive call limit in sql server). This strikes me as a terrible solution for system longevity, not to mention a tremendous effort just to avoid using a simple cursor. what is the reason for this level of insane hatred? has some 'noted authority' issued a fatwa against cursors? does some unspeakable evil lurk in the heart of cursors that corrupts the morals of the children or something? wiki question, more interested in the answer than the rep thanks in advance! Related Info: http://stackoverflow.com/questions/37029/sql-server-fast-forward-cursors EDIT: let me be more precise: I understand that cursors should not be used instead of normal relational operations, that is a no-brainer. What I don't understand is people going waaaaay out of their way to avoid cursors like they have cooties or something, even when a cursor is a simpler and/or more efficient solution. It's the irrational hatred that baffles me, not the obvious technical efficiencies.

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  • Templates vs. coded HTML

    - by Alan Harris-Reid
    I have a web-app consisting of some html forms for maintaining some tables (SQlite, with CherryPy for web-server stuff). First I did it entirely 'the Python way', and generated html strings via. code, with common headers, footers, etc. defined as functions in a separate module. I also like the idea of templates, so I tried Jinja2, which I find quite developer-friendly. In the beginning I thought templates were the way to go, but that was when pages were simple. Once .css and .js files were introduced (not necessarily in the same folder as the .html files), and an ever-increasing number of {{...}} variables and {%...%} commands were introduced, things started getting messy at design-time, even though they looked great at run-time. Things got even more difficult when I needed additional javascript in the or sections. As far as I can see, the main advantages of using templates are: Non-dynamic elements of page can easily be viewed in browser during design. Except for {} placeholders, html is kept separate from python code. If your company has a web-page designer, they can still design without knowing Python. while some disadvantages are: {{}} delimiters visible when viewed at design-time in browser Associated .css and .js files have to be in same folder to see effects in browser at design-time. Data, variables, lists, etc., must be prepared in advanced and either declared globally or passed as parameters to render() function. So - when to use 'hard-coded' HTML, and when to use templates? I am not sure of the best way to go, so I would be interested to hear other developers' views. TIA, Alan

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  • How should I setup my Visual Studio projects/solutions in a Mercurial repository?

    - by Dave A
    At my company we have a few different web apps that each share some common libraries. The Visual Studio setup looks like this. Website 1 Solution Website 1 Shared Library 1 Project Shared Library 2 Project Website 2 Solution Website 2 Shared Library 1 Project Shared Library 2 Project Windows Service Solution Windows Service Project Shared Library 1 Project Shared Library 2 Project Shared Library Solution Shared Library 1 Project Shared Library 2 Project All Projects Solution Website 1 Website 2 Windows Service Project Shared Library 1 Project Shared Library 2 Project We want to start using Mercurial for source control, but I'm still not sure the best way to do it. From what I've read you're supposed to use a separate repository for each project. No problem there, but where do the Visual Studio solution files (.sln) go? Should there be a separate repository with just an .sln file? Ideally the projects that use the shared libraries should all use the same version, and the solution "All Projects Solution" should build without errors, but sometimes we need to branch the shared libraries. What is the best way to do this, and how would the repositories be setup? How do I get a working copy of a certain branch/tag of the Website 1 solution when every project is in a separate repository. Do I have to pull each one separately, or write a script to do it all at once? Can tortoise hg do that for me? Any other tips to make this process easier?

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  • Rendering LaTeX on third-party websites

    - by A. Rex
    There are some sites on the web that render LaTeX into some more readable form, such as Wikipedia, some Wordpress blogs, and MathOverflow. They may use images, MathML, jsMath, or something like that. There are other sites on the web where LaTeX appears inline and is not rendered, such as the arXiv, various math forums, or my email. In fact, it is quite common to see an arXiv paper's abstract with raw LaTeX in it, e.g. this paper. Is there a plugin available for Firefox, or would it be possible to write one, that renders LaTeX within pages that do not provide a rendering mechanism themselves? Some notes: It may be impossible to render some of the code, because authors often copy-paste code directly from their source TeX files, which may contain things like "\cite{foo}" or undefined commands. These should be left alone. This question is a repost of a question from MathOverflow that was closed for not being related to math. I program a lot, but Javascript is not my specialty, so comments along the lines of "look at this library" are not particularly helpful to me (but may be to others).

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  • Good resources for building web-app in Tapestry

    - by Rich
    Hi, I'm currently researching into Tapestry for my company and trying to decide if I think we can port our pre-existing proprietary web applications to something better. Currently we are running Tomcat and using JSP for our front end backed by our own framework that eventually uses JDBC to connect to an Oracle database. I've gone through the Tapestry tutorial, which was really neat and got me interested, but now I'm faced with what seems to be a common issue of documentation. There are a lot of things I'd need to be sure that I could accomplish with Tapestry before I'd be ready to commit fully to it. Does anyone have any good resources, be it a book or web article or anything else, that go into more detail beyond what the Tapestry tutorial explains? I am also considering integrating with Hibernate, and have read a little bit about Spring too. I'm still having a hard time understanding how Spring would be more useful than cumbersome in tandem with Tapestry,as they seem to have a lot of overlapping features. An example I read seemed to use Spring to interface with Hibernate, and then Tapestry to Spring, but I was under the impression Tapestry integrates to the same degree with Hibernate. The resource I'm speaking of is http://wiki.apache.org/tapestry/Tapstry5First_project_with_Tapestry5,_Spring_and_Hibernate . I was interested because I hadn't found information anywhere else on how to maintain user levels and sessions through a Tapestry application before, but wasn't exactly impressed by the need to use Spring in the example.

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  • Not all TFS Build type files are getting copied

    - by k4k4sh1
    Because I have several builds sharing some assemblies containing common build tasks, I have one TFSBuild.proj for all builds and import different targets depending on the build, like the following: <Project DefaultTargets="DesktopBuild" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="3.5"> <Import Project="Build_1.targets" Condition="'$(BuildDefinition)'=='Build_1'" /> <Import Project="Build_2.targets" Condition="'$(BuildDefinition)'=='Build_2'" /> <Import Project="Build_3.targets" Condition="'$(BuildDefinition)'=='Build_3'" /> </Project> Each target for a particular build has your usual content for a build type file, but in my case, I also reference some tasks inside assemblies checked into the same folder as TFSBuild.proj in source control. I wanted to add folders to contain some test build targets, since my folder was getting a bit full and cluttered. The following illustrates what I mean. $(TFS project)\build\ TFSBuild.proj Build_1.targets ... Assembly1.dll Assembly2.dll ... Folder\ Test_target_1.targets .... When I stated my build, however, I found that Test_target_1.targets and other files in Folder were not being copied to the build directory, while TFSBuild.proj and other files in the root level, as it were, of the build type folder were being copied. This caused my test build to not be able to reference files inside Folder, causing my build to immediately fail. I realize the simplest work-around would be to get rid of Folder and move all of its contents up to the build folder, but I would really like to have Folder if at all possible. Thanks for your help in advance.

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  • Enterprise Eclipse Provisioning - Or - How to share your standard Eclipse setup with other developer

    - by nikhil
    We use Eclipse as the IDE for developing all sorts of Java/J2EE applications in our 150 people odd IT department. One of the common problems we have been seeing is that developers download and install different versions of Eclipse and plugins based on their personal likes and dislikes. We have been trying to bring some consistency to this and have standardized on the version and the plugins that developers should be using. So the problem now is how do we distribute this installation to the team. We have zipped the directories and shared it through a shared drive. But I am looking for a better solution using some kind of provisioning tool for Eclipse using which people can install the IDE or get updates. Has anyone faced this problem? What are your solutions to this? How do you ensure a standard Eclipse environment across developers? I found Yoxos as a potential solution to this. Does anyone have any experience with it? Can p2 be used to do this?

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  • Django deployment - can't import app.urls

    - by hora
    I just moved a django project to a deployment server from my dev server, and I'm having some issues deploying it. My apache config is as follows: <Location "/"> Order allow,deny Allow from all SetHandler python-program PythonHandler django.core.handlers.modpython SetEnv DJANGO_SETTINGS_MODULE project.settings PythonDebug On PythonPath "['/home/django/'] + sys.path" </Location> Django does work, since it renders the Django debug views, but I get the following error: ImportError at / No module named app.urls And here is all the information Django gives me: Request Method: GET Request URL: http://myserver.com/ Django Version: 1.1.1 Python Version: 2.6.5 Installed Applications: ['django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'django.contrib.admin', 'django.contrib.admindocs', 'project.app'] Installed Middleware: ('django.middleware.common.CommonMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware') Traceback: File "/usr/lib64/python2.6/site-packages/django/core/handlers/base.py" in get_response 83. request.path_info) File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in resolve 218. sub_match = pattern.resolve(new_path) File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in resolve 216. for pattern in self.url_patterns: File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in _get_url_patterns 245. patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module) File "/usr/lib64/python2.6/site-packages/django/core/urlresolvers.py" in _get_urlconf_module 240. self._urlconf_module = import_module(self.urlconf_name) File "/usr/lib64/python2.6/site-packages/django/utils/importlib.py" in import_module 35. __import__(name) Exception Type: ImportError at / Exception Value: No module named app.urls Any ideas as to why I get an import error?

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  • Ways std::stringstream can set fail/bad bit?

    - by Evan Teran
    A common piece of code I use for simple string splitting looks like this: inline std::vector<std::string> split(const std::string &s, char delim) { std::vector<std::string> elems; std::stringstream ss(s); std::string item; while(std::getline(ss, item, delim)) { elems.push_back(item); } return elems; } Someone mentioned that this will silently "swallow" errors occurring in std::getline. And of course I agree that's the case. But it occurred to me, what could possibly go wrong here in practice that I would need to worry about. basically it all boils down to this: inline std::vector<std::string> split(const std::string &s, char delim) { std::vector<std::string> elems; std::stringstream ss(s); std::string item; while(std::getline(ss, item, delim)) { elems.push_back(item); } if(ss.fail()) { // *** How did we get here!? *** } return elems; } A stringstream is backed by a string, so we don't have to worry about any of the issues associated with reading from a file. There is no type conversion going on here since getline simply reads until it sees a newline or EOF. So we can't get any of the errors that something like boost::lexical_cast has to worry about. I simply can't think of something besides failing to allocate enough memory that could go wrong, but that'll just throw a std::bad_alloc well before the std::getline even takes place. What am I missing?

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  • looking for a license key algorithm.

    - by giulio
    There are a lot of questions relating to license keys asked on stackoverflow. But they don't answer this question. Can anyone provide a simple license key algorithm that is technology independent and doesn't required a diploma in mathematics to understand ? The license key algorithm is similar to public key encryption. I just need something simple that can be implemented in any platform .Net/Java and uses simple data like characters. Preferably no byte translations required. So if a person presents a string, a complementary string can be generated that is the authorisation code. Below is a common scenario that it would be used for. Customer downloads s/w which generates a unique key upon initial startup/installation. S/w runs during trial period. At end of trial period an authorisation key is required. Customer goes to designated web-site, enters their code and get authorisation code to enable s/w, after paying :) Don't be afraid to describe your answer as though you're talking to a 5 yr old as I am not a mathemtician. Just need a decent basic algorithm, we're not launching nukes... NB: Please no philosophy on encryption nor who is Diffie-Hellman. I just need a basic solution.

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  • Hiring a programmer: looking for the "right attitude"

    - by Totophil
    It's actually two questions in one: What is the right attitude for a programmer? How do you (or would you) look for one when interviewing or during hiring process? Please note this question is not about personality or traits of a candidate, it is about their attitude towards what they do for living. This is also not about reverse of programmers pet peeves. The question has been made community wiki, since I am interested in a good answer rather than reputation. I disagree that the question is purely subjective and just a matter of opinion: clearly some attitudes make a better programmer than others. Consecutively, there might quite possibly exist an attitude that is common to the most of the better programmers. Update: After some deliberation I came up with the following attitude measurement scales: identifies themselves with the job ? fully detached perceives code as a collection of concepts ? sees code as a sequence of steps thinks of creating software as an art ? takes 100% rational approach to design and development Answers that include some sort of a comment on the appropriateness of these scales are greatly appreciated. Definition of "attitude": a complex mental state involving beliefs and feelings and values and dispositions to act in certain ways; "he had the attitude that work was fun" The question came as a result of some reflection on the top voted answer to "How do you ensure code quality?" here on Stack Overflow.

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  • F# passing an operator with arguments to a function

    - by dan
    Can you pass in an operation like "divide by 2" or "subtract 1" using just a partially applied operator, where "add 1" looks like this: List.map ((+) 1) [1..5];; //equals [2..6] // instead of having to write: List.map (fun x-> x+1) [1..5] What's happening is 1 is being applied to (+) as it's first argument, and the list item is being applied as the second argument. For addition and multiplication, this argument ordering doesn't matter. Suppose I want to subtract 1 from every element (this will probably be a common beginners mistake): List.map ((-) 1) [1..5];; //equals [0 .. -4], the opposite of what we wanted 1 is applied to the (-) as its first argument, so instead of (list_item - 1), I get (1 - list_item). I can rewrite it as adding negative one instead of subtracting positive one: List.map ((+) -1) [1..5];; List.map (fun x -> x-1) [1..5];; // this works too I'm looking for a more expressive way to write it, something like ((-) _ 1), where _ denotes a placeholder, like in the Arc language. This would cause 1 to be the second argument to -, so in List.map, it would evaluate to list_item - 1. So if you wanted to map divide by 2 to the list, you could write: List.map ((/) _ 2) [2;4;6] //not real syntax, but would equal [1;2;3] List.map (fun x -> x/2) [2;4;6] //real syntax equivalent of the above Can this be done or do I have to use (fun x -> x/2)? It seems that the closest we can get to the placeholder syntax is to use a lambda with a named argument.

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  • JScrollPane Scrolls Down with Long Text in JEditorPane

    - by Jim
    Hello, I want to have a JEditorPane inside a JScrollPane. When the user clicks a button, the click listener will create a textEditor, call jscrollpane.setViewPort(textEditor), call textEditor.setText(String) to fill it with editable text, and call jscrollpane.getVerticalScrollBar().setValue(0). In case you're wondering, yes, the setText() must come after the setViewPort() for reasons that aren't on topic. Here is the problem: After the user clicks the button, the JScrollPane's view scrolls all the way to the bottom. I want the scrollbar to be at the top, as per the last line in my click listener. I popped open a debugger, and to my horror, discovered that the jscrollpane's viewport is being forced down to the bottom after the conclusion of the click listener (when pumping filters). It appears that Swing is delaying the population of the editor/jscrollpane until after the conclusion of the clicklistener, but is calling the scrollbar command first. Thus, the undesired behavior. Anyway, I'm wondering if there is a clean solution. It seems that wanting a scrollpane to be scrolled to the top after modification would be a reasonably common requirement, so I'm assuming this is a well-solved problem. Thanks!

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  • Maven webapp with Eclipse and WTP plugin deploy files in stranges ways in Tomcat

    - by hokkos
    Hi, I use Eclipse J2EE 3.5 with Maven and tomcat. To deploy my maven webapp with WTP I added a Dynamic Web Module facet and changed the "org.eclipse.wst.common.component" file of the project because the webapp is not in a WebContent directory, here is the content of the file: <?xml version="1.0" encoding="UTF-8"?> <project-modules id="moduleCoreId" project-version="1.5.0"> <wb-module deploy-name="tkey-ca-web"> <wb-resource deploy-path="/" source-path="/src/main/webapp"/> <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/java"/> <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/resources"/> <property name="context-root" value="toto"/> <property name="java-output-path" value="/toto/target/classes"/> </wb-module> </project-modules> But it never deploy the content correctly, in "workspace.metadata.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\toto\" the directory structure is correct with WEB-INF and META-INF but empty, the jsp, html, css files are in "workspace.metadata.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\toto\WEB-INF\classes\" with another WEB-INF and META-INF structure but with the files. I don't understand this at all, thanks.

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  • How can I display a language according to the user's browser's language inside this code?

    - by janoChen
    How can I display a language according to the user's browser's language inside this mini-framework for my multilingual website? Basically, it has to display the default language of the user if there's no cookies. Example of index.php: (rendered output) <h2><?php echo l('tagline_h2'); ?></h2> common.php: (controller of which language to output) <?php session_start(); header('Cache-control: private'); // IE 6 FIX if(isSet($_GET['lang'])) { $lang = $_GET['lang']; // register the session and set the cookie $_SESSION['lang'] = $lang; setcookie("lang", $lang, time() + (3600 * 24 * 30)); } else if(isSet($_SESSION['lang'])) { $lang = $_SESSION['lang']; } else if(isSet($_COOKIE['lang'])) { $lang = $_COOKIE['lang']; } else { $lang = 'en'; } //use appropiate lang.xx.php file according to the value of the $lang switch ($lang) { case 'en': $lang_file = 'lang.en.php'; break; case 'es': $lang_file = 'lang.es.php'; break; case 'tw': $lang_file = 'lang.tw.php'; break; case 'cn': $lang_file = 'lang.cn.php'; break; default: $lang_file = 'lang.en.php'; } //translation helper function function l($translation) { global $lang; return $lang[$translation]; } include_once 'languages/'.$lang_file; ?> Example of /languages/lang.en.php: (where multilingual content is being stored) <?php $lang = array( 'tagline_h2' => '...',

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  • Boost.Python wrapping hierarchies avoiding diamond inheritance

    - by stbuton
    I'm having some trouble seeing what the best way to wrap a series of classes with Boost.Python while avoiding messy inheritance problems. Say I have the classes A, B, and C with the following structure: struct A { virtual void foo(); virtual void bar(); virtual void baz(); }; struct B : public A { virtual void quux(); }; struct C : public A { virtual void foobar(); }; I want to wrap all classes A, B, and C such that they are extendable from Python. The normal method for accomplishing this would be along the lines of: struct A_Wrapper : public A, boost::python::wrapper<A> { //dispatch logic for virtual functions }; Now for classes B and C which extend from A I would like to be able to inherit and share the wrapping implementation for A. So I'd like to be able to do something along the lines of: struct B_Wrapper : public B, public A_Wrapper, public boost::python::wrapper<B> { //dispatch logic specific for B }; struct C_Wrapper : public C, public A_Wrapper, public boost::python::wrapper<C> { //dispatch logic specific for C } However, it seems like that would introduce all manner of nastiness with the double inheritance of the boost wrapper base and the double inheritance of A in the B_Wrapper and C_Wrapper objects. Is there a common way that this instance is solved that I'm missing? thanks.

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  • Vertical-Align: A Full Explanation

    - by Livvy Jeffs
    I've been struggling with vertical alignments, a seemingly simple enough process that has a lot of idiosyncrasies throughout different languages and element types. I've done a lot of reading through stackexchange and can't seem to find a common thread of understanding. Here are the rules that I have been able to gather: 1) Vertical-align does not work in <\div>s, you have to set div {display: table-cell; vertical-align: middle} This seems like a big hassle, especially since table-cells override the height limitation even when overflow is set to hidden and expands to fit content, which means the vertical "center" is variable. I just read some source-code from Pinterest where button {vertical-align: middle}, but no other vertical-align commands seem to work. It seems as if button is by default aligned in the middle. Can someone provide a clear explanation for the vertical-align attribute? What html elements respond to vertical-align? Which html elements have default vertical-align attributes? Which html elements have non-overridable vertical-align attributes? And any clues as to understanding the idiosyncracies would help as well! Thanks in advance!

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  • How to implement Master-Detail with Multi-Selection in WPF?

    - by gehho
    Hi, I plan to create a typical Master-Detail scenario, i.e. a collection of items displayed in a ListView via DataBinding to an ICollectionView, and details about the selected item in a separate group of controls (TextBoxes, NumUpDowns...). No problem so far, actually I have already implemented a pretty similar scenario in an older project. However, it should be possible to select multiple items in the ListView and get the appropriate shared values displayed in the detail view. This means, if all selected items have the same value for a property, this value should be displayed in the detail view. If they do not share the same value, the corresponding control should provide some visual clue for the user indicating this, and no value should be displayed (or an "undefined" state in a CheckBox for example). Now, if the user edits the value, this change should be applied to all selected items. Further requirements are: MVVM compatibility (i.e. not too much code-behind) Extendability (new properties/types can be added later on) Does anyone have experience with such a scenario? Actually, I think this should be a very common scenario. However, I could not find any details on that topic anywhere. Thanks! gehho. PS: In the older project mentioned above, I had a solution using a subclass of the ViewModel which handles the special case of multi-selection. It checked all selected items for equality and returned the appropriate values. However, this approach had some drawbacks and somehow seemed like a hack because (besides other smelly things) it was necessary to break the synchronization between the ListView and the detail view and handle it manually.

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  • Product Catalog Schema design

    - by FlySwat
    I'm building a proof of concept schema for a product catalog to possibly replace a very aging and crufty one we use. In our business, we sell both physical materials and services (one time and reoccurring charges). The current catalog schema has each distinct category broken out into individual tables, while this is nicely normalized and performs well, it is fairly difficult to extend. Adding a new attribute to a particular product involves changing the table schema and backpopulating old data. An idea I've been toying with has been something along the line of a base set of entity tables in 3rd normal form, these will contain the facts that are common among ALL products. Then, I'd like to build an Attribute-Entity-Value schema that allows each entity type to be extended in a flexible way using just data and no schema changes. Finally, I'd like to denormalize this data model into materialized views for each individual entity type. This views are what the application would access. We also have many tables that contain business rules and compatibility rules. These would join against the base entity tables instead of the views. My big concerns here are: Performance - Attribute-Entity-Value schemas are flexible, but typically perform poorly, should I be concerned? More Performance - Denormalizing using materialized views may have some risks, I'm not positive on this yet. Complexity - While this schema is flexible and maintainable using just data, I worry that the complexity of the design might make future schema changes difficult. For those who have designed product catalogs for large scale enterprises, am I going down the totally wrong path? Is there any good best practice schema design reading available for product catalogs?

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  • Class/Model Level Validation (as opposed to Property Level)? (ASP.NET MVC 2.0)

    - by Erx_VB.NExT.Coder
    Basically, what the title says. I have several properties that combine together to really make one logical answer, and i would like to run a server-side validation code (that i write) which take these multiple fields into account and hook up to only one validation output/error message that users see on the webpage. I looked at scott guthries method of extending an attribute and using it in yoru dataannotations declarations, but, as i can see, there is no way to declare a dataannotations-style attribute on multiple properties, and you can only place the declarations (such as [Email], [Range], [Required]) over one property :(. i have looked at the PropertiesMustMatchAttribute in the default mvc 2.0 project that appears when you start a new project, this example is as useful as using a pair of pins to check your motor oil - useless! i have tried this method, however, creating a class level attribute, and have no idea how to display the error from this in my aspx page. i have tried html.ValidationMessage("ClassNameWhereAttributeIsAdded") and a variety of other thing, and it has not worked. and i should mention, there is NOT ONE blog post on doing validation at this level - despite this being a common need in any project or business logic scenario! can anyone help me in having my message displayed in my aspx page, and also if possible a proper document or reference explaining validation at this level?

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  • A Django form for entering a 0 to n email addresses

    - by Erik
    I have a Django application with some fairly common models in it: UserProfile and Organization. A UserProfile or an Organization can both have 0 to n emails, so I have an Email model that has a GenericForeignKey. UserProfile and Organization Models both have a GenericRelation called emails that points back to the Email model (summary code provided below). The question: what is the best way to provide an Organization form that allows a user to enter organization details including 0 to n email addresses? My Organization create view is a Django class-based view. I'm leading towards creating a dynamic form and an enabling it with Javascript to allow the user to add as many email addresses as necessary. I will render the form with django-crispy-forms. I've thought about doing this with a formset embedded within the form, but this seems like overkill for email addresses. Embedding a formset in a form delivered by a class-based view is cumbersome too. Note that the same issue occurs with the Organization fields phone_numbers and locations. emails.py: from django.db import models from parent_mixins import Parent_Mixin class Email(Parent_Mixin,models.Model): email_type = models.CharField(blank=True,max_length=100,null=True,default=None,verbose_name='Email Type') email = models.EmailField() class Meta: app_label = 'core' organizations.py: from emails import Email from locations import Location from phone_numbers import Phone_Number from django.contrib.contenttypes import generic from django.db import models class Organization(models.Model): active = models.BooleanField() duns_number = models.CharField(blank=True,default=None,null=True,max_length=9) # need to validate this emails = generic.GenericRelation(Email,content_type_field='parent_type',object_id_field='parent_id') legal_name = models.CharField(blank=True,default=None,null=True,max_length=200) locations = generic.GenericRelation(Location,content_type_field='parent_type',object_id_field='parent_id') name = models.CharField(blank=True,default=None,null=True,max_length=200) organization_group = models.CharField(blank=True,default=None,null=True,max_length=200) organization_type = models.CharField(blank=True,default=None,null=True,max_length=200) phone_numbers = generic.GenericRelation(Phone_Number,content_type_field='parent_type',object_id_field='parent_id') taxpayer_id_number = models.CharField(blank=True,default=None,null=True,max_length=9) # need to validate this class Meta: app_label = 'core' parent_mixins.py from django.contrib.contenttypes.models import ContentType from django.contrib.contenttypes import generic from django.db import models class Parent_Mixin(models.Model): parent_type = models.ForeignKey(ContentType,blank=True,null=True) parent_id = models.PositiveIntegerField(blank=True,null=True) parent = generic.GenericForeignKey('parent_type', 'parent_id') class Meta: abstract = True app_label = 'core'

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  • mercurial: how to synchronize mq patches from a master repo as mq patches to a set of clone repos

    - by dim
    I have to run a dozen of different build tests on a code base maintained in a mercurial repository. I don't want to run serially these tests on same repository because they modify a set of common files and I want to run them in parallel on different machines. Also, after all tests are run I want to have access to latest test results from those test work areas. Currently I'm cloning the master repository a dozen of times and run in each clone one different test. Before each test execution I do a pull/update/purge preparation sequence in order to start the test on latest clean state. That's good for me. I'm also preparing new changes using mq extension that I would test on all clones as above before committing them. For testing some ready candidate mq patches I want somehow to deploy/synchronize them to be available in test clones and apply those ready for testing using some guard before running the test. Did anybody do this synchronization before? What's the most simple way to do it? Do I need to have versioned mq patches for that?

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