Search Results

Search found 14576 results on 584 pages for 'community building'.

Page 513/584 | < Previous Page | 509 510 511 512 513 514 515 516 517 518 519 520  | Next Page >

  • Problems with Backbone.Model callback and THIS

    - by Rev. Samuel
    I'm building a simple weather widget. The current weather conditions are read out of the National Weather Service xml file and then I want to parse and store the relevant data in the model but the callback for the $.ajax won't connect (the way I'm doing it). var Weather = Backbone.Model.extend({ initialize: function(){ _.bindAll( this, 'update', 'startLoop', 'stopLoop' ); this.startLoop(); }, startLoop: function(){ this.update(); this.interval = window.setInterval( _.bind( this.update, this ), 1000 * 60 * 60 ); }, stopLoop: function(){ this.interval = window.clearInterval( this.interval ); }, store: function( data ){ this.set({ icon : $( data ).find( 'icon_url_name' ).text() }); }, update: function(){ $.ajax({ type: 'GET', url: 'xml/KROC.xml', datatype: 'xml' }) .done( function( data ) { var that = this; that.store( $( data ).find( 'current_observation' )[ 0 ] ); }); } }); var weather = new Weather(); The data is read correctly but I can't get the done function of the call back to call the store function. (I would be happy if the "done" would just parse and then do "this.set". Thanks in advance for your help.

    Read the article

  • How to handle duplicate values in d3.js

    - by Mario
    First I'm a d3.js noob :) How you can see from the title I've got a problem with duplicated data and aggregate the values is no option, because the name represent different bus stops. In this example maybe the stops are on the fron side and the back side of a building. And of course I like to show the names on the x-axis. If i created an example and the result is a bloody mess, see jsFiddel. x = index name = bus stop name n = value I've got a json e.g.: [{ "x": 0, "name": "Corniche St / Abu Dhabi Police GHQ", "n": 113 }, { "x": 1, "name": "Corniche St / Nation Towers", "n": 116 }, { "x": 2, "name": "Zayed 1st St / Al Khalidiya Public Garden", "n": 146 }, ... { "x": 49, "name": "Hamdan St / Tariq Bin Zeyad Mosque", "n": 55 }] The problem: It is possible that the name could appear more then once e.g. { "x": 1, "name": "Corniche St / Nation Towers", "n": 116 } and { "x": 4, "name": "Corniche St / Nation Towers", "n": 105 } I like to know is there a way to tell d3.js not to use distinct names and instead just show all names in sequence with their values. Any ideas or suggestions are very welcome :) If you need more information let me know. Thanks in advanced Mario

    Read the article

  • what is the best way to optimize my json on an asp.net-mvc site

    - by ooo
    i am currently using jqgrid on an asp.net mvc site and we have a pretty slow network (internal application) and it seems to be taking the grid a long time to load (the issue is both network as well as parsing, rendering) I am trying to determine how to minimized what i send over to the client to make it as fast as possible. Here is a simplified view of my controller action to load data into the grid: [AcceptVerbs(HttpVerbs.Get)] public ActionResult GridData1(GridData args) { var paginatedData = applications.GridPaginate(args.page ?? 1, args.rows ?? 10, i => new { i.Id, Name = "<div class='showDescription' id= '" + i.id+ "'>" + i.Name + "</div>", MyValue = GetImageUrl(_map, i.value, "star"), ExternalId = string.Format("<a href=\"{0}\" target=\"_blank\">{1}</a>", Url.Action("Link", "Order", new { id = i.id }), i.Id), i.Target, i.Owner, EndDate = i.EndDate, Updated = "<div class='showView' aitId= '" + i.AitId + "'>" + GetImage(i.EndDateColumn, "star") + "</div>", }) return Json(paginatedData); } So i am building up a json data (i have about 200 records of the above) and sending it back to the GUI to put in the jqgrid. The one thing i can thihk of is Repeated data. In some of the json fields i am appending HTML on top of the raw "data". This is the same HTML on every record. It seems like it would be more efficient if i could just send the data and "append" the HTML around it on the client side. Is this possible? Then i would just be sending the actual data over the wire and have the client side add on the rest of the HTML tags (the divs, etc) be put together. Also, if there are any other suggestions on how i can minimize the size of my messages, that would be great. I guess at some point these solution will increase the client side load but it may be worth it to cut down on network traffic.

    Read the article

  • How to add a gwt widget to a gwt Composite already visible at runtime using MVP?

    - by mary4pfc
    Hi! I'm building an application whose menus depend on user roles. Once user is logged in and, therefore, her roles are known, I want to create the Hyperlinks related to the user and add them to the menu. I'm using MVP. Here's my code for the presenter: public class AdminMenuAreaPresenter extends WidgetPresenter<AdminMenuAreaPresenter.Display> { public interface Display extends WidgetDisplay{ public void addLink(String link); } private DispatchAsync dispatcher; private SessionManager sessionManager; @Inject public AdminMenuAreaPresenter(AdminMenuAreaPresenter.Display display, EventBus bus, DispatchAsync dispatcher, SessionManager sessionManager){ super(display, bus); this.dispatcher = dispatcher; this.sessionManager = sessionManager; this.bind(); } @Override protected void onBind() { super.onBind(); registerHandler(eventBus.addHandler(LoginEvent.TYPE, new LoginEventHandler() { @Override public void onLogin(LoginEvent event) { display.addLink("register user"); } })); } @Override protected void onUnbind() { // TODO Auto-generated method stub } @Override protected void onRevealDisplay() { // TODO Auto-generated method stub } } And here's the View: public class AdminMenuAreaView extends Composite implements AdminMenuAreaPresenter.Display{ private VerticalPanel vPanel; private Hyperlink registerUserLink; public AdminMenuAreaView(){ vPanel = new VerticalPanel(); initWidget(vPanel); } @Override public Widget asWidget() { return this; } public void addLink(String s){ registerUserLink = new Hyperlink(s, "this is new target"); this.vPanel.add(registerUserLink); registerUserLink.setVisible(true); } public HasClickHandlers getRegisterUserLink(){ return registerUserLink; } What am I doing wrong? Flow program goes throgh the addLink() method, but nothing is added to the view either dom document. Thank you.

    Read the article

  • Maven 3 plugin - How to programatically exclude a dependency and all its transitive dependencies?

    - by electrotype
    I'm developing a Maven 3 plugin and I want to exclude some dependencies, and their transitive dependencies, when a configuration is set to true in the plugin. I don't want to use <exclusions> in the POM itself, even in a profile. I want to exclude those dependencies programatically. In fact, what I want is to prevent the dependency jars to be included in the final war (I'm building a war), when a plugin configuration is set to true. I tried : @Mojo(requiresDependencyResolution=ResolutionScope.COMPILE, name="compileHook",defaultPhase=LifecyclePhase.COMPILE) public class compileHook extends AbstractMojo { @Override public void execute() throws MojoExecutionException, MojoFailureException { // ... Set<Artifact> artifacts = this.project.getArtifacts(); for(Artifact artifact : artifacts) { if("org.package.to.remove".equalsIgnoreCase(artifact.getGroupId())) { artifact.setScope("provided"); } } // ... } } Since this occures at the compile phase, it will indeed remove the artifacts with a group id "org.package.to.remove" from having their jars included in the war when packaged. But this doesn't remove the transitive artifacts those dependencies add! What is the best way to programatically remove some dependencies, and their transitive dependencies, from being included in a final .jar/.war?

    Read the article

  • How to understand existing projects

    - by John
    Hi. I am a trainee developer and have been writing .NET applications for about a year now. Most of the work I have done has involved building new applications (mainly web apps) from scratch and I have been given more or less full control over the software design. This has been a great experience however, as a trainee developer my confidence about whether the approaches I have taken are the best is minimal. Ideally I would love to collaborate with more experienced developers (I find this the best was I learn) however in the company I work for developers tend to work in isolation (a great shame for me). Recently I decided that a good way to learn more about how experienced developers approach their design might be to explore some open source projects. I found myself a little overwhelmed by the projects I looked at. With my level of experience it was hard to understand the body of code I faced. My question is slight fuzzy one. How do developers approach the task of understanding a new medium to large scale project. I found myself pouring over lots of code and struggling to see the wood for the trees. At any one time I felt that I could understand a small portion of the system but not see how its all fits together. Do others get this same feeling? If so what approaches do you take to understanding the project? Do you have any other advice about how to learn design best practices? Any advice will be very much appreciated. Thank you.

    Read the article

  • What's the best approach for modifying PDF interactive form fields on iOS?

    - by gbreen
    I've been doing some head banging on this one and solicit your advice. I am building an app that as part of it's features is to present PDF forms; meaning display them, allow fields to be changed and save the modified PDF file back out. UIWebViews do not support PDF interactive forms. Using the CGPDF apis (and benefit from other questions posted here and elsewhere), I can certainly present the PDF (without the form fields/widgets), scan and find the fields in the document, figure out where on the screen to draw something and make them interactive. What I can't seem to figure out is how to change the CGPDFDictionary objects and write them back out to a file. One could use the CGPDF Apis to create a new PDF document from whole cloth, but how do you use it to modify an existing file? Should I be looking elsewhere such as 3rd party PDF libs like PoDoFo or libHaru? I'd love to hear from anyone who has successfully modified a PDF and written it back out as to your approach. Thanks!

    Read the article

  • Can't get node.js built on cygwin

    - by mwt
    Following the instructions here: https://github.com/ry/node/wiki/Building-node.js-on-Cygwin-(Windows) I've tried installing on two machines, either of which I'd be happy to get up and running. WinXP On 'make', I get: Build failed: -> task failed <err #2>: {task: libv8.a SConstruct -> libv8.a} According to the instructions, this is caused by having $SHELL set to a Windows style path, but I've set it to /bin/bash and get the same error. Win7 On './configure', I get: $ ./configure Checking for program g++ or c++ : /usr/bin/g++ Checking for program cpp : /usr/bin/cpp Checking for program ar : /usr/bin/ar Checking for program ranlib : /usr/bin/ranlib Checking for g++ : ok Checking for program gcc or cc : /usr/bin/gcc 0 [main] python 1092 C:\bin\python.exe: *** fatal error - unable to remap \\?\C:\lib\python2.6\lib-dynload\_functools.dll to same address as parent: 0x360000 != 0x3E0000 Stack trace: Frame Function Args 002891E8 6102749B (002891E8, 00000000, 00000000, 00000000) 002894D8 6102749B (61177B80, 00008000, 00000000, 61179977) 0028A508 61004AFB (611A136C, 61241CF4, 00360000, 003E0000) End of stack trace 0 [main] python 3536 fork: child 1092 - died waiting for dll loading, errno 11 /Users/Michael/Desktop/node/wscript:177: error: could not configure a c compiler! I've run 'rebaseall' and restarted the machine but still get that error. Edit: Ok, rebaseall was apparently erroring on some mingw stuff, so I edited the rebaseall script to fix that, and now it configures on Win7. The new problem is that it emits the exact same error as my XP machine now when I try to make. This is on tag v0.3.5.

    Read the article

  • jQuery.data() works in Mac OS WebKit, but not on iPhone OS?

    - by rpj
    I'm playing around with jQTouch for an iPhone OS app that I've been toying with off and on for a while. I wanted to try my hand building it as a web app so I started playing with jQTouch. For reference, here is the page+source (all my code is currently in index.html so you can just "View Source" to see it all): http://rpj.me/doughapp.com/wd/ Essentially, I'm trying to save pertinent JSON objects retrieved from Google Local into DOM objects using the data() method (in this example, obj is the Google Local object): $('#locPane').data('selected', obj); then later (in a different "pane"), retrieving that object to be used: $('#locPane').bind('pageAnimationEnd', function(e, inf) { var selobj = $(this).data('selected'); // use 'selobj' here ... } In Chromium and Safari on the desktop OS (Snow Leopard in my case), this works perfectly (try it out). However, the same code returns undefined for the call to $(this).data('selected') in the second snippet above. I've also tried $('#' + e.target.id).data('selected') and even the naive $('#locPane').data('selected'). All variants return undefined in the iPhone OS version of WebKit, but not on the desktop. Interestingly, the running this on Mobile Safari in the iPhone Simulator fails as well. If you look at the full source, you'll see that I even try to save this object into my global jQTouch object (named jqt in my code). This, too, fails on the mobile platform. Has anyone else ever ran into this? I'll admit to not being a web/javascript programmer by trade, so if I'm making an idiot's error please call me out on it. Thank you in advance for the help! -RPJ Update: I didn't make it clear in the original post, but I'm open to any workaround if it works consistently. Since I'm having trouble storing these objects in general, anything that allows me to keep them around is good enough for now. Thanks!

    Read the article

  • Which cms or script for social network wiki?

    - by Jason
    Hi, I am building a social network. I need a cms that will allow users to contribute content. Each content item will need to have a google map, list of features, ratings, comments, etc. And the content must be editable by other users with revision control. Also, each user should have a profile with their bookmarked content items, contributed items, comments, etc. It's very important that I can create a template for the wiki/content entries so that each item looks uniform. (and as a kick in the teeth, I would like to be able to search for wiki items using a radial search or map) Joomla was my first choice, as I've used it for many projects, but the wiki functionality is not there. I was also setting up a grou.ps site, but the wiki is so-so - not feature rich and it really doesn't have the option I need. Additionally, I know someone out there will mention Drupal. I may consider it if I can see it put to use without and overabundance of custom programming (I don't mind initial coding, but drupal requires constant coding & recoding - with this site, I dont' have that time commitment) I thought about using mediawiki with buddypress, but i'm not sure if that's the way to go. Thoughts?

    Read the article

  • Database locking: ActiveRecord + Heroku

    - by JP
    I'm building a Sinatra based app for deployment on Heroku. You can imagine it like a standard URL shortener but where old shortcodes expire and become available for new URLs (I realise this is a silly concept but its easier to explain this way). I'm representing the shortcode in my database as an integer and redefining its reader to give a nice short and unique string from the integer. As some rows will be deleted, I've written code that goes thru all the shortcode integers and picks the first free one to use just before_save. Unfortunately I can make my code create two rows with identical shortcode integers if I run two instances very quickly one after another, which is obviously no good! How should I implement a locking system so that I can quickly save my record with a unique shortcode integer? Here's what I have so far: Chars = ('a'..'z').to_a + ('A'..'Z').to_a + ('0'..'9').to_a CharLength = Chars.length class Shorts < ActiveRecord::Base before_save :gen_shortcode after_save :done_shortcode def shortcode i = read_attribute(:shortcode).to_i return '0' if i == 0 s = '' while i > 0 s << Chars[i.modulo(CharLength)] i /= 62 end s end private def gen_shortcode shortcode = 0 self.class.find(:all,:order=>"shortcode ASC").each do |s| if s.read_attribute(:shortcode).to_i != shortcode # Begin locking? break end shortcode += 1 end write_attribute(:shortcode,shortcode) end def done_shortcode # End Locking? end end

    Read the article

  • Multithreaded linked list traversal

    - by Rob Bryce
    Given a (doubly) linked list of objects (C++), I have an operation that I would like multithread, to perform on each object. The cost of the operation is not uniform for each object. The linked list is the preferred storage for this set of objects for a variety of reasons. The 1st element in each object is the pointer to the next object; the 2nd element is the previous object in the list. I have solved the problem by building an array of nodes, and applying OpenMP. This gave decent performance. I then switched to my own threading routines (based off Windows primitives) and by using InterlockedIncrement() (acting on the index into the array), I can achieve higher overall CPU utilization and faster through-put. Essentially, the threads work by "leap-frog'ing" along the elements. My next approach to optimization is to try to eliminate creating/reusing the array of elements in my linked list. However, I'd like to continue with this "leap-frog" approach and somehow use some nonexistent routine that could be called "InterlockedCompareDereference" - to atomically compare against NULL (end of list) and conditionally dereference & store, returning the dereferenced value. I don't think InterlockedCompareExchangePointer() will work since I cannot atomically dereference the pointer and call this Interlocked() method. I've done some reading and others are suggesting critical sections or spin-locks. Critical sections seem heavy-weight here. I'm tempted to try spin-locks but I thought I'd first pose the question here and ask what other people are doing. I'm not convinced that the InterlockedCompareExchangePointer() method itself could be used like a spin-lock. Then one also has to consider acquire/release/fence semantics... Ideas? Thanks!

    Read the article

  • ASP.NET Web Service returning XML result and nodevalue is always null

    - by kburnsmt
    I have an ASP.NET web service which returns an XMLDocument. The web service is called from a Firefox extension using XMLHttpRequest. var serviceRequest = new XMLHttpRequest(); serviecRequest.setRequestHeader("Content-Type", "text/xml; charset=utf-8"); I consume the result using responseXML. So far so good. But when I iterate through the XML I retrieve nodeValue - nodeValue is always null. When I check the nodeType the nodeType is type 1 (Node.ELEMENT_NODE == 1). Node.NodeValue states all nodes of type Element will return null. In my webservice I have created a string with the XML i.e. xml="Hank" I then create the XmlDocument XmlDocument doc = new XmlDocument(); doc.LoadXML(string); I know I can specify the nodetype using using CreateNode. But when I am just building the xml by appending string values is there a way to change the nodeType to Text so Node.nodeValue will be "content of the text node".

    Read the article

  • How can I design a custom control in Javascript (possibly using jQuery)

    - by Mathieu Pagé
    I'd like to create a custom control in javascript. The goal is to create a building block that has methods, properties and events and render into a div. An example of one such control would be a calendar. It would render into a div, it would have properties that would define how it's displayed and what date is selected or highlighted, it would have methods to change the current month or to select some date and it would raise events when a day is clicked or the current month is changed by a user input. I can think of lots of way to implement this and I'm not sure what is the best way. I seem to remember that it's a bad thing to augment a DOM elements with properties and method, so I ruled that out. A jQuery plugin seems like a good idea, however I'm not sure if it's appropriate to create a plugin for each and every method my control would have so I could then use it like : $('#control').method1(); $('#control').method2(); And if I do use jQuery, where do I store the private data of my control? Another idea I got was to create a new kind of object that would have a reference to a div in which it could render it's elements. So what is the prefered way to do this. If I can I would like to do this as a jQuery plugin, but I'd need guidlines on how to create methods and where to store private data. I've loked at Plugins/Authoring on jQuery website and it did not helped that much in this regard.

    Read the article

  • Howcome some C++ functions with unspecified linkage build with C linkage?

    - by christoffer
    This is something that makes me fairly perplexed. I have a C++ file that implements a set of functions, and a header file that defines prototypes for them. When building with Visual Studio or MingW-gcc, I get linking errors on two of the functions, and adding an 'extern "C"' qualifier resolved the error. How is this possible? Header file, "some_header.h": // Definition of struct DEMO_GLOBAL_DATA omitted DWORD WINAPI ThreadFunction(LPVOID lpData); void WriteLogString(void *pUserData, const char *pString, unsigned long nStringLen); void CheckValid(DEMO_GLOBAL_DATA *pData); int HandleStart(DEMO_GLOBAL_DATA * pDAta, TCHAR * pLogFileName); void HandleEnd(DEMO_GLOBAL_DATA *pData); C++ file, "some_implementation.cpp" #include "some_header.h" DWORD WINAPI ThreadFunction(LPVOID lpData) { /* omitted */ } void WriteLogString(void *pUserData, const char *pString, unsigned long nStringLen) { /* omitted */ } void CheckValid(DEMO_GLOBAL_DATA *pData) { /* omitted */ } int HandleStart(DEMO_GLOBAL_DATA * pDAta, TCHAR * pLogFileName) { /* omitted */ } void HandleEnd(DEMO_GLOBAL_DATA *pData) { /* omitted */ } The implementations compile without warnings, but when linking with the UI code that calls these, I get a normal error LNK2001: unresolved external symbol "int __cdecl HandleStart(struct _DEMO_GLOBAL_DATA *, wchar_t *) error LNK2001: unresolved external symbol "void __cdecl CheckValid(struct _DEMO_MAIN_GLOBAL_DATA * What really confuses me, now, is that only these two functions (HandleStart and CheckValid) seems to be built with C linkage. Explicitly adding "extern 'C'" declarations for only these two resolved the linking error, and the application builds and runs. Adding "extern 'C'" on some other function, such as HandleEnd, introduces a new linking error, so that one is obviously compiled correctly. The implementation file is never modified in any of this, only the prototypes.

    Read the article

  • How to cache code in PHP?

    - by Janis Peisenieks
    I am creating a custom form building system, which includes various tokens. These tokens are found using Regular Expressions, and depending on the type of toke, parsed. Some require simple replacement, some require cycles, and so forth. Now I know, that RegExp is quite resource and time consuming, so I would like to be able to parse the code for the form once, creating a php code, and then save the PHP code, for next uses. How would I go about doing this? So far I have only seen output caching. Is there a way to cache commands like echo and cycles like foreach()? Because of misunderstandings, I'll create an example. Unparsed template data: Thank You for Your interest, [*Title*] [*Firstname*] [*Lastname*]. Here are the details of Your order! [*KeyValuePairs*] Here is the link to Your request: [*LinkToRequest*]. Parsed template: "Thank You for Your interest, <?php echo $data->title;?> <?php echo $data->firstname;?> <?php echo $data->lastname;?>. Here are the details of Your order! <?php foreach($data->values as $key=>$value){ echo $key."-".$value }?> Here is the link to Your request: <?php echo $data->linkToRequest;?>. I would then save the parsed template, and instead of parsing the template every time, just pass the $data variable to the already parsed one, which would generate an output.

    Read the article

  • How to build a windows/web application that stores data locally and sync's with remote database?

    - by Jason
    Hello, I am needing to build an application that stores data locally and then synchronizes with a remote MS SQL database. I am not sure how to go about doing this. Enter data offline on a form and store the data. Synchronize the data with a remote MS SQL database when online. There will be many users who enter data offline, the local database on each pc needs to update when online and grab the 30 most recent records for use offline. Example: Each day users will enter data on their "form". The users will be offline. The users will return to the office and need to sync with the "online" database. The next morning the users will need to sync with the online database before going offline. They will need to have offline access to the 30 most recent records. (They will use the 30 records for charting/graphing while they are offline) I am very new to building apps. I have VS 2010. I am wondering where to start? What language to use? Is there a "framework" for doing this type of app? Any info or suggestions would be greatly appreciated. Thanks!

    Read the article

  • Should I be using Expression Blend to design really dynamic UIs?

    - by Robert Rossney
    My company's product is, at its core, a framework for developing metadata-driven UIs. I don't know how to characterize it less succinctly than that, and hope I won't need to for purposes of this question, but we'll see. I've been trying to come up to speed on WPF, and have been building UI prototypes here and there, and recently I decided to see if I could use Expression Blend to help with the design of these UIs. And I'm pretty mystified at this point. It appears to me as though Expresssion Blend is designed with the expectation that you already know all of the objects that are going to be present in the UI at design time. But our program generates these object dynamically at runtime. For instance, a data row might be presented in a horizontal StackPanel containing alternating TextBlocks (for captions) and TextBoxes (for data fields). The number of these objects depends on metadata about the number of columns in the data row. I can, pretty readily, write code that runs through a metadata record and populates a StackPanel dynamically, setting up the binding of all of the controls to properties in either the data or metadata. (A TextBox's Width might be bound to metadata, while its Text is bound to data.) But I can't even begin to figure out how to do something like this in Expression Blend. I can manually create all these controls, so that I have a set of controls that I can apply styles to and work out the visual design of the app, but it's really a pain to do this. I can write code that goes through my data model and emits XAML for all these controls, I suppose, and then copy and paste it. But I'm going to feel really stupid if it turns out there a way to do this sort of thing in Expression Blend and I've dropped back and punted because I'm too dim to figure out the right way to think of it. Is this enough information for someone to try formulating an answer?

    Read the article

  • Web Audio API and mobile browsers

    - by Michael
    I've run into a problem while implementing sound and music into an HTML game that I'm building. I'm using the Web Audio API, loading all the sound files with XMLHttpRequests and decoding them into an AudioBufferSourceNode with AudioContext.prototype.decodeAudioData(). It looks something like this: var request = new XMLHttpRequest(); request.open("GET", "soundfile.ogg", true); request.responseType = "arraybuffer"; request.onload = function() { context.decodeAudioData(request.response) } request.send(); Everything plays fine, but on mobile the decodeAudioData takes an absurdly long time for the background music. I then tried using AudioContext.prototype.createMediaElementSource() to load the music from an HTML Audio object, since they support streaming and don't have to load the whole file into memory at once. It looked something like this: var audio = new Audio('soundfile.ogg'); var source = context.createMediaElementSource(audio); var mainVolume = context.createGain(); source.connect(mainVolume); mainVolume.connect(context.destination); This loads much faster, but the audio volume isn't affected by the gain node. Works fine on desktop, so I'm assuming this is a bug/limitation of mobile Chrome (testing on Android). Is there actually no good, well-performing way to handle sound on mobile browsers or am just I doing something stupid?

    Read the article

  • return Queryable<T> or List<T> in a Repository<T>

    - by Danny Chen
    Currently I'm building an windows application using sqlite. In the data base there is a table say User, and in my code there is a Repository<User> and a UserManager. I think it's a very common design. In the repository there is a List method: //Repository<User> class public List<User> List(where, orderby, topN parameters and etc) { //query and return } This brings a problem, if I want to do something complex in UserManager.cs: //UserManager.cs public List<User> ListUsersWithBankAccounts() { var userRep = new UserRepository(); var bankRep = new BankAccountRepository(); var result = //do something complex, say "I want the users live in NY //and have at least two bank accounts in the system } You can see, returning List<User> brings performance issue, becuase the query is executed earlier than expected. Now I need to change it to something like a IQueryable<T>: //Repository<User> class public TableQuery<User> List(where, orderby, topN parameters and etc) { //query and return } TableQuery<T> is part of the sqlite driver, which is almost equals to IQueryable<T> in EF, which provides a query and won't execute it immediately. But now the problem is: in UserManager.cs, it doesn't know what is a TableQuery<T>, I need to add new reference and import namespaces like using SQLite.Query in the business layer project. It really brings bad code feeling. Why should my business layer know the details of the database? why should the business layer know what's SQLite? What's the correct design then?

    Read the article

  • How to generate a monotone MART ROC in R?

    - by user1521587
    I am using R and applying MART (Alg. for multiple additive regression trees) on a training set to build prediction models. When I look at the ROC curve, it is not monotone. I would be grateful if someone can help me with how I should fix this. I am guessing the issue is that initially, MART generates n trees and if these trees are not the same for all the models I am building, the results will not be comparable. Here are the steps I take: 1) Fix the false-negative cost, c_fn. Let cost = c(0, 1, c_fn, 0). 2) use the following line to build the mart model: mart(x, y, lx, martmode='class', niter=2000, cost.mtx=cost) where x is the matrix of training set variables, y is the observation matrix, lx is the matrix which specifies which of the variables in x is numerical, which one categorical. 3) I predict the test set observations using the mart model found in step 2 using this line: y_pred = martpred(x_test, probs=T) 4) I compute the false-positive and false-negative errors as follows: t = 1/(1+c_fn) %threshold based on Bayes optimal rule where c_fp=1 and c_fn. p_0 = length(which(y_test==1))/dim(y_test)[1] p_01 = sum(1*(y_pred[,2]t & y_test==0))/dim(y_test)[1] p_11 = sum(1*(y_pred[,2]t & y_test==1))/dim(y_test)[1] p_fp = p_01/(1-p_0) p_tp = p_11/p_0 5) repeat step 1-4 for a new false-negative cost.

    Read the article

  • C++ BigInt multiplication conceptual problem

    - by Kapo
    I'm building a small BigInt library in C++ for use in my programming language. The structure is like the following: short digits[ 1000 ]; int len; I have a function that converts a string into a bigint by splitting it up into single chars and putting them into digits. The numbers in digits are all reversed, so the number 123 would look like the following: digits[0]=3 digits[1]=3 digits[2]=1 I have already managed to code the adding function, which works perfectly. It works somewhat like this: overflow = 0 for i ++ until length of both numbers exceeded: add numberA[ i ] to numberB[ i ] add overflow to the result set overflow to 0 if the result is bigger than 10: substract 10 from the result overflow = 1 put the result into numberReturn[ i ] (Overflow is in this case what happens when I add 1 to 9: Substract 10 from 10, add 1 to overflow, overflow gets added to the next digit) So think of how two numbers are stored, like those: 0 | 1 | 2 --------- A 2 - - B 0 0 1 The above represents the digits of the bigints 2 (A) and 100 (B). - means uninitialized digits, they aren't accessed. So adding the above number works fine: start at 0, add 2 + 0, go to 1, add 0, go to 2, add 1 But: When I want to do multiplication with the above structure, my program ends up doing the following: Start at 0, multiply 2 with 0 (eek), go to 1, ... So it is obvious that, for multiplication, I have to get an order like this: 0 | 1 | 2 --------- A - - 2 B 0 0 1 Then, everything would be clear: Start at 0, multiply 0 with 0, go to 1, multiply 0 with 0, go to 2, multiply 1 with 2 How can I manage to get digits into the correct form for multiplication? I don't want to do any array moving/flipping - I need performance!

    Read the article

  • Is excessive DataTable usage bad?

    - by Justin R.
    I was recently asked to assist another team in building an ASP .NET website. They already have a significant amount of code written -- I was specifically asked build a few individual pages for the site. While exploring the code for the rest of the site, the amount of DataTables being constructed jumped out at me. Being a relatively new in the field, I've never worked on an application that utilizes a database as much as this site does, so I'm not sure how common this is. It seems that whenever data is queried from our database, the results are stored in a DataTable. This DataTable is then usually passed around by itself, or it's passed to a constructor. Classes that are initialized with a DataTable always assign the DataTable to a private/protected field, however only a few of these classes implement IDisposable. In fact, in the thousands of lines of code that I've browsed so far, I have yet to see the Dispose method called on a DataTable. If anything, this doesn't seem to be good OOP. Is this something that I should worry about? Or am I just paying more attention to detail than I should? Assuming you're most experienced developers than I am, how would you feel or react if someone who was just assigned to help you with your site approached you about this "problem"?

    Read the article

  • How to prevent the user from leaving the page

    - by JohnathanKong
    Hey Everyone, I am currently building a registration site where if the user leaves, I want to pop up a CSS box asking him if he is sure or not. I can accomplish this feat using confirm boxes, but the client says that they are too ugly. I've tried using unload and beforeunload, but both cannot stop the page from being redirected. Using those to events, I return false, so maybe there's a way to cancel other than returning false? Another solution that I've had was redirecting them to another page that has my popup, but the problem with that is that if they do want to leave the page, and it wasn't a mistake, they lose the page they were originally trying to go to. If I was a user, that would irritate me. The last solution was real popup window. The only thing I don't like about that is that the main winow will have their destination page while the pop will have my page. In my opinion it looks disjoint. On top of that, I'd be worried about popup blockers.

    Read the article

  • How to make Spring load a JDBC Driver BEFORE initializing Hibernate's SessionFactory?

    - by Bill_BsB
    I'm developing a Spring(2.5.6)+Hibernate(3.2.6) web application to connect to a custom database. For that I have custom JDBC Driver and Hibernate Dialect. I know for sure that these custom classes work (hard coded stuff on my unit tests). The problem, I guess, is with the order on which things get loaded by Spring. Basically: Custom Database initializes Spring load beans from web.xml Spring loads ServletBeans(applicationContext.xml) Hibernate kicks in: shows version and all the properties correctly loaded. Hibernate's HbmBinder runs (maps all my classes) LocalSessionFactoryBean - Building new Hibernate SessionFactory DriverManagerConnectionProvider - using driver: MyCustomJDBCDriver at CustomDBURL I get a SQLException: No suitable driver found for CustomDBURL Hibernate loads the Custom Dialect My CustomJDBCDriver finally gets registered with DriverManager (log messages) SettingsFactory runs SchemaExport runs (hbm2ddl) I get a SQLException: No suitable driver found for CustomDBURL (again?!) Application get successfully deployed but there are no tables on my custom Database. Things that I tried so far: Different techniques for passing hibernate properties: embedded in the 'sessionFactory' bean, loaded from a hibernate.properties file. Nothing worked but I didn't try with hibernate.cfg.xml file neither with a dataSource bean yet. MyCustomJDBCDriver has a static initializer block that registers it self with the DriverManager. Tried different combinations of lazy initializing (lazy-init="true") of the Spring beans but nothing worked. My custom JDBC driver should be the first thing to be loaded - not sure if by Spring but...! Can anyone give me a solution for this or maybe a hint for what else I could try? I can provide more details (huge stack traces for instance) if that helps. Thanks in advance.

    Read the article

< Previous Page | 509 510 511 512 513 514 515 516 517 518 519 520  | Next Page >