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  • nullable bool is being passed to the controller null all the time regardless of the value

    - by user1807954
    I'm trying to pass a nullable bool to my controller. But when I pass the bool value from my view to the controller, it's being passed null all the time regardless of the value it has in my view. Here is my view: @model Cars.Models.Car @using (Html.BeginForm("Index", "Home", FormMethod.Post, new { id = "CategoryFormID"})) { <label>Convertible:</label> <input type="checkbox" id="ConvertibleID" name="convertible"/> <button type="submit" name="submit" value="search" id="SubmitID">Search</button> } And my controller: [HttpPost] public ActionResult Index(bool? convertible){ var cars = from d in db.Car select d; if (convertible.HasValue) { cars = cars.Where(x => x.Convertible == convertible); } return View("SearchResult", cars); } I also have other fields such as drop down lists and text fields, but they're being passed flawless. Any help would be really appreciated. Update: Thank you for your fast responds. However, I did try giving it a value="True" as you guys suggested. There is only 2 options now: null and true. But my intention is to use nullable bool to have three options: null (when user doesn't touch the checkbox), true(checked) and false(unchecked). I know it sounds not smart and silly, but I'm just trying to figure out how nullable bool is working, and what is the intention of having such a thing in C# (I'm new with C#). I was wondering if it is possible to do so with just checkbox and without the use of dropdownlist or radio buttons.

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  • The perfect web UI framework (with Microsoft stack?) - architecture question?

    - by Igorek
    I'm looking for suggestions for the following issue, and I realize there is really not going to be a perfect answer to my question: I have a UI built in WinForms.NET (v4.0 framework) with WCF back-end and EF4 model objects, that I am looking to port to the web. UI is not huge and is not super complex and is structured well. But it is not a super simple system either. I am looking to pick a technology stack for the web-frontend that will target desktop & partially mobile platforms, provide a good development platform to build on, and facilitate code reuse across UI and back-end tiers... I would rather avoid: custom coding of UI-centric scripts, because they are hard to debug, non-compiled, usually a maintenance nightmare, almost always start to contain business logic, and duplicate some of the logic that back-end tiers have (especially validation) custom-coding for Desktop Web and Mobile Web UI's separately (although I realize that mobile web UI will likely contain fewer of data-entry screens and more reporting screens) non-.NET technology stacks I would love to: target the reporting capabilities of the system toward mobile web browsers not have to write a single line of script (javascript, jquery, etc.) utilize a good collection of controls that produces an elegant UI use .NET for everything The way I see it right now, I need to re-write this app in Silverlight, utilize a 3rd party UI framework like Telerik, and re-do the reports UI again for mobile platforms separately. However, I'm rather concerned about the shelf-life of Silverlight and the needed to deploy a different architecture to deal with mobile platform. Is there an ASP.NET/MVC/Ajax architecture/framework/library that would allow me to get at the power of .NET and without painful (imho) client-side scripting, while providing a decent user experience Thank you

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  • Using an ORM with a database that has no defined relationships?

    - by Ahmad
    Consider a database(MSSQL 2005) that consists of 100+ tables which have primary keys defined to a certain degree. There are 'relationships' between tables, however these are not enforced with foreign key constraints. Consider the following simplified example of typical types of tables I am dealing with. The are clear relations between the User and City and Province tables. However, they key issues is the inconsistent data types in the tables and naming conventions. User: UserRowId [int] PK Name [varchar(50)] CityId [smallint] ProvinceRowId [bigint] City: CityRowId [bigint] PK CityDescription [varchar(100)] Province: ProvinceId [int] PK ProvinceDesc [varchar(50)] I am considering a rewrite of the application (in ASP.net MVC) that uses this data source as is similar in design to MVC storefront. However I am going through a proof of concept phase and this is one of the stumbling blocks I have come across. What are my options in terms of ORM choice that can be easily used and why? Should I even be considering an ORM? (The reason I ask this is that most explanations and tutorials all work with relatively cleanly designed existing databases, or newly created ones when compared to mine. I am thus having a very hard time trying to find a way forward with this problem) There is a huge amount of existing SQL queries, would a datamappper(eg IBatis.net) be more suitable since we could easily modify them to work and reuse the investment already made? I have found this question on SO which indicates to me that an ORM can be used - however I get the impression that this a question of mapping? Note: at the moment, the object model is not clearly defined as it was non-existent. The existing system pretty much did almost everything in SQL or consisted of overly complicated, and numerous queries to complete fucntionality. I am pretty much a noob and have zero experience around ORMs and MVC - so this an awesome learning curve I am on.

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  • Asp.net mvc retriev images from db and display on Page

    - by Trey Carroll
    //Inherits="System.Web.Mvc.ViewPage<FilmFestWeb.Models.ListVideosViewModel>" <h2>ListVideos</h2> <% foreach(BusinessObjects.Video vid in Model.VideoList){%> <div class="videoBox"> <%= Html.Encode(vid.Name) %> <img src="<% vid.ThumbnailImage; %>" /> </div> <%} %> //ListVideosViewModel public class ListVideosViewModel { public IList<Video> VideoList { get; set; } } //Video public class Video { public long VideoId { get; set; } public long TeamId { get; set; } public string Name { get; set; } public string Tags { get; set; } public string TeamMembers { get; set; } public string TranscriptFileName { get; set; } public string VideoFileName { get; set; } public int TotalNumRatings { get; set; } public int CumulativeTotalScore { get; set; } public string VideoUri { get; set; } public Image ThumbnailImage { get; set; } } I am getting the "red x" that I usually associate with image file not found. I have verified that my database table shows <binary data> after the stored proc that uploads the image executes. Any insight or advice would be greatly appreciated.

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  • How to efficiently compare the sign of two floating-point values while handling negative zeros

    - by François Beaune
    Given two floating-point numbers, I'm looking for an efficient way to check if they have the same sign, given that if any of the two values is zero (+0.0 or -0.0), they should be considered to have the same sign. For instance, SameSign(1.0, 2.0) should return true SameSign(-1.0, -2.0) should return true SameSign(-1.0, 2.0) should return false SameSign(0.0, 1.0) should return true SameSign(0.0, -1.0) should return true SameSign(-0.0, 1.0) should return true SameSign(-0.0, -1.0) should return true A naive but correct implementation of SameSign in C++ would be: bool SameSign(float a, float b) { if (fabs(a) == 0.0f || fabs(b) == 0.0f) return true; return (a >= 0.0f) == (b >= 0.0f); } Assuming the IEEE floating-point model, here's a variant of SameSign that compiles to branchless code (at least with with Visual C++ 2008): bool SameSign(float a, float b) { int ia = binary_cast<int>(a); int ib = binary_cast<int>(b); int az = (ia & 0x7FFFFFFF) == 0; int bz = (ib & 0x7FFFFFFF) == 0; int ab = (ia ^ ib) >= 0; return (az | bz | ab) != 0; } with binary_cast defined as follow: template <typename Target, typename Source> inline Target binary_cast(Source s) { union { Source m_source; Target m_target; } u; u.m_source = s; return u.m_target; } I'm looking for two things: A faster, more efficient implementation of SameSign, using bit tricks, FPU tricks or even SSE intrinsics. An efficient extension of SameSign to three values.

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  • What would be the best way to dynamically add a set of rows to a table using JQuery?

    - by user312157
    I have a following table using MVC that shows number of items the user has. <table border = "1" id="tblItems"> <% var itemnum = 1; foreach (var item in Model.Items) {%> <tr> <td colspan="2" bgcolor="Silver"><strong>Item#<%=itemnum%></strong></td> <td><%=Html.ActionLink("Delete", "DeleteItem", "Item", new { id = item.ID })%></td> </tr> <tr> <td><strong>Name:</strong></td> <td><%=Html.TextBox("ItemName_" + itemnum, item.Name)%></td> </tr> <tr> <td><strong>Description:</strong></td> <td><%=Html.TextBox("ItemDescription_" + itemnum, item.Description)%></td> </tr> <%itemnum++; } %> </table> I will have a button that will Add New Item that will dynamically add identical structure. Any ideas on what is the best way to do this using JQuery? Thanks for all the suggestions!

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  • How to access global variable in a view in Ruby on Rails?

    - by ben
    I have a User model. I have a Session controller, in which I have a global user variable that is assigned as follows: $user = User.authenticate(params[:session][:email], params[:session][:password]) (I've made user global just to try to solve this problem, so if there's a better way please let me know!) I need to use the email of the logged in user as a parameter to send to Flex part of my website. At the moment I'm creating the link as follows: <%= link_to "secondpage", secondpage_path(:email => @session.$user.email) But I'm getting the following error: compile error /Users/benhartney/rails_projects/talk/app/views/layouts/_header.html.erb:12: syntax error, unexpected tGVAR ..._path(:email = @session.$user.email) ).to_s); @output_buffe... There's also a little arrow pointing at $user If I remove the $ from $user, I get this error: undefined method `user' for nil:NilClass If I remove the (:email => @session.user.email) part, everything works fine, so I think all of the code except for this is ok. Can anyone tell me what I'm doing wrong? Thanks for reading!

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  • Web development scheme for staging and production servers using Git Push

    - by ServAce85
    I am using git to manage a dynamic website (PHP + MySQL) and I want to send my files from my localhost to my staging and development servers in the most efficient and hassle-free way. I am currently convinced that the best way for me to approach this problem is to use this git branching model to organize my local git repo. From there, I will use the release branches to push to my staging server for testing. Once I am happy that the release code works on the staging server, I can then merge with my master branch and push that to my production server. Pushing to Staging Server: As noted in many introductory git posts, I could run into problems pushing into a non-bare repo, so, as suggested in this response, I plan to push the release branch to a bare repo on the server and have a post-receive hook that clones the bare repo to a non-bare repo that also acts as the web-hosted directory. Pushing to Production Server: Here's my newest source of confusion... In the response that I cited above, it made me curious as to why @Paul states that it's a completely different story when pushing to a live, development server. I guess I don't see the problem. Would it be safe and hassle-free to follow the same steps as above, but for the master branch? Where are the potential pit-falls? Config Files: With respect to configuration files that are unique to each environment (.htaccess, config.php, etc), it seems simplest to .gitignore each of those files in their respective repos on their respective servers. Can you see anything immediately wrong with this? Better solutions? Accessing Data: Finally, as I initially stated, the site uses MySQL databases to store data. How would you suggest I access that data (for testing purposes) from the staging server and localhost? I realize that I may have asked way too many questions for a single post, but since they're all related to the best way to set up this development scheme, I thought it was necessary.

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  • Executing logic before save or validation with EF Code-First Models

    - by Ryan Norbauer
    I'm still getting accustomed to EF Code First, having spent years working with the Ruby ORM, ActiveRecord. ActiveRecord used to have all sorts of callbacks like before_validation and before_save, where it was possible to modify the object before it would be sent off to the data layer. I am wondering if there is an equivalent technique in EF Code First object modeling. I know how to set object members at the time of instantiation, of course, (to set default values and so forth) but sometimes you need to intervene at different moments in the object lifecycle. To use a slightly contrived example, say I have a join table linking Authors and Plays, represented with a corresponding Authoring object: public class Authoring { public int ID { get; set; } [Required] public int Position { get; set; } [Required] public virtual Play Play { get; set; } [Required] public virtual Author Author { get; set; } } where Position represents a zero-indexed ordering of the Authors associated to a given Play. (You might have a single "South Pacific" Play with two authors: a "Rodgers" author with a Position 0 and a "Hammerstein" author with a Position 1.) Let's say I wanted to create a method that, before saving away an Authoring record, it checked to see if there were any existing authors for the Play to which it was associated. If no, it set the Position to 0. If yes, it would find set the Position of the highest value associated with that Play and increment by one. Where would I implement such logic within an EF code first model layer? And, in other cases, what if I wanted to massage data in code before it is checked for validation errors? Basically, I'm looking for an equivalent to the Rails lifecycle hooks mentioned above, or some way to fake it at least. :)

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  • How can I show print statements in debug mode of OPNET Modeler?

    - by Here now
    I'm writing C++ code in OPNET Modeler. I try to simulate my scenario in debugger mode & I need to trace the function that I wrote it. I need to show print statements which I put it in my code. I used in debugger mode: ***ltr function_name()*** then ***c*** But the result looks like: Type 'help' for Command Summary ODB> ltr enqueue_packet() Added trace #0: trace on label (enqueue_packet()) ODB> c |-----------------------------------------------------------------------------| | Progress: Time (1 min. 52 sec.); Events (500,002) | | Speed: Average (82,575 events/sec.); Current (82,575 events/sec.) | | Time : Elapsed (6.1 sec.) | | DES Log: 28 entries | |-----------------------------------------------------------------------------| |-----------------------------------------------------------------------------| | Progress: Time (1 min. 55 sec.); Events (1,000,002) | | Speed: Average (69,027 events/sec.); Current (59,298 events/sec.) | | Time : Elapsed (14 sec.) | | DES Log: 28 entries | |-----------------------------------------------------------------------------| |-----------------------------------------------------------------------------| | Progress: Time (1 min. 59 sec.); Events (1,500,002) | | Speed: Average (51,464 events/sec.); Current (34,108 events/sec.) | | Time : Elapsed (29 sec.) | | DES Log: 28 entries | |-----------------------------------------------------------------------------| |-----------------------------------------------------------------------------| | Simulation Completed - Collating Results. | | Events: Total (1,591,301); Average Speed (48,803 events/sec.) | | Time : Elapsed (33 sec.); Simulated (2 min. 0 sec.) | | DES Log: 29 entries | |-----------------------------------------------------------------------------| |-----------------------------------------------------------------------------| | Reading network model. | |-----------------------------------------------------------------------------| I need to show the print statements in my code. Where it has to be appeared? Is there any step before run the simulation to insure that OPNET debugger using Visual Studio & go through my code??

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  • How to store child objects on GAE using JDO from Scala

    - by Gero
    Hi, I'm have a parent-child relation between 2 classes, but the child objects are never stored. I do get an warning: "org.datanucleus.store.appengine.MetaDataValidator checkForIllegalChildField: Unable to validate relation net.vermaas.kivanotify.model.UserCriteria.internalCriteria" but it is unclear to me why this occurs. Already tried several alternatives without luck. The parent class is "UserCriteria" which has a List of "Criteria" as children. The classes are defined as follows (Scala): class UserCriteria(tu: String, crit: Map[String, String]) extends LogHelper { @PrimaryKey @Persistent{val valueStrategy = IdGeneratorStrategy.IDENTITY} var id = KeyFactory.createKey("UserCriteria", System.nanoTime) @Persistent var twitterUser = tu @Persistent var internalCriteria: java.util.List[Criteria] = flatten(crit) def flatten(crits: Map[String, String]) : java.util.List[Criteria] = { val list = new java.util.ArrayList[Criteria] for (key <- crits.keySet) { list.add(new Criteria(this, key, crits(key))) } list } def criteria: Map[String, String] = { val crits = mutable.Map.empty[String, String] for (i <- 0 to internalCriteria.size-1) { crits(internalCriteria.get(i).name) = internalCriteria.get(i).value } Map.empty ++ crits } // Stripped the equals, canEquals, hashCode, toString code to keep the code snippet short... } @PersistenceCapable @EmbeddedOnly class Criteria(uc: UserCriteria, nm: String, vl: String) { @Persistent var userCriteria = uc @Persistent var name = nm @Persistent var value = vl override def toString = { "Criteria name: " + name + " value: " + value } } Any ideas why the childs are not stored? Or why I get the error message? Thanks, Gero

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  • MonoRail CheckboxList?

    - by Justin
    I'm trying to use a Checkboxlist in MonoRail to represent a many to many table relationship. There is a Special table, SpecialTag table, and then a SpecialTagging table which is the many to many mapping table between Special and SpecialTag. Here is an excerpt from the Special model class: [HasAndBelongsToMany(typeof(SpecialTag), Table = "SpecialTagging", ColumnKey = "SpecialId", ColumnRef = "SpecialTagId")] public IList<SpecialTag> Tags { get; set; } And then in my add/edit special view: $Form.LabelFor("special.Tags", "Tags")<br/> #set($items = $FormHelper.CreateCheckboxList("special.Tags", $specialTags)) #foreach($specialTag in $items) $items.Item("$specialTag.Id") $Form.LabelFor("$specialTag.Id", $specialTag.Name) #end The checkboxlist renders correctly, but if I select some and then click Save, it doesn't save the special/tag associations to the SpecialTagging table (the entity passed to the Save controller action has an empty Tags list.) One thing I noticed was that the name and value attributes on the checkboxes are funky: <label for="special_Tags">Tags</label><br> <input id="3" name="special.Tags[0]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="3">Buy 1 Get 1 Free</label> <input id="1" name="special.Tags[1]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="1">Free</label> <input id="2" name="special.Tags[2]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="2">Half Price</label> <input id="5" name="special.Tags[3]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="5">Live Music</label> <input id="4" name="special.Tags[4]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="4">Outdoor Seating</label> Anyone have any ideas? Thanks! Justin

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  • What is a fast way to set debugging code at a given line in a function?

    - by Josh O'Brien
    Preamble: R's trace() is a powerful debugging tool, allowing users to "insert debugging code at chosen places in any function". Unfortunately, using it from the command-line can be fairly laborious. As an artificial example, let's say I want to insert debugging code that will report the between-tick interval calculated by pretty.default(). I'd like to insert the code immediately after the value of delta is calculated, about four lines up from the bottom of the function definition. (Type pretty.default to see where I mean.) To indicate that line, I need to find which step in the code it corresponds to. The answer turns out to be step list(c(12, 3, 3)), which I zero in on by running through the following steps: as.list(body(pretty.default)) as.list(as.list(body(pretty.default))[[12]]) as.list(as.list(as.list(body(pretty.default))[[12]])[[3]]) as.list(as.list(as.list(body(pretty.default))[[12]])[[3]])[[3]] I can then insert debugging code like this: trace(what = 'pretty.default', tracer = quote(cat("\nThe value of delta is: ", delta, "\n\n")), at = list(c(12,3,3))) ## Try it a <- pretty(c(1, 7843)) b <- pretty(c(2, 23)) ## Clean up untrace('pretty.default') Questions: So here are my questions: Is there a way to print out a function (or a parsed version of it) with the lines nicely labeled by the steps to which they belong? Alternatively, is there another easier way, from the command line, to quickly set debugging code for a specific line within a function? Addendum: I used the pretty.default() example because it is reasonably tame, but with real/interesting functions, repeatedly using as.list() quickly gets tiresome and distracting. Here's an example: as.list(as.list(as.list(as.list(as.list(as.list(as.list(as.list(as.list(body(# model.frame.default))[[26]])[[3]])[[2]])[[4]])[[3]])[[4]])[[4]])[[4]])[[3]]

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  • Disable validation in an object in Ruby on Rails

    - by J. Pablo Fernández
    I have an object which whether validation happens or not should depend on a boolean, or in another way, validation is optional. I haven't found a clean way to do it. What I'm currently doing is this (disclaimer: you cannot unsee, leave this page if you are too sensitive): def valid? if perform_validation super else super # Call valid? so that callbacks get called and things like encrypting passwords and generating salt in before_validation actually happen errors.clear # but then clear the errors true # and claim ourselves to be valid. This is super hacky! end end Any better ways? Before you point to the :if argument of many validations, this is for a user model which is using authlogic so it has a lot of validation rules. You can stop reading here if you belive me. If you don't, authlogic already sets some :ifs like: :if => :email_changed? which I have to turn into :if => Proc.new {|user| user.email_changed? and user.perform_validation} and in some other cases, since I'm also using authlogic-oid (OpenID) I just don't have control over the :if, authlogic-oid sets it in a way I cannot change it (in time) without further monkey patching. So I have to override seemingly unrelated functions, catch exceptions if a method doesn't exist, etc. The previous hacky solution if the best of my two attempts.

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  • SystemStackError in Rails::ActiveSupport::Callbacks

    - by coreyward
    I'm building a Rails app that connects to Dropbox and syncs with a folder to update a personal site. I'm using Rails 3.0.3, Ruby 1.9.2, and the Dropbox gem. Right now I have a DropboxAccounts Controller, and two models: DropboxSession, which wraps calls to the gem with application-specific functionality, and DropboxAccount, which stores the session and settings in the database. After the user authorizes their account with Dropbox they're redirected back over and the DropboxAccount is saved with the authorized session. That all works just fine. My problem is that when I try to call Dropbox::API#create_folder(any path) I end up with a SystemStackError in lib/activesupport/callbacks.rb:421 which refers to the code below. If I remove the call to create the folder, it works. If I call create folder from another request, it works. I doubled the stack size to 16K to no avail. # This is called the first time a callback is called with a particular # key. It creates a new callback method for the key, calculating # which callbacks can be omitted because of per_key conditions. # def __create_keyed_callback(name, kind, object, &blk) #:nodoc: @_keyed_callbacks ||= {} @_keyed_callbacks[name] ||= begin str = send("_#{kind}_callbacks").compile(name, object) class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 def #{name}() #{str} end # THIS IS LINE 421 protected :#{name} RUBY_EVAL true end end I'm not very familiar with Rails yet, and I'm not sure what the intention of the code above is or why it would cause a stack overflow. I'm not using any method_missing/ghost method magic in my code. I suspected it was something with a callback serialize :files but commenting it out did nothing. My DropboxAccount model contains only a call to belongs_to :user, and DropboxSession is just a handful of methods, none of which contain callbacks. Bypassing them and using the Dropbox::Session methods directly doesn't help. I hope someone on StackOverflow can help me with this stack overflow. ;)

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  • Lost Array After Validation Error

    - by Georges Kmeid
    I'm working on a CakePHP project and I have User, Post and Location models among others. User hasMany Location and Post belongsTo User so Location is not directly related to Post. This is my code in the Post controller: public function add() { if ($this->request->is('get')) { $this->loadModel('Location'); $this->set('locations', $this->Location->find('all', array('conditions' => array('user_id' => $this->Auth->user('id'))))); } ... } And this is my code in the posts/add view: <?php $i = 0; $j = 0; foreach ($locations as $location): $location_names[$i] = $location['Location']['name']; $i++; endforeach; echo "<select name=\"location\" onchange=\"select(this.value)\">"; echo "<option value=\"\">Select a saved location</option>"; foreach ($locations as $location): echo "<option value=\"" . $location['Location']['latitude'] . "," . $location['Location']['longitude'] . "\">" . $location_names[$j] . "</option>"; $j++; endforeach; ?> </select> If I enter a wrong value in one of the post inputs that has a validation rule in Post model, it redirects to the current add view, shows what is the validation error, but then the $locations array passed from controller to view disappears and can't use it in view and I get this error: Notice (8): Undefined variable: locations [APP\View\Posts\add.ctp, line 68]

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  • How should I organize complex SQL views in Rails?

    - by Benjamin Oakes
    I manage a research database with Ruby on Rails. The data that is entered is primarily used by scientists who prefer to have all the relevant information for a study in one single massive table for use in their statistics software of choice. I'm currently presenting it as CSV, as it's very straightforward to do and compatible with the tools people want to use. I've written many views (the SQL kind, not the Rails HTML/ERB kind) to make the output they expect a reality. Some of these views are quite large and have a fair amount of complexity behind them. I wrote them in SQL because there are many calculations and comparisons that are more easily done with SQL. They're currently loaded into the database straight from a file named views.sql. To get the requested data, I do a select * from my_view;. The views.sql file is getting quite large. Part of the problem is that we're still figuring out what the data we collect means, so there's a lot of changes being made to the views all the time -- and a ton of them are being created. Many of them need to be repeatable. I've recently run into issues organizing and testing these views. Rails works great for user interface stuff and business logic, but I'm not aware of much existing structure for handling the reporting we require. Some options I've thought of: Should I move them into the most relevant models somehow? Several of the views interact with each other, which makes this situation more complex than just doing a single find_by_sql, so I don't know if they should only be part of the model. Perhaps they should be treated as a "view" in the MVC sense? (That is, they could be moved into app/views/ and live alongside the HTML, perhaps as files named something like my_view.csv.sql which return CSV.) How would you deal with a complex reporting problem like this?

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  • What OOP pattern to use when only adding new methods, not data?

    - by Jonathon Reinhart
    Hello eveyone... In my app, I have deal with several different "parameters", which derive from IParameter interface, and also ParamBase abstract base class. I currently have two different parameter types, call them FooParameter and BarParameter, which both derive from ParamBase. Obviously, I can treat them both as IParameters when I need to deal with them generically, or detect their specific type when I need to handle their specific functionality. My question lies in specific FooParameters. I currently have a few specific ones with their own classes which derive from FooParameter, we'll call them FP12, FP13, FP14, etc. These all have certain characteristics, which make me treat them differently in the UI. (Most have names associated with the individual bits, or ranges of bits). Note that these specific, derived FP's have no additional data associated with them, only properties (which refer to the same data in different ways) or methods. Now, I'd like to keep all of these parameters in a Dictionary<String, IParameter> for easy generic access. The problem is, if I want to refer to a specific one with the special GUI functions, I can't write: FP12 fp12 = (FP12)paramList["FP12"] because you can't downcast to a derived type (rightfully so). But in my case, I didn't add any data, so the cast would theoretically work. What type of programming model should I be using instead? Thanks!

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  • ASP.net MVC Linq-To-SQL Many-To-Many Field Binding

    - by user336858
    Hi there, The short version of this question is "Is there a way to gracefully handle database insertion for an object that has a many-to-many field that has been set up in a partial class?" Apologies if it's been asked before. Example Suppose I have a typical MVC setup with the tables: Posts {PostID, ...} Categories {CategoryID, ...} A post can have more than one category, and a category can identify more than one post. Thus suppose further that I need an extra table: PostCategories {PostID, CategoryID, ...} This handles the many-to-many relationship between posts and categories. As far as I know, there's no way to do this in Linq-to-SQL right now so I have to shoehorn it in by adding a partial Post class to the project to add that functionality. Something like: public partial class Post { public IEnumerable<Category> Categories{ get { ... } set { ... } } } So I can now create a "Create" view that automatically populates a "Categories" UI item. This is where the trouble starts. So here's my question: How do you get automatic object model binding to work cleanly with an object that has a many-to-many relationship to control? The workaround that makes many-to-many relationships possible relies on the Post object having a PostID in order to be associated with CategoryID(s), which is only issued after the Post object has been submitted for validation and insertion. Bit of a Catch22 here. Any terminology, links, or tips you can provide would be tremendously helpful!

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  • How to implement an ID field on a POCO representing an Identity field in SQL Server?

    - by Dr. Zim
    If I have a Domain Model that has an ID that maps to a SQL Server identity column, what does the POCO look like that contains that field? Candidate 1: Allows anyone to set and get the ID. I don't think we want anyone setting the ID except the Repository, from the SQL table. public class Thing { public int ID {get;set;} } Candidate 2: Allows someone to set the ID upon creation, but we won't know the ID until after we create the object (factory creates a blank Thing object where ID = 0 until we persist it). How would we set the ID after persisting? public class Thing { public Thing () : This (ID: 0) {} public Thing (int ID) { this.ID = ID } private int _ID; public int ID { get { return this.ID;}; } Candidate 3: Methods to set ID? Somehow we would need to allow the Repository to set the ID without allowing the consumer to change it. Any ideas? Is this barking up the wrong tree? Do we send the object to the Repository, save it, throw it away, then create a new object from the loaded version and return that as a new object?

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  • Rails: Getting rid of generic "X is invalid" validation errors

    - by DJTripleThreat
    I have a sign-up form that has nested associations/attributes whatever you want to call them. My Hierarchy is this: class User < ActiveRecord::Base acts_as_authentic belongs_to :user_role, :polymorphic => true end class Customer < ActiveRecord::Base has_one :user, :as => :user_role, :dependent => :destroy accepts_nested_attributes_for :user, :allow_destroy => true validates_associated :user end class Employee < ActiveRecord::Base has_one :user, :as => :user_role, :dependent => :destroy accepts_nested_attributes_for :user, :allow_destroy => true validates_associated :user end I have some validation stuff in these classes as well. My problem is that if I try to create and Customer (or Employee etc) with a blank form I get all of the validation errors I should get plus some Generic ones like "User is invalid" and "Customer is invalid" If I iterate through the errors I get something like: user.login can't be blank User is invalid customer.whatever is blah blah blah...etc customer.some_other_error etc etc Since there is at least one invalid field in the nested User model, an extra "X is invalid" message is added to the list of errors. This gets confusing to my client and so I'm wondering if there is a quick way to do this instead of having to filer through the errors myself.

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  • Using jQuery with Windows 8 Metro JavaScript App causes security error

    - by patridge
    Since it sounded like jQuery was an option for Metro JavaScript apps, I was starting to look forward to Windows 8 dev. I installed Visual Studio 2012 Express RC and started a new project (both empty and grid templates have the same problem). I made a local copy of jQuery 1.7.2 and added it as a script reference. <!-- SomeTestApp references --> <link href="/css/default.css" rel="stylesheet" /> <script src="/js/jquery-1.7.2.js"></script> <script src="/js/default.js"></script> Unfortunately, as soon as I ran the resulting app it tosses out a console error: HTML1701: Unable to add dynamic content ' a' A script attempted to inject dynamic content, or elements previously modified dynamically, that might be unsafe. For example, using the innerHTML property to add script or malformed HTML will generate this exception. Use the toStaticHTML method to filter dynamic content, or explicitly create elements and attributes with a method such as createElement. For more information, see http://go.microsoft.com/fwlink/?LinkID=247104. I slapped a breakpoint in a non-minified version of jQuery and found the offending line: div.innerHTML = " <link/><table></table><a href='/a' style='top:1px;float:left;opacity:.55;'>a</a><input type='checkbox'/>"; Apparently, the security model for Metro apps forbids creating elements this way. This error doesn't cause any immediate issues for the user, but given its location, I am worried it will cause capability-discovery tests in jQuery to fail that shouldn't. I definitely want jQuery $.Deferred for making just about everything easier. I would prefer to be able to use the selector engine and event handling systems, but I would live without them if I had to. How does one get the latest jQuery to play nicely with Metro development?

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  • Dynamically generate client-side HTML form control using JavaScript and server-side Python code in Google App Engine

    - by gisc
    I have the following client-side front-end HTML using Jinja2 template engine: {% for record in result %} <textarea name="remark">{{ record.remark }}</textarea> <input type="submit" name="approve" value="Approve" /> {% endfor %} Thus the HTML may show more than 1 set of textarea and submit button. The back-end Python code retrieves a variable number of records from a gql query using the model, and pass this to the Jinja2 template in result. When a submit button is clicked, it triggers the post method to update the record: def post(self): if self.request.get('approve'): updated_remark = self.request.get('remark') record.remark = db.Text(updated_remark) record.put() However, in some instances, the record updated is NOT the one that correspond to the submit button clicked (eg if a user clicks on record 1 submit, record 2 remark gets updated, but not record 1). I gather that this is due to the duplicate attribute name remark. I can possibly use JavaScript/jQuery to generate different attribute names. The question is, how do I code the back-end Python to get the (variable number of) names generated by the JavaScript? Thanks.

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  • Does fast typing influence fast programming? [closed]

    - by Lukasz Lew
    Many young programmers think that their bottleneck is typing speed. After some experience one realizes that it is not the case, you have to think much more than type. At some point my room-mate forced me to turn of the light (he sleeps during the night). I had to learn to touch type and I experienced an actual improvement in programming skill. The most surprising was that the improvement not due to sheer typing speed, but to a change in mindset. I'm less afraid now to try new things and refactor them later if they work well. It's like having a new tool in the bag. Have anyone of you had similar experience? Now I trained a touch typing a little with KTouch. I find auto-generate lessons the best. I can use this program to create new lessons out of text files but it's only verbatim training, not auto-generated based on a language model. Do you know any touch typing program that allows creation of custom, but randomized lessons?

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  • GSM Cell Towers Location & Triangulation Algorithm (Similar to OpenCellID / Skyhook / Google's MyLocation)

    - by ranabra
    Hi all, assuming I have a Fingerprint DB of Cell towers. The data (including Long. & Lat. CellID, signal strength, etc) is achieved by 'wardriving', similar to OpenCellID.org. I would like to be able to get the location of the client mobile phone without GPS (similar to OpenCellID / Skyhook Wireless/ Google's 'MyLocation'), which sends me info on the Cell towers it "sees" at the moment: the Cell tower connected to, and another 6 neighboring cell towers (assuming GSM). I have read and Googled it for a long time and came across several effective theories, such as using SQL 2008 Spatial capabilities, or using an euclidean algorithm, or Markov Model. However, I am lacking a practical solution, preferably in C# or using SQL 2008 :) The location calculation will be done on the server and not on the client mobile phone. the phone's single job is to send via HTTP/GPRS, the tower it's connected to and other neighboring cell towers. Any input is appreciated, I have read so much and so far haven't really advanced much. Thanx

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