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  • Defining a select list through controller and view model

    - by Ibrar Hussain
    I have a View Model that looks like this: public class SomeViewModel { public SomeViewModel(IEnumerable<SelectListItem> orderTemplatesListItems) { OrderTemplateListItems = orderTemplatesListItems; } public IEnumerable<SelectListItem> OrderTemplateListItems { get; set; } } I then have an Action in my Controller that does this: public ActionResult Index() { var items = _repository.GetTemplates(); var selectList = items.Select(i => new SelectListItem { Text = i.Name, Value = i.Id.ToString() }).ToList(); var viewModel = new SomeViewModel { OrderTemplateListItems = selectList }; return View(viewModel); } Lastly my view: @Html.DropDownListFor(n => n.OrderTemplateListItems, new SelectList(Model.OrderTemplateListItems, "value", "text"), "Please select an order template") The code works fine and my select list populates wonderfully. Next thing I need to do is set the selected value that will come from a Session["orderTemplateId"] which is set when the user selects a particular option from the list. Now after looking online the fourth parameter should allow me to set a selected value, so if I do this: @Html.DropDownListFor(n => n.OrderTemplateListItems, new SelectList(Model.OrderTemplateListItems, "value", "text", 56), "Please select an order template") 56 is the Id of the item that I want selected, but to no avail. I then thought why not do it in the Controller? As a final attempt I tried building up my select list items in my Controller and then passing the items into the View: public ActionResult Index() { var items = _repository.GetTemplates(); var orderTemplatesList = new List<SelectListItem>(); foreach (var item in items) { if (Session["orderTemplateId"] != null) { if (item.Id.ToString() == Session["orderTemplateId"].ToString()) { orderTemplatesList.Add(new SelectListItem { Text = item.Name, Value = item.Id.ToString(), Selected = true }); } else { orderTemplatesList.Add(new SelectListItem { Text = item.Name, Value = item.Id.ToString() }); } } else { orderTemplatesList.Add(new SelectListItem { Text = item.Name, Value = item.Id.ToString() }); } } var viewModel = new SomeViewModel { OrderTemplateListItems = orderTemplatesList }; return View(viewModel); } Leaving my View like so: @Html.DropDownListFor(n => n.OrderTemplateListItems, new SelectList(Model.OrderTemplateListItems, "value", "text"), "Please select an order template") Nothing! Why isn't this working for me?

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  • JavaScript - Inheritance in Constructors

    - by j0ker
    For a JavaScript project we want to introduce object inheritance to decrease code duplication. However, I cannot quite get it working the way I want and need some help. We use the module pattern. Suppose there is a super element: a.namespace('a.elements.Element'); a.elements.Element = (function() { // public API -- constructor Element = function(properties) { this.id = properties.id; }; // public API -- prototype Element.prototype = { getID: function() { return this.id; } }; return Element; }()); And an element inheriting from this super element: a.namespace('a.elements.SubElement'); a.elements.SubElement = (function() { // public API -- constructor SubElement = function(properties) { // inheritance happens here // ??? this.color = properties.color; this.bogus = this.id + 1; }; // public API -- prototype SubElement.prototype = { getColor: function() { return this.color; } }; return SubElement; }()); You will notice that I'm not quite sure how to implement the inheritance itself. In the constructor I have to be able to pass the parameter to the super object constructor and create a super element that is then used to create the inherited one. I need a (comfortable) possibility to access the properties of the super object within the constructor of the new object. Ideally I could operate on the super object as if it was part of the new object. I also want to be able to create a new SubElement and call getID() on it. What I want to accomplish seems like the traditional class based inheritance. However, I'd like to do it using prototypal inheritance since that's the JavaScript way. Is that even doable? Thanks in advance! EDIT: Fixed usage of private variables as suggested in the comments. EDIT2: Another change of the code: It's important that id is accessible from the constructor of SubElement.

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  • Send a variable on the heap to another thread

    - by user1201889
    I have a strange problem in C++. An address of a Boolean gets "destroyed" but it doesn't get touched. I know that there are beater way's to accomplish what I try to do, but I want to know what I do wrong. I have a main class; this main class contains a vector of another class. There is a strange problem when a new instance gets created of this object. This is how my code works: There will start a thread when the constructor gets called of the “2nd”object. This thread gets as Parameter a struct. This is the struct: struct KeyPressData { vector<bool> *AutoPressStatus; vector<int> *AutoPressTime; bool * Destroy; bool * Ready; }; The struct gets filled in the constructor: MultiBoxClient::MultiBoxClient() { //init data DestroyThread = new bool; ReadyThread = new bool; AutoThreadData = new KeyPressData; //Reseting data *DestroyThread = false; *ReadyThread = false; //KeyPressData configurating AutoThreadData->AutoPressStatus = &AutoPressStatus; AutoThreadData->AutoPressTime = &AutoPressTime; AutoThreadData->Destroy = DestroyThread; AutoThreadData->Ready = ReadyThread; //Start the keypress thread CreateThread(NULL,NULL,(LPTHREAD_START_ROUTINE)AutoKeyThread,AutoThreadData,NULL,NULL); } As long as the constructor is running will the program run fine. But when the constructor closes the address of the “AutoThreadData-Destroy” will get corrupted. The program will crash when I call the value of the pointer. void WINAPI AutoKeyThread(void * ThreadData) { KeyPressData * AutoThreadData = (KeyPressData*)ThreadData; while(true) { if(*AutoThreadData->Destroy == true) //CRASH { *AutoThreadData->Ready = true; return; } Sleep(100); } } What did I test: I logged the address of the AutoThreadData and the AutoThreadData-Destroy when the constrcutor is running and clossed; the AutoThreadData address is equal to AutoThreadData when the constructor is closed. So there is no problem here. The address of AutoThreadData-Destroy gets destroyed when the constructor is closed. But how can this happen? The Boolean is on the heap and the KeyPressData struct (AutoThreadData) is on the heap. Destroy before: 00A85328 Destroy after: FEEEFEEE Can someone maby explain why this crash? I know that I can send a pointer to my class to the thread. But I want to know what goes wrong here. That way I can learn from my mistakes. Could someone help me with this problem? Thanks!

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  • Fail to save a managed object to core-data after its properties were updated.

    - by Tzur Gazit
    I have to trouble to create the object, but updating it fails. Here is the creation code: // Save data from pList to core data fro the first time - (void) saveToCoreData:(NSDictionary *)plistDictionary { // Create system parameter entity SystemParameters *systemParametersEntity = (SystemParameters *)[NSEntityDescription insertNewObjectForEntityForName:@"SystemParameters" inManagedObjectContext:mManagedObjectContext]; //// // GPS SIMULATOR //// NSDictionary *GpsSimulator = [plistDictionary valueForKey:@"GpsSimulator"]; [systemParametersEntity setMGpsSimulatorEnabled:[[GpsSimulator objectForKey:@"Enabled"] boolValue]]; [systemParametersEntity setMGpsSimulatorFileName:[GpsSimulator valueForKey:@"FileName"]]; [systemParametersEntity setMGpsSimulatorPlaybackSpeed:[[GpsSimulator objectForKey:@"PlaybackSpeed"] intValue]]; [self saveAction]; } During execution the cached copy is changed and then it is saved (or trying) to the database. Here is the code to save the changed copy: // Save data from pList to core data fro the first time - (void) saveSystemParametersToCoreData:(SystemParameters *)theSystemParameters { // Step 1: Select Data NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"SystemParameters" inManagedObjectContext:mManagedObjectContext]; [fetchRequest setEntity:entity]; NSError *error = nil; NSArray *items = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error]; [fetchRequest release]; if (error) { NSLog(@"CoreData: saveSystemParametersToCoreData: Unresolved error %@, %@", error, [error userInfo]); abort(); } // Step 2: Update Object SystemParameters *systemParameters = [items objectAtIndex:0]; //// // GPS SIMULATOR //// [systemParameters setMGpsSimulatorEnabled:[theSystemParameters mGpsSimulatorEnabled]]; [systemParameters setMGpsSimulatorFileName:[theSystemParameters mGpsSimulatorFileName]]; [systemParameters setMGpsSimulatorPlaybackSpeed:[theSystemParameters mGpsSimulatorPlaybackSpeed]]; // Step 3: Save Updates [self saveAction]; } As to can see, I fetch the object that I want to update, change its values and save. Here is the saving code: - (void)saveAction { NSError *error; if (![[self mManagedObjectContext] save:&error]) { NSLog(@"ERROR:saveAction. Unresolved Core Data Save error %@, %@", error, [error userInfo]); exit(-1); } } The Persistent store method: - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { if (mPersistentStoreCoordinator != nil) { return mPersistentStoreCoordinator; } NSString *path = [self databasePath]; NSURL *storeUrl = [NSURL fileURLWithPath:path]; NSError *error = nil; mPersistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; if (![mPersistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } return mPersistentStoreCoordinator; } There is no error but the sqLite file is not updated, hence the data is not persistent. Thanks in advance.

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  • How to reference a particular JSON in a function call.

    - by Jane Wilkie
    Hi guys! I have two javascript routines.. the first one declares some JSON and it contains a function that takes two arguments, the first argument being the json object that needs traversing and the second argument is the tab that the rendering is done in. The second routine merely passes the name of the JSON that needs traversing and tab to render in. The code is below.... <script language="JavaScript1.2" type="text/javascript"> var arr = [ {"id":"10", "class":"child-of-9", "useless":"donotneed"}, {"id":"11", "class":"child-of-10", "useless":"donotneed"}]; var arrtwo = [ {"id":"12", "class":"child-of-12", "useless":"donotneed"}, {"id":"13", "class":"child-of-13", "useless":"donotneed"}]; function render_help(json,tab){ var html=''; for(var i=0;i<json.length;i++){ var obj = json[i]; for(var key in obj){ var attrName = key; var attrValue = obj[key]; if (attrName == "id"){ html = html +'<B>'+attrValue+'</B>'+'<BR><BR>'; }else if (attrName == "class"){ html = html + attrValue + '<BR><BR>'; } } } document.getElementById(tab).innerHTML=(html); } </script> <script language="JavaScript1.2" type="text/javascript"> render_help(arr,"helptab"); </script> Various testing and strategically placed alert boxes indicate that the tab parameter is being passed and interpreted correctly. I know this because when I change .... document.getElementById(tab).innerHTML=(html); to document.getElementById(tab).innerHTML=("Howdy"); and it renders "Howdy" just fine. Putting an alert box (alert(json)) in to check the value of json yields.... [object.Object],[object.Object] The JSON object remains elusive. For the purposes of this scripting I need the JSON "arr" to be iterated over. I feel like the answer is fairly obvious so far no luck. Admittedly I am new with Javascript and I am apparently missing something. Does anyone have a clue as to what I'm overlooking here? Happy New Year to you all! Janie

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  • Should we use temporary variables for the returned values of functions?

    - by totymedli
    I thought about this: Is there a performance difference in these two practices: Store the return value of a function in a temporary variable than give that variable as a parameter to another function. Put the function into the other function. Specification Assuming all classes and functions are written correctly. Case 1. ClassA a = function1(); ClassB b = function2(a); function3(b); Case 2. function3(function2(function1())); I know there aren't a big difference with only one run, but supposed that we could run this a lot of times in a loop, I created some tests. Test #include <iostream> #include <ctime> #include <math.h> using namespace std; int main() { clock_t start = clock(); clock_t ends = clock(); // Case 1. start = clock(); for (int i=0; i<10000000; i++) { double a = cos(1); double b = pow(a, 2); sqrt(b); } ends = clock(); cout << (double) (ends - start) / CLOCKS_PER_SEC << endl; // Case 2. start = clock(); for (int i=0; i<10000000; i++) sqrt(pow(cos(1),2)); ends = clock(); cout << (double) (ends - start) / CLOCKS_PER_SEC << endl; return 0; } Results Case 1 = 6.375 Case 2 = 0.031 Why is the first one is much slower, and if the second one is faster why dont we always write code that way? Anyway does the second pratice has a name? I also wondered what happens if I create the variables outside the for loop in the first case, but the result was the same. Why?

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  • Request URL in Javascript, Fetch URL Content using Java Applet, return to Javascript?

    - by Sam G
    I'm in the process of making a little experiment, it grabs a YouTube page, and returns the highest quality MP4 link, then plays this in a HTML 5 Video element. Now I was using PHP with cURL to get the URL content (YouTube), but that only works on my local server (MP4 link is locked to IP address). I can't think of any other way to get the page content due to cross domain rules except a Java applet. So I've built a Java applet that should return the content of a URL. Java import java.applet.Applet; import java.awt.*; import java.io.ByteArrayOutputStream; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; public class URLFetcherabc extends Applet { public void init() { } public void paint(Graphics g) { g.drawString("Java loaded. Waiting for URL", 0, 10); } public String getURL(String url, String httpMethod) { try { URL u = new URL(url); HttpURLConnection conn = (HttpURLConnection)u.openConnection(); conn.setRequestMethod(httpMethod); InputStream is = conn.getInputStream(); ByteArrayOutputStream output = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; for (int bytesRead = 0; (bytesRead = is.read(buffer)) != -1; ) { output.write(buffer, 0, bytesRead); } return output.toString(); } catch (Exception e) { }return null; } } Now I've got the applet on the page, but every-time I call the function it returns nothing. Heres my HTML for including the applet. HTML <applet id="URLFetcher" name="URLFetcher" code="URLFetcherabc.class" archive="URLFetcher.jar" height="200" width="200" mayscript=""></applet> Java-Script function fetchurl(urltofetch) { var URLFetcher = document.getElementById("URLFetcher"); var result = URLFetcher.getURL(urltofetch); //Result = URL Content return result; } The function always returns null, in Java the function does work when passed a variable via other means (parameter etc). I've tried running other functions through Javascript and the Java applet does respond. I'm new to Java applets and communicating with them via Javascript, so I'm probably making either a small mistake somewhere or its completely wrong. Any ideas? Thanks

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  • No more memory available in Mathematica, Fit the parameters of system of differential equation

    - by user1058051
    I encountered a memory problem in Mathematica, when I tried to process my experimental data. It's a system of two differential equations and I need to find most suitable parameters. Unfortunately I am not a Pro in Mathematica, so the program used a lot of memory, when the parameter epsilon is more than 0.4. When it less than 0.4, the program work properly. The command 'historylength = 0' and attempts to reduce the Accuracy Goal and WorkingPrecision didn`t help. I can't use ' clear Cache ', because there isnt a circle. I'm trying to understand what mistakes I made, and how I may limit the memory usage. I have already bought extra-RAM, now its 4GB, and now I haven't free memory-slots in motherboard Remove["Global`*"]; T=13200; L = 0.085; e = 0.41; v = 0.000557197; q = 0.1618; C0 = 0.0256; R = 0.00075; data = {{L,600,0.141124587},{L,1200,0.254134509},{L,1800,0.342888644}, {L,2400,0.424476295},{L,3600,0.562844542},{L,4800,0.657111356}, {L,6000,0.75137817},{L,7200,0.815876516},{L,8430,0.879823594}, {L,9000,0.900771775},{L,13200,1}}; model[(De_)?NumberQ, (Kf_)?NumberQ, (Y_)?NumberQ] := model[De, Kf, Y] = yeld /.Last[Last[ NDSolve[{ v (Ci^(1,0))[z,t]+(Ci^(0,1))[z,t]== -((3 (1-e) Kf (Ci[z,t]-C0))/ (R e (1-(R Kf (1-R/r[z,t]))/De))), (r^(0,1))[z,t]== (R^2 Kf (Ci[z,t]-C0))/ (q r[z,t]^2 (1-(R Kf (1-R/r[z,t]))/De)), (yeld^(0,1))[z,t]== Y*(v e Ci[z,t])/(L q (1-e)), r[z,0]==R, Ci[z,0]==0, Ci[0,t]==0, yeld[z,0]==0}, {r[z,t],Ci[z,t],yeld},{z,0,L},{t,0,T}]]] fit = FindFit[data, {model[De, Kf, Y][z, t], {Y > 0.97, Y < 1.03, Kf > 10^-6, Kf < 10^-4, De > 10^-13, De < 10^-9}}, {{De,7*10^-13}, {Kf, 10^-5}, {Y, 1}}, {z, t}, Method -> NMinimize] data = {{600,0.141124587},{1200,0.254134509},{1800,0.342888644}, {2400,0.424476295},{3600,0.562844542},{4800,0.657111356}, {6000,0.75137817},{7200,0.815876516},{8430,0.879823594}, {9000,0.900771775},{13200,1}}; YYY = model[ De /. fit[[1]], Kf /. fit[[2]], Y /. fit[[3]]]; Show[Plot[Evaluate[YYY[L,t]],{t,0,T},PlotRange->All], ListPlot[data,PlotStyle->Directive[PointSize[Medium],Red]]] the link on the .nb file http://www.4shared.com/folder/249TSjlz/_online.html

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  • Populating data in multiple cascading dropdown boxes in Access 2007

    - by miCRoSCoPiC_eaRthLinG
    Hello all, I've been assigned the task to design a temporary customer tracking system in MS Access 2007 (sheeeesh!). The tables and relationships have all been setup successfully. But I'm running into a minor problem while trying to design the data entry form for one table... Here's a bit of explanation first. The screen contains 3 dropdown boxes (apart from other fields). 1st dropdown The first dropdown (cboMarket) represents the Market lets users select between 2 options: Domestic International Since the first dropdown contains only 2 items I didn't bother making a table for it. I added them as pre-defined list items. 2nd dropdown Once the user makes a selection in this one, the second dropdown (cboLeadCategory) loads up a list of Lead Categories, namely, Fairs & Exhibitions, Agents, Press Ads, Online Ads etc. Different sets of lead categories are utilized for the 2 markets. Hence this box is dependent on the 1st one. Structure of the bound table, named Lead_Cateogries for the 2nd combo is: ID Autonumber Lead_Type TEXT <- actually a list that takes up Domestic or International Lead_Category_Name TEXT 3rd dropdown And based on the choice of category in the 2nd one, the third one (cboLeadSource) is supposed to display a pre-defined set of lead sources belonging to the particular category. Table is named Lead_Sources and the structure is: ID Autonumber Lead_Category NUMBER <- related to ID of Lead Categories table Lead_Source TEXT When I make the selection in the 1st dropdown, the AfterUpdate event of the combo is called, which instructs the 2nd dropdown to load contents: Private Sub cboMarket_AfterUpdate() Me![cboLead_Category].Requery End Sub The Row Source of the 2nd combo contains a query: SELECT Lead_Categories.ID, Lead_Categories.Lead_Category_Name FROM Lead_Categories WHERE Lead_Categories.Lead_Type=[cboMarket] ORDER BY Lead_Categories.Lead_Category_Name; The AfterUpdate event of 2nd combo is: Private Sub cboLeadCategory_AfterUpdate() Me![cboLeadSource].Requery End Sub The Row Source of 3rd combo contains: SELECT Leads_Sources.ID, Leads_Sources.Lead_Source FROM Leads_Sources WHERE [Lead_Sources].[Lead_Category]=[Lead_Categories].[ID] ORDER BY Leads_Sources.Lead_Source; Problem When I select Market type from cboMarket, the 2nd combo cboLeadCategory loads up the appropriate Categories without a hitch. But when I select a particular Category from it, instead of the 3rd combo loading the lead source names, a modal dialog is displayed asking me to Enter a Parameter. When I enter anything into this prompt (valid or invalid data), I get yet another prompt: Why is this happening? Why isn't the 3rd box loading the source names as desired. Can any one please shed some light on where I am going wrong? Thanks, m^e

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  • Calling compiled C from R with .C()

    - by Sarah
    I'm trying to call a program (function getNBDensities in the C executable measurementDensities_out) from R. The function is passed several arrays and the variable double runsum. Right now, the getNBDensities function basically does nothing: it prints to screen the values of passed parameters. My problem is the syntax of calling the function: array(.C("getNBDensities", hr = as.double(hosp.rate), # a vector (s x 1) sp = as.double(samplingProbabilities), # another vector (s x 1) odh = as.double(odh), # another vector (s x 1) simCases = as.integer(x[c("xC1","xC2","xC3")]), # another vector (s x 1) obsCases = as.integer(y[c("yC1","yC2","yC3")]), # another vector (s x 1) runsum = as.double(runsum), # double DUP = TRUE, NAOK = TRUE, PACKAGE = "measurementDensities_out")$f, dim = length(y[c("yC1","yC2","yC3")]), dimnames = c("yC1","yC2","yC3")) The error I get, after proper execution of the function (i.e., the right output is printed to screen), is Error in dim(data) <- dim : attempt to set an attribute on NULL I'm unclear what the dimensions are that I should be passing the function: should it be s x 5 + 1 (five vectors of length s and one double)? I've tried all sorts of combinations (including sx5+1) and have found only seemingly conflicting descriptions/examples online of what's supposed to happen here. For those who are interested, the C code is below: #include <R.h> #include <Rmath.h> #include <math.h> #include <Rdefines.h> #include <R_ext/PrtUtil.h> #define NUM_STRAINS 3 #define DEBUG void getNBDensities( double *hr, double *sp, double *odh, int *simCases, int *obsCases, double *runsum ); void getNBDensities( double *hr, double *sp, double *odh, int *simCases, int *obsCases, double *runsum ) { #ifdef DEBUG for ( int s = 0; s < NUM_STRAINS; s++ ) { Rprintf("\nFor strain %d",s); Rprintf("\n\tHospitalization rate = %lg", hr[s]); Rprintf("\n\tSimulation probability = %lg",sp[s]); Rprintf("\n\tSimulated cases = %d",simCases[s]); Rprintf("\n\tObserved cases = %d",obsCases[s]); Rprintf("\n\tOverdispersion parameter = %lg",odh[s]); } Rprintf("\nRunning sum = %lg",runsum[0]); #endif } naive solution While better (i.e., potentially faster or syntactically clearer) solutions may exist (see Dirk's answer below), the following simplification of the code works: out<-.C("getNBDensities", hr = as.double(hosp.rate), sp = as.double(samplingProbabilities), odh = as.double(odh), simCases = as.integer(x[c("xC1","xC2","xC3")]), obsCases = as.integer(y[c("yC1","yC2","yC3")]), runsum = as.double(runsum)) The variables can be accessed in >out.

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  • Trouble with abstract generic methods

    - by DanM
    Let's say I have a class library that defines a couple entity interfaces: public interface ISomeEntity { /* ... */ } public interface ISomeOtherEntity { /* ... */ } This library also defines an IRepository interface: public interface IRepository<TEntity> { /* ... */ } And finally, the library has an abstract class called RepositorySourceBase (see below), which the main project needs to implement. The goal of this class is to allow the base class to grab new Repository objects at runtime. Because certain repositories are needed (in this example a repository for ISomeEntity and ISomeOtherEntity), I'm trying to write generic overloads of the GetNew<TEntity>() method. The following implementation doesn't compile (the second GetNew() method gets flagged as "already defined" even though the where clause is different), but it gets at what I'm trying to accomplish: public abstract class RepositorySourceBase // This doesn't work! { public abstract Repository<TEntity> GetNew<TEntity>() where TEntity : SomeEntity; public abstract Repository<TEntity> GetNew<TEntity>() where TEntity : SomeOtherEntity; } The intended usage of this class would be something like this: public class RepositorySourceTester { public RepositorySourceTester(RepositorySourceBase repositorySource) { var someRepository = repositorySource.GetNew<ISomeEntity>(); var someOtherRepository = repositorySource.GetNew<ISomeOtherEntity>(); } } Meanwhile, over in my main project (which references the library project), I have implementations of ISomeEntity and ISomeOtherEntity: public class SomeEntity : ISomeEntity { /* ... */ } public class SomeOtherEntity : ISomeOtherEntity { /* ... */ } The main project also has an implementation for IRepository<TEntity>: public class Repository<TEntity> : IRepository<TEntity> { public Repository(string message) { } } And most importantly, it has an implementation of the abstract RepositorySourceBase: public class RepositorySource : RepositorySourceBase { public override Repository<SomeEntity> GetNew() { return new Repository<SomeEntity>("stuff only I know"); } public override Repository<SomeOtherEntity> GetNew() { return new Repository<SomeOtherEntity>("other stuff only I know"); } } Just as with RepositorySourceBase, the second GetNew() method gets flagged as "already defined". So, C# basically think I'm repeating the same method because there's no way to distinguish the methods from parameters, but if you look at my usage example, it seems like I should be able to distinguish which GetNew() I want from the generic type parameter, e.g, <ISomeEntity> or <ISomeOtherEntity>. What do I need to do to get this to work?

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  • Class Template Instantiation: any way round this circular reference?

    - by TimYorke34
    I have two classes that I'm using to represent some hardware: A Button and an InputPin class which represent a button that will change the value of an IC's input pin when it's pressed down. A simple example of them is: template <int pinNumber> class InputPin { static bool IsHigh() { return ( (*portAddress) & (1<<pinNumber) ); } }; template <typename InputPin> class Button { static bool IsPressed() { return !InputPin::IsHigh(); } }; This works beautifully and by using class templates, the condition below will compile as tightly as if I'd handwritten it in assembly (a single instruction). Button < InputPin<1> > powerButton; if (powerButton.IsPressed()) ........; However, I am extending it to deal with interrupts and have got a problem with circular references. Compared to the original InputPin, a new InputPinIRQ class has an extra static member function that will be called automatically by the hardware when the pin value changes. I'd like it to be able to notify the Button class of this, so that the Button class can then notify the main application that it has been pressed/released. I am currently doing this with function pointers to callbacks. In order for the callback code to be inlined by the compiler, I need to pass the function pointers as template parameters. So now, both of the new classes have an extra template parameter that is a pointer to a callback function. Unfortunately this gives me a circular reference because to instantiate a ButtonIRQ class I now have to do something like this: ButtonIRQ< InputPinIRQ< A1, ButtonIRQ<....>::OnPinChange, OnButtonChange > pB; where the <...... represents the circular reference. Does anyone know how I can avoid this circular reference? I am new to templates, so might be missing something really simple. It's important that the compiler knows exactly what code will be run when the interrupt occurs as it then does some very useful optimisation - it is able to inline the callback function and literally inserts the callback function's code at the exact address that is called on a h/w interrupt.

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  • What's the best way to handle modules that use each other?

    - by Axeman
    What's the best way to handle modules that use each other? Let's say I have a module which has functions for hashes: # Really::Useful::Functions::On::Hash.pm use base qw<Exporter>; use strict; use warnings; use Really::Useful::Functions::On::List qw<transform_list>; our @EXPORT_OK = qw<transform_hash transform_hash_as_list ...>; #... sub transform_hash { ... } #... sub transform_hash_as_list { return transform_list( %{ shift() } ); } #... 1 And another module has been segmented out for lists: # Really::Useful::Functions::On::List.pm use base qw<Exporter>; use strict; use warnings; use Really::Useful::Functions::On::Hash qw<transform_hash>; our @EXPORT_OK = qw<transform_list some_func ...>; #... sub transform_list { ... } #... sub some_func { my %params = transform_hash @_; #... } #... 1 Suppose that enough of these utility functions are handy enough that I'll want to use them in BEGIN statements and import functions to process parameter lists or configuration data. I have been putting sub definitions into BEGIN blocks to make sure they are ready to use whenever somebody includes the module. But I have gotten into hairy race conditions where a definition is not completed in a BEGIN block. I put evolving code idioms into modules so that I can reuse any idiom I find myself coding over and over again. For instance: sub list_if { my $condition = shift; return unless $condition; my $more_args = scalar @_; my $arg_list = @_ > 1 ? \@_ : @_ ? shift : $condition; if (( reftype( $arg_list ) || '' ) eq 'ARRAY' ) { return wantarray ? @$arg_list : $arg_list; } elsif ( $more_args ) { return $arg_list; } return; } captures two idioms that I'm kind of tired of typing: @{ func_I_hope_returns_a_listref() || [] } and ( $condition ? LIST : ()) The more I define functions in BEGIN blocks, the more likely I'll use these idiom bricks to express the logic the more likely that bricks are needed in BEGIN blocks. Do people have standard ways of dealing with this sort of language-idiom-brick model? I've been doing mostly Pure-Perl; will XS alleviate some of this?

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  • How to give properties to c++ classes (interfaces)

    - by caas
    Hello, I have built several classes (A, B, C...) which perform operations on the same BaseClass. Example: struct BaseClass { int method1(); int method2(); int method3(); } struct A { int methodA(BaseClass& bc) { return bc.method1(); } } struct B { int methodB(BaseClass& bc) { return bc.method2()+bc.method1(); } } struct C { int methodC(BaseClass& bc) { return bc.method3()+bc.method2(); } } But as you can see, each class A, B, C... only uses a subset of the available methods of the BaseClass and I'd like to split the BaseClass into several chunks such that it is clear what it used and what is not. For example a solution could be to use multiple inheritance: // A uses only method1() struct InterfaceA { virtual int method1() = 0; } struct A { int methodA(InterfaceA&); } // B uses method1() and method2() struct InterfaceB { virtual int method1() = 0; virtual int method2() = 0; } struct B { int methodB(InterfaceB&); } // C uses method2() and method3() struct InterfaceC { virtual int method2() = 0; virtual int method3() = 0; } struct C { int methodC(InterfaceC&); } The problem is that each time I add a new type of operation, I need to change the implementation of BaseClass. For example: // D uses method1() and method3() struct InterfaceD { virtual int method1() = 0; virtual int method3() = 0; } struct D { int methodD(InterfaceD&); } struct BaseClass : public A, B, C // here I need to add class D { ... } Do you know a clean way I can do this? Thanks for your help edit: I forgot to mention that it can also be done with templates. But I don't like this solution either because the required interface does not appear explicitly in the code. You have to try to compile the code to verify that all required methods are implemented correctly. Plus, it would require to instantiate different versions of the classes (one for each BaseClass type template parameter) and this is not always possible nor desired.

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  • Is it possible to create a throttle function that can take in as parameters another function (that also has parameters), and the time delay

    - by Stan Quinn
    So I've already written a function that works (based on underscores throttle) for functions that don't take in a parameter, but I'd like to make it generic enough to pass in a function with a variable number of parameters. Here's what I have: (function () { var lastTime = new Date().getTime(); function foo() { var newTime = new Date().getTime(); var gap = newTime - lastTime; // Travels up scope chain to use parents lastTime. Function has access to variables declared in the same scope console.log('foo called, gap:' + gap); lastTime = newTime; // Updates lastTime //console.log(x); //x++; } var throttle = function(func, wait) { var result; var timeout = null; // flag updated through closure var previous = 0; // time last run updated through closure return function() { //func, wait, timeout, previous available through scope var now = new Date().getTime(); var remaining = wait - (now - previous); if (remaining <= 0) { clearTimeout(timeout); timeout = null; previous = now; result = func.apply(this, arguments); //func is available through closure } return result; }; }; document.addEventListener("scroll", throttle(foo, 1000)); //document.addEventListener("scroll", throttle(foo(5), 2000)); }()); But I'd like to modify foo to foo(x) and get this to work (function () { var lastTime = new Date().getTime(); function foo(x) { var newTime = new Date().getTime(); var gap = newTime - lastTime; // Travels up scope chain to use parents lastTime. Function has access to variables declared in the same scope console.log('foo called, gap:' + gap); lastTime = newTime; // Updates lastTime console.log(x); x++; } var throttle = function(func, wait) { var result; var timeout = null; // flag updated through closure var previous = 0; // time last run updated through closure return function() { //func, wait, timeout, previous available through scope var now = new Date().getTime(); var remaining = wait - (now - previous); if (remaining <= 0) { clearTimeout(timeout); timeout = null; previous = now; result = func.apply(this, arguments); //func is available through closure } return result; }; }; document.addEventListener("scroll", throttle(foo(5), 2000)); }());

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  • How to use method hiding (new) with generic constrained class

    - by ongle
    I have a container class that has a generic parameter which is constrained to some base class. The type supplied to the generic is a sub of the base class constraint. The sub class uses method hiding (new) to change the behavior of a method from the base class (no, I can't make it virtual as it is not my code). My problem is that the 'new' methods do not get called, the compiler seems to consider the supplied type to be the base class, not the sub, as if I had upcast it to the base. Clearly I am misunderstanding something fundamental here. I thought that the generic where T: xxx was a constraint, not an upcast type. This sample code basically demonstrates what I'm talking about. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace GenericPartialTest { class ContextBase { public string GetValue() { return "I am Context Base: " + this.GetType().Name; } public string GetOtherValue() { return "I am Context Base: " + this.GetType().Name; } } partial class ContextSub : ContextBase { public new string GetValue() { return "I am Context Sub: " + this.GetType().Name; } } partial class ContextSub { public new string GetOtherValue() { return "I am Context Sub: " + this.GetType().Name; } } class Container<T> where T: ContextBase, new() { private T _context = new T(); public string GetValue() { return this._context.GetValue(); } public string GetOtherValue() { return this._context.GetOtherValue(); } } class Program { static void Main(string[] args) { Console.WriteLine("Simple"); ContextBase myBase = new ContextBase(); ContextSub mySub = new ContextSub(); Console.WriteLine(myBase.GetValue()); Console.WriteLine(myBase.GetOtherValue()); Console.WriteLine(mySub.GetValue()); Console.WriteLine(mySub.GetOtherValue()); Console.WriteLine("Generic Container"); Container<ContextBase> myContainerBase = new Container<ContextBase>(); Container<ContextSub> myContainerSub = new Container<ContextSub>(); Console.WriteLine(myContainerBase.GetValue()); Console.WriteLine(myContainerBase.GetOtherValue()); Console.WriteLine(myContainerSub.GetValue()); Console.WriteLine(myContainerSub.GetOtherValue()); Console.ReadKey(); } } }

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  • C# recursive programming with lists

    - by David Torrey
    I am working on a program where each item can hold an array of items (i'm making a menu, which has a tree-like structure) currently i have the items as a list, instead of an array, but I don't feel like I'm using it to its full potential to simplify code. I chose a list over a standard array because the interface (.add, .remove, etc...) makes a lot of sense. I have code to search through the structure and return the path of the name (i.e. Item.subitem.subsubitem.subsubsubitem). Below is my code: public class Item { //public Item[] subitem; <-- Array of Items public List<Item> subitem; // <-- List of Items public Color itemColor = Color.FromArgb(50,50,200); public Rectangle itemSize = new Rectangle(0,0,64,64); public Bitmap itemBitmap = null; public string itemName; public string LocateItem(string searchName) { string tItemName = null; //if the item name matches the search parameter, send it up) if (itemName == searchName) { return itemName; } if (subitem != null) { //spiral down a level foreach (Item tSearchItem in subitem) { tItemName = tSearchItem.LocateItem(searchName); if (tItemName != null) break; //exit for if item was found } } //do name logic (use index numbers) //if LocateItem of the subitems returned nothing and the current item is not a match, return null (not found) if (tItemName == null && itemName != searchName) { return null; } //if it's not the item being searched for and the search item was found, change the string and return it up if (tItemName != null && itemName != searchName) { tItemName.Insert(0, itemName + "."); //insert the parent name on the left --> TopItem.SubItem.SubSubItem.SubSubSubItem return tItemName; } //default not found return null; } } My question is if there is an easier way to do this with lists? I've been going back and forth in my head as to whether I should use lists or just an array. The only reason I have a list is so that I don't have to make code to resize the array each time I add or remove an item.

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  • AllowSetForegroundWindow & SetForegroundWindow: NPAPI plug-in wants to allow a desktop application with no success

    - by David Robert Jones
    Here it's what I have: a web browser plug-in written in C++ and a Windows application written in C#. They communicate through a named pipe. The plug-in instructs the C# application to open a file (suppose that the file is a .txt and it opens in Notepad). Once the C# application is given the command, it opens the file but Notepad doesn't show in the foreground, which isn't acceptable, I must open Notepad in the foreground. I modified the C# application so that it calls the SetForegroundWindow function. This time Notepad didn't open in the foreground, but the taskbar flashes. After reading the documentation for SetForegroundWindow and many articles I think that now I understand what the problem is: the C# application can't bring Notepad to the foreground because it wasn't the the foreground process, the browser was (?). After reading this: "A process that can set the foreground window can enable another process to set the foreground window by calling the AllowSetForegroundWindow function." I decided to modify the plug-in. This time the plug-in calls the AllowSetForegroundWindow function passing ASFW_ANY as a parameter (I know, ASFW_ANY could be risky, but I wanted to make sure that AllowSetForegroundWindow would do it). After I did the modification to the plug-in I tested it and it worked! (Opera 12.02). Then I tested it on Internet Explorer and it worked too. But the problem came when I tested it in Firefox and Chrome. The C# application didn't have the ability to bring Notepad to the foreground. I noticed that for those browsers the AllowSetForegroundWindow function was returning false. So I started investigating and I come to the conclusion that maybe it's because the plugin container that Firefox uses. An idea came to my mind: it worked in Opera 12.02, but they don't have a plugin container, although they did in Opera 12.00. So I downloaded Opera 12.00, I did the test and it failed, which makes me conclude that the plugin container is the culprit. The question is: how can I give to the C# application the ability to set foreground? I don't know how to continue, and I think that I tried all the legitimate ways. The AllowSetForegroundWindow & SetForegroundWindow seems to not apply here.

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  • Mysql select most frequent and sort alphabetically

    - by user2605793
    I am trying to select the most common 100 names from a table then display the list showing the names and count. I want the user to be able to re-sort the list alphabetically rather than based on count. I thought the following code would do it. It works for the default sort by count but fails on the sort alphabetically. The line "$count = mysql_num_rows($table);" gives an error: mysql_num_rows() expects parameter 1 to be resource, boolean given. Any help would be greatly appreciated. // Get most popular surnames echo '<h2>Most Common Surnames</h2>'; if ($sort == "") { // default sort by count echo '<a href="http://mysite/names.php?id='.$id.'&sort=name">Sort by name</a><br>'; $query = "SELECT family_name, COUNT(*) as count FROM namefile WHERE record_key = $id GROUP BY family_name ORDER BY count DESC LIMIT 100"; } else { // sort alphabetically echo '<a href="http://mysite/names.php?id='.$id.'">Sort by count</a><br>'; $query = "SELECT * FROM ( SELECT family_name, COUNT(*) as count FROM namefile WHERE record_key = $id GROUP BY family_name ORDER BY count DESC LIMIT 100) AS alpha ORDER BY family_name"; } $table = mysql_query($query); $count = mysql_num_rows($table); $tot = 0; $i = 0; echo '<table><tr>'; while ($tot < $count2) { $rec2 = mysql_fetch_array($table2); echo '<td>'.$rec2[0].'</td><td>'.$rec2[1].'</td><td width="40">&nbsp;</td><td>'; if ($i++ == 6) { echo '</tr><tr>'; $i = 0; } $tot++; } echo '</tr></table><br>'; UPDATE: I needed to add "AS alpha" to give the outer select a unique name. (alpha is just a random name I made up.) It now works perfectly. Code updated for the benefit of any others who need something similar.

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  • Passing values between pages in JavaScript

    - by buni
    using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Data.SqlClient; using System.Configuration; using System.Text; using System.Web.Services; using System.IO; namespace T_Smade { public partial class ConferenceManagement : System.Web.UI.Page { volatile int i = 0; protected void Page_Load(object sender, EventArgs e) { GetSessionList(); } public void GetSessionList() { string secondResult = ""; string userName = ""; try { if (HttpContext.Current.User.Identity.IsAuthenticated) { userName = HttpContext.Current.User.Identity.Name; } SqlConnection thisConnection = new SqlConnection(@"data Source=ZOLA-PC;AttachDbFilename=D:\2\5.Devp\my DB\ASPNETDB.MDF;Integrated Security=True"); thisConnection.Open(); SqlCommand secondCommand = thisConnection.CreateCommand(); secondCommand.CommandText = "SELECT myApp_Session.session_id FROM myApp_Session, myApp_Role_in_Session where myApp_Role_in_Session.user_name='" + userName + "' and myApp_Role_in_Session.session_id=myApp_Session.session_id"; SqlDataReader secondReader = secondCommand.ExecuteReader(); while (secondReader.Read()) { secondResult = secondResult + secondReader["session_id"].ToString() + ";"; } secondReader.Close(); SqlCommand thisCommand = thisConnection.CreateCommand(); thisCommand.CommandText = "SELECT * FROM myApp_Session;"; SqlDataReader thisReader = thisCommand.ExecuteReader(); while (thisReader.Read()) { test.Controls.Add(GetLabel(thisReader["session_id"].ToString(), thisReader["session_name"].ToString())); string[] compare = secondResult.Split(';'); foreach (string word in compare) { if (word == thisReader["session_id"].ToString()) { test.Controls.Add(GetButton(thisReader["session_name"].ToString(), "Join Session")); } } } thisReader.Close(); thisConnection.Close(); } catch (SqlException ex) { } } private Button GetButton(string id, string name) { Button b = new Button(); b.Text = name; b.ID = "Button_" + id + i; b.Command += new CommandEventHandler(Button_Click); b.CommandArgument = id; i++; return b; } private Label GetLabel(string id, string name) { Label tb = new Label(); tb.Text = name; tb.ID = id; return tb; } protected void Button_Click(object sender, CommandEventArgs e) { Response.Redirect("EnterSession.aspx?session=" + e.CommandArgument.ToString()); } } I have this code when a user clicks a button www.mypage/EnterSession.aspx?session=session_name in the EnterSession.aspx i have used the code below to track the current URL _gaq.push(['pageTrackerTime._trackEvent', 'Category', 'Action', document.location.href, roundleaveSiteEnd]); Now I would also like to track in the Action parameter the session_name from the previous page.see the code below from the previous page test.Controls.Add(GetButton(thisReader["session_name"].ToString(), "Join Session")); Some idea how to do it? Thanx

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  • Constructors from extended class in Java

    - by Crystal
    I'm having some trouble with a hw assignment. In one assignment, we had to create a Person class. Mine was: public class Person { String firstName; String lastName; String telephone; String email; public Person() { firstName = ""; lastName = ""; telephone = ""; email = ""; } public Person(String firstName) { this.firstName = firstName; } public Person(String firstName, String lastName, String telephone, String email) { this.firstName = firstName; this.lastName = lastName; this.telephone = telephone; this.email = email; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public String getTelephone() { return telephone; } public void setTelephone(String telephone) { this.telephone = telephone; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public boolean equals(Object otherObject) { // a quick test to see if the objects are identical if (this == otherObject) { return true; } // must return false if the explicit parameter is null if (otherObject == null) { return false; } if (!(otherObject instanceof Person)) { return false; } Person other = (Person) otherObject; return firstName.equals(other.firstName) && lastName.equals(other.lastName) && telephone.equals(other.telephone) && email.equals(other.email); } public int hashCode() { return 7 * firstName.hashCode() + 11 * lastName.hashCode() + 13 * telephone.hashCode() + 15 * email.hashCode(); } public String toString() { return getClass().getName() + "[firstName = " + firstName + '\n' + "lastName = " + lastName + '\n' + "telephone = " + telephone + '\n' + "email = " + email + "]"; } } Now we have to extend that class and use that class in our constructor. The function protoype is: public CarLoan(Person client, double vehiclePrice, double downPayment, double salesTax, double interestRate, CAR_LOAN_TERMS length) I'm confused on how I use the Person constructor from the superclass. I cannot necessarily do super(client); in my constructor which is what the book did with some primitive types in their example. Not sure what the correct thing to do is... Any thoughts? Thanks!

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  • XNA 4.0 draw a cube with DrawUserIndexedPrimitives method [on hold]

    - by Leggy7
    EDIT Since I read what Mark H suggested (thanks a lot, I found it very useful) I think my question can become clearer structured this way: Using XNA 4.0, I'm trying to draw a cube. Im using this method: GraphicsDevice.DrawUserIndexedPrimitives<VertexPositionColor>( PrimitiveType.LineList, primitiveList, 0, // vertex buffer offset to add to each element of the index buffer 8, // number of vertices in pointList lineListIndices, // the index buffer 0, // first index element to read 7 // number of primitives to draw ); I got the code sample from this page which simply draw a serie of triangles. I want to modify this code in order to draw a cube. I was able to slitghly move the camera so I can have the perception of solidity, I set the vertex array to contain the 8 points defining a cube. But I can't fully understand how many primitives I have to draw (last parameter) for each of PrimitiveType. So, I wasn't able to draw the cube (just some of the edges in a non-defined order). More in detail: to build the vertex index list, the sample used // Initialize an array of indices of type short. lineListIndices = new short[(points * 2) - 2]; // Populate the array with references to indices in the vertex buffer for (int i = 0; i < points - 1; i++) { lineListIndices[i * 2] = (short)(i); lineListIndices[(i * 2) + 1] = (short)(i + 1); } I'm ashamed to say I cannot do the same in the case of a cube. what has to be the size of the lineListIndices? how should I populate it? In which order? And how do these things change when I use a different PrimitiveType? In the code sample there are also another couple of calls which I cannot fully understand, which are: // Initialize the vertex buffer, allocating memory for each vertex. vertexBuffer = new VertexBuffer(graphics.GraphicsDevice, vertexDeclaration, points, BufferUsage.None); // Set the vertex buffer data to the array of vertices. vertexBuffer.SetData<VertexPositionColor>(pointList); and vertexDeclaration = new VertexDeclaration(new VertexElement[] { new VertexElement(0, VertexElementFormat.Vector3, VertexElementUsage.Position, 0), new VertexElement(12, VertexElementFormat.Color, VertexElementUsage.Color, 0) } ); that is, for VertexBuffer and VertexDeclaration I could not find and significant (monkey-like) guide. I reported them too because I think they could be involded in understanding things. I think I also have to understand something related to the order the vertexes are stored in the array. But actually I have no clue of what I should learn to have this function drawing a cube. So, if anybody could point me to the right direction, it wil be appreciated. Hope to have made myself clear this time

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  • Passing a panel widget to a function

    - by user2939801
    I have written a quite complex script which calls a server handler to refresh elements in a grid at the press of a button. For code re-use and consistent behaviour, I am wanting to call that server handler directly during the initial painting of the grid. When the server handler gets called by clicking on the button, all expected widgets are available and can be queried with e.parameter.widget etc. When I call the function directly and pass it the panel variable, the value of e is just 'AbsolutePanel'. Is there some way I can emulate the addCallbackElement way of passing the entire panel and all widgets it contains to the function? Or a way of automatically firing a server handler on script start? Please forgive any syntax errors below, I have pruned 500 lines of code down to the pertinent bits! Thanks Tony function doGet() { var app = UiApp.createApplication(); var mainPanel = app.createAbsolutePanel(); var monthsAbbr = ['Jan.', 'Feb.', 'Mar.', 'Apr.', 'May.', 'Jun.', 'Jul.', 'Aug.', 'Sep.', 'Oct.', 'Nov.', 'Dec.']; var Dates = Array(); var period = 5; var dateHidden = Array(); var dayOfMonth = new Date(((period * 28) + 15887) * 86400000); var dateString = ''; var dayOfWeek = 0; for (var i=0; i<84; i++) { dateString = dayOfMonth.getDate() + ' ' + monthsAbbr[dayOfMonth.getMonth()] + ' ' + (dayOfMonth.getFullYear() - 2000); Dates [i] = dateString; dateHidden[i] = app.createHidden('dates'+i, dateString).setId('dates'+i); mainPanel.add(dateHidden[i]); dayOfMonth = new Date(dayOfMonth.getTime() + 86400000); } var buttonReset = app.createButton('Reset').setId('buttonReset'); var handlerChange = app.createServerHandler('myHandlerChange'); handlerChange.addCallbackElement(mainPanel); mainPanel.add(buttonReset.addChangeHandler(handlerChange)); app.add(mainPanel); myHandlerChange(mainPanel); return app; } function myHandlerChange(e) { var app = UiApp.getActiveApplication(); Logger.log('Here are the widgets passed into the function: ' + Utilities.jsonStringify(e)); return app; }

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  • ASP.NET MVC Paging/Sorting/Filtering a list using ModelMetadata

    - by rajbk
    This post looks at how to control paging, sorting and filtering when displaying a list of data by specifying attributes in your Model using the ASP.NET MVC framework and the excellent MVCContrib library. It also shows how to hide/show columns and control the formatting of data using attributes.  This uses the Northwind database. A sample project is attached at the end of this post. Let’s start by looking at a class called ProductViewModel. The properties in the class are decorated with attributes. The OrderBy attribute tells the system that the Model can be sorted using that property. The SearchFilter attribute tells the system that filtering is allowed on that property. Filtering type is set by the  FilterType enum which currently supports Equals and Contains. The ScaffoldColumn property specifies if a column is hidden or not The DisplayFormat specifies how the data is formatted. public class ProductViewModel { [OrderBy(IsDefault = true)] [ScaffoldColumn(false)] public int? ProductID { get; set; }   [SearchFilter(FilterType.Contains)] [OrderBy] [DisplayName("Product Name")] public string ProductName { get; set; }   [OrderBy] [DisplayName("Unit Price")] [DisplayFormat(DataFormatString = "{0:c}")] public System.Nullable<decimal> UnitPrice { get; set; }   [DisplayName("Category Name")] public string CategoryName { get; set; }   [SearchFilter] [ScaffoldColumn(false)] public int? CategoryID { get; set; }   [SearchFilter] [ScaffoldColumn(false)] public int? SupplierID { get; set; }   [OrderBy] public bool Discontinued { get; set; } } Before we explore the code further, lets look at the UI.  The UI has a section for filtering the data. The column headers with links are sortable. Paging is also supported with the help of a pager row. The pager is rendered using the MVCContrib Pager component. The data is displayed using a customized version of the MVCContrib Grid component. The customization was done in order for the Grid to be aware of the attributes mentioned above. Now, let’s look at what happens when we perform actions on this page. The diagram below shows the process: The form on the page has its method set to “GET” therefore we see all the parameters in the query string. The query string is shown in blue above. This query gets routed to an action called Index with parameters of type ProductViewModel and PageSortOptions. The parameters in the query string get mapped to the input parameters using model binding. The ProductView object created has the information needed to filter data while the PageAndSorting object is used for paging and sorting the data. The last block in the figure above shows how the filtered and paged list is created. We receive a product list from our product repository (which is of type IQueryable) and first filter it by calliing the AsFiltered extension method passing in the productFilters object and then call the AsPagination extension method passing in the pageSort object. The AsFiltered extension method looks at the type of the filter instance passed in. It skips properties in the instance that do not have the SearchFilter attribute. For properties that have the SearchFilter attribute, it adds filter expression trees to filter against the IQueryable data. The AsPagination extension method looks at the type of the IQueryable and ensures that the column being sorted on has the OrderBy attribute. If it does not find one, it looks for the default sort field [OrderBy(IsDefault = true)]. It is required that at least one attribute in your model has the [OrderBy(IsDefault = true)]. This because a person could be performing paging without specifying an order by column. As you may recall the LINQ Skip method now requires that you call an OrderBy method before it. Therefore we need a default order by column to perform paging. The extension method adds a order expressoin tree to the IQueryable and calls the MVCContrib AsPagination extension method to page the data. Implementation Notes Auto Postback The search filter region auto performs a get request anytime the dropdown selection is changed. This is implemented using the following jQuery snippet $(document).ready(function () { $("#productSearch").change(function () { this.submit(); }); }); Strongly Typed View The code used in the Action method is shown below: public ActionResult Index(ProductViewModel productFilters, PageSortOptions pageSortOptions) { var productPagedList = productRepository.GetProductsProjected().AsFiltered(productFilters).AsPagination(pageSortOptions);   var productViewFilterContainer = new ProductViewFilterContainer(); productViewFilterContainer.Fill(productFilters.CategoryID, productFilters.SupplierID, productFilters.ProductName);   var gridSortOptions = new GridSortOptions { Column = pageSortOptions.Column, Direction = pageSortOptions.Direction };   var productListContainer = new ProductListContainerModel { ProductPagedList = productPagedList, ProductViewFilterContainer = productViewFilterContainer, GridSortOptions = gridSortOptions };   return View(productListContainer); } As you see above, the object that is returned to the view is of type ProductListContainerModel. This contains all the information need for the view to render the Search filter section (including dropdowns),  the Html.Pager (MVCContrib) and the Html.Grid (from MVCContrib). It also stores the state of the search filters so that they can recreate themselves when the page reloads (Viewstate, I miss you! :0)  The class diagram for the container class is shown below.   Custom MVCContrib Grid The MVCContrib grid default behavior was overridden so that it would auto generate the columns and format the columns based on the metadata and also make it aware of our custom attributes (see MetaDataGridModel in the sample code). The Grid ensures that the ShowForDisplay on the column is set to true This can also be set by the ScaffoldColumn attribute ref: http://bradwilson.typepad.com/blog/2009/10/aspnet-mvc-2-templates-part-2-modelmetadata.html) Column headers are set using the DisplayName attribute Column sorting is set using the OrderBy attribute. The data is formatted using the DisplayFormat attribute. Generic Extension methods for Sorting and Filtering The extension method AsFiltered takes in an IQueryable<T> and uses expression trees to query against the IQueryable data. The query is constructed using the Model metadata and the properties of the T filter (productFilters in our case). Properties in the Model that do not have the SearchFilter attribute are skipped when creating the filter expression tree.  It returns an IQueryable<T>. The extension method AsPagination takes in an IQuerable<T> and first ensures that the column being sorted on has the OrderBy attribute. If not, we look for the default OrderBy column ([OrderBy(IsDefault = true)]). We then build an expression tree to sort on this column. We finally hand off the call to the MVCContrib AsPagination which returns an IPagination<T>. This type as you can see in the class diagram above is passed to the view and used by the MVCContrib Grid and Pager components. Custom Provider To get the system to recognize our custom attributes, we create our MetadataProvider as mentioned in this article (http://bradwilson.typepad.com/blog/2010/01/why-you-dont-need-modelmetadataattributes.html) protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName) { ModelMetadata metadata = base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);   SearchFilterAttribute searchFilterAttribute = attributes.OfType<SearchFilterAttribute>().FirstOrDefault(); if (searchFilterAttribute != null) { metadata.AdditionalValues.Add(Globals.SearchFilterAttributeKey, searchFilterAttribute); }   OrderByAttribute orderByAttribute = attributes.OfType<OrderByAttribute>().FirstOrDefault(); if (orderByAttribute != null) { metadata.AdditionalValues.Add(Globals.OrderByAttributeKey, orderByAttribute); }   return metadata; } We register our MetadataProvider in Global.asax.cs. protected void Application_Start() { AreaRegistration.RegisterAllAreas();   RegisterRoutes(RouteTable.Routes);   ModelMetadataProviders.Current = new MvcFlan.QueryModelMetaDataProvider(); } Bugs, Comments and Suggestions are welcome! You can download the sample code below. This code is purely experimental. Use at your own risk. Download Sample Code (VS 2010 RTM) MVCNorthwindSales.zip

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  • CodePlex Daily Summary for Sunday, February 28, 2010

    CodePlex Daily Summary for Sunday, February 28, 2010New ProjectsESB Toolkit Extensions: ESB Extensions is a solution containing multiple .Net Projects and artifacts: Unit Tests, Itineraries, Business Rules, Binding Files, and C# Class ...Event-Based Components Binder: The Binder automatically connects output-pins to input-pins of Event-Based Components based on message type information and naming conventions. ...Haze Anti-Virus: Haze Anti-Virus is a anti virus written in C# and has features such a realtime process watching and a Process Blacklist, and is able to download Da...latex2mathml: A .NET 2.0 library written in C# which allows the conversion of LaTeX documents to XHTML+MathML format. A stand-alone converter is included. The li...Project Lyrebird: Project lyrebird is a attempt to create a all-purpose media player. It is designed to be simple, yet powerful. Its written in C#QueryToGrid Module for DotNetNuke®: This is a module that allows you to execute and display the results of T-SQL queries in DotNetNuke using your choice of AJAX grids.Reusable Library Demo: A demonstration of reusable abstractions for enterprise application developerSharePoint 2010 Conference Samples: This project contains source code from various SharePoint 2010 conferences where Scot Hillier presented.Silverlight Photo Blogger: Silverlight Photo Blogger gives you the tools you need to capture and blog about your travels in a rich and interactive web experience. Enjoy som...SMTP Test: Several times we are faced with applications that send email, the SMTP Tester principle objective is to test various possibilities of sendingSolution Tools - tools for Visual Studio solutions and projects: Solution Tools are a collection of tools that you can use with your Visual Studio Solutions and projects.New ReleasesAgile Poker Cards for Windows Mobile: Agile Poker Cards v1.1.0.0: Agile Poker Cards v1.1.0.0 Use this application to display poker cards in a planning session on a Windows Mobile device. Release notes Added new ...BuildTools - Toolset for automated builds: BuildTools 2.0 Feb 2010 Milestone: The Feb 2010 Milestone release is a complete rewrite of the old codebase in Visual Studio 2010 RC. It features MSBuild tasks for generating build v...Composure: NHibernate-Trunk-2010-02-25-VS2010.NET4 Alpha1: Recent NHibernate-Trunk conversion for Visual Studio 2010 Beta2 against .NET 4.0. Although all of the tests pass (other than the "Ignored"), this ...Employee Scheduler: Employee Scheduler 2.4: Extract the files to a directory and run Lab Hours.exe. Add an employee. Double click an employee to modify their times. Please contact me through ...ESB Toolkit Extensions: Tellago BizTalk ESB 2.0 Toolkit Extensions: Windows Installer file that installs Library on a BizTalk ESB 2.0 system. This Install automatically configures the esb.config to use the new compo...Haze Anti-Virus: Haze Anti-Virus Binary v1.0.3: This is the Compiled version of Haze Anti-Virus, please let me know about any bugs, thanks Please Note that Database updating is currently not avai...Haze Anti-Virus: Haze Anti-Virus Source v1.0.3: This is the source for Haze Anti-VirusHOG Project: HOG Visual Studio Template: This is Visual Studio HOG Template. Created by the great tool: Solution FactoryHOG Project: Template user guide: HOW TOiTuner - The iTunes Companion: iTuner 1.1.3711: Two new features are available: the Automated Librarian and Playlist Exporter. The iTuner Automated Librarian automatically cleans the iTunes libr...johanleino.codeplex.com: SilverlightMultiLevelNavigationExample: The source code for SilverlightMultiLevelNavigationExample (VS 2010)MDownloader: MDownloader-0.15.3.56128: Fixed filefactory provider implementation after site changes.MiniTwitter: 1.09: MiniTwitter 1.09 更新内容 変更 スクロール位置がトップ以外の時は自動更新や発言時に位置を保持するように変更 タブ毎にスクロール位置が変わらないように変更 URL に ? や ! が含まれている時は短縮 URL に変換するように変更NMock3: NMock3 - Beta 4, .NET 3.5: This release includes the most current version of the NMock2 project code from Source Forge. Please start providing feedback on the tutorials. The...QueryUnit: QueryUnitPOC v. 0.0.0.7: - This version fixes problems related to the fact that in previous releases you had to specify expected values using locale-specific formats. Now e...RapidWebDev - .NET Enterprise Software Development Infrastructure: RapidWebDev 1.51: This is a hot-fix version for 1.5 which is added a new restful web service for concrete data and fixed some major bugs. The change list is as follo...Rawr: Rawr 2.3.11: - Load from Armory code cleaned up. - Tiny Abomination in a Jar's proc how now been more accurately modeled. - You should now be able to reload...Resharper Settings Manager: RSM v1.2: Changes Added Default Settings File option. The selected settings file will be loaded automatically for solutions with no settings sharing. Added...Reusable Library Demo: Reusable Library Demo v1.0.0: A demonstration of reusable abstractions for enterprise application developerRounded Corners / DIV Container: MJC RoundedDiv 3.2: This is the first public release on Codeplex.com. Versions previous to 3.2 were created before this control was made available on Codeplex.com.SharePoint 2010 Conference Samples: Samples: Download the samples from the conferencesSharePoint Outlook Connector: Version 1.2.2.8: Saving email message as list item and attachments as attachment of the list item functionality has been addedSharePoint URL Ping Tool: Url Ping Tool Solution: A solution that contain one fram fature that will add a link under Site Administration section in the Site Settings page.SMTP Test: Fist SMTP Tester: First ReleaseSolution Tools - tools for Visual Studio solutions and projects: SolutionTools binary: Initial release of the tool. Turns out, this project was just a big waste of effort - use Project Linker instead!Solution Tools - tools for Visual Studio solutions and projects: SolutionTools source - don't use this tool: Initial release of the tool. Turns out, this project was just a big waste of effort - use Project Linker instead! Anyway, here's the source code...Spark View Engine: Spark v1.1 RC1: Overview This build is a preview of v1.1. Among other changes it provides support for ASP.NET MVC 2 RC2. Spark v1.1 release will be created soon ...Sprite Sheet Packer: 2.0 Release: I'm calling this a full new release because I can. Refactored all of the build logic to sspack.exe. This allows you to run this from the command l...SPSF SharePoint Software Factory: SPSF SharePoint Software Factory 2.4.3: New features: WSPBuilder support, Simple Application now with optional multilanguage support, Extending deployment skript for large deployments Fix...TortoiseHg: Beta for TortoiseHg 1.0 (0.9.31201): Beta for TortoiseHg 1.0 (0.9.31201) Please backup your user Mercurial.ini file and then uninstall any 0.9.X release before installing Use the x86...UI Compiler .NET - JavaScript compiler/minifier built on Google Closure Compiler: UI Compiler .NET 1.5 Beta: UI Compiler .NET does not include Java. To be able to run Google Closure Compiler locally you must make sure that Java 6 is installed. If Java 6 (o...VCC: Latest build, v2.1.30227.0: Automatic drop of latest buildVisual Studio DSite: File Encryption and Decryption (Visual Basic 2008): This program will create an encrypted copy of the file specified. Also decrypt the file specified. This program contains the source code but if yo...Visual Studio DSite: Visual C++ 2008 CLR Console Application Random Int: This source code includes an example of generating a random integer between the numbers 1-100.Weather Forecast Control: MJC MyWeather 2.2: This is the first public release on Codeplex.com. Versions previous to 2.2 were created before this control was made available on Codeplex.com.Most Popular ProjectsRawrWBFS ManagerAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)Microsoft SQL Server Community & SamplesASP.NETDotNetNuke® Community EditionBlogEngine.NETMost Active ProjectsDinnerNow.netRawrBlogEngine.NETMapWindow GISSLARToolkit - Silverlight Augmented Reality ToolkitCommon Context Adapterspatterns & practices – Enterprise LibrarySharpMap - Geospatial Application Framework for the CLRNB_Store - Free DotNetNuke Ecommerce Catalog ModuleRapid Entity Framework. (ORM). CTP 2

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