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  • Sort MySQL query result by a alphanumeric field

    - by Jason Shultz
    I'm querying a table in a db using php. one of the fields is a column called "rank" and has data like the following: none 1-bronze 2-silver 3-gold ... 10-ambassador 11-president I want to be able to sort the results based on that "rank" column. any results where the field is "none" get excluded, so those don't factor in. As you can already guess, right now the results are coming back like this: 1-bronze 10-ambassador 11-president 2-silver 3-gold Of course, I would like for it to be sorted so it is like the following: 1-bronze 2-silver 3-gold ... 10-ambassador 11-president Right now the query is being returned as an object. I've tried different sort options like natsort, sort, array_multisort but haven't got it to work the way I'm sure it can. I would prefer keeping the results in an object form if possible. I'm passing the data on to a view in the next step. although, it's perfectly acceptable to pass the object to the view and then do the work there. so it's not an issue after all. :) thank you for your help. i'm hoping I'm making sense.

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  • SLRequest return nil before block complete

    - by jaytr0n
    I'm having a little trouble thinking through this and deciding if it's a design flaw on my behalf or if I'm missing a piece that could make this work. Basically I'm using the new SLRequest to make a Twitter API call. After the data is returned, I'd like to put it into an object and return that object: -(AUDSlide *) getFollowerSlide { SLRequest *getRequest = [SLRequest requestForServiceType:SLServiceTypeTwitter requestMethod:SLRequestMethodGET URL:[NSURL URLWithString:[NSString stringWithFormat:@"https://api.twitter.com/1.1/followers/ids.json?user_id=%@", [[self.twitterAccount valueForKey:@"properties"] valueForKey:@"user_id"]]] parameters:nil]; getRequest.account = twitterAccount; AUDSlide *slide = [[AUDSlide alloc] init]; [getRequest performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) { if ([urlResponse statusCode] == 200) { NSError *jsonError = nil; NSDictionary *list = [NSJSONSerialization JSONObjectWithData:responseData options:0 error:&jsonError]; NSLog(@"Number of Followers: %u", [[list objectForKey:@"ids"] count]); slide.title = @"Followers"; slide.number = [NSString stringWithFormat:@"%u",[[list objectForKey:@"ids"] count]]; } else{ slide.title = @"Error"; slide.number = [NSString stringWithFormat: @"E%u", [urlResponse statusCode]]; } }]; return slide; } Of course the slide is returned before the call is complete and returns a nil object. So I'm not sure if I should try to force this into a synchronous request (that seems like it could be a bad idea) or rethink the design. Does anyone have any advice?

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  • Share variable across site ASP.NET

    - by Anders
    I have a class isSearching with a single boolean property in a 'functions' file in my webapp. On my search page, I have a variable oSearchHandler declared as a Public Shared variable. How can I access the contents of oSearchHandler on other pages in my webapp? Code with Session.... 'search.aspx Public Function oSearchString(ByVal oTextBoxName As String) As String For Each oKey As String In Request.Form.AllKeys If oKey.Contains(oTextBoxName) Then Session.Add("searching", True) Session.Add("search-term", Request.Form(oKey)) Return Request.Form(oKey) End If Next Return "" End Function 'theMaster.master <% If Session("searching") Then %><ul style="float: right;"> <li> <div class="gsSearch"> <asp:TextBox ID="searchbox" runat="server"></asp:TextBox> </div> </li> <li> <div class="gsSearch"> <asp:Button ID="searchbutton" runat="server" Text="search" UseSubmitBehavior="true" PostBackUrl="search.aspx" CssClass="searchBtn" /> </div> </li> </ul> <% End If %> I think that the session will work just fine.

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  • Virtual functions - base class pointer

    - by user980411
    I understood why a base class pointer is made to point to a derived class object. But, I fail to understand why we need to assign to it, a base class object, when it is a base class object by itself. Can anyone please explain that? #include <iostream> using namespace std; class base { public: virtual void vfunc() { cout << "This is base's vfunc().\n"; } }; class derived1 : public base { public: void vfunc() { cout << "This is derived1's vfunc().\n"; } }; int main() { base *p, b; derived1 d1; // point to base p = &b; p->vfunc(); // access base's vfunc() // point to derived1 p = &d1; p->vfunc(); // access derived1's vfunc() return 0; }

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  • How to add a checkbox for each row in Rails 3.2 index page?

    - by user938363
    We would like to add a checkbox to each row on Rails index page to flag for the row. This checkbox is not part of the object (no checkbox boolean in database). When the index page shows, a user can check the box to trigger an event for the row in following process: #objects/checkbox_index.html.erb <table> <tr> <th>CheckBox</th> <th>Object Name</th> <th>Object ID</th> </tr> <%= @objects.each do |obj| %> <tr> <td><%= checkbox %></td> <td><%= obj.name %></td> <td><%= obj.id %></td> </tr> <% end %> </table> In controller, the process will be like this: @objects.each do |obj| some_event if obj.checked end There are a couple of questions we don't quite understand: 1. How to declare an array checkbox variable on the form and link it to each row of obj? We have been using `attr_accessor` to declare var for a form. 2. How to retrieve each row on checkbox_index form and pass them back to controller? We are using simple_form for new/edit. Can anyone point me towards any good examples of this sort of behavior, or suggest what we should be thinking about? Many Thanks.

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  • Minimal framework in Scala for collections with inheriting return type

    - by Rex Kerr
    Suppose one wants to build a novel generic class, Novel[A]. This class will contain lots of useful methods--perhaps it is a type of collection--and therefore you want to subclass it. But you want the methods to return the type of the subclass, not the original type. In Scala 2.8, what is the minimal amount of work one has to do so that methods of that class will return the relevant subclass, not the original? For example, class Novel[A] /* What goes here? */ { /* Must you have stuff here? */ def reverse/* What goes here instead of :Novel[A]? */ = //... def revrev/*?*/ = reverse.reverse } class ShortStory[A] extends Novel[A] /* What goes here? */ { override def reverse: /*?*/ = //... } val ss = new ShortStory[String] val ss2 = ss.revrev // Type had better be ShortStory[String], not Novel[String] Does this minimal amount change if you want Novel to be covariant? (The 2.8 collections do this among other things, but they also play with return types in more fancy (and useful) ways--the question is how little framework one can get away with if one only wants this subtypes-always-return-subtypes feature.)

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  • Best way to store data in database when you don't know the type

    - by stiank81
    I have a table in my database that represents datafields in a custom form. The DataField gives some representation of what kind of control it should be represented with, and what value type it should take. Simplified you can say that I have 2 entities in this table - Textbox taking any string and Textbox only taking numbers. Now I have the different values stored in a separate table, referencing the datafield definition. What is the best way to store the data value here, when the type differs? One possible solution is to have the FieldValue table hold one field per possible value type. Now this would certainly be redundant, but at least I would get the value stored in its correct form - simplifying queries later. FieldValue ---------- Id DataFieldId IntValue DoubleValue BoolValue DataValue .. Another possibility is just storing everything as String, and casting this in the queries. I am using .Net with NHibernate, and I see that at least here there is a Projections.Cast that can be used to cast e.g. string to int in the query. Either way in these two solutions I need to know which type to use when doing the query, but I will know that from the DataField, so that won't be a problem. Anyway; I don't think any of these solutions sounds good. Are they? Or is there a better way?

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  • ASP.NET 'Check all checkboxes' control

    - by RUiHAO
    I am using visual studio 2005 c#, and doing server side coding. I have a list of checkboxes in my gridview via checkbox template. I have tried to assign a checkbox in my header template, and assigned a checkbox_checkchange method to make it such that when the checkbox at the header is checked, the list of checkboxes in the template will be checked as well. However, it does not work and I am not able to spot the mistake. Below is my code for my checkbox in header template: protected void CheckAllCB_CheckedChanged(object sender, EventArgs e) { CheckBox chk = (CheckBox)GridView1.HeaderRow.FindControl("CheckAll"); if (chk.Checked) { for (int i = 0; i < GridView1.Rows.Count; i++) { CheckBox chkrow = (CheckBox)GridView1.Rows[i].FindControl("UserSelector"); chkrow.Checked = true; } } else { for (int i = 0; i < GridView1.Rows.Count; i++) { CheckBox chkrow = (CheckBox)GridView1.Rows[i].FindControl("UserSelector"); chkrow.Checked = false; } } } Thus I tried using a button to assign the checkall command instead. However, when I clicked on the button, the page does nothing but just refreshes itself. Below is my code for the checkall and uncheckall button: private void ToggleCheckState(bool checkState) { // Iterate through the Products.Rows property foreach (GridViewRow row in GridView1.Rows) { // Access the CheckBox CheckBox cb = (CheckBox)row.FindControl("UserSelector"); if (cb != null) cb.Checked = checkState; } } protected void CheckAll_Click(object sender, EventArgs e) { ToggleCheckState(true); } protected void UncheckAll_Click(object sender, EventArgs e) { ToggleCheckState(false); } Anyone can help me identify the mistake I did in my method? Thank you UserSelection GridView template:

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  • Casting error in my form

    - by Siva
    I have a ComboBox in a DataGridView. However I get an error when I run it: Unable to cast object of type 'System.Windows.Forms.DataGridView' to type 'System.Windows.Forms.ComboBox'. What can I do to resolve this error? ComboBox comboBox; private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e) { if (e.Control is ComboBox) { comboBox = e.Control as ComboBox; if (dataGridView1.CurrentCell.ColumnIndex >= 0) { System.Diagnostics.Debug.WriteLine("Edit Control Showing"); comboBox.SelectedIndexChanged -= new EventHandler(comboBoxItems_SelectedIndexChanged); comboBox.SelectedIndexChanged += new EventHandler(comboBoxItems_SelectedIndexChanged); } } } void comboBoxItems_SelectedIndexChanged(object sender, EventArgs e) { try { int comboBoxSelectedIndex = ((ComboBox)sender).SelectedIndex; string comboboxSelectedValue = ((ComboBox)sender).SelectedText; int gridViewSelectedRow = dataGridView1.CurrentRow.Index; if (comboBoxSelectedIndex >= 0 && gridViewSelectedRow >= 0) { System.Diagnostics.Debug.WriteLine("ComboBox Index - " + comboBoxSelectedIndex); System.Diagnostics.Debug.WriteLine("GridView Index - " + gridViewSelectedRow); if (comboBox != null) { comboBox.SelectedIndexChanged -= new EventHandler(comboBoxItems_SelectedIndexChanged); } } } catch(Exception E) { } }

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  • c# How to implement a collection of generics

    - by Amy
    I have a worker class that does stuff with a collection of objects. I need each of those objects to have two properties, one has an unknown type and one has to be a number. I wanted to use an interface so that I could have multiple item classes that allowed for other properties but were forced to have the PropA and PropB that the worker class requires. This is the code I have so far, which seemed to be OK until I tried to use it. A list of MyItem is not allowed to be passed as a list of IItem even though MyItem implements IItem. This is where I got confused. Also, if possible, it would be great if when instantiating the worker class I don't need to pass in the T, instead it would know what T is based on the type of PropA. Can someone help get me sorted out? Thanks! public interface IItem<T> { T PropA { get; set; } decimal PropB { get; set; } } public class MyItem : IItem<string> { public string PropA { get; set; } public decimal PropB { get; set; } } public class WorkerClass<T> { private List<T> _list; public WorkerClass(IEnumerable<IItem<T>> items) { doStuff(items); } public T ReturnAnItem() { return _list[0]; } private void doStuff(IEnumerable<IItem<T>> items) { foreach (IItem<T> item in items) { _list.Add(item.PropA); } } } public void usage() { IEnumerable<MyItem> list= GetItems(); var worker = new WorkerClass<string>(list);//Not Allowed }

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  • Is there a way in VS2008 (c#) to see all the possible exception types that can originate from a meth

    - by Matt
    Is there a way in VS2008 IDE for c# to see all the possible exception types that can possibly originate from a method call or even for an entire try-catch block? I know that intellisense or the object browser tells me this method can throw these types of exceptions but is there another way than using the object browser everytime? Something more accessible when coding? Furthermore, I don't think intellisense or the object browser do anything more than read the XML code comments. Shouldn't it be possible to scan a class's source and find all the exception types that can be thrown. (Forget path-ing based on method input, just scan the code for exception types) Am I wrong? Extending this idea, you should be able to hover over the 'try' or 'catch' keywords and present a tooltip with all the types of exceptions that can be thrown. My question boils down to, does a VS2008 add on like this exist? Does VS2010 do this perhaps? If not, could you implement it the way I've described, by scanning the class code for thrown exception types and would people find it useful. Exceptions bubble up so you have to scan every bit of code every method call, which I guess could be impractical, though I suppose you could build an index the first time and increase your speed that way. (It might be a cool little project....)

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  • Rails Form Submission, User can't be blank

    - by pmanning
    I'm trying to create an event through an event form and I keep getting a form error that says "User can't be blank". The event needs a user_id to post a feed_item showing who created the event. Why can't this event get created? event.rb class Event < ActiveRecord::Base attr_accessible :description, :location, :title, :category_id, :start_date, :start_time, :end_date, :end_time, :image belongs_to :user belongs_to :category has_many :rsvps has_many :users, through: :rsvps, dependent: :destroy mount_uploader :image, ImageUploader validates :title, presence: true, length: { maximum: 60 } validates :user_id, presence: true create_events.rb (database) class CreateEvents < ActiveRecord::Migration def change create_table :events do |t| t.string :title t.date :start_date t.time :start_time t.date :end_date t.time :end_time t.string :location t.string :description t.integer :category_id t.integer :user_id t.timestamps end add_index :events, [:user_id, :created_at] end end events_controller.rb def new @event = Event.new @user = current_user end def create @event = current_user.events.build(params[:event]) if @event.save flash[:success] = "Sesh created!" redirect_to root_url else @feed_items = [] render 'static_pages/home' end end routes.rb SampleApp::Application.routes.draw do resources :users do member do get :following, :followers, :events end end resources :events do member do get :members end end root to: 'static_pages#home' events/new.html.erb <%= form_for @event, :html => {:multipart => true} do |f| %> <%= render 'shared/error_messages', object: @event %>

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  • WCF client side List<> problem

    - by MrKanin
    Hey there.. i got a WCF service with a method (GetUserSoftware)to send a List to a client. the software i have difined like this: [DataContract] public class Software { public string SoftwareID { get; set; } public string SoftwareName { get; set; } public string DownloadPath { get; set; } public int PackageID { get; set; } } the method is going through my db to get all software availeble to the clien, and generates a list of that to send back to the client. problem is i on the client side the list is turned into an array. and every item in that array dont contain any of my software attributs. i have debugged my way through the server side. and seen that the list its about to send is correct. with the expected software and attributs in it. any one know how to work around this or know what i can do ?

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  • VB.NET: WithEvents not Working

    - by Hei
    Hello All, I have the following classes: Public Class Email Private Shared ReadOnly EMAIL_REGEX = "\b[a-zA-Z]+[a-zA-Z0-9._+-]+@" + _ "[a-zA-Z0-9.-]+\.[a-zA-Z]{2,3}\b" Private _email As String Public Event emailCreated() ' Declare empty constructor private so the only way to create an object ' is using new (email) Private Sub New() End Sub Sub New(ByVal email As String) If Regex.IsMatch(email, EMAIL_REGEX) Then _email = email RaiseEvent emailCreated() Else Throw New Exception("Email Not Valid") End If End Sub ReadOnly Property Email() As String Get Return _email End Get End Property End Class And Public Class EmailForm WithEvents myEmail As Email Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Try myEmail = New Email(TextBox1.Text) Catch ex As Exception MessageBox.Show("Exception: " & ex.Message) End Try End Sub Public Sub emailCreated() Handles myEmail.emailCreated MessageBox.Show("New Email Created") End Sub End Class If a create a wrong email lets say "email" the exception is correctly cached and a message is showed however is i input a valid email the event is not raised, the object is being created but no message is shown and no error or exception is thrown i suspect it has something to do with using "myemail = new Email(email)" but i have seen examples of using new with withevents with no problem. I would apreciate any input about this problem thank you

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  • Deserializing child elements as attributes of parent

    - by LloydPickering
    I have XML files which I need to deserialize. I used the XSD tool from Visual Studio to create c# object files. the generated classes do deserialize the files except not in the way which I need. I would appreciate any help figuring out how to solve this problem. The child elements named 'data' should be attributes of the parent element 'task'. A shortened example of the XML is below: <task type="Nothing" id="2" taskOnFail="false" > <data value="" name="prerequisiteTasks" /> <data value="" name="exclusionTasks" /> <data value="" name="allowRepeats" /> <task type="Wait for Tasks" id="10" taskOnFail="false" > <data value="" name="prerequisiteTasks" /> <data value="" name="exclusionTasks" /> <data value="" name="allowRepeats" /> </task> <task type="Wait for Tasks" id="10" taskOnFail="false" > <data value="" name="prerequisiteTasks" /> <data value="" name="exclusionTasks" /> <data value="" name="allowRepeats" /> </task> </task> The Class definition I am trying to deserialize to is in the form: public class task { public string prerequisiteTasks {get;set;} public string exclusionTasks {get;set;} public string allowRepeats {get;set;} [System.Xml.Serialization.XmlElementAttribute("task")] public List<task> ChildTasks {get;set;} } The child 'task's are fine, but the generated files put the 'data' elements into an array of data[] rather than as named members of the task class as I need.

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  • XML in Authorware 7.01

    - by Mikael
    Let me explain the setup that is being used. Right now I have an authorware program which loads an ocx control. This control receives data in the form on an XML string. This part is working properly. However I need parse this XML string in authorware and have not been successful. I have been trying to use the XMLParser Xtra. The documentation listed here shows how to create a new XMLParser object and then shows how to call the object but never explains how to link the Parser to a XML file or XML string. The information I have been using can be found here https://www.adobe.com/livedocs/authorware/7/using_aw_en/wwhelp/wwhimpl/common/html/wwhelp.htm?context=Using_Authorware_7&file=09_va110.htm#224295 I need more information on how to Parse XML with this function or if there is another way to do this in Authorware. As a side note the documentation says it cannot create or append to XML, I will need to do this also inside of Authorware. Is this possible and if so, how?

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  • method works fine, until it is called in a function, then UnboundLocalError

    - by user1776100
    I define a method called dist, to calculate the distance between two points which I does it correctly when directly using the method. However, when I get a function to call it to calculate the distance between two points, I get UnboundLocalError: local variable 'minkowski_distance' referenced before assignment edit sorry, I just realised, this function does work. However I have another method calling it that doesn't. I put the last method at the bottom This is the method: class MinkowskiDistance(Distance): def __init__(self, dist_funct_name_str = 'Minkowski distance', p=2): self.p = p def dist(self, obj_a, obj_b): distance_to_power_p=0 p=self.p for i in range(len(obj_a)): distance_to_power_p += abs((obj_a[i]-obj_b[i]))**(p) minkowski_distance = (distance_to_power_p)**(1/p) return minkowski_distance and this is the function: (it basically splits the tuples x and y into their number and string components and calculates the distance between the numeric part of x and y and then the distance between the string parts, then adds them. def total_dist(x, y, p=2, q=2): jacard = QGramDistance(q=q) minkowski = MinkowskiDistance(p=p) x_num = [] x_str = [] y_num = [] y_str = [] #I am spliting each vector into its numerical parts and its string parts so that the distances #of each part can be found, then summed together. for i in range(len(x)): if type(x[i]) == float or type(x[i]) == int: x_num.append(x[i]) y_num.append(y[i]) else: x_str.append(x[i]) y_str.append(y[i]) num_dist = minkowski.dist(x_num,y_num) str_dist = I find using some more steps #I am simply adding the two types of distance to get the total distance: return num_dist + str_dist class NearestNeighbourClustering(Clustering): def __init__(self, data_file, clust_algo_name_str='', strip_header = "no", remove = -1): self.data_file= data_file self.header_strip = strip_header self.remove_column = remove def run_clustering(self, max_dist, p=2, q=2): K = {} #dictionary of clusters data_points = self.read_data_file() K[0]=[data_points[0]] k=0 #I added the first point in the data to the 0th cluster #k = number of clusters minus 1 n = len(data_points) for i in range(1,n): data_point_in_a_cluster = "no" for c in range(k+1): distances_from_i = [total_dist(data_points[i],K[c][j], p=p, q=q) for j in range(len(K[c]))] d = min(distances_from_i) if d <= max_dist: K[c].append(data_points[i]) data_point_in_a_cluster = "yes" if data_point_in_a_cluster == "no": k += 1 K[k]=[data_points[i]] return K

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  • Help with java threads or executors: Executing several MySQL selects, inserts and updates simmultane

    - by Martin
    Hi. I'm writing an application to analyse a MySQL database, and I need to execute several DMLs simmultaneously; for example: // In ResultSet rsA: Select * from A; rsA.beforeFirst(); while (rsA.next()) { id = rsA.getInt("id"); // Retrieve data from table B: Select * from B where B.Id=" + id; // Crunch some numbers using the data from B // Close resultset B } I'm declaring an array of data objects, each with its own Connection to the database, which in turn calls several methods for the data analysis. The problem is all threads use the same connection, thus all tasks throw exceptios: "Lock wait timeout exceeded; try restarting transaction" I believe there is a way to write the code in such a way that any given object has its own connection and executes the required tasks independent from any other object. For example: DataObject dataObject[0] = new DataObject(id[0]); DataObject dataObject[1] = new DataObject(id[1]); DataObject dataObject[2] = new DataObject(id[2]); ... DataObject dataObject[N] = new DataObject(id[N]); // The 'DataObject' class has its own connection to the database, // so each instance of the object should use its own connection. // It also has a "run" method, which contains all the tasks required. Executor ex = Executors.newFixedThreadPool(10); for(i=0;i<=N;i++) { ex.execute(dataObject[i]); } // Here where the problem is: Each instance creates a new connection, // but every DML from any of the objects is cluttered in just one connection // (in MySQL command line, "SHOW PROCESSLIST;" throws every connection, and all but // one are idle). Can you point me in the right direction? Thanks

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  • seriouosly elusive for loop (racking my brains!)

    - by user1693359
    I've got a loop issue in Python 2.72 that's really frustrating me. Basically the loop is not iterating fast the first index (j), and I've tried all sorts of ways to fix it with no luck. def learn(dataSet): for i in dataSet.getNext(): recall = raw_input("Enter all members of %s you are able to recall >>> (separated by commas) " % (i.getName())) missed = i.getMembers() missedString = [] for a in missed: missedString.append(a.getName()) Here is the loop I can't get to iterate. The first for loop only goes through the first iteration of 'j' in the split string list, then removes it from 'missedString'. I would like for all members of the split-string 'recall' to be removed from 'missedString'. for j in string.split(recall, ','): if j in missedString: missedString.remove(j) continue for b in missed: if b.getName() not in missedString: missed.remove(b) print 'You missed %d. ' % (len(missed)) if (len(missed)) > 0: print 'Maybe a hint or two will help...' for miss in missed: remind(miss.getSecs(), i.getName(), missed) I really have no clue, help would be appreciated!

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  • Dynamic WebService implementation

    - by chardex
    I have a set of different interfaces and I need to give them access via web services. I have implemented this task in .NET as follows: dynamically generated interface implementation on the IL, marked methods with WebMethod annotation, and in *.asmx handler called generated stub. More needs to be able to change the method signatures (eg change the type of certain argument or add new arguments), ie not always explicitly implement an interface, and use it as a decorator pattern. Example: interface ISomeService { void simpleMetod (String arg1); void customMetod (CusomType arg1, Integer arg2); } // Need to dynamically generate such class @WebService class SomeWebService { private ISomeService someService = new SomeServiceImpl (); @WebMethod public void simpleMethod (String arg1) { someService.simpleMethod (arg1); } @WebMethod public void customMethod (String arg1, Integer arg2) { someService.customMethod (CusomType.fromString (arg1), arg2); } } Interfaces such as ISomeService quite a lot. And manually write code like this I don't want. I work with Java recently, what technology/libraries should be used to solve such task. Thanks.

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  • Obj-c method override/polymorphism problem

    - by Rod
    Ok, so I'm using Objective-C. Now, say I have: TopClass : NSObject - (int) getVal {return 1;} MidClass : TopClass - (int) getVal {return 2;} BotClass : MidClass - (int) getVal {return 3;} I then put objects of each type into an NSMutableArray and take one out. What I want to do is run the getVal func on the appropriate object type, but when I put id a = [allObjects objectAtIndex:0]; if ([a isKindOfClass:[TopClass class]]) { int i; i = [a getVal]; } I get firstly a warning about multiple methods called getVal (presumably because the compiler can't determine the actual object type until runtime). But more seriously I also get an error "void value not ignored as it should be" and it won't compile. If I don't try and use the return from [a getVal] then it compiles fine e.g. [a getval]; //obviously no good if I want to use the return value It will also work if I use isMemberOfClass statements to cast the object to a class before running the function e.g. if ([a isMemberOfClass:[BotClass]) i = [(BotClass*) a getVal]; But surely I shouldn't have to do this to get the functionality I require? Otherwise I'll have to put in a statement for every single subclass, and worse have to add a new line if I add a new sub class, which rather defeats the point of method overriding doesn't it? Surely there is a better way?

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  • How to detect if a RGB is fully transparent?

    - by omega
    In java, I want to make a fully transparent RGBA, and I do that by using public static int getTransparentRGB() { int r = 0; int g = 0; int b = 0; int a = 0; int new_pixel = (a << 24) | (r << 16) | (g << 8) | b; return new_pixel; } Color color = new Color(getTransparentRGB()); System.out.println(color.getAlpha()); // -> 255 ?! I purposely keep all rgba values 0. However after I create the Color object with the rgba value as the constructor, if I call .getAlpha(), I get 255 even though I made the rgb value with a 0 alpha. If it returns 255, how could I tell the difference between a Color object that wasn't transparent, because that would also have a 255 alpha. I expect the color object to return a 0 alpha based on the function above. Does anyone know whats going on? Thanks

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  • null reference problems with c#

    - by alex
    Hi: In one of my window form, I created an instance of a class to do some works in the background. I wanted to capture the debug messages in that class and displayed in the textbox in the window form. Here is what I did: class A //window form class { public void startBackGroundTask() { B backGroundTask = new B(this); } public void updateTextBox(string data) { if (data != null) { if (this.Textbox.InvokeRequired) { appendUIDelegate updateDelegate = new appendUIDelegate(updateUI); try { this.Invoke(updateDelegate, data); } catch (Exception e) { Console.WriteLine(e.Message); } } else { updateUI(data); } } } private void updateUI(string data) { if (this.Textbox.InvokeRequired) { this.Textbox.Invoke(new appendUIDelegate(this.updateUI), data); } else { //update the text box this.Textbox.AppendText(data); this.Textbox.AppendText(Environment.NewLine); } } private delegate void appendUIDelegate(string data); } class B // background task { A curUI; public b( A UI) { curUI = UI; } private void test() { //do some works here then log the debug message to UI. curUI.updateTextBox("message); } } I keep getting a null reference exception after this.Invoke(updateDelegate, data); is called. I know passing "this" as a parameter is strange. But I want to send the debug message to my window form. Please help. Thanks

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  • self-destructing objects in php5?

    - by user151841
    I am working on a class in php that is basically an interface to a database row. I wanted to create a delete() method that would 1. delete the database row and 2. destroy the instance of itself so that further attempts to manipulate the row via the object would throw warnings. Doing some googling, it seems that, in php5, it's not possible for an object to unset itself. http://bugs.php.net/bug.php?id=36971 In fact they discuss the very situation I was wanting to do :( So how should I proceed? I could make boolean flag as a class property, for whether the row still exists, and have each operation check that flag and throw an error if the row has been deleted. This maintains the oo structure of code, so I would have $objDbRow->delete(); But then I have to put checks at the beginning of each method. Or, I could implement a __destruct method that deletes the row. But that would seem counter-intuitive to me; if I saw in code unset($objDbRow); All I would suspect that's happening is that the object is being discarded, not that a row is being deleted. So that to me would seem like bad practice.

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  • Retrieving an element by array index in jQuery vs the each() function.

    - by Alex Ciminian
    I was writing a "pluginable" function when I noticed the following behavior (tested in FF 3.5.9 with Firebug 1.5.3). $.fn.computerMove = function () { var board = $(this); var emptySquares = board.find('div.clickable'); var randPosition = Math.floor(Math.random() * emptySquares.length); emptySquares.each(function (index) { if (index === randPosition) { // logs a jQuery object console.log($(this)); } }); target = emptySquares[randPosition]; // logs a non-jQuery object console.log(target); // throws error: attr() not a function for target board.placeMark({'position' : target.attr('id')}); } I noticed the problem when the script threw an error at target.attr('id') (attr not a function). When I checked the log, I noticed that the output (in Firebug) for target was: <div style="width: 97px; height: 97px;" class="square clickable" id="8"></div> If I output $(target), or $(this) from the each() function, I get a nice jQuery object: [ div#8.square ] Now here comes my question: why does this happen, considering that find() seems to return an array of jQuery objects? Why do I have to do $() to target all over again? [div#0.square, div#1.square, div#2.square, div#3.square, div#4.square, div#5.square, div#6.square, div#7.square, div#8.square] Just a curiosity :).

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