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• LINQ to XML, a problem conceptualizing how the tree should look.

  - by snark

  Have you ever had one of those days when you've dug a hole but your so deep in now that the only option is to keep on digging and see where you come out? I thought just for giggles in the latest component I'm writing to use LINQ to XML because it was about time I saw what all the hooplah was about. The problem: I am making a graph component that contains series of data that get graphed and then you can apply a formula to that series and graph another series then apply a formula to that series and so on. So I figured that I would do so in 2 steps, create (and manage) an XML representaion of the series and how they relate to each other, then pass this xml to a draw engine which draws. Conceptually its a tree, with the exception of the root all child series being based upon a parent (1 parent can have many children. So I should always be adding child nodes to their parent and if I delete a node(series) then I can simply delete the series and its descendants (then draw) and voila all the messy iterating through each node finding parents and children is unneccessary. Trouble is I dont know how to represent this tree in XML i.e. the structure. My first attempt saw me programatically adding each series as siblings, which worked like a treat because I ended up with an ordered list and thus my order of rendering was maintained. I had this <Chart> <Series id="1">seriesText1</Series> <Series id="2">seriesText2</Series> <Series id="3">seriesText3</Series> <Series id="4">seriesText4</Series> </Chart> I'm in a muddle now ... how can I represent a series and a series that has children series. If some-one can give me a hint to how my tree should look (perhaps with a snippet on how to programatically add nodes to their parents) All the examples I have read usually have some container elements such as <ContactS> or <BookS> but my head says I have <series> some of them parent some of them children. Would appreciate a nudge in the right direction.

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• Matlab wont extract first row & column because of matrix dimensions !

  - by ZaZu

  Hey guys, I am tracking an object that is thrown in air, and this object governs a parabolic pattern. Im tracking the object through a series of 30 images. I managed to exclude all the background and keep the object apparent, then used its centroid to get its coordinates and plot them. Now im supposed to predict where the object is going to fall, so I used polyfit & polyval .. the problem is, matlab says ??? Index exceeds matrix dimensions. Now the centroid creates its own structure with a row and 2 columns. Everytime the object moves in the loop, it updates the first row only .. Here is part of the code : For N=1:30 . . . x=centroid(1,1); % extract first row and column for x y=centroid(1,2); % extract secnd row and column for x plot_xy=plot(x,y) set(plot_xy,'XData',x(1:N),'YData',y(1:N)); fitting=polyfit(x(1:N),y(1:N),2); parabola=plot(x,nan(23,1)); evaluate=polyval(fitting,x); set(parabola,'YData',evaluate) . . end The error message I get is ??? Index exceeds matrix dimensions. It seems that (1:N) is causing the problems .. I honestly do not know why .. But when I remove N, the object is plotted along with its points, but polyfitting wont work, it gives me an error saying : Warning: Polynomial is not unique; degree >= number of data points. > In polyfit at 72 If I made it (1:N-1) or something, it plots more points before it starts giving me the same error (not unique ...) . Any ideas why ?? Thanks alot !!

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• SQL efficiency argument, add a column or solvable by query?

  - by theTurk

  I am a recent college graduate and a new hire for software development. Things have been a little slow lately so I was given a db task. My db skills are limited to pet projects with Rails and Django. So, I was a little surprised with my latest task. I have been asked by my manager to subclass Person with a 'Parent' table and add a reference to their custodian in the Person table. This is to facilitate going from Parent to Form when the custodian, not the Parent, is the FormContact. Here is a simplified, mock structure of a sql-db I am working with. I would have drawn the relationship tables if I had access to Visio. We have a table 'Person' and we have a table 'Form'. There is a table, 'FormContact', that relates a Person to a Form, not all Persons are related to a Form. There is a relationship table for Person to Person relationships (Employer, Parent, etc.) I've asked, "Why this couldn't be handled by a query?" Response, Inefficient. (Really!?!) So, I ask, "Why not have a reference to the Form? That would be more efficient since you wouldn't be querying the FormContacts table with the reference from child/custodian." Response, this would essentially make the Parent is a FormContact. (Fair enough.) I went ahead an wrote a query to get from non-FormContact Parent to Form, and tested on the production server. The response time was instantaneous. *SOME_VALUE* is the Parent's fk ID. SELECT FormID FROM FormContact WHERE FormContact.ContactID IN (SELECT SourceContactID FROM ContactRelationship WHERE (ContactRelationship.RelatedContactID = *SOME_VALUE*) AND (ContactRelationship.Relationship = 'Parent')); If I am right, "This is an unnecessary change." What should I do, defend my position or should I concede to the managers request? If I am wrong. What is my error? Is there a better solution than the manager's?

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• array data taking XML value is not taking css value in as3

  - by Sagar S. Ranpise

  I have xml structure all data comes here inside CDATA I am using css file in it to format text and classes are mentioned in xml Below is the code which shows data but does not format with CSS. Thanks in advance! var myXML:XML = new XML(); var myURLLoader:URLLoader = new URLLoader(); var myURLRequest:URLRequest = new URLRequest("test.xml"); myURLLoader.load(myURLRequest); //////////////For CSS/////////////// var myCSS:StyleSheet = new StyleSheet(); var myCSSURLLoader:URLLoader = new URLLoader(); var myCSSURLRequest:URLRequest = new URLRequest("test.css"); myCSSURLLoader.load(myCSSURLRequest); myCSSURLLoader.addEventListener(Event.COMPLETE,processXML); var i:int; var textHeight:int = 0; var textPadding:int = 10; var txtName:TextField = new TextField(); var myMov:MovieClip = new MovieClip(); var myMovGroup:MovieClip = new MovieClip(); var myArray:Array = new Array(); function processXML(e:Event):void { myXML = new XML(myURLLoader.data); trace(myXML.person.length()); var total:int = myXML.person.length(); trace("total" + total); for(i=0; i<total; i++) { myArray.push({name: myXML.person[i].name.toString()}); trace(myArray[i].name); } processCSS(); } function processCSS():void { myCSS.parseCSS(myCSSURLLoader.data); for(i=0; i<myXML.person.length(); i++) { myMov.addChild(textConvertion(myArray[i].name)); myMov.y = textHeight; textHeight += myMov.height + textPadding; trace("Text: "+myXML.person[i].name); myMovGroup.addChild(myMov); } this.addChild(myMovGroup); } function textConvertion(textConverted:String) { var tc:TextField = new TextField(); tc.htmlText = textConverted; tc.multiline = true; tc.wordWrap = true; tc.autoSize = TextFieldAutoSize.LEFT; tc.selectable = true; tc.y = textHeight; textHeight += tc.height + textPadding; tc.styleSheet = myCSS; return tc; }

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• What is the best way to read and write cXML documents in C# ?

  - by tetranz

  I know this is a vague open ended question. I'm hoping to get some general direction. I need to add cXML punchout to an ASP.NET C# site / application. This is replacing something that I wrote years ago in ColdFusion. I'm a reasonably experienced C# developer but I haven't done much with XML. There seems to be lots of different options for processing XML in .NET. Here's the open ended question: Assuming that I have an XML document in some form, eg a file or a string, what is the best way to read it into my code? I want to get the data and then query databases etc. The cXML document size and our traffic volumes are easily small enough so that loading the a cXML document into memory is not a problem. Should I: 1) Manually build classes based on the dtd and use the XML Serializer? 2) Use a tool to generate classes. There are sample cXML files downloadable from Ariba.com. I tried xsd.exe to generate an xsd and then xsd.exe /c to generate classes. When I try to deserialize I get errors because there seems to be "confusion" around whether some elements should be single values or arrays. I tried the CodeXS online tool but that gives errors in it's log and errors if I try to deserialize a sample document. 2) Create a dataset and ReadXml()? 3) Create a typed dataset and ReadXml()? 4) Use Linq to XML. I often use Linq to Objects so I'm familiar with Linq in general but I'm struggling to see what it gives me in this situation. 5) Some other means. I guess I need to improve my understanding of XML in general but even so ... am I missing some obvious way of doing this? In the old ColdFusion site I found a free component ("tag") which basically ignored any schema and read the XML into a "structure" which is essentially a series of nested hash tables which was then easy to read in code. That was probably quite sloppy but it worked. I also need to generate XML files from my C# objects. Maybe Linq to XML will be good for that. I could start with a default "template" document and manipulate it before saving. Thanks for any pointers ...

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• Special scheduling Algorithm (pattern expansion)

  - by tovare

  Question Do you think genetic algorithms worth trying out for the problem below, or will I hit local-minima issues? I think maybe aspects of the problem is great for a generator / fitness-function style setup. (If you've botched a similar project I would love hear from you, and not do something similar) Thank you for any tips on how to structure things and nail this right. The problem I'm searching a good scheduling algorithm to use for the following real-world problem. I have a sequence with 15 slots like this (The digits may vary from 0 to 20) : 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 (And there are in total 10 different sequences of this type) Each sequence needs to expand into an array, where each slot can take 1 position. 1 1 0 0 1 1 1 0 0 0 1 1 1 0 0 1 1 0 0 1 1 1 0 0 0 1 1 1 0 0 0 0 1 1 0 0 0 1 1 1 0 0 0 1 1 0 0 1 1 0 0 0 1 1 1 0 0 0 1 1 The constraints on the matrix is that: [row-wise, i.e. horizontally] The number of ones placed, must either be 11 or 111 [row-wise] The distance between two sequences of 1 needs to be a minimum of 00 The sum of each column should match the original array. The number of rows in the matrix should be optimized. The array then needs to allocate one of 4 different matrixes, which may have different number of rows: A, B, C, D A, B, C and D are real-world departments. The load needs to be placed reasonably fair during the course of a 10-day period, not to interfere with other department goals. Each of the matrix is compared with expansion of 10 different original sequences so you have: A1, A2, A3, A4, A5, A6, A7, A8, A9, A10 B1, B2, B3, B4, B5, B6, B7, B8, B9, B10 C1, C2, C3, C4, C5, C6, C7, C8, C9, C10 D1, D2, D3, D4, D5, D6, D7, D8, D9, D10 Certain spots on these may be reserved (Not sure if I should make it just reserved/not reserved or function-based). The reserved spots might be meetings and other events The sum of each row (for instance all the A's) should be approximately the same within 2%. i.e. sum(A1 through A10) should be approximately the same as (B1 through B10) etc. The number of rows can vary, so you have for instance: A1: 5 rows A2: 5 rows A3: 1 row, where that single row could for instance be: 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 etc.. Sub problem* I'de be very happy to solve only part of the problem. For instance being able to input: 1 1 2 3 4 2 2 3 4 2 2 3 3 2 3 And get an appropriate array of sequences with 1's and 0's minimized on the number of rows following th constraints above.

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• Many-To-Many Query with Linq-To-NHibernate

  - by rjygraham

  Ok guys (and gals), this one has been driving me nuts all night and I'm turning to your collective wisdom for help. I'm using Fluent Nhibernate and Linq-To-NHibernate as my data access story and I have the following simplified DB structure: CREATE TABLE [dbo].[Classes]( [Id] [bigint] IDENTITY(1,1) NOT NULL, [Name] [nvarchar](100) NOT NULL, [StartDate] [datetime2](7) NOT NULL, [EndDate] [datetime2](7) NOT NULL, CONSTRAINT [PK_Classes] PRIMARY KEY CLUSTERED ( [Id] ASC ) CREATE TABLE [dbo].[Sections]( [Id] [bigint] IDENTITY(1,1) NOT NULL, [ClassId] [bigint] NOT NULL, [InternalCode] [varchar](10) NOT NULL, CONSTRAINT [PK_Sections] PRIMARY KEY CLUSTERED ( [Id] ASC ) CREATE TABLE [dbo].[SectionStudents]( [SectionId] [bigint] NOT NULL, [UserId] [uniqueidentifier] NOT NULL, CONSTRAINT [PK_SectionStudents] PRIMARY KEY CLUSTERED ( [SectionId] ASC, [UserId] ASC ) CREATE TABLE [dbo].[aspnet_Users]( [ApplicationId] [uniqueidentifier] NOT NULL, [UserId] [uniqueidentifier] NOT NULL, [UserName] [nvarchar](256) NOT NULL, [LoweredUserName] [nvarchar](256) NOT NULL, [MobileAlias] [nvarchar](16) NULL, [IsAnonymous] [bit] NOT NULL, [LastActivityDate] [datetime] NOT NULL, PRIMARY KEY NONCLUSTERED ( [UserId] ASC ) I omitted the foreign keys for brevity, but essentially this boils down to: A Class can have many Sections. A Section can belong to only 1 Class but can have many Students. A Student (aspnet_Users) can belong to many Sections. I've setup the corresponding Model classes and Fluent NHibernate Mapping classes, all that is working fine. Here's where I'm getting stuck. I need to write a query which will return the sections a student is enrolled in based on the student's UserId and the dates of the class. Here's what I've tried so far: 1. var sections = (from s in this.Session.Linq<Sections>() where s.Class.StartDate <= DateTime.UtcNow && s.Class.EndDate > DateTime.UtcNow && s.Students.First(f => f.UserId == userId) != null select s); 2. var sections = (from s in this.Session.Linq<Sections>() where s.Class.StartDate <= DateTime.UtcNow && s.Class.EndDate > DateTime.UtcNow && s.Students.Where(w => w.UserId == userId).FirstOrDefault().Id == userId select s); Obviously, 2 above will fail miserably if there are no students matching userId for classes the current date between it's start and end dates...but I just wanted to try. The filters for the Class StartDate and EndDate work fine, but the many-to-many relation with Students is proving to be difficult. Everytime I try running the query I get an ArgumentNullException with the message: Value cannot be null. Parameter name: session I've considered going down the path of making the SectionStudents relation a Model class with a reference to Section and a reference to Student instead of a many-to-many. I'd like to avoid that if I can, and I'm not even sure it would work that way. Thanks in advance to anyone who can help. Ryan

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• transforming binary data using ssis and sql server 2008

  - by Rick

  Hello All - I have a task to import/transform and extract zipped binary files that contain both text data as well as embeded binary data. Within the data is data that is relational in nature and needs to be processed into a defined database structure. Currently I have a C# single threaded app that essentially grabs all the files from the directory (currently there is 13K files of varying sizes) and extracts the data on a single thread line by line inserts to the database. As you could imagine this is a very slow process and unacceptable. There are several different parsing routines used depending on the header record in the file. There are potentially upto a million rows per file when all the data is extracted to the row level of detail. Follow on task is to parse those rows into their appropriate tables based on is content. i.e. the textual content has to be parsed further into "buckets" of like data in the database. That about sums up the big picture. Now for the problem task list. How do i iterate through a packet of data using SSIS? In the app the file is decompressed and then is parsed using streams data type and byte arrays and is routed to the required parsing routine based on the header data of each packet. There is bit swapping involved as well. Should i wrap up the app code into a script task(s) and let it do the custom processing? The data is seperated by year and the sql server tables is partitioned by year as well. I need to be able to "catch" bad file data as well and process by hand most likely. Should i simply load the zipped file to sql as a blob and parse the file with T-SQL? Would that be multi threaded if done that way? Not sure how to do the parsing in tsql that is involved here. Which do you think would be faster? Potentially the data that is currently processed via files could come to us via a socket. Can SSIS collect that data in real time? How would i go about setting that up? Processing these new files from the directorys will become a daily task. I can manage the data once i get it to sql server. Getting it there in a timely fashion seems to be the long pole in the tent for me. I would appreciate any comments or suggestions from the group. Rick

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• how to get child nodes in xsl

  - by ppp

  here my code- <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="ArrayOfLinkEntity" name="bindLink"> <ul> <xsl:for-each select="LinkEntity[ParentLinkId=0]"> <li> <xsl:variable name="linkId" select="LinkId"/> <xsl:variable name="child" select="count(/ArrayOfLinkEntity/LinkEntity[ParentLinkId=$linkId])"/> <xsl:value-of select="$child"/> <xsl:choose> <xsl:when test="($child &gt; 0)"> <a href="#" data-flexmenu="flexmenu1" onclick="javascript:setPageLinkId({$linkId});"> <xsl:value-of select="LinkTitle"/> <img src="../images/down.gif" border="0"/> </a> </xsl:when> <xsl:otherwise > <a href="#" onclick="javascript:setPageLinkId({$linkId});"> <xsl:value-of select="LinkTitle"/> </a> </xsl:otherwise> </xsl:choose> </li> </xsl:for-each> </ul> </xsl:template> </xsl:stylesheet> but I am getting $child=0 always.but there exists children. my xml structure- <ArrayOfLinkEntity xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <LinkEntity> <EntityId>00000000-0000-0000-0000-000000000000</EntityId> <LinkId>1</LinkId> <SequenceNo>1</SequenceNo> <ParentLinkId>0</ParentLinkId> <LinkTitle>Home</LinkTitle> <SubLink /> </LinkEntity> ... </ArrayOfLinkEntity> What should I do? Please suggest.

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• Stored procedure error when use computed column for ID

  - by Hari

  I got the error: Procedure or function usp_User_Info3 has too many arguments specified When I run the program. I don't know the error in SP or in C# code. I have to display the Vendor_ID after the user clicks the submit button. Where the thing going wrong here ? Table structure : CREATE TABLE User_Info3 ( SNo int Identity (2000,1) , Vendor_ID AS 'VEN' + CAST(SNo as varchar(16)) PERSISTED PRIMARY KEY, UserName VARCHAR(16) NOT NULL, User_Password VARCHAR(12) NOT NULL, User_ConPassword VARCHAR(12) NOT NULL, User_FirstName VARCHAR(25) NOT NULL, User_LastName VARCHAR(25) SPARSE NULL, User_Title VARCHAR(35) NOT NULL, User_EMail VARCHAR(35) NOT NULL, User_PhoneNo VARCHAR(14) NOT NULL, User_MobileNo VARCHAR(14)NOT NULL, User_FaxNo VARCHAR(14)NOT NULL, UserReg_Date DATE DEFAULT GETDATE() ) Stored Procedure : ALTER PROCEDURE [dbo].[usp_User_Info3] @SNo INT OUTPUT, @Vendor_ID VARCHAR(10) OUTPUT, @UserName VARCHAR(30), @User_Password VARCHAR(12), @User_ConPassword VARCHAR(12), @User_FirstName VARCHAR(25), @User_LastName VARCHAR(25), @User_Title VARCHAR(35), @User_OtherEmail VARCHAR(30), @User_PhoneNo VARCHAR(14), @User_MobileNo VARCHAR(14), @User_FaxNo VARCHAR(14) AS BEGIN SET NOCOUNT ON; INSERT INTO User_Info3 (UserName,User_Password,User_ConPassword,User_FirstName, User_LastName,User_Title,User_OtherEmail,User_PhoneNo,User_MobileNo,User_FaxNo) VALUES (@UserName,@User_Password,@User_ConPassword,@User_FirstName,@User_LastName, @User_Title,@User_OtherEmail,@User_PhoneNo,@User_MobileNo,@User_FaxNo) SET @SNo = Scope_Identity() SELECT Vendor_ID From User_Info3 WHERE SNo = @SNo END C# Code : protected void BtnUserNext_Click(object sender, EventArgs e) { cmd.CommandType = CommandType.StoredProcedure; cmd.CommandText = "usp_User_Info3"; System.Data.SqlClient.SqlParameter SNo=cmd.Parameters.Add("@SNo",System.Data.SqlDbType.Int); System.Data.SqlClient.SqlParameter Vendor_ID=cmd.Parameters.Add("@Vendor_ID", System.Data.SqlDbType.VarChar,10); cmd.Parameters.Add("@UserName", SqlDbType.VarChar).Value = txtUserName.Text; cmd.Parameters.Add("@User_Password", SqlDbType.VarChar).Value = txtRegPassword.Text; cmd.Parameters.Add("@User_ConPassword", SqlDbType.VarChar).Value = txtRegConPassword.Text; cmd.Parameters.Add("@User_FirstName", SqlDbType.VarChar).Value = txtRegFName.Text; cmd.Parameters.Add("@User_LastName", SqlDbType.VarChar).Value = txtRegLName.Text; cmd.Parameters.Add("@User_Title", SqlDbType.VarChar).Value = txtRegTitle.Text; cmd.Parameters.Add("@User_OtherEmail", SqlDbType.VarChar).Value = txtOtherEmail.Text; cmd.Parameters.Add("@User_PhoneNo", SqlDbType.VarChar).Value =txtRegTelephone.Text; cmd.Parameters.Add("@User_MobileNo", SqlDbType.VarChar).Value =txtRegMobile.Text; cmd.Parameters.Add("@User_FaxNo", SqlDbType.VarChar).Value =txtRegFax.Text; cmd.Connection = SqlCon; try { Vendor_ID.Direction = System.Data.ParameterDirection.Output; SqlCon.Open(); cmd.ExecuteNonQuery(); string VendorID = cmd.ExecuteScalar() as string; } catch (Exception ex) { throw new Exception(ex.Message); } finally { string url = "../CompanyBasicInfo.aspx?Parameter=" + Server.UrlEncode(" + VendorID + "); SqlCon.Close(); } }

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• Count total children divs inside a container

  - by kuswantin

  I want to count the total divs inside a container and toggle their visibilities with structure like this. Please also note that the div.content may also reside inside another nested or even nested-nested containers. That's why I handle it with jquery to add div.topmost for each topmost parent container: <div id="parent"> <div class="counter">There are 3 div.contents inside the container below</div> <div class="container"> <div class="content"> 1 </div> <div class="container"> <!--container inside container --> <div class="content"> 2 </div> <div class="content"> 3 </div> </div> </div> <div class="counter">There are 5 div.contents inside the container below</div> <div class="container"> <div class="content"> 1 </div> <div class="content"> 2 </div> <div class="content"> 3 </div> <div class="content"> 4 </div> <div class="content"> 5 </div> </div> </div> And the jquery: // only grab the top most container $('#parent > .container').addClass('topmost'); var topMost = $(".topmost"); var totContent = topMost.children('.content').size(); if (topMost.length > 0) { topMost.before('<div class="toggle">There are ' + totContent + ' div.contents inside the container below</div>'); } topMost.hide(); $('#parent > .counter').click(function() { $(this).next('.topmost').toggle(); //alert(totContent); return false; }); But I can't make it work to loop for each div.counter. The counter always shows all div.content. So placing the each function is suspected to be the problem. Any hep would be very much appreciated. Thanks

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• help me "dry" out this .net XML serialization code

  - by Sarah Vessels

  I have a base collection class and a child collection class, each of which are serializable. In a test, I discovered that simply having the child class's ReadXml method call base.ReadXml resulted in an InvalidCastException later on. First, here's the class structure: Base Class // Collection of Row objects [Serializable] [XmlRoot("Rows")] public class Rows : IList<Row>, ICollection<Row>, IEnumerable<Row>, IEquatable<Rows>, IXmlSerializable { public Collection<Row> Collection { get; protected set; } public void ReadXml(XmlReader reader) { reader.ReadToFollowing(XmlNodeName); do { using (XmlReader rowReader = reader.ReadSubtree()) { var row = new Row(); row.ReadXml(rowReader); Collection.Add(row); } } while (reader.ReadToNextSibling(XmlNodeName)); } } Derived Class // Acts as a collection of SpecificRow objects, which inherit from Row. Uses the same // Collection<Row> that Rows defines which is fine since SpecificRow : Row. [Serializable] [XmlRoot("MySpecificRowList")] public class SpecificRows : Rows, IXmlSerializable { public new void ReadXml(XmlReader reader) { // Trying to just do base.ReadXml(reader) causes a cast exception later reader.ReadToFollowing(XmlNodeName); do { using (XmlReader rowReader = reader.ReadSubtree()) { var row = new SpecificRow(); row.ReadXml(rowReader); Collection.Add(row); } } while (reader.ReadToNextSibling(XmlNodeName)); } public new Row this[int index] { // The cast in this getter is what causes InvalidCastException if I try // to call base.ReadXml from this class's ReadXml get { return (Row)Collection[index]; } set { Collection[index] = value; } } } And here's the code that causes a runtime InvalidCastException if I do not use the version of ReadXml shown in SpecificRows above (i.e., I get the exception if I just call base.ReadXml from within SpecificRows.ReadXml): TextReader reader = new StringReader(serializedResultStr); SpecificRows deserializedResults = (SpecificRows)xs.Deserialize(reader); SpecificRow = deserializedResults[0]; // this throws InvalidCastException So, the code above all compiles and runs exception-free, but it bugs me that Rows.ReadXml and SpecificRows.ReadXml are essentially the same code. The value of XmlNodeName and the new Row()/new SpecificRow() are the differences. How would you suggest I extract out all the common functionality of both versions of ReadXml? Would it be silly to create some generic class just for one method? Sorry for the lengthy code samples, I just wanted to provide the reason I can't simply call base.ReadXml from within SpecificRows.

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• Go - Using a container/heap to implement a priority queue

  - by Seth Hoenig

  In the big picture, I'm trying to implement Dijkstra's algorithm using a priority queue. According to members of golang-nuts, the idiomatic way to do this in Go is to use the heap interface with a custom underlying data structure. So I have created Node.go and PQueue.go like so: //Node.go package pqueue type Node struct { row int col int myVal int sumVal int } func (n *Node) Init(r, c, mv, sv int) { n.row = r n.col = c n.myVal = mv n.sumVal = sv } func (n *Node) Equals(o *Node) bool { return n.row == o.row && n.col == o.col } And PQueue.go: // PQueue.go package pqueue import "container/vector" import "container/heap" type PQueue struct { data vector.Vector size int } func (pq *PQueue) Init() { heap.Init(pq) } func (pq *PQueue) IsEmpty() bool { return pq.size == 0 } func (pq *PQueue) Push(i interface{}) { heap.Push(pq, i) pq.size++ } func (pq *PQueue) Pop() interface{} { pq.size-- return heap.Pop(pq) } func (pq *PQueue) Len() int { return pq.size } func (pq *PQueue) Less(i, j int) bool { I := pq.data.At(i).(Node) J := pq.data.At(j).(Node) return (I.sumVal + I.myVal) < (J.sumVal + J.myVal) } func (pq *PQueue) Swap(i, j int) { temp := pq.data.At(i).(Node) pq.data.Set(i, pq.data.At(j).(Node)) pq.data.Set(j, temp) } And main.go: (the action is in SolveMatrix) // Euler 81 package main import "fmt" import "io/ioutil" import "strings" import "strconv" import "./pqueue" const MATSIZE = 5 const MATNAME = "matrix_small.txt" func main() { var matrix [MATSIZE][MATSIZE]int contents, err := ioutil.ReadFile(MATNAME) if err != nil { panic("FILE IO ERROR!") } inFileStr := string(contents) byrows := strings.Split(inFileStr, "\n", -1) for row := 0; row < MATSIZE; row++ { byrows[row] = (byrows[row])[0 : len(byrows[row])-1] bycols := strings.Split(byrows[row], ",", -1) for col := 0; col < MATSIZE; col++ { matrix[row][col], _ = strconv.Atoi(bycols[col]) } } PrintMatrix(matrix) sum, len := SolveMatrix(matrix) fmt.Printf("len: %d, sum: %d\n", len, sum) } func PrintMatrix(mat [MATSIZE][MATSIZE]int) { for r := 0; r < MATSIZE; r++ { for c := 0; c < MATSIZE; c++ { fmt.Printf("%d ", mat[r][c]) } fmt.Print("\n") } } func SolveMatrix(mat [MATSIZE][MATSIZE]int) (int, int) { var PQ pqueue.PQueue var firstNode pqueue.Node var endNode pqueue.Node msm1 := MATSIZE - 1 firstNode.Init(0, 0, mat[0][0], 0) endNode.Init(msm1, msm1, mat[msm1][msm1], 0) if PQ.IsEmpty() { // make compiler stfu about unused variable fmt.Print("empty") } PQ.Push(firstNode) // problem return 0, 0 } The problem is, upon compiling i get the error message: [~/Code/Euler/81] $ make 6g -o pqueue.6 Node.go PQueue.go 6g main.go main.go:58: implicit assignment of unexported field 'row' of pqueue.Node in function argument make: *** [all] Error 1 And commenting out the line PQ.Push(firstNode) does satisfy the compiler. But I don't understand why I'm getting the error message in the first place. Push doesn't modify the argument in any way.

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• Help with css selector for jquery

  - by NachoF

  I have this wordpress blog that has many pages with subpages that dropdown on hover.... the thing is, I dont want the pages that you hover to link to anything unless they dont have any ul with many anchors inside so just the subpages will have a href different than "#" So basically Im hacking my way through this with some simple javascript. jQuery(document).ready(function(){ jQuery("#menus li > a").attr("href","#"); }); This is selecting every a.. and I dont want that... I just want the anchors that are main pages, not subpages... heres the html so maybe you can think of a better way to select this. Ill explain first the structure is an ul with many li that have an anchor inside if the li also has a ul inside then those are subpages that will appear on hover. hence the initial anchor should have href="#" if there is no ul inside the li then the li a should keep its href. <ul id="menus"> <li> <a href="somelink">Main Page</a> //href should be changed to # <ul> <li> <a href="somelink2/">Subpage1</a> </li> <li> <a href="somelink3">Subpage2</a> </li> </ul> </li> <li> <a href="somelink">MainPage-with-no-subpages</a> //href should not be changed </li> <li> <a href="somelink4">MainPage</a> //href should be changed to # <ul> <li> <a href="somelink5">Subpage</a> </li> <li> <a href="somelink6">Subpage</a> </li> </ul> </li> </ul>

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• Embedded QGraphicsView do not hide after Dialog closes

  - by torsten

  I call a QDialog in to modes, showNormal and showFullscreen. In normal mode all works fine. With a Keyevent the Dialog closes as expected. In Fullscreen, after a keyevent the Dialog closes, but the QGraphicsView will stay on top. All things i've tried (like closing/updating the view) failed. the View sta on top. view = new QGraphicsView(scene); view->setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers))); view->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff); view->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff); view->setViewportUpdateMode(QGraphicsView::FullViewportUpdate); view->setFrameStyle(QFrame::NoFrame); view->setBackgroundBrush(Qt::white); view->setRenderHints(QPainter::Antialiasing); view->setSceneRect(0,0,resolution.x(),resolution.y()); Maybe my structure will help to solve the Problem: This call the QDialog named GraphicsWidgetDialog. void DemoArrowDialog::setDemo() { gwd->graphicsWidget->setListenKeyEvents(true); gwd->setWindowTitle("Demo"); gwd->setFixedSize(500,500); gwd->restoreGeometry(settings); gwd->setContentsMargins(0,0,0,0); gwd->setModal(false); gwd->showNormal(); gwd->graphicsWidget->show(); gwd->setFocus(); } void DemoArrowDialog::setFullScreenDemo() { settings = gwd->saveGeometry(); gwd->graphicsWidget->setListenKeyEvents(true); gwd->setContentsMargins(0,0,0,0); gwd->setModal(true); gwd->graphicsWidget->showFullScreen(); gwd->showFullScreen(); gwd->setFocus(); } This is the Definition of the GraphicsWidgetDialog GraphicsWidgetDialog::GraphicsWidgetDialog(QWidget *parent) : QDialog(parent) { graphicsWidget = new GraphicsWidget; QGridLayout *layout = new QGridLayout; layout->addWidget(graphicsWidget); layout->setContentsMargins(0,0,0,0); graphicsWidget->loadConfig(); graphicsWidget->loadArrowConfig("Arrow"); graphicsWidget->setArrowPosition(arrowPosition(arrowCenter)); graphicsWidget->update(); setLayout(layout); connect(graphicsWidget,SIGNAL(closeEvent()),this,SLOT(reject())); } The GraphicsWidget is the Widget that contains the QGraphcisView and Scene On keyPessEvent it will emit the closeEvent(). Any Idea?

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• many-to-many performance concerns with fluent nhibernate.

  - by Ciel

  I have a situation where I have several many-to-many associations. In the upwards of 12 to 15. Reading around I've seen that it's generally believed that many-to-many associations are not 'typical', yet they are the only way I have been able to create the associations appropriate for my case, so I'm not sure how to optimize any further. Here is my basic scenario. class Page { IList<Tag> Tags { get; set; } IList<Modification> Modifications { get; set; } IList<Aspect> Aspects { get; set; } } This is one of my 'core' classes, and coincidentally one of my core tables. Virtually half of the objects in my code can have an IList<Page>, and some of them have IList<T> where T has its own IList<Page>. As you can see, from an object oriented standpoint, this is not really a problem. But from a database standpoint this begins to introduce a lot of junction tables. So far it has worked fine for me, but I am wondering if anyone has any ideas on how I could improve on this structure. I've spent a long time thinking and in order to achieve the appropriate level of association required, I cannot think of any way to improve it. The only thing I have come up with is to make intermediate classes for each object that has an IList<Page>, but that doesn't really do anything that the HasManyToMany does not already do except introduce another class. It does not extend the functionality and, from what I can tell, it does not improve performance. Any thoughts? I am also concerned about Primary Key limits in this scenario. Most everything needs to be able to have these properties, but the Pages cannot be unique to each object, because they are going to be frequently shared and joined between multiple objects. All relationships are one-sided. (That is, a Page has no knowledge of what owns it). Because of this, I also have no Inverse() mapped HasManyToMany collections. Also, I have read the similar question : Usage of ORMs like NHibernate when there are many associations - performance concerns But it really did not answer my concerns.

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• I could use some help with my SQL command

  - by SuperSpy

  I've got a database table called 'mesg' with the following structure: receiver_id | sender_id | message | timestamp | read Example: 2 *(«me)* | 6 *(«nice girl)* | 'I like you, more than ghoti' | yearsago | 1 *(«seen it)* 2 *(«me)* | 6 *(«nice girl)* | 'I like you, more than fish' | now | 1 *(«seen it)* 6 *(«nice girl)* | 2 *(«me)* | 'Hey, wanna go fish?' | yearsago+1sec | 0 *(«she hasn't seen it)* It's quite a tricky thing that I want to achieve. I want to get: the most recent message(=ORDER BY time DESC) + 'contact name' + time for each 'conversation'. Contact name = uname WHERE uid = 'contact ID' (the username is in another table) Contact ID = if(sessionID*(«me)*=sender_id){receiver_id}else{sender_id} Conversation is me = receiver OR me = sender For example: From: **Bas Kreuntjes** *(« The message from bas is the most recent)* Hey $py, How are you doing... From: **Sophie Naarden** *(« Second recent)* Well hello, would you like to buy my spam? ... *(«I'll work on that later >p)* To: **Melanie van Deijk** *(« My message to Melanie is 3th)* And? Did you kiss him? ... That is a rough output. QUESTION: Could someone please help me setup a good SQL command. This will be the while loup <?php $sql = "????"; $result = mysql_query($sql); while($fetch = mysql_fetch_assoc($result)){ ?> <div class="message-block"> <h1><?php echo($fetch['uname']); ?></h1> <p><?php echo($fetch['message']); ?></p> <p><?php echo($fetch['time']); ?></p> </div> <?php } ?> I hope my explanation is good enough, if not, please tell me. Please don't mind my English, and the Dutch names (I am Dutch myself) Feel free to correct my English UPDATE1: Best I've got until now: But I do not want more than one conversation to show up... u=user table m=message table SELECT u.uname, m.message, m.receiver_uid, m.sender_uid, m.time FROM m, u WHERE (m.receiver_uid = '$myID' AND u.uid = m.sender_uid) OR (m.sender_uid = '$myID' AND u.uid = m.receiver_uid) ORDER BY time DESC;

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• Idiomatic use of auto_ptr to transfer ownership to a container

  - by heycam

  I'm refreshing my C++ knowledge after not having used it in anger for a number of years. In writing some code to implement some data structure for practice, I wanted to make sure that my code was exception safe. So I've tried to use std::auto_ptrs in what I think is an appropriate way. Simplifying somewhat, this is what I have: class Tree { public: ~Tree() { /* delete all Node*s in the tree */ } void insert(const string& to_insert); ... private: struct Node { ... vector<Node*> m_children; }; Node* m_root; }; template<T> void push_back(vector<T*>& v, auto_ptr<T> x) { v.push_back(x.get()); x.release(); } void Tree::insert(const string& to_insert) { Node* n = ...; // find where to insert the new node ... push_back(n->m_children, auto_ptr<Node>(new Node(to_insert)); ... } So I'm wrapping the function that would put the pointer into the container, vector::push_back, and relying on the by-value auto_ptr argument to ensure that the Node* is deleted if the vector resize fails. Is this an idiomatic use of auto_ptr to save a bit of boilerplate in my Tree::insert? Any improvements you can suggest? Otherwise I'd have to have something like: Node* n = ...; // find where to insert the new node auto_ptr<Node> new_node(new Node(to_insert)); n->m_children.push_back(new_node.get()); new_node.release(); which kind of clutters up what would have been a single line of code if I wasn't worrying about exception safety and a memory leak. (Actually I was wondering if I could post my whole code sample (about 300 lines) and ask people to critique it for idiomatic C++ usage in general, but I'm not sure whether that kind of question is appropriate on stackoverflow.)

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• Catch Multiple Custom Exceptions? - C++

  - by Alex

  Hi all, I'm a student in my first C++ programming class, and I'm working on a project where we have to create multiple custom exception classes, and then in one of our event handlers, use a try/catch block to handle them appropriately. My question is: How do I catch my multiple custom exceptions in my try/catch block? GetMessage() is a custom method in my exception classes that returns the exception explanation as a std::string. Below I've included all the relevant code from my project. Thanks for your help! try/catch block // This is in one of my event handlers, newEnd is a wxTextCtrl try { first.ValidateData(); newEndT = first.ComputeEndTime(); *newEnd << newEndT; } catch (// don't know what do to here) { wxMessageBox(_(e.GetMessage()), _("Something Went Wrong!"), wxOK | wxICON_INFORMATION, this);; } ValidateData() Method void Time::ValidateData() { int startHours, startMins, endHours, endMins; startHours = startTime / MINUTES_TO_HOURS; startMins = startTime % MINUTES_TO_HOURS; endHours = endTime / MINUTES_TO_HOURS; endMins = endTime % MINUTES_TO_HOURS; if (!(startHours <= HOURS_MAX && startHours >= HOURS_MIN)) throw new HourOutOfRangeException("Beginning Time Hour Out of Range!"); if (!(endHours <= HOURS_MAX && endHours >= HOURS_MIN)) throw new HourOutOfRangeException("Ending Time Hour Out of Range!"); if (!(startMins <= MINUTE_MAX && startMins >= MINUTE_MIN)) throw new MinuteOutOfRangeException("Starting Time Minute Out of Range!"); if (!(endMins <= MINUTE_MAX && endMins >= MINUTE_MIN)) throw new MinuteOutOfRangeException("Ending Time Minute Out of Range!"); if(!(timeDifference <= P_MAX && timeDifference >= P_MIN)) throw new PercentageOutOfRangeException("Percentage Change Out of Range!"); if (!(startTime < endTime)) throw new StartEndException("Start Time Cannot Be Less Than End Time!"); } Just one of my custom exception classes, the others have the same structure as this one class HourOutOfRangeException { public: // param constructor // initializes message to passed paramater // preconditions - param will be a string // postconditions - message will be initialized // params a string // no return type HourOutOfRangeException(string pMessage) : message(pMessage) {} // GetMessage is getter for var message // params none // preconditions - none // postconditions - none // returns string string GetMessage() { return message; } // destructor ~HourOutOfRangeException() {} private: string message; };

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• Array within Form collecting multiple values with the same name possible?

  - by JM4

  Good afternoon, I will first start with the goal I am trying to accomplish and then give a very basic sample of what I need to do. Goal Instead of collecting several variables and naming them with keys individually, I have decided to give in and use an array structure to handle all inputs of the same type and rules. Once I have the variables, I will validate against them and if 'ok' store them in a MySQL table. The table will hold consumer information and will need to store multiple rows of the same type of information. First Pass I will leave out the validation portion of this question because I feel I need to first understand the basics. <form action="?" method="POST" name="Form"> Member 1 First Name:<input type="text" name="MemberFirstName[]" /><br /> Member 1 Last Name: <input type="text" name="MemberLastName[]" /><br /> Member 1 Email: <input type="text" name="MemberEmail[]" /><br /> Member 2 First Name:<input type="text" name="MemberFirstName[]" /><br /> Member 2 Last Name: <input type="text" name="MemberLastName[]" /><br /> Member 2 Email: <input type="text" name="MemberEmail[]" /><br /> Member 3 First Name:<input type="text" name="MemberFirstName[]" /><br /> Member 3 Last Name: <input type="text" name="MemberLastName[]" /><br /> Member 3 Email: <input type="text" name="MemberEmail[]" /><br /> <input type="submit" name="submit" value="Continue" /> </form> I am hoping that each input given for First Name (a required field) will generate a unique key for that particular entry and not overwrite any data entered. Because I am carrying information from page to page (checkout form), I am turning the POST variables into SESSION variables then storing in a mysql database in the end. My hope is to have: <?php $conn = mysql_connect("localhost", "username", "password"); mysql_select_db("DBname",$conn); $sql = "INSERT INTO tablename VALUES ('$_SESSION[Member1FirstName]', '$_SESSION[Member1LastName]', '$_SESSION[Member1Email]', '$_SESSION[Member2FirstName]', '$_SESSION[Member2LastName]', '$_SESSION[Member2Email]', '$_SESSION[Member1FirstName]', '$_SESSION[Member3LastName]', '$_SESSION[Member3Email]')"; $result = mysql_query($sql, $conn) or die(mysql_error()); Header ("Location: completed.php"); ?> Where Member1, Member2, and Member3 values will appear on their own row within the table. I KNOW my code is wrong but I am giving a first shot at the overall business purpose I am trying to achieve and trying to learn how to code the right way. I am very, very new to programming so any 'baby advice' is greatly appreciated.

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• PHP: Condense array of similar strings into one merged array

  - by Matt Andrews

  Hi everyone. Working with an array of dates (opening times for a business). I want to condense them to their briefest possible form. So far, I started out with this structure Array ( [Mon] => 12noon-2:45pm, 5:30pm-10:30pm [Tue] => 12noon-2:45pm, 5:30pm-10:30pm [Wed] => 12noon-2:45pm, 5:30pm-10:30pm [Thu] => 12noon-2:45pm, 5:30pm-10:30pm [Fri] => 12noon-2:45pm, 5:30pm-10:30pm [Sat] => 12noon-11pm [Sun] => 12noon-9:30pm ) What I want to achieve is this: Array ( [Mon-Fri] => 12noon-2:45pm, 5:30pm-10:30pm [Sat] => 12noon-11pm [Sun] => 12noon-9:30pm ) I've tried writing a recursive function and have managed to output this so far: Array ( [Mon-Fri] => 12noon-2:45pm, 5:30pm-10:30pm [Tue-Fri] => 12noon-2:45pm, 5:30pm-10:30pm [Wed-Fri] => 12noon-2:45pm, 5:30pm-10:30pm [Thu-Fri] => 12noon-2:45pm, 5:30pm-10:30pm [Sat] => 12noon-11pm [Sun] => 12noon-9:30pm ) Can anybody see a simple way of comparing the values and combining the keys where they're similar? My recursive function is basically two nested foreach() loops - not very elegant. Thanks, Matt EDIT: Here's my code so far, which produces the 3rd array above (from the first one as input): $last_time = array('t' => '', 'd' => ''); // blank array for looping $i = 0; foreach($final_times as $day=>$time) { if($last_time['t'] != $time ) { // it's a new time if($i != 0) { $print_times[] = $day . ' ' . $time; } // only print if it's not the first, otherwise we get two mondays } else { // this day has the same time as last time $end_day = $day; foreach($final_times as $day2=>$time2) { if($time == $time2) { $end_day = $day2; } } $print_times[] = $last_time['d'] . '-' . $end_day . ' ' . $time; } $last_time = array('t' => $time, 'd' => $day); $i++; }

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• USB windows xp final USB access issues

  - by Lex Dean

  I basically understand you C++ people, Please do not get distracted because I'm writing in Delphi. I have a stable USB Listing method that accesses all my USB devices I get the devicepath, and this structure: TSPDevInfoData = packed record Size: DWORD; ClassGuid: TGUID; DevInst: DWORD; // DEVINST handle Reserved: DWord; end; I get my ProductID and VenderID successfully from my DevicePath Lists all USB devices connected to the computer at the time That enables me to access the registry data to each device in a stable way. What I'm lacking is a little direction Is friendly name able to be written inside the connected USB Micro chips by the firmware programmer? (I'm thinking of this to identify the device even further, or is this to help identify Bulk data transfer devices like memory sticks and camera's) Can I use SPDRP_REMOVAL_POLICY_OVERRIDE to some how reset these polices What else can I do with the registry details. Identifying when some one unplugs a device The program is using (in windows XP standard) I used a documented windows event that did not respond. Can I read a registry value to identify if its still connected? using CreateFileA (DevicePath) to send and receive data I have read when some one unplugs in the middle of a data transfer its difficult clearing resources. what can IoCreateDevice do for me and how does one use it for that task This two way point of connection status and system lock up situations is very concerning. Has some one read anything about this subject recently? My objectives are to 1. list connected USB devices identify a in development Micro Controller from everything else send and receive data in a stable and fast way to the limits of the controller No lock up's transferring data Note I'm not using any service packs I understand everything USB is in ANSI when windows xp is not and .Net is all about ANSI (what a waste of memory) I plan to continue this project into a .net at a later date as an addition. MSDN gives me Structures and Functions and what should link to what ok but say little to what they get used for. What is available in my language Delphi is way over priced that it needs a major price drop.

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• std::ostream interface to an OLE IStream

  - by PaulH

  I have a Visual Studio 2008 C++ application using IStreams. I would like to use the IStream connection in a std::ostream. Something like this: IStream* stream = /*create valid IStream instance...*/; IStreamBuf< WIN32_FIND_DATA > sb( stream ); std::ostream os( &sb ); WIN32_FIND_DATA d = { 0 }; // send the structure along the IStream os << d; To accomplish this, I've implemented the following code: template< class _CharT, class _Traits > inline std::basic_ostream< _CharT, _Traits >& operator<<( std::basic_ostream< _CharT, _Traits >& os, const WIN32_FIND_DATA& i ) { const _CharT* c = reinterpret_cast< const _CharT* >( &i ); const _CharT* const end = c + sizeof( WIN32_FIND_DATA ) / sizeof( _CharT ); for( c; c < end; ++c ) os << *c; return os; } template< typename T > class IStreamBuf : public std::streambuf { public: IStreamBuf( IStream* stream ) : stream_( stream ) { setp( reinterpret_cast< char* >( &buffer_ ), reinterpret_cast< char* >( &buffer_ ) + sizeof( buffer_ ) ); }; virtual ~IStreamBuf() { sync(); }; protected: traits_type::int_type FlushBuffer() { int bytes = std::min< int >( pptr() - pbase(), sizeof( buffer_ ) ); DWORD written = 0; HRESULT hr = stream_->Write( &buffer_, bytes, &written ); if( FAILED( hr ) ) { return traits_type::eof(); } pbump( -bytes ); return bytes; }; virtual int sync() { if( FlushBuffer() == traits_type::eof() ) return -1; return 0; }; traits_type::int_type overflow( traits_type::int_type ch ) { if( FlushBuffer() == traits_type::eof() ) return traits_type::eof(); if( ch != traits_type::eof() ) { *pptr() = ch; pbump( 1 ); } return ch; }; private: /// data queued up to be sent T buffer_; /// output stream IStream* stream_; }; // class IStreamBuf Yes, the code compiles and seems to work, but I've not had the pleasure of implementing a std::streambuf before. So, I'd just like to know if it's correct and complete. Thanks, PaulH

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• C++ Virtual Constructor, without clone()

  - by Julien L.

  I want to perform "deep copies" of an STL container of pointers to polymorphic classes. I know about the Prototype design pattern, implemented by means of the Virtual Ctor Idiom, as explained in the C++ FAQ Lite, Item 20.8. It is simple and straightforward: struct ABC // Abstract Base Class { virtual ~ABC() {} virtual ABC * clone() = 0; }; struct D1 : public ABC { virtual D1 * clone() { return new D1( *this ); } // Covariant Return Type }; A deep copy is then: for( i = 0; i < oldVector.size(); ++i ) newVector.push_back( oldVector[i]->clone() ); Drawbacks As Andrei Alexandrescu states it: The clone() implementation must follow the same pattern in all derived classes; in spite of its repetitive structure, there is no reasonable way to automate defining the clone() member function (beyond macros, that is). Moreover, clients of ABC can possibly do something bad. (I mean, nothing prevents clients to do something bad, so, it will happen.) Better design? My question is: is there another way to make an abstract base class clonable without requiring derived classes to write clone-related code? (Helper class? Templates?) Following is my context. Hopefully, it will help understanding my question. I am designing a class hierarchy to perform operations on a class Image: struct ImgOp { virtual ~ImgOp() {} bool run( Image & ) = 0; }; Image operations are user-defined: clients of the class hierarchy will implement their own classes derived from ImgOp: struct CheckImageSize : public ImgOp { std::size_t w, h; bool run( Image &i ) { return w==i.width() && h==i.height(); } }; struct CheckImageResolution; struct RotateImage; ... Multiple operations can be performed sequentially on an image: bool do_operations( std::vector< ImgOp* > v, Image &i ) { std::for_each( v.begin(), v.end(), /* bind2nd(mem_fun(&ImgOp::run), i ...) don't remember syntax */ ); } int main( ... ) { std::vector< ImgOp* > v; v.push_back( new CheckImageSize ); v.push_back( new CheckImageResolution ); v.push_back( new RotateImage ); Image i; do_operations( v, i ); } If there are multiple images, the set can be split and shared over several threads. To ensure "thread-safety", each thread must have its own copy of all operation objects contained in v -- v becomes a prototype to be deep copied in each thread.

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• If array is thread safe, what the issue with this function?

  - by Ajay Sharma

  I am totally lost with the things that is happening with my code.It make me to think & get clear with Array's thread Safe concept. Is NSMutableArray OR NSMutableDictionary Thread Safe ? While my code is under execution, the values for the MainArray get's changes although, that has been added to Array. Please try to execute this code, onyour system its very much easy.I am not able to get out of this Trap. It is the function where it is returning Array. What I am Looking to do is : -(Array) (Main Array) --(Dictionary) with Key Value (Multiple Dictionary in Main Array) ----- Above dictionary has 9 Arrays in it. This is the structure I am developing for Array.But even before #define TILE_ROWS 3 #define TILE_COLUMNS 3 #define TILE_COUNT (TILE_ROWS * TILE_COLUMNS) -(NSArray *)FillDataInArray:(int)counter { NSMutableArray *temprecord = [[NSMutableArray alloc] init]; for(int i = 0; i <counter;i++) { if([temprecord count]<=TILE_COUNT) { NSMutableDictionary *d1 = [[NSMutableDictionary alloc]init]; [d1 setValue:[NSString stringWithFormat:@"%d/2011",i+1] forKey:@"serial_data"]; [d1 setValue:@"Friday 13 Sep 12:00 AM" forKey:@"date_data"]; [d1 setValue:@"Description Details " forKey:@"details_data"]; [d1 setValue:@"Subject Line" forKey:@"subject_data"]; [temprecord addObject:d1]; d1= nil; [d1 release]; if([temprecord count]==TILE_COUNT) { NSMutableDictionary *holderKey = [[NSMutableDictionary alloc]initWithObjectsAndKeys:temprecord,[NSString stringWithFormat:@"%d",[casesListArray count]+1],nil]; [self.casesListArray addObject:holderKey]; [holderKey release]; holderKey =nil; [temprecord removeAllObjects]; } } else { [temprecord removeAllObjects]; NSMutableDictionary *d1 = [[NSMutableDictionary alloc]init]; [d1 setValue:[NSString stringWithFormat:@"%d/2011",i+1] forKey:@"serial_data"]; [d1 setValue:@"Friday 13 Sep 12:00 AM" forKey:@"date_data"]; [d1 setValue:@"Description Details " forKey:@"details_data"]; [d1 setValue:@"Subject Line" forKey:@"subject_data"]; [temprecord addObject:d1]; d1= nil; [d1 release]; } } return temprecord; [temprecord release]; } What is the problem with this Code ? Every time there are 9 records in Array, it just replaces the whole Array value instead of just for specific key Value.

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