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  • Java hangs when trying to close a ProcessBuilder OutputStream

    - by Jeff Bullard
    I have the following Java code to start a ProcessBuilder, open an OutputStream, have the process write a string to an OutputStream, and then close the OutputStream. The whole thing hangs indefinitely when I try to close the OutputStream. This only happens on Windows, never on Mac or Linux. Some of the related questions seem to be close to the same problem I'm having, but I haven't been able to figure out how to apply the answers to my problem, as I am a relative newbie with Java. Here is the code. You can see I have put in a lot of println statements to try to isolate the problem. System.out.println("GenMic trying to get the input file now"); System.out.flush(); OutputStream out = child.getOutputStream(); try { System.out.println("GenMic getting ready to write the input file to out"); System.out.flush(); out.write(intext.getBytes()); System.out.println("GenMic finished writing to out"); System.out.flush(); out.close(); System.out.println("GenMic closed OutputStream"); System.out.flush(); } catch (IOException iox) { System.out.println("GenMic caught IOException 2"); System.out.flush(); String detailedMessage = iox.getMessage(); System.out.println("Exception: " + detailedMessage); System.out.flush(); throw new RuntimeException(iox); } And here is the output when this chunk is executed: GenMic trying to get the input file now GenMic getting ready to write the input file to out GenMic finished writing to out

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  • Too many open files in one of my java routine.

    - by Irfan Zulfiqar
    I have a multithreaded code that has to generated a set of objects and write them to a file. When I run it I sometime get "Too many open files" message in Exception. I have checked the code to make sure that all the file streams are being closed properly. Here is the stack trace. When I do ulimit -a, open files allowed is set to 1024. We think increasing this number is not a viable option / solution. [java] java.io.FileNotFoundException: /export/event_1_0.dtd (Too many open files) [java] at java.io.FileInputStream.open(Native Method) [java] at java.io.FileInputStream.<init>(FileInputStream.java:106) [java] at java.io.FileInputStream.<init>(FileInputStream.java:66) [java] at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:70) [java] at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:161) [java] at java.net.URL.openStream(URL.java:1010) Now what we have identified so far by looking closely at the list of open files is that the VM is opening same class file multiple times. /export/BaseEvent.class 236 /export/EventType1BaseEvent.class 60 /export/EventType2BaseEvent.class 48 /export/EventType2.class 30 /export/EventType1.class 14 Where BaseEvent is partent of all the classes and EventType1 ant EventType2 inherits EventType1BaseEvent and EventType2BaseEvent respectively. Why would a class loader load the same class file 200+ times. It seems it is opening up the base class as many time it create any child instance. Is this normal? Can it be handler any other way apart from increasing the number of open files?

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  • Bulk Insert of hundreds of millions of records

    - by Dave Jarvis
    What is the fastest way to insert 237 million records into a table that has rules (for distributing the data across 84 child tables)? First I tried inserts. No go. Then I tried inserts with BEGIN/COMMIT. Not nearly fast enough. Next, I tried COPY FROM, but then noticed the documentation states that the rules are ignored. (And it was having difficulties with the column order and date format -- it said that '1984-07-1' was not a valid integer; true, but a bit unexpected.) Some example data: station_id,taken,amount,category_id,flag 1,'1984-07-1',0,4, 1,'1984-07-2',0,4, 1,'1984-07-3',0,4, 1,'1984-07-4',0,4,T Here is the table structure (with one rule included): CREATE TABLE climate.measurement ( id bigserial NOT NULL, station_id integer NOT NULL, taken date NOT NULL, amount numeric(8,2) NOT NULL, category_id smallint NOT NULL, flag character varying(1) NOT NULL DEFAULT ' '::character varying ) WITH ( OIDS=FALSE ); ALTER TABLE climate.measurement OWNER TO postgres; CREATE OR REPLACE RULE i_measurement_01_001 AS ON INSERT TO climate.measurement WHERE date_part('month'::text, new.taken)::integer = 1 AND new.category_id = 1 DO INSTEAD INSERT INTO climate.measurement_01_001 (id, station_id, taken, amount, category_id, flag) VALUES (new.id, new.station_id, new.taken, new.amount, new.category_id, new.flag); I can generate the data into any format. Am looking for something that won't take four days. I originally had the data in MySQL (still do), but am hoping to get a performance increase by switching to PostgreSQL and am eager to use its PL/R extensions for stats. I was also thinking about using: http://pgbulkload.projects.postgresql.org/ Any help, tips, or guidance would be greatly appreciated. Thank you!

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  • I need a true mouseOver...

    - by invertedSpear
    Ok, so mouseOver and RollOver, and their respective outs work great as long as your mouse is actually over the item, or one of it's children. My problem is that I may have another UI component "between" my mouse and the item I want to process the mouse/rollover(maybe a button that is on top of a canvas, but is not a child of the canvas). The mouse is still over the component, there's just something else that it's over at the same time. Any tips or help how to deal with this? Let me know if I'm not being clear enough. Here is a simplified code example detailing my question copy/paste that into your flex/flash builder and you'll see what I mean: <?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" width="500" height="226" creationComplete="ccInit()"> <mx:Script> <![CDATA[ private function ccInit():void{ myCanv.addEventListener(MouseEvent.ROLL_OVER,handleRollOver); } private function handleRollOver(evt:MouseEvent):void{ myCanv.setStyle("backgroundAlpha",1); myCanv.addEventListener(MouseEvent.ROLL_OUT,handleRollOut); } private function handleRollOut(evt:MouseEvent):void{ myCanv.setStyle("backgroundAlpha",0); myCanv.removeEventListener(MouseEvent.ROLL_OUT,handleRollOut); } ]]> </mx:Script> <mx:Canvas id="myCanv" x="10" y="10" width="480" height="200" borderStyle="solid" borderColor="#000000" backgroundColor="#FFFFFF" backgroundAlpha="0"> </mx:Canvas> <mx:Button x="90" y="50" label="Button" width="327" height="100"/> </mx:Application>

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  • Iterating XML nodes using VBA

    - by ydobonmai
    Note:- It just might be a iterating XML nodes using VBA question. Please look at the bottom of this question. It would be good If we can iterate without using MSXML2.DOMDocument I see the this question which answers part of my question on how to retrieve the CustomXMLPart. However, I am not able to iterate through the Xml. That way, this might not be specific to CustomXmlPart, It just might be a iterating XML using VBA question. Following is the XML I have in my CustomXMLPart. <Items> <Item1>Item1</Item1> <Item2>Item2</Item2> <Item3>Item3</Item3> </Items> This is how I add the above XML as CustomXmlPart:- static void AddCustomTableXmlPart(WordprocessingDocument document) { MainDocumentPart mainDocumentPart = document.MainDocumentPart; XDocument itemXml = GetItemsAsCustomXML(); if (mainDocumentPart.GetPartsCountOfType<CustomXmlPart>() > 0) mainDocumentPart.DeleteParts<CustomXmlPart>(mainDocumentPart.CustomXmlParts); //Add a new customXML part and then add content var customXmlPart = mainDocumentPart.AddCustomXmlPart(CustomXmlPartType.CustomXml); //copy the XML into the new part... using (var ts = new StreamWriter(customXmlPart.GetStream())) { ts.Write(itemXml.ToString()); ts.Flush(); } } and this is how I am accessing it in the macro:- Dim itemNode As xmlNode Dim itemChildren As XMLNodes ' The below line throws a run-time error 'Run-time error '13' - 'type mismatch ' not sure why. **Set itemChildren= ActiveDocument.CustomXMLParts(ActiveDocument.CustomXMLParts.Count).SelectSingleNode("//Items").ChildNodes** Interestingly, when I quick watch ActiveDocument.CustomXMLParts(ActiveDocument.CustomXMLParts.Count).SelectSingleNode("//Items").ChildNodes, I see child items in the quick watch window. Is the assignment to the itemChildren variable incorrect? I want to iterate through all the items and get get text for all of them. Could anybody help?

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  • How to get node without children in xQuery?

    - by mbrevoort
    So I have two nodes of elements that I'm essentially trying to join. I want the top level node to stay the same but the child nodes to be replaced by those cross referenced. Given: <stuff> <item foo="foo" boo="1"/> <item foo="bar" boo="2" /> <item foo="baz" boo="3"/> <item foo="blah boo="4""/> </stuff> <list a="1" b="2"> <foo>bar</foo> <foo>baz</foo> </list> I want to loop through "list" and cross reference elements in "stuff" for this result: <list a="1" b="2"> <item foo="bar" boo="2" /> <item foo="baz" boo="3"/> </list> I want to do this without having to know about what attributes might be on "list". In other words I don't want to have to explicitly call them out like attribute a { $list/@a }, attribute b { $list/@b }

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  • MXML composite container initialization error

    - by mkorpela
    I'm getting an odd error from my composite canvas component: An ActionScript error has occurred: Error: null at mx.core::Container/initialize()[C:\autobuild\galaga\frameworks\projects\framework\src\mx\core\Container.as:2560] at -REMOVED THIS FOR STACK OVERFLOW-.view::EditableCanvas/initialize()[.../view/EditableCanvas .... It seems to be related to the fact that my composite component has a child and I'm trying to add one in the place I'm using the component. So how can I do this correctly? Component code looks like this (EditableCanvas.mxml): <?xml version="1.0" encoding="utf-8"?> <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Script> <mx:Image id="editTextImage" source="@Embed('/../assets/icons/small/edit.png')"/> </mx:Canvas> The code that is using the code looks like this: <view:EditableCanvas width="290" height="120" backgroundColor="#FFFFFF" horizontalScrollPolicy="off" borderStyle="solid" cornerRadius="3"> <mx:Text id="textContentBox" width="270" fontFamily="nautics" fontSize="12" text="{_text}"/> </view:EditableCanvas>

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  • Apply shortcut keys to sliverlight page

    - by sankar
    Hi.. In application requirement is as follows.. In the Silverlight child page(Usercontrol, when you click menu item )open page it requires to fill some data then for saving we have Save button for cancel it we have Cancel button. Here i am looking for Saving data i need to use ShortCut Keys(Ctrl + S). If i write the following code in KeyDown event it is not Functioning well, because Generally we punch the 'Ctrl' key in Presssed mode and then we punch the "S" key here if i punch 'Ctrl' key is not released then it is not working.. Otherwise ie. if punch "Ctrl" key then release it then punch "S" it is working fine.. //Code //int count=0;--Global--- protected override void OnKeyDown(KeyEventArgs e) { base.OnKeyDown(e); if (e.Key == Key.Ctrl) { count = 1; } string str = e.Key.ToString(); if (count >0 && str == "S") { //MessageBox.Show("Saved"); //Saving the data count = 0; } } I am looking for it works on With "Ctrl" key is in pressed mode please look into this... Thanks

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  • Displaying tree path of record in SQL Server 2005

    - by jskiles1
    An example of my tree table is: ([id] is an identity) [id], [parent_id], [path] 1, NULL, 1 2, 1, 1-2 3, 1, 1-3 4, 3, 1-3-4 My goal is to query quickly for multiple rows of this table and view the full path of the node from its root, through its superiors, down to itself. The ultimate question is, should I generate this path on inserts and maintain it in its own column or generate this path on query to save disk space? I guess it depends if this table is write heavy or read heavy. I've been contemplating several approaches to using the "path" characteristic of this parent/child relationship and I just can't seem to settle on one. This "path" is simply for display purposes and serves absolutely no purpose other than that. Here is what I have done to implement this "path." AFTER INSERT TRIGGER - requires passing a NULL path to the insert and updating the path for the record at the inserted rows identity INSTEAD OF INSERT TRIGGER - does not require insert to have NULL path passed, but does require the trigger to insert with a NULL path and updating the path for the record at SCOPE_IDENTITY() STORED PROCEDURE - requiring all inserts into this table to be done through the stored procedure implementing the trigger logic VIEW - requires building the path in the view 1 and 2 seem annoying if massive amounts of data are entered at once. 3 seems annoying because all inserts must go through the procedure in order to have a valid path populated. 1, 2, and 3 require maintaining a path column on the table. 4 removes all the limitations of the above but require the view to perform the path logic and requires use of the view if a path is to be displayed. I have successfully implemented all of the above approaches and I'm mainly looking for some advice. Am I way off the mark here or are any of the above acceptable? Each has it's advantages and disadvantages.

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  • Linking to an item in another node (XSLT)

    - by Andrew Parisi
    I have an XML document with companies listed in it. I want to create a link with XSLT that contains the <link> child of the next node. Sorry if this is confusing..here is some sample XML of what i'm trying to obtain: <portfolio> <company> <name>Dano Industries</name> <link>dano.xml</link> </company> <company> <name>Mike and Co.</name> <link>mike.xml</link> </company> <company> <name>Steve Inc.</name> <link>steve.xml</link> </company> </portfolio> I want two links, "BACK" and "NEXT". While currently on mike.xml, I want BACK to link to "dano.xml" and NEXT linked to "steve.xml"...etc..and have it dynamically change when on a different page based on the nodes around it. I want to do this because I may add and change the list as I go along, so I don't want to have to manually re-link everything. How can I obtain this? Sorry I am new to XSLT, so please explain with solution if possible! Thanks in advance!

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  • wxpython: adding panel to wx.Frame disables/conflicts with wx.Frame's OnPaint?!

    - by sdaau
    Hi all, I just encountered this strange situation: I found an example, where wx.Frame's OnPaint is overridden, and a circle is drawn. Funnily, as soon as I add even a single panel to the frame, the circle is not drawn anymore - in fact, OnPaint is not called at all anymore ! Can anyone explain me if this is the expected behavior, and how to correctly handle a wx.Frame's OnPaint, if the wx.Frame has child panels ? Small code example is below.. Thanks in advance for any answers, Cheers! The code: #!/usr/bin/env python # http://www.linuxquestions.org/questions/programming-9/wxwidgets-wxpython-drawing-problems-with-onpaint-event-703946/ import wx class MainWindow(wx.Frame): def __init__(self, parent, title, size=wx.DefaultSize): wx.Frame.__init__(self, parent, wx.ID_ANY, title, wx.DefaultPosition, size) self.circles = list() self.displaceX = 30 self.displaceY = 30 circlePos = (self.displaceX, self.displaceY) self.circles.append(circlePos) ## uncommenting either only first, or both of ## the commands below, causes OnPaint *not* to be called anymore! #~ self.panel = wx.Panel(self, wx.ID_ANY) #~ self.mpanelA = wx.Panel(self.panel, -1, size=(200,50)) self.Bind(wx.EVT_PAINT, self.OnPaint) def OnPaint(self, e): print "OnPaint called" dc = wx.PaintDC(self) dc.SetPen(wx.Pen(wx.BLUE)) dc.SetBrush(wx.Brush(wx.BLUE)) # Go through the list of circles to draw all of them for circle in self.circles: dc.DrawCircle(circle[0], circle[1], 10) def main(): app = wx.App() win = MainWindow(None, "Draw delayed circles", size=(620,460)) win.Show() app.MainLoop() if __name__ == "__main__": main()

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  • Firebug error causing code to fail in Sitecore when using IE8 to view the Content Editor

    - by iamdudley
    Hi, I have a Sitecore 6 CMS with a custom data provider to create child items on the fly based on items added to a field in the parent item. This was working okay (about a week ago was the last time I was working on this project), but now I am getting errors in the web client which are originating in the FirebugLite html and JS files. Basically, I click on a content item, the FirebugLite js fails, and then my code in my custom data provider fails to run. I would have thought any FirebugLite scripts would be disabled or ignored when running under IE8 (isn't FirebugLite a Firefox addin?) When I remove the FirebugLite folder from ..\sitecore\shell\Controls\Lib\ my code runs fine and I don't get the clientside errors. I'm not really sure what my question is. I guess it is should FirebugLite affect IE8? What am I missing out on if I remove FirebugLite from the Sitecore directory tree? I'm running WindowsXP SP3, VS2008. The errors I get are the following: Webpage error details User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729) Timestamp: Fri, 14 May 2010 06:42:04 UTC Message: Invalid argument. Line: 301 Char: 9 Code: 0 URI: http://xxxxxxx.com.au/sitecore/shell/controls/lib/FirebugLite/firebug.js Message: Object doesn't support this property or method Line: 21 Char: 1 Code: 0 URI: http://xxxxxxxx.com.au/sitecore/shell/controls/lib/FirebugLite/firebug.html Message: Invalid argument. Line: 301 Char: 9 Code: 0 URI: http://xxxxxxxx.com.au/sitecore/shell/controls/lib/FirebugLite/firebug.js Message: Object doesn't support this property or method Line: 21 Char: 1 Code: 0 URI: http://xxxxxxxx.com.au/sitecore/shell/controls/lib/FirebugLite/firebug.html Cheers, James.

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  • Is it possible to group records belonging to an entity in dbunit?

    - by Joshua
    Our JPA entity model auto-generates primary key identifiers for user, user_address tables. Would it be possible to group these entities given below via dbunit, so that I don't need to provide neither the primary key as well as the foreign key reference from user_address.user_id. It is getting very hard to maintain these keys (i.e. I would prefer to group the primary record 'user' and the child records 'user_address' so that dbunit can group them automatically by looking up the entity metadata). Is it achievable? <user id="1" first_name="Josh" creation_date="2009-07-11 15:45:28"/> <user_address id="1" user_id="1" address="Main St" city="Los Angeles"/> I would prefer something like this <!-- First user --> <user first_name="Josh" creation_date="2009-07-11 15:45:28"/> <user_address address="Main St" city="Los Angeles"/> <!-- Second user --> <user first_name="Mary" creation_date="2009-07-11 15:45:28"/> <user_address address="Taylors St" city="San Jose"/>

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  • libxml2 on iPhone

    - by mellkord
    I'm trying to parse HTML file with libxml2. Usually this works fine, but not in this case: <p> <b>Titles</b> (Some Text) <table> <tr> <td valign="top"> …Something1... </td> <td align="right" valign="top"> …Something2... </td> </tr> </table> </p> I do this query to get the first <td> //p[b='Titles']/table/tr/td[0] but nothing is returned because libxml think that <table> tag is not a child of a tag <p> and following him. And finally the question WHY?

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  • How do I get XML path by its value?

    - by user299938
    I need to get the xml path opf the xml file by providing the value of an xml child element as the input. For example: XML file: <?xml version="1.0"?> <document-inquiry xmlns="http://ops.epo.org"> <publication-reference data-format="docdb" xmlns="http://www.epo.org/exchange"> <document-id> <country>EP</country> <doc-number>1000</doc-number> <kind>A1</kind> </document-id> </publication-reference> </document-inquiry> For the above XML file. I need to get the XML path by using the value "1000". If my input is value of the element "1000" Output i need is : <document-id> <country>EP</country> <doc-number>1000</doc-number> <kind>A1</kind> </document-id> I need to achieve this using c# code. Can anyone please help me out on this...

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  • DTGridView losting content while scrolling

    - by Wim Haanstra
    I am using DTGridView from the DTKit by Daniel Tull. I implemented it in a very simple ViewController and the test I am doing is to place a button in the last row of the grid, which should add another row to the grid (and therefor moving the button to a row beneath it). The problem is, when I click the button a couple of times and then start scrolling, the grid seems to lose its content. As I am not completly sure this is a bug in the grid, but more in my code, I hope you guys can help me out and track down the bug. First I have my header file, which is quite simple, because this is a test: #import <UIKit/UIKit.h> #import "DTGridView.h" @interface TestController : UIViewController <DTGridViewDelegate, DTGridViewDataSource> { DTGridView* thumbGrid; } @end I declare a DTGridView, which will be my grid, where I want to put content in. Now, my code file: #import "TestController.h" @implementation TestController int rows = 1; - (NSInteger)numberOfRowsInGridView:(DTGridView *)gridView { return rows; } - (NSInteger)numberOfColumnsInGridView:(DTGridView *)gridView forRowWithIndex:(NSInteger)index { if (index == rows - 1) return 1; else return 3; } - (CGFloat)gridView:(DTGridView *)gridView heightForRow:(NSInteger)rowIndex { return 57.0f; } - (CGFloat)gridView:(DTGridView *)gridView widthForCellAtRow:(NSInteger)rowIndex column:(NSInteger)columnIndex { if (rowIndex == rows - 1) return 320.0f; else return 106.6f; } - (DTGridViewCell *)gridView:(DTGridView *)gridView viewForRow:(NSInteger)rowIndex column:(NSInteger)columnIndex { DTGridViewCell *view = [[gridView dequeueReusableCellWithIdentifier:@"thumbcell"] retain]; if (!view) view = [[DTGridViewCell alloc] initWithReuseIdentifier:@"thumbcell"]; if (rowIndex == rows - 1) { UIButton* btnLoadMoreItem = [[UIButton alloc] initWithFrame:CGRectMake(10, 0, 301, 57)]; [btnLoadMoreItem setTitle:[NSString stringWithFormat:@"Button %d", rowIndex] forState:UIControlStateNormal]; [btnLoadMoreItem.titleLabel setFont:[UIFont boldSystemFontOfSize:20]]; [btnLoadMoreItem setBackgroundImage:[[UIImage imageNamed:@"big-green-button.png"] stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0] forState:UIControlStateNormal]; [btnLoadMoreItem addTarget:self action:@selector(selectLoadMoreItems:) forControlEvents:UIControlEventTouchUpInside]; [view addSubview:btnLoadMoreItem]; [btnLoadMoreItem release]; } else { UILabel* label = [[UILabel alloc] initWithFrame:CGRectMake(10,0,100,57)]; label.text = [NSString stringWithFormat:@"%d x %d", rowIndex, columnIndex]; [view addSubview:label]; [label release]; } return [view autorelease]; } - (void) selectLoadMoreItems:(id) sender { rows++; [thumbGrid setNeedsDisplay]; } - (void)viewDidLoad { [super viewDidLoad]; thumbGrid = [[DTGridView alloc] initWithFrame:CGRectMake(0,0, 320, 320)]; thumbGrid.dataSource = self; thumbGrid.gridDelegate = self; [self.view addSubview:thumbGrid]; } - (void)viewDidUnload { [super viewDidUnload]; } - (void)dealloc { [super dealloc]; } @end I implement all the methods for the DataSource, which seem to work. The grid is filled with as many rows as my int 'rows' ( +1 ) has. The last row does NOT contain 3 columns, but just one. That cell contains a button which (when pressed) adds 1 to the 'rows' integer. The problem starts, when it starts reusing cells (I am guessing) and content start disappearing. When I scroll back up, the UILabels I am putting in the cells are gone. Is there some bug, code error, mistake, dumb-ass-move I am missing here? Hope anyone can help.

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  • javascript equivalent of ASP preInit event

    - by Pankaj Kumar
    Hi guys, searching for this has yielded no resuts.. i have a middle page that has an iframe and all the pages open in that iframe...i have to implement a chat system just like in Google and so to ensure that the chat windows did not close whwn the page would postback i am opening all pages in iframe.... this is a social networking site and user can have themes which have background images per theme now when i visit a friends profile the backgrounf image of the middle page should change... i have this code to find parent of iframe and change background image $(document).ready(function(){ var theme=document.getElementById("ctl00_decideFooterH").value; var t= parent.document.getElementsByTagName("body"); if(theme=='basicTheme'){ t[0].className="basic"; } else if(theme=='Tranquility') { t[0].className="Tranquility"; } else if(theme=='AbstractPink') { t[0].className="abstractPink"; } }); and this code is the master page that all child pages that would open in iframe would access..the trouble is that there is a lag between the theme application on server side(which happens at PreInit) and the background image change which is done by this document.ready that gets executed after the iframe has loaded.. so essentially i need a javascript function that would either execute parallel to PreInit or some other logic....so guys plz help its urgent

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  • Is my method for avoiding dynamic_cast<> faster than dynamic_cast<> itself ?

    - by ereOn
    Hi, I was answering a question a few minutes ago and it raised to me another one: In one of my projects, I do some network message parsing. The messages are in the form of: [1 byte message type][2 bytes payload length][x bytes payload] The format and content of the payload are determined by the message type. I have a class hierarchy, based on a common class Message. To instanciate my messages, i have a static parsing method which gives back a Message* depending on the message type byte. Something like: Message* parse(const char* frame) { // This is sample code, in real life I obviously check that the buffer // is not NULL, and the size, and so on. switch(frame[0]) { case 0x01: return new FooMessage(); case 0x02: return new BarMessage(); } // Throw an exception here because the mesage type is unknown. } I sometimes need to access the methods of the subclasses. Since my network message handling must be fast, I decived to avoid dynamic_cast<> and I added a method to the base Message class that gives back the message type. Depending on this return value, I use a static_cast<> to the right child type instead. I did this mainly because I was told once that dynamic_cast<> was slow. However, I don't know exactly what it really does and how slow it is, thus, my method might be as just as slow (or slower) but far more complicated. What do you guys think of this design ? Is it common ? Is it really faster than using dynamic_cast<> ? Any detailed explanation of what happen under the hood when one use dynamic_cast<> is welcome !

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  • WPF EventRouting to Children

    - by Shaun Bowe
    Is there any way to broadcast a RoutedEvent to all of my children in WPF? For example lets say I have a Window that has 4 children. 2 of them know about the RoutedEvent 'DisplayYourself' and are listening for it. How can I raise this event from the window and have it sent to all children? I looked at RoutingStrategy and Bubble is the wrong direction, Tunnel and Direct don't work because I don't know which children I want to send this to. I just want to broadcast this message and have whoever cares about it handle it. update: I declared the events in a static class. public static class StaticEventClass { public static readonly RoutedEvent ClickEvent = EventManager.RegisterRoutedEvent("Click", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(StaticEventClass)); public static readonly RoutedEvent DrawEvent = EventManager.RegisterRoutedEvent("Draw", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(StaticEventClass)); } The problem is when I raise the event from my window, the children never see it. RoutedEventArgs args = new RoutedEventArgs(StaticEventClass.DrawEvent, this); this.RaiseEvent(args); update again.. Here is the handler in the child. public ChildClass() { this.AddHandler(StaticEventClass.DrawEvent, new RoutedEventHandler(ChildClass_Draw)); }

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  • nhibernate fluent repository pattern insert problem

    - by voam
    I am trying to use Fluent NHibernate and the repository pattern. I would like my business layer to not be knowledgeable of the data persistence layer. Ideally I would pass in an initialized domain object to the insert method of the repository and all would be well. Where I run into problems is if the object being passed in has a child object. For example say I want to insert an a new order for a customer, and the customer is a property of the order object. I would like to do something like this: Customer c = new Customer; c.CustomerId = 1; Order o = new Order; o.Customer = c; repository.InsertOrder(o); The problem is that using NHiberate the CustomerId field is only privately settable so I can not set it directly like this. so what I have ended up doing is have my repository have an interface of Order InsertOrder(int customerId) where all the foreign keys get passed in as parameters. Somehow this just doesn't seem right. The other approach was to use the NHibernate session variable to load a customer object in my business model and then have the order passed in to the repository but this defeats my persistence ignorance ideal. Should I throw this persistence ignorance out the window or am I missing something here? Thanks

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  • Family Tree :- myheritage.com

    - by Nitesh Panchal
    Hello, The other day i just accidently visited the site myheritage.com. I was just wondering, how they must have created one? Can anybody tell me what can be their database design? and if possible, algorithm that we can use to generate such a tree? Generating simple binary tree is very easy using recursion. But if you have a look at the site(if you have time please make account on it and add few nodes to feel) when we add son to a father, it's mother is automatically added(if you don't add explicitly). Mother's family tree is also generated side by side and many such fancy things are happening. In a simple binary tree we have a root node and then many nodes below it. Thus we cannot show wife and husband in the tree and then show a line from wife and husband to child. In spare time, can anybody discuss what can be it's database design and the recursive algorithm that we can follow to generate it? I hope i am not asking too much from you :).

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  • Should I define a single "DataContext" and pass references to it around or define muliple "DataConte

    - by Nate Bross
    I have a Silverlight application that consists of a MainWindow and several classes which update and draw images on the MainWindow. I'm now expanding this to keep track of everything in a database. Without going into specifics, lets say I have a structure like this: MainWindow Drawing-Surface Class1 -- Supports Drawing DataContext + DataServiceCollection<T> w/events Class2 -- Manages "transactions" (add/delete objects from drawing) Class3 Each "Class" is passed a reference to the Drawing Surface so they can interact with it independently. I'm starting to use WCF Data Services in Class1 and its working well; however, the other classes are also going to need access to the WCF Data Services. (Should I define my "DataContext" in MainWindow and pass a reference to each child class?) Class1 will need READ access to the "transactions" data, and Class2 will need READ access to some of the drawing data. So my question is, where does it make the most sense to define my DataContext? Does it make sense to: Define a "global" WCF Data Service "Context" object and pass references to that in all of my subsequent classes? Define an instance of the "Context" for each Class1, Class2, etc Have each method that requires access to data define its own instance of the "Context" and use closures handle the async load/complete events? Would a structure like this make more sense? Is there any danger in keeping an active "DataContext" open for an extended period of time? Typical usecase of this application could range from 1 minute to 40+ minutes. MainWindow Drawing-Surface DataContext Class1 -- Supports Drawing DataServiceCollection<DrawingType> w/events Class2 -- Manages "transactions" (add/delete objects from drawing) DataServiceCollection<TransactionType> w/events Class3 DataServiceCollection<T> w/events

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  • How to bundle extension methods requiring configuration in a library

    - by Greg
    Hi, I would like to develop a library that I can re-use to add various methods involved in navigating/searching through a graph (nodes/relationships, or if you like vertexs/edges). The generic requirements would be: There are existing classes in the main project that already implement the equivalent of the graph class (which contains the lists of nodes / relationships), node class and relationship class (which links nodes together) - the main project likely already has persistence mechanisms for the info (e.g. these classes might be built using Entity Framework for persistance) Methods would need to be added to each of these 3 classes: (a) graph class - methods like "search all nodes", (b) node class - methods such as "find all children to depth i", c) relationship class - methods like "return relationship type", "get parent node", "get child node". I assume there would be a need to inform the library with the extending methods the class names for the graph/node/relationships table (as different project might use different names). To some extent it would need to be like how a generics collection works (where you pass the classes to the collection so it knows what they are). Need to be a way to inform the library of which node property to use for equality checks perhaps (e.g. if it were a graph of webpages the equality field to use might be the URI path) I'm assuming that using abstract base classes wouldn't really work as this would tie usage down to have to use the same persistence approach, and same class names etc. Whereas really I want to be able to, for a project that has "graph-like" characteristics, the ability to add graph searching/walking methods to it.

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  • Best method to select an object from another unknown jQuery object

    - by Yosi
    Lets say I have a jQuery object/collection stored in a variable named obj, which should contain a DOM element with an id named target. I don't know in advance if target will be a child in obj, i.e.: obj = $('<div id="parent"><div id="target"></div></div>'); or if obj equals target, i.e.: obj = $('<div id="target"></div>'); or if target is a top-level element inside obj, i.e.: obj = $('<div id="target"/><span id="other"/>'); I need a way to select target from obj, but I don't know in advance when to use .find and when to use .filter. What would be the fastest and/or most concise method of extracting target from obj? What I've come up with is: var $target = obj.find("#target").add(obj.filter("#target")); UPDATE I'm adding solutions to a JSPERF test page to see which one is the best. Currently my solution is still the fastest. Here is the link, please run the tests so that we'll have more data: http://jsperf.com/jquery-selecting-objects

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  • How to use associated Model as datasource for DataView

    - by Chris Gilbert
    I have a Model structure as shown below and I want to know how to use the Bookings array as the datasource of my DataView. Model Structure: Client ClientId Name Bookings (HasManyAssociation) Contacts (HasManyAssociation) AjaxProxy JsonReader (ImplicitIncludes is set to true so child models are created with one call) Booking BookingNodeId BookingDetails Contact ContactNodeId ContactDetails The above gives me a data structure as follows: Client Bookings[ Booking Booking ] Contacts[ Contact Contact ] What I want to be able to do is either, create a Store from my Bookings array and then use that store as the datasource for my DataView OR directly use the Bookings array as the datasource (I don't really care how I do it to be honest). If I setup the AjaxProxy on my Booking model it works fine but then obviously I cannot automatically create my Client and Contacts when I load my JSON. It seems to me to make sense that the Client model, being the top level model hierarchically, is the one to load the data. EDIT: I figured it out as follows (with special thanks to handet87 below for his dataview.setStore() pointer). The key in this case is to know that creating the relationship actually sets up another store called, in this case BookingsStore and ContactsStore. All I needed to do was dataview.setStore("BookingsStore")

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