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  • Centering Divisions Around Zero

    - by Mark
    I'm trying to create something that sort of resembles a histogram. I'm trying to create buckets from an array. Suppose I have a random array doubles between -10 and 10; this is very simplified. I then want to specify a center point, in this case 0 and the number of buckets. If I want 4 buckets the division would be -10 to -5, -5 to 0, 0 to 5 and 5 to 10. Not that complicated right. Now if I change the min and max to -12 and -9 and as for 4 divisions its more complicated. I either want a division at -3 and 3; it is centered around 0 ; or one at -6 to 0 and 0 to 6. Its not that hard to find the division size = Math.Ceiling((Abs(Max) + Abs(Min)) / Divisions) Then you would basically have an if statement to determine whether you want it centered on 0 or on an edge. You then iterate out from either 0 or DivisionSize/2 depending on the situation. You may not ALWAYS end up with the specified number of divisions but it will be close. Then you iterate through the array and increment the bin count. Does this seem like a good way to go about this? This method would surely work but it does not seem to be the most elegant. I'm curious as to whether the creation of the bins and the counting from the list could be done in a clever class with linq in a more elegant way? Something like creating the bins and then having each bin be a property {get;} that returns list.Count(x=> x >= Lower && x < Upper).

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  • How to preserve the state of JavaScript closure?

    - by Uccio
    I am working on a migration platform to migrate web applications from a device to another. I am extending it to add the support for preserving JavaScript state. My main task is to create a file representing the current state of the executing application, to transmit it to another device and to reload the state in the destination device. The basic solution I adopted is to navigate the window object and to save all its descendant properties using JSON as base format for exportation and extending it to implement some features: preserving object reference, even if cyclic (dojox.json.ref library) support for timers Date non-numericproperties of arrays reference to DOM elements The most important task I need to solve now is exportation of closures. At this moment I didn't know how to implement this feature. I read about the internal EcmaScript property [[scope]] containing the scope chain of a function, a list-like object composed by all the nested activation context of the function. Unfortunately it is not accessible by JavaScript. Anyone know if there is a way to directly access the [[scope]] property? Or another way to preserve the state of a closure?

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  • Do the 'up to date' guarantees provided by final field in Java's memory model extend to indirect ref

    - by mattbh
    The Java language spec defines semantics of final fields in section 17.5: The usage model for final fields is a simple one. Set the final fields for an object in that object's constructor. Do not write a reference to the object being constructed in a place where another thread can see it before the object's constructor is finished. If this is followed, then when the object is seen by another thread, that thread will always see the correctly constructed version of that object's final fields. It will also see versions of any object or array referenced by those final fields that are at least as up-to-date as the final fields are. My question is - does the 'up-to-date' guarantee extend to the contents of nested arrays, and nested objects? An example scenario: Thread A constructs a HashMap of ArrayLists, then assigns the HashMap to final field 'myFinal' in an instance of class 'MyClass' Thread B sees a (non-synchronized) reference to the MyClass instance and reads 'myFinal', and accesses and reads the contents of one of the ArrayLists In this scenario, are the members of the ArrayList as seen by Thread B guaranteed to be at least as up to date as they were when MyClass's constructor completed?

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  • Firefox "intelligently" and silently fixes incorrect file references in CSS and Scripts at runtime.

    - by bobsoap
    Well this is a really weird issue, I really didn't find anything on this elsewhere so I thought I'd address it here. Say I have an "image.jpg" and accidentally reference it in the CSS like so: url(imag.jpg) Note the missing "e". Now for me, Firefox is so incredibly clever that it will still find the correct image, but NOT SPIT OUT A WARNING. So I assume that everything is ok. But later, when I test the page in any other browser, all of a sudden the image doesn't display (and rightly so). That's because Firefox thought it was a good idea to correct my error without telling me. This becomes more critical with scripts. Firefox will also auto-correct a typo in a reference. I just wasted a whole hour scratching my head and trying to debug an ajax function in Webkit - turns out, I just had a typo where I included the file. Why on earth does Firefox do this without telling, and where the heck can I turn this off? This has first occured somewhere around FF 3.0 and still persists in 3.6.3. /rant an thank fo any inpu ;)

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  • Reordering columns (fields) in a ADO Recordset

    - by Sukotto
    I have a classic asp webpage written in vbscript that outputs the results from a third-party stored procedure. My user wants the page to display the columns of data in a different order than they come in from the database. Is there an easy and safe way to re-order the columns in an ADO recordset? I did not write this page and cannot change the SP. What is the minimum change I can make here to get the job done and not risk screwing up all the other stuff in the page? The code looks something like dim Conn, strSQL, RS Set Conn = Server.CreateObject("ADODB.Connection") Conn.Open ServerName Set strSQL = "EXEC storedProc @foo = " & Request("fooParam") 'This stored procedure returns a date column, an arbitrary ' ' number of data columns, and two summation columns. We ' ' want the two summation columns to move so they appear ' ' immediately after the data column ' Set RS = Server.CreateObject("ADODB.RecordSet") RS.ActiveConnection = Nothing RS.CursorLocation = adUseClient RS.CursorType = adOpenStatic RS.LockType = adLockBatchOptimistic RS.Open strSQL, Conn, adOpenDynamic, adLockOptimistic dim A ' ----- ' ' Insert some code here to move the columns of the RS around ' ' to suit the whim of my user ' ' ----- ' ' Several blocks of code that iterate over the RS and display it various ways ' RS.MoveFirst For A = 0 To RS.Fields.Count -1 ' do stuff ' Next ... RS.MoveFirst For A = 0 To RS.Fields.Count -1 ' do more stuff ' Next RS.Close : Set RS = Nothing Conn.Close : Set Conn = Nothing

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  • Hibernate saveOrUpdate fails when I execute it on empty table.

    - by Vladimir
    I'm try to insert or update db record with following code: Category category = new Category(); category.setName('catName'); category.setId(1L); categoryDao.saveOrUpdate(category); When there is a category with id=1 already in database everything works. But if there is no record with id=1 I got following exception: org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1: Here is my Category class setters, getters and constructors ommited for clarity: @Entity public class Category { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; private String name; @ManyToOne private Category parent; @OneToMany(fetch = FetchType.LAZY, mappedBy = "parent") private List<Category> categories = new ArrayList<Category>(); } In the console I see this hibernate query: update Category set name=?, parent_id=? where id=? So looks like hibernates tryis to update record instead of inserting new. What am I doing wrong here?

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  • Subitems are not all added to a list view in C# using XmlNodeList

    - by tim
    I'm working on extracting data from an RSS feed. In my listview (rowNews), I've got two columns: Title and URL. When the button is clicked, all of the titles of the articles are showing up in the title column, but only one URL is added to the URL column. I switched them around so that the URLs would be added to the first column and all of the correct URLs appeared... leading me to think this is a problem with my listview source (it's my first time working with subitems). Here's the original, before I started experimenting with the order: private void button1_Click(object sender, EventArgs e) { XmlTextReader rssReader = new XmlTextReader(txtUrl.Text); XmlDocument rssDoc = new XmlDocument(); rssDoc.Load(rssReader); XmlNodeList titleList = rssDoc.GetElementsByTagName("title"); XmlNodeList urlList = rssDoc.GetElementsByTagName("link"); ListViewItem lvi = new ListViewItem(); for (int i = 0; i < titleList.Count; i++) { rowNews.Items.Add(titleList[i].InnerXml); } for (int i = 0; i < urlList.Count; i++) { lvi.SubItems.Add(urlList[i].InnerXml); } rowNews.Items.Add(lvi); }

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  • Help on MySQL table indexing when GROUP BY is used in a query

    - by Silver Light
    Thank you for your attention. There are two INNODB tables: Table authors id INT nickname VARCHAR(50) status ENUM('active', 'blocked') about TEXT Table books author_id INT title VARCHAR(150) I'm running a query against these tables, to get each author and a count of books he has: SELECT a. * , COUNT( b.id ) AS book_count FROM authors AS a, books AS b WHERE a.status != 'blocked' AND b.author_id = a.id GROUP BY a.id ORDER BY a.nickname This query is very slow (takes about 6 seconds to execute). I have an index on books.author_id and it works perfectly, but I do not know how to create an index on authors table, so that this query could use it. Here is how current EXPLAIN looks: id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE a ALL PRIMARY,id_status_nickname NULL NULL NULL 3305 Using where; Using temporary; Using filesort 1 SIMPLE b ref key_author_id key_author_id 5 a.id 2 Using where; Using index I've looked at MySQL manual on optimizing queries with group by, but could not figure out how I can apply it on my query. I'll appreciate any help and hints on this - what must be the index structure, so that MySQL could use it?

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  • Why my jquery function is not firing on Firefox

    - by Cristian Boariu
    I have some trouble with some jquery method (for some checkboxes I want them to fire on checked/unchecked so I can do something then). This method works perfectly on Chrome and IE but not on latest FF. jQuery(function () { jQuery(':checkbox').change(function () { var counter = jQuery('.count').text(); var thisCheck = jQuery(this); if (thisCheck.is(':checked')) { counter++; //apply green color to the selected row jQuery(this).closest('tr').addClass('checked'); } else { counter--; //remove green color to the selected row jQuery(this).closest('tr').removeClass('checked'); } jQuery('.count').html(counter); //enable export button when there are selected emails to be exported if (counter > 0) { jQuery(".exportButton").removeAttr("disabled", ""); } else { jQuery(".exportButton").attr("disabled", "disabled"); } }); }); Basically it's simply not firing...Even with Debug is not catching the first line (function declare nor other lines too). If I move this javascript(without function declare) inside jQuery(document).ready(function ($) { all works nice on Firefox too... Yes, I do use jQuery.noConflict(); before jQuery(document).ready(function ($) { Do you know why this happens?

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  • How To: Custom HTML / CSS Text Button for "Facebook like" & "Twitter Follow"

    - by 1Line
    So i have had a little hunt online about creating custom Facebook like buttons and custom twitter follow button but not really found a solution so thought i would ask here and see if anyone knows of a solution for this (currently i have coded some jQuery to get Facebook and Twitter counts using JSON which works but want some custom buttons as per below) I have the count working all ok, just need to tackle the like and follow buttons - it is done in jquery at the moment so would like to continue to use that if this has to be done via that. at the moment i use the API for each to get the count, if i can integrate into the current js i have to get the calls / functions i require would be good: // grab from facebook var facebook = $.getJSON('https://graph.facebook.com/'+f_page+'?callback=?', function(data) { fb_count = data['likes'].toString(); fb_count_gt = data['likes'].toString(); fb_count = add_commas(fb_count); $('#fb_count').html(fb_count); }); // grab from twitter var twitter = $.getJSON("https://twitter.com/users/"+t_page+".json?callback=?",function(data) { twit_count = data['followers_count'].toString(); twit_count_gt = data['followers_count'].toString(); twit_count = add_commas(twit_count); $('#twitter_count').html(twit_count); }); Thanks in advance!

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  • [PHP, CSS, & ?] fixed width div, resizing text on the fly based on length

    - by Andrew Heath
    Let's say you've got a simple fixed-width layout that pulls a title from a MySQL database. CSS: #wrapper { width: 800px; } h1 { width: 100%; } HTML: <html> <body> <div id="wrapper"> <h1> $titleString </h1> </div> </body> </html> But the catch is, the length of the title string pulled from your MySQL database varies wildly. Sometimes it might be 10 characters, sometimes it might be 80. It's possible to establish a min & max character count. How, if at all possible, do I get the text-size of my <h1>$titleString</h1> to enlarge/decrease on-the-fly such that the string is only ever on one line and best fit to that line length? I've seen a lot of questions about resizing the div - but in my case the div must always be 100% (800px) and I want to best-fit the title. Obviously a maximum text-size value would have to be set so 5 character strings don't become gargantuan. Does anyone have a suggestion? I'm only using PHP/MySQL/CSS on this page at the moment, but incorporation of another language is fine if it means I can solve the problem. The only thing I can think of is a bruteforce approach whereby through trial and error I establish acceptable string character count ranges matched with CSS em sizes, but that'd be a pretty ugly implementation from the code side.

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  • VB.NET CInt(Long) behaving differently in 32- and 64-bit environments

    - by LocoDelAssembly
    Hello everybody, this is my first message here. Today I had a problem converting a Long (Int64) to an Integer (Int32). The problem is that my code was always working in 32-bit environments, but when I try THE SAME executable in a 64-bit computer it crashes with a System.OverflowException exception. I've prepared this test code in VS2008 in a new project with default settings: Module Module1 Sub Main() Dim alpha As Long = -1 Dim delta As Integer Try delta = CInt(alpha And UInteger.MaxValue) Console.WriteLine("CINT OK") delta = Convert.ToInt32(alpha And UInteger.MaxValue) Console.WriteLine("Convert.ToInt32 OK") Catch ex As Exception Console.WriteLine(ex.GetType().ToString()) Finally Console.ReadLine() End Try End Sub End Module On my 32-bit setups (Windows XP SP3 32-bit and Windows 7 32-bit) it prints "CINT OK", but in the 64-bit computer (Windows 7 64-bit) that I've tested THE SAME executable it prints the exception name only. Is this behavior documented? I tried to find a reference but failed miserably. For reference I leave the MSIL code too: .method public static void Main() cil managed { .entrypoint .custom instance void [mscorlib]System.STAThreadAttribute::.ctor() = ( 01 00 00 00 ) // Code size 88 (0x58) .maxstack 2 .locals init ([0] int64 alpha, [1] int32 delta, [2] class [mscorlib]System.Exception ex) IL_0000: nop IL_0001: ldc.i4.m1 IL_0002: conv.i8 IL_0003: stloc.0 IL_0004: nop .try { .try { IL_0005: ldloc.0 IL_0006: ldc.i4.m1 IL_0007: conv.u8 IL_0008: and IL_0009: conv.ovf.i4 IL_000a: stloc.1 IL_000b: ldstr "CINT OK" IL_0010: call void [mscorlib]System.Console::WriteLine(string) IL_0015: nop IL_0016: ldloc.0 IL_0017: ldc.i4.m1 IL_0018: conv.u8 IL_0019: and IL_001a: call int32 [mscorlib]System.Convert::ToInt32(int64) IL_001f: stloc.1 IL_0020: ldstr "Convert.ToInt32 OK" IL_0025: call void [mscorlib]System.Console::WriteLine(string) IL_002a: nop IL_002b: leave.s IL_0055 } // end .try catch [mscorlib]System.Exception { IL_002d: dup IL_002e: call void [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::SetProjectError(class [mscorlib]System.Exception) IL_0033: stloc.2 IL_0034: nop IL_0035: ldloc.2 IL_0036: callvirt instance class [mscorlib]System.Type [mscorlib]System.Exception::GetType() IL_003b: callvirt instance string [mscorlib]System.Type::ToString() IL_0040: call void [mscorlib]System.Console::WriteLine(string) IL_0045: nop IL_0046: call void [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::ClearProjectError() IL_004b: leave.s IL_0055 } // end handler } // end .try finally { IL_004d: nop IL_004e: call string [mscorlib]System.Console::ReadLine() IL_0053: pop IL_0054: endfinally } // end handler IL_0055: nop IL_0056: nop IL_0057: ret } // end of method Module1::Main I suspect that the instruction that is behaving differently is either conv.ovf.i4 or the ldc.i4.m1/conv.u8 pair. If you know what is going on here please let me know Thanks

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  • Automaically select the lastrow in PivotTable SourceData to avoid (blanks)

    - by Adam
    Hi A little help needed, I have a Macro automatically creating pivot tables and charts, this is all working fine but I am getting (blank) in my pivot table becuase my range is all the way to 65536. How do I automatically get the lastrow / column in my source data so I dont get any blanks. The data is changing constantly so this needs to be automatic Here is the source data, I am looking to get the R65536C37 to be automatically generated based on the lastcolumn of the "raw" sheet ActiveWorkbook.PivotCaches.Add(SourceType:=xlDatabase, SourceData:= _ "raw!R1C1:R65536C37").CreatePivotTable _ TableDestination:="Frontpage!R7C1", TableName:="PivotTable2", _ DefaultVersion:=xlPivotTableVersion10 I have tried; LastRow = ActiveSheet.UsedRange.Rows.Count SourceData:= "raw!R1C1:" & LastRow & C37" Pivot Macro Sheets("Frontpage").Select Range("A7").Select ActiveWorkbook.PivotCaches.Add(SourceType:=xlDatabase, SourceData:= _ "raw!R1C1:R65536C37").CreatePivotTable _ TableDestination:="Frontpage!R7C1", TableName:="PivotTable2", _ DefaultVersion:=xlPivotTableVersion10 Sheets("Frontpage").Select Cells(7, 1).Select ActiveSheet.Shapes.AddChart.Select ActiveChart.SetSourceData Source:=Range("Frontpage!$A$7:$H$22") ActiveChart.ChartType = xlColumnClustered With ActiveSheet.PivotTables("PivotTable2").PivotFields("Priority") .Orientation = xlRowField .Position = 1 End With ActiveSheet.PivotTables("PivotTable2").AddDataField ActiveSheet.PivotTables( _ "PivotTable2").PivotFields("Case ID"), "Count of Case ID", xlCount ActiveChart.Parent.Name = "IncidentsbyPriority" ActiveChart.ChartTitle.Text = "Incidents by Priority" Dim RngToCover As Range Dim ChtOb As ChartObject Set RngToCover = ActiveSheet.Range("D7:L16") Set ChtOb = ActiveSheet.ChartObjects("IncidentsbyPriority") ChtOb.Height = RngToCover.Height ' resize ChtOb.Width = RngToCover.Width ' resize ChtOb.Top = RngToCover.Top ' reposition ChtOb.Left = RngToCover.Left ' reposition Any help would be greatly appreciated. I need to repeat this in four other pivots so as to avoid getting (blank) in my tables and charts.

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  • can I store an id value in array of float type ?

    - by srikanth rongali
    I used, for(id value in values) to get the value from an NSArray. Now I want to store it in 2 dimensional float array[][]. When I try to assign the values to array it is giving error:incompatible types in assignment. I tried to cast the value but I got error: pointer value used where a floating point value was expected. I need to store the values in an 2 dimensional array . How can I make it ? Thank You. @implementation fromFileRead1 NSString *fileNameString; int numberOfEnemies, numberOfValues; -(id)init { if( (self = [super init]) ) { NSString *path = @"/Users/sridhar/Desktop/Projects/exampleOnFile2/enemyDetals.txt"; NSString *contentsOfFile = [[NSString alloc] initWithContentsOfFile:path]; NSArray *lines = [contentsOfFile componentsSeparatedByString:@"\n"]; numberOfEnemies = [lines count]; NSLog(@"The number of Lines: %d", numberOfEnemies); for (id line in lines) { NSLog(@"Line %@", line ); NSString *string1 = line; NSArray *split1 = [string1 componentsSeparatedByString:@","]; numberOfValues = [split1 count]; NSLog(@"The number of values in Row: %d", numberOfValues); for (id value in split1) { NSLog(@"value %@", value); float value1; value1 = [split1 objectAtIndex:2]); NSLog(@"VAlue of Value1 at index 2: %f", value1 ); } } } return self; } @end In enemyDetal.txt I have 1,3,3 2,3,2.8 10,2,1.6

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  • C++ Conceptual problem with (Pointer) Pointers

    - by Ptr
    I have a structure usually containing a pointer to an int. However, in some special cases, it is necessary that this int pointer points to another pointer which then points to an int. Wow: I mentioned the word pointer 5 times so far! Is this even possible? I thought about it that way: Instead of using a second int pointer, which is most likely not possible as my main int pointer can only point to an int and not to another int pointer, I could make it a reference like this: int intA = 1; int intB = 2; int& intC = intB; int* myPointers[ 123 ]; myPointers[ 0 ] = &intA; myPointers[ 1 ] = &intB; myPointers[ 3 ] = &intC; So the above would do what I want: The reference to intB (intC) behaves quite like I want it to (If it gets changed it also changes intB) The problem: I can't change references once they are set, right? Or is there a way? Everything in short: How do I get a value to work with * (pointers) and ** (pointers to pointers)?

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  • mvc design in a card game

    - by Hong
    I'm trying to make a card game. some classes I have are: CardModel, CardView; DeckModel, DeckView. The deck model has a list of card model, According to MVC, if I want to send a card to a deck, I can add the card model to the deck model, and the card view will be added to the deck view by a event handler. So I have a addCard(CardModel m) in the DeckModel class, but if I want to send a event to add the card view of that model to the deck view, I only know let the model has a reference to view. So the question is: If the card model and deck model have to have a reference to their view classes to do it? If not, how to do it better? Update, the code: public class DeckModel { private ArrayList<CardModel> cards; private ArrayList<EventHandler> actionEventHandlerList; public void addCard(CardModel card){ cards.add(card); //processEvent(event x); //must I pass a event that contain card view here? } CardModel getCards(int index){ return cards.get(index); } public synchronized void addEventHandler(EventHandler l){ if(actionEventHandlerList == null) actionEventHandlerList = new ArrayList<EventHandler>(); if(!actionEventHandlerList.contains(l)) actionEventHandlerList.add(l); } public synchronized void removeEventHandler(EventHandler l){ if(actionEventHandlerList!= null && actionEventHandlerList.contains(l)) actionEventHandlerList.remove(l); } private void processEvent(Event e){ ArrayList list; synchronized(this){ if(actionEventHandlerList!= null) list = (ArrayList)actionEventHandlerList.clone(); else return; } for(int i=0; i<actionEventHandlerList.size(); ++i){ actionEventHandlerList.get(i).handle(e); } } }

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  • JavaScript: Is there a better way to retain your array but efficiently concat or replace items?

    - by Michael Mikowski
    I am looking for the best way to replace or add to elements of an array without deleting the original reference. Here is the set up: var a = [], b = [], c, i, obj; for ( i = 0; i < 100000; i++ ) { a[ i ] = i; b[ i ] = 10000 - i; } obj.data_list = a; Now we want to concatenate b INTO a without changing the reference to a, since it is used in obj.data_list. Here is one method: for ( i = 0; i < b.length; i++ ) { a.push( b[ i ] ); } This seems to be a somewhat terser and 8x (on V8) faster method: a.splice.apply( a, [ a.length, 0 ].concat( b ) ); I have found this useful when iterating over an "in-place" array and don't want to touch the elements as I go (a good practice). I start a new array (let's call it keep_list) with the initial arguments and then add the elements I wish to retain. Finally I use this apply method to quickly replace the truncated array: var keep_list = [ 0, 0 ]; for ( i = 0; i < a.length; i++ ){ if ( some_condition ){ keep_list.push( a[ i ] ); } // truncate array a.length = 0; // And replace contents a.splice.apply( a, keep_list ); There are a few problems with this solution: there is a max call stack size limit of around 50k on V8 I have not tested on other JS engines yet. This solution is a bit cryptic Has anyone found a better way?

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  • Saving Data to Relational Database (Entity Framework)

    - by sheefy
    I'm having a little bit of trouble saving data to a database. Basically, I have a main table that has associations to other tables (Example Below). Tbl_Listing ID UserID - Associated to ID in User Table CategoryID - Associated to ID in Category Table LevelID - Associated to ID in Level Table. Name Address Normally, it's easy for me to add data to the DB (using Entity Framework). However, I'm not sure how to add data to the fields with associations. The numerous ID fields just need to hold an int value that corresponds with the ID in the associated table. For example; when I try to access the column in the following manner I get a "Object reference not set to an instance of an object." error. Listing NewListing = new Listing(); NewListing.Tbl_User.ID = 1; NewListing.Tbl_Category.ID = 2; ... DBEntities.AddToListingSet(NewListing); DBEntities.SaveChanges(); I am using NewListing.Tbl_User.ID instead of NewListing.UserID because the UserID field is not available through intellisense. If I try and create an object for each related field I get a "The relationship between the two objects cannot be defined because they are attached to different ObjectContext objects." error. With this method, I am trying to add the object without the .ID shown above - example NewListing.User = UserObject. I know this should be simple as I just want to reference the ID from the associated table in the main Listing's table. Any help would be greatly appreciated. Thanks in advance, -S

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  • Trouble accessing Mutable array

    - by Jared Gross
    Im having trouble with my for loop where I am trying to index user names. I am able to separate my original array into individual objects but am not able to send the value to a new array that I need to reference later on. The value and count for userNames in my self.userNamesArray = userNames; line is correct. But right after that when I log self.userNamesArray, I get (null). Any tips cause I'm not completely sure I'm cheers! .h @property (nonatomic, copy) NSMutableArray *userNamesArray; .m - (void)viewWillAppear:(BOOL)animated { self.friendsRelation = [[PFUser currentUser] objectForKey:@"friendsRelation"]; PFQuery *query = [self.friendsRelation query]; [query orderByAscending:@"username"]; [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) { if (error) { NSLog(@"Error: %@ %@", error, [error userInfo]); } else { self.friends = objects; NSArray *users = [self.friends valueForKey:@"username"]; NSLog(@"username:%@", users); //Create an array of name wrappers and pass to the root view controller. NSMutableArray *userNames = [[NSMutableArray alloc] initWithCapacity:[self.friends count]]; for (NSString *user in users) { componentsSeparatedByCharactersInSet:charSet]; NSArray *nameComponents = [user componentsSeparatedByString:@" "]; UserNameWrapper *userNameWrapper = [[UserNameWrapper alloc] initWithUserName:nil nameComponents:nameComponents]; [userNames addObject:userNameWrapper]; } self.userNamesArray = userNames; NSLog(@"userNamesArray:%@",self.userNamesArray); [self.tableView reloadData]; } Here's the code where I need to reference the self.userNamesArray where again, it is comping up nil. - (void)setUserNamesArray:(NSMutableArray *)newDataArray { if (newDataArray != self.userNamesArray) { self.userNamesArray = [newDataArray mutableCopy]; if (self.userNamesArray == nil) { self.sectionsArray = nil; NSLog(@"user names empty"); } else { [self configureSections]; } } }

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  • Does ReleaseStringUTF do more than free memory?

    - by Bayou Bob
    Consider the following C code segments. Segment 1: char * getSomeString(JNIEnv *env, jstring jstr) { char * retString; retString = (*env)->GetStringUTFChars(env, jstr, NULL); return retString; } void useSomeString(JNIEnv *env, jobject jobj, char *mName) { jclass cl = (*env)->GetObjectClass(env, jobj); jmethodId mId = (*env)->GetMethodID(env, cl, mName, "()Ljava/lang/String;"); jstring jstr = (*env)->CallObjectMethod(env, obj, id, NULL); char * myString = getSomeString(env, jstr); /* ... use myString without modifing it */ free(myString); } Because myString is freed in useSomeString, I do not think I am creating a memory leak; however, I am not sure. The JNI spec specifically requires the use of ReleaseStringUTFChars. Since I am getting a C style 'char *' pointer from GetStringUTFChars, I believe the memory reference exists on the C stack and not in the JAVA heap so it is not in danger of being Garbage Collected; however, I am not sure. I know that changing getSomeString as follows would be safer (and probably preferable). Segment 2: char * getSomeString(JNIEnv *env, jstring jstr) { char * retString; char * intermedString; intermedString = (*env)->GetStringUTFChars(env, jstr, NULL); retString = strdup(intermedString); (*env)->ReleaseStringUTFChars(env, jstr, intermedString); return retString; } Because of our 'process' I need to build an argument on why getSomeString in Segment 2 is preferable to Segment 1. Is anyone aware of any documentation or references which detail the behavior of GetStringUTFChars and ReleaseStringUTFChars in relation to where memory is allocated or what (if any) additional bookkeeping is done (i.e. local Reference Pointer to the Java Heap being created, etc). What are the specific consequences of ignoring that bookkeeping. Thanks in advance.

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  • IS operator behaving a bit strangely

    - by flockofcode
    1) According to my book, IS operator can check whether expression E (E is type) can be converted to the target type only if E is either a reference conversion, boxing or unboxing. Since in the following example IS doesn’t check for either of the three types of conversion, the code shouldn’t work, but it does: int i=100; if (i is long) //returns true, indicating that conversion is possible l = i; 2) a) B b; A a = new A(); if (a is B) b = (B)a; int i = b.l; class A { public int l = 100; } class B:A { } The above code always causes compile time error “Use of unassigned variable”. If condition a is B evaluates to false, then b won’t be assigned a value, but if condition is true, then it will. And thus by allowing such a code compiler would have no way of knowing whether the usage of b in code following the if statement is valid or not ( due to not knowing whether a is b evaluates to true or false) , but why should it know that? Intsead why couldn’t runtime handle this? b) But if instead we’re dealing with non reference types, then compiler doesn’t complain, even though the code is identical.Why? int i = 100; long l; if (i is long) l = i; thank you

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  • Delete on a very deep tree

    - by Kathoz
    I am building a suffix trie (unfortunately, no time to properly implement a suffix tree) for a 10 character set. The strings I wish to parse are going to be rather long (up to 1M characters). The tree is constructed without any problems, however, I run into some when I try to free the memory after being done with it. In particularly, if I set up my constructor and destructor to be as such (where CNode.child is a pointer to an array of 10 pointers to other CNodes, and count is a simple unsigned int): CNode::CNode(){ count = 0; child = new CNode* [10]; memset(child, 0, sizeof(CNode*) * 10); } CNode::~CNode(){ for (int i=0; i<10; i++) delete child[i]; } I get a stack overflow when trying to delete the root node. I might be wrong, but I am fairly certain that this is due to too many destructor calls (each destructor calls up to 10 other destructors). I know this is suboptimal both space, and time-wise, however, this is supposed to be a quick-and-dirty solution to a the repeated substring problem. tl;dr: how would one go about freeing the memory occupied by a very deep tree? Thank you for your time.

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  • Conditional compilation hackery in C# - is there a way to pull this off?

    - by Chris
    I have an internal API that I would like others to reference in their projects as a compiled DLL. When it's a standalone project that's referenced, I use conditional compilation (#if statements) to switch behavior of a key web service class depending on compilation symbols. The problem is, once an assembly is generated, it appears that it's locked into whatever the compilation symbols were when it was originally compiled - for instance, if this assembly is compiled with DEBUG and is referenced by another project, even if the other project is built as RELEASE, the assembly still acts as if it was in DEBUG as it doesn't need recompilation. That makes sense, just giving some background. Now I'm trying to work around that so I can switch the assembly's behavior by some other means, such as scanning the app/web config file for a switch. The problem is, some of the assembly's code I was switching between are attributes on methods, for example: #if PRODUCTION [SoapDocumentMethodAttribute("https://prodServer/Service_Test", RequestNamespace = "https://prodServer", ResponseNamespace = "https://prodServer")] #else [SoapDocumentMethodAttribute("https://devServer/Service_Test", RequestNamespace = "https://devServer", ResponseNamespace = "https://devServer")] #endif public string Service_Test() { // test service } Though there might be some syntactical sugar that allows me to flip between two attributes of the same type in another fashion, I don't know it. Any ideas? The alternative method would be to reference the entire project instead of the assembly, but I'd rather stick with just referencing the compiled DLL if I can. I'm also completely open to a whole new approach to solve the problem if that's what it takes.

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  • copy rows with special condition

    - by pooria_googooli
    I have a table with a lot of columns. For example I have a table with these columns : ID,Fname,Lname,Tel,Mob,Email,Job,Code,Company,...... ID column is auto number column. I want to copy all rows in this table to this table and change the company column value to 12 in this copied row. I don't want to write name all of the columns because I have a lot of table with a lot of columns. I tried this code but I had this error : declare @c int; declare @i int; select * into CmDet from CmDet; select @C= count(id) from CmDet; while @i < @C begin UPDATE CmDet SET company =12 WHERE company=11 set @i += 1 end error : Msg 2714, Level 16, State 6, Line 3 There is already an object named 'CmDet' in the database. I changed the code to this declare @c int declare @i int insert into CmDet select * from CmDet; select @C= count(id) from CmDet; while @i < @C begin UPDATE CmDet SET company =12 WHERE company=11 set @i += 1 end and I had this error : Msg 8101, Level 16, State 1, Line 3 An explicit value for the identity column in table 'CmDet' can only be specified when a column list is used and IDENTITY_INSERT is ON. What should I do ?

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  • Does std::vector change its address? How to avoid

    - by kunigami
    Since vector elements are stored contiguously, I guess it may not have the same address after some push_back's , because the initial allocated space could not suffice. I'm working on a code where I need a reference to an element in a vector, like: int main(){ vector<int> v; v.push_back(1); int *ptr = &v[0]; for(int i=2; i<100; i++) v.push_back(i); cout << *ptr << endl; //? return 0; } But it's not necessarily true that ptr contains a reference to v[0], right? How would be a good way to guarantee it? My first idea would be to use a vector of pointers and dynamic allocation. I'm wondering if there's an easier way to do that? PS.: Actually I'm using a vector of a class instead of int, but I think the issues are the same.

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