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  • Best way to make a WYSIWYG in Flex?

    - by hngry4powr
    Hello, I have a client that wants a WYSIWYG form that behaves like MS word. It will have some section labels in it, with users expected to enter notes for each section, and it needs a place holder for a chart. The trick is that the user needs to know where page breaks are going to fall when printed. The customer agrees to fixed size paper with fixed sized margins. How should I approach this challenge? Thank you very much for your suggestions. Here is an example: Section 1: Explain Idea Here { As user types in this section, the space between this section and the next section expands, but I as the user can't delete the lines that say Section 1 or 2, or the place holder for the chart. However if I type a lot of text, I need to display where the page breaks are with a dashed line or something, so the user can make sure the content enters appears on the desired page. If I type a lot here for example, section 2 will get pushed onto the next page} Section 2: State why this is a Good Idea [ PLACE HOLDER FOR CHART . . . ] Section 3: Additional Remarks:

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  • Question about cloning in Java

    - by devoured elysium
    In Effective Java, the author states that: If a class implements Cloneable, Object's clone method returns a field-by-field copy of the object; otherwise it throws CloneNotSupportedException. What I'd like to know is what he means with field-by-field copy. Does it mean that if the class has X bytes in memory, it will just copy that piece of memory? If yes, then can I assume all value types of the original class will be copied to the new object? class Point { private int x; private int y; @Override public Point clone() { return (Point)super.clone(); } } If what Object.clone() does is a field by field copy of the Point class, I'd say that I wouldn't need to explicitly copy fields x and y, being that the code shown above will be more than enough to make a clone of the Point class. That is, the following bit of code is redundant: @Override public Point clone() { Point newObj = (Point)super.clone(); newObj.x = this.x; //redundant newObj.y = this.y; //redundant } Am I right? I know references of the cloned object will point automatically to where the original object's references pointed to, I'm just not sure what happens specifically with value types. If anyone could state clearly what Object.clone()'s algorithm specification is (in easy language) that'd be great. Thanks

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  • How do I install websocket module for Node.js on Debian VPS?

    - by Ollie Shaw
    I currently am renting a VPS from Dreamhost which runs Debian. I am still learning command line on this OS, but fast! I have successfully installed Node.js, now I want to install the websocket module found here: https://github.com/Worlize/WebSocket-Node From the root user, I have run the following command: npm install websocket The error thrown is: [websocket v1.0.7] Native code compile failed!! On Windows, native extensions require Visual Studio and Python. On Unix, native extensions require Python, make and a C++ compiler. Start npm with --websocket:verbose to show compilation output (if any). What commands should I issue to install this websocket module and its requirements? Thanks very much! Edit: When I run sudo apt-get install gcc make I get this message: Reading package lists... Done Building dependency tree Reading state information... Done gcc is already the newest version. gcc set to manually installed. make is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 44 not upgraded. And the same error when trying to install WebSocket.

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  • Varchar columns: Nullable or not.

    - by NYSystemsAnalyst
    The database development standards in our organization state the varchar fields should not allow null values. They should have a default value of an empty string (""). I know this makes querying and concatenation easier, but today, one of my coworkers questioned me about why that standard only existed for varchar types an not other datatypes (int, datetime, etc). I would like to know if others consider this to be a valid, defensible standard, or if varchar should be treated the same as fields of other data types? I believe this standard is valid for the following reason: I believe that an empty string and null values, though technically different, are conceptually the same. An empty, zero length string is a string that does not exist. It has no value. However, a numeric value of 0 is not the same as NULL. For example, if a field called OutstandingBalance has a value of 0, it means there are $0.00 remaining. However, if the same field is NULL, that means the value is unknown. On the other hand, a field called CustomerName with a value of "" is basically the same as a value of NULL because both represent the non-existence of the name. I read somewhere that an analogy for an empty string vs. NULL is that of a blank CD vs. no CD. However, I believe this to be a false analogy because a blank CD still phyically exists and still has physical data space that does not have any meaningful data written to it. Basically, I believe a blank CD is the equivalent of a string of blank spaces (" "), not an empty string. Therefore, I believe a string of blank spaces to be an actual value separate from NULL, but an empty string to be the absense of value conceptually equivalent to NULL. Please let me know if my beliefs regarding variable length strings are valid, or please enlighten me if they are not. I have read several blogs / arguments regarding this subject, but still do not see a true conceptual difference between NULLs and empty strings.

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  • Autoselect, focus and highlight a new NSOutlineView row

    - by coneybeare
    This is probably just lack of experience with the NSOutlineView but I can't see a way to do this. I have a NSOutlineView (implemented with the excellent PXSourceList) with an add button that is totally functional in the aspect that I save/write/insert/delete rows correctly. I do not use a NSTreeController, and I don't use bindings. I add the entity using the following code: - (void)addEntity:(NSNotification *)notification { // Create the core data representation, and add it as a child to the parent node UABaseNode *node = [[UAModelController defaultModelController] createBaseNode]; [sourceList reloadData]; for (int i = 0; i < [sourceList numberOfRows]; i++) { if (node == [sourceList itemAtRow:i]) { [sourceList selectRowIndexes:[NSIndexSet indexSetWithIndex:i] byExtendingSelection:NO]; [sourceList editColumn:0 row:i withEvent:nil select:NO]; break; } } } When the add button is pressed, a new row is inserted like this: If I click away, then select the row and press enter to edit it, it now looks like this: My question is: How can I programmatically get the same state (focus, selected, highlighted) the first time, to make the user experience better?

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  • Transitioning from Domain Authentication to SQL Server Authentication

    - by Albert Perrien
    Greetings all, I've run into a problem that has me stumped. I've put together a database in SQL Server Express, and I'm having a strange permissions problem. The database is on my development machine with a domain user: DOMAIN\albertp. My development database server is set for "SQL Server and Windows Authentication" mode. I can edit and query my database without any problems when I log in using Windows Authentication. However, when I log in to any user that uses SQL Server authentication (Including sa) I get this message when I run queries against my database. SELECT * FROM [Testing].[dbo].[AuditingReport] I get: Msg 18456, Level 14, State 1, Line 1 Login failed for user 'auditor'. I'm logged into the server from SQL Server Management Studio as 'auditor' and I don't see anything in the error log about the login failure. I've already run: Use Testing; Grant All to auditor; Go And I still get the same error. What permissions do I have to set for the database to be usable by others outside of my personal domain login? Or am I looking at the wrong problem? My ultimate goal is to have the database be accessible from a set of PHP pages, using a either a common login (hence 'auditor') or a login specific to a set of individual users.

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  • Common Lisp condition system for transfer of control

    - by Ken
    I'll admit right up front that the following is a pretty terrible description of what I want to do. Apologies in advance. Please ask questions to help me explain. :-) I've written ETLs in other languages that consist of individual operations that look something like: // in class CountOperation IEnumerable<Row> Execute(IEnumerable<Row> rows) { var count = 0; foreach (var row in rows) { row["record number"] = count++; yield return row; } } Then you string a number of these operations together, and call The Dispatcher, which is responsible for calling Operations and pushing data between them. I'm trying to do something similar in Common Lisp, and I want to use the same basic structure, i.e., each operation is defined like a normal function that inputs a list and outputs a list, but lazily. I can define-condition a condition (have-value) to use for yield-like behavior, and I can run it in a single loop, and it works great. I'm defining the operations the same way, looping through the inputs: (defun count-records (rows) (loop for count from 0 for row in rows do (signal 'have-value :value `(:count ,count @,row)))) The trouble is if I want to string together several operations, and run them. My first attempt at writing a dispatcher for these looks something like: (let ((next-op ...)) ;; pick an op from the set of all ops (loop (handler-bind ((have-value (...))) ;; records output from operation (setq next-op ...) ;; pick a new next-op (call next-op))) But restarts have only dynamic extent: each operation will have the same restart names. The restart isn't a Lisp object I can store, to store the state of a function: it's something you call by name (symbol) inside the handler block, not a continuation you can store for later use. Is it possible to do something like I want here? Or am I better off just making each operation function explicitly look at its input queue, and explicitly place values on the output queue?

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  • Pre-populate iPhone Safari SQLite DB

    - by Matt Rogish
    I'm working with a PhoneGap app that uses Safari local storage (SQlite DB) via Javascript: http://developer.apple.com/safari/library/documentation/iPhone/Conceptual/SafariJSDatabaseGuide/UsingtheJavascriptDatabase/UsingtheJavascriptDatabase.html On first load, the app creates the database, tables, and populates the data via a series of INSERT statements. If the user closes the app while this processing is happening, then my app database is left in an inconsistent state. What I prefer to do is deploy the SQLite DB as part of my iTunes App packaging so nothing must be populated at app cold start. However, I'm not sure if that is possible -- all of the google hits for this topic that I can find are referring to the core-data provided SQLite which is not what we're using... If it's not possible, could I wrap the entire thing in a transaction and keep re-trying it when the app is restarted? Failing that, I guess I can create a simple table with one boolean column "is_app_db_loaded?" and set it to true after I've processed all my inserts. But that's really gross... Ideas? Thanks!!

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  • How to detect that the internet connection has got disconnected through a java desktop application?

    - by Yatendra Goel
    I am developing a Java Desktop Application that access internet. It is a multi-threaded application, each thread do the same work (means each thread is an instance of same Thread class). Now, as all the threads need internet connection to be active, there should be some mechanism that detects whether an internet connection is active or not. Q1. How to detect whether the internet connection is active or not? Q2. Where to implement this internet-status-check-mechanism code? Should I start a separate thread for checking internet status regularly and notifies all the threads when the status changes from one state to another? Or should I let each thread check for the internet-status itself? Q3. This issue should be a very common issue as every application accessing an internet should deal with this problem. So how other developers usually deal with this problem? Q4. If you could give me a reference to a good demo application that addresses this issue then it would greatly help me.

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  • Standard and reliable mouse-reporting with GLUT

    - by Victor
    Hello! I'm trying to use GLUT (freeglut) in my OpenGL application, and I need to register some callbacks for mouse wheel events. I managed to dig out a fairly undocumented function: api documentation But the man page and the API entry for this function both state the same thing: Note: Due to lack of information about the mouse, it is impossible to implement this correctly on X at this time. Use of this function limits the portability of your application. (This feature does work on X, just not reliably.) You are encouraged to use the standard, reliable mouse-button reporting, rather than wheel events. Fair enough, but how do I use this standard, reliable mouse-reporting? And how do I know which is the standard? Do I just use glutMouseFunc() and use button values like 4 and 5 for the scroll up and down values respectively, say if 1, 2 and 3 are the left, middle and right buttons? Is this the reliable method? Bonus question: it seems the `xev' tool is reporting different values for my buttons. My mouse buttons are numbered from 1 to 5 with xev, but glut is reporting buttons from 0 to 4, i.e. an off-by-one. Is this common?

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  • Qt/PyQt dialog with togglable fullscreen mode - problem on Windows

    - by Guard
    I have a dialog created in PyQt. It's purpose and functionality don't matter. The init is: class MyDialog(QWidget, ui_module.Ui_Dialog): def __init__(self, parent=None): super(MyDialog, self).__init__(parent) self.setupUi(self) self.installEventFilter(self) self.setWindowFlags(Qt.Dialog | Qt.WindowTitleHint) self.showMaximized() Then I have event filtering method: def eventFilter(self, obj, event): if event.type() == QEvent.KeyPress: key = event.key() if key == Qt.Key_F11: if self.isFullScreen(): self.setWindowFlags(self._flags) if self._state == 'm': self.showMaximized() else: self.showNormal() self.setGeometry(self._geometry) else: self._state = 'm' if self.isMaximized() else 'n' self._flags = self.windowFlags() self._geometry = self.geometry() self.setWindowFlags(Qt.Tool | Qt.FramelessWindowHint) self.showFullScreen() return True elif key == Qt.Key_Escape: self.close() return QWidget.eventFilter(self, obj, event) As can be seen, Esc is used for dialog hiding, and F11 is used for toggling full-screen. In addition, if the user changed the dialog mode from the initial maximized to normal and possibly moved the dialog, it's state and position are restored after exiting the full-screen. Finally, the dialog is created on the MainWindow action triggered: d = MyDialog(self) d.show() It works fine on Linux (Ubuntu Lucid), but quite strange on Windows 7: if I go to the full-screen from the maximized mode, I can't exit full-screen (on F11 dialog disappears and appears in full-screen mode again). If I change the dialog's mode to Normal (by double-clicking its title), then go to full-screen and then return back, the dialog is shown in the normal mode, in the correct position, but without the title line. Most probably the reason for both cases is the same - the setWindowFlags doesn't work. But why? Is it also possible that it is the bug in the recent PyQt version? On Ubuntu I have 4.6.x from apt, and on Windows - the latest installer from the riverbank site.

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  • C++: parsing with simple regular expression or shoud I use sscanf?

    - by Helltone
    I need to parse a string like func1(arg1, arg2); func2(arg3, arg4);. It's not a very complex parsing problem, so I would prefer to avoid resorting to flex/bison or similar utilities. My first approch was to try to use POSIX C regcomp/regexec or Boost implementation of C++ std::regex. I wrote the following regular expression, which does not work (I'll explain why further on). "^" "[ ;\t\n]*" "(" // (1) identifier "[a-zA-Z_][a-zA-Z0-9_]*" ")" "[ \t\n]*" "(" // (2) non-marking "\[" "(" // (3) non-marking "[ \t]*" "(" // (4..n-1) argument "[a-zA-Z0-9_]+" ")" "[ \t\n]*" "," ")*" "[ \t\n]*" "(" // (n) last argument "[a-zA-Z0-9_]+" ")" "]" ")?" "[ \t\n]*" ";" Note that the group 1 captures the identifier and groups 4..n-1 are intended to capture arguments except the last, which is captured by group n. When I apply this regex to, say func(arg1, arg2, arg3) the result I get is an array {func, arg2, arg3}. This is wrong because arg1 is not in it! The problem is that in the standard regex libraries, submarkings only capture the last match. In other words, if you have for instance the regex "((a*|b*))*" applied on "babb", the results of the inner match will be bb and all previous captures will have been forgotten. Another thing that annoys me here is that in case of error there is no way to know which character was not recognized as these functions provide very little information about the state of the parser when the input is rejected. So I don't know if I'm missing something here... In this case should I use sscanf or similar instead? Note that I prefer to use C/C++ standard libraries (and maybe boost).

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  • Retrieving license type (linux/windows/windows+sqlserver) for an Amazon EC2 instance via the API?

    - by Geir
    I need to calculate the hourly running costs for my Amazon EC2 instances. This varies even between instances with same hardware configs (instance types) because I use different amazon images (AMIs): some plain windows server and some windows server with sql server (both of them have additional costs compared with plain linux instances) The EC2 Java API has a describeInstances() method which returns Instance objects with metadata such as instance id, instance type (m1.small/large...), state (running,stopped..) public ip, etc. This Instance object also has a .getLicense().getPool() which according to the Java API should return "The license pool from which this license was used (ex: 'windows')." I thought this is were it may also give 'windows+sqlserver' or something to that effect. The getLicense() method does however return null.. I've navigated around the EC2 web console, not being able to find this information, but I'm hoping that it is possible - otherwise it would mean that you cannot identify the true hourly cost of an particular instance unless you know which AMI was used to create it in the first place (plain windows server or windows server with sql server). Anyone? Thanks :) /Geir

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  • How do you keep text from wrapping in an NSTableView using NSAttributedString

    - by Justin
    I have an NSTableView that has 2 columns, one for an icon and the other for two lines of text. In the second column, the text column, I have some larger text that is for the name of an item. Then I have a new line and some smaller text that describes the state of the item. When the name becomes so large that it doesn't fit on one line it wraps (or when you shrink the window down so small that it causes the names to not fit on a single line). row1=============== | image |  some name   | | image |   idle               | row2================ | image |  some name really long name   | <- this gets wrapped pushing 'idle' out of the view | image |   idle               | =================== My question is, how could I keep the text from wrapping and just have the NSTableView display a horizontal scroll-bar once the name is too large to fit?

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  • Insert data in an object to a database.

    - by paul
    I am facing the following design/implementation dilemma. I have a class Customer which is below with getters and setters. I would like to insert the value of the Customer into a "Customer" table of a database. But Customer has an address which is of type "Address". How do I go about inserting this field into the database?(I am using sqlite3). I thought of writing a separate table "Address(customerId,doorNo,city,state,country,pinCode)". But I am having second thoughts about generating the primary key(customerId) which should be same for both the "customer" and "Address" table. Sqlite3 faq states that I can do "Integer Primary Key" to use the field to generate an auto number. But if I do that in customer table, I would have to retrieve the same Id to be used in Address table. This kinda looks wrong to me :-?. There should be an elegant method to solve this. Any ideas would be much appreciated. Thanks in advance. import java.io.*; import java.sql.*; class Customer { private String id; private String name; private Address address; private Connection connection; private ResultSet resultSet; private PreparedStatement preparedStatement; public void insertToDatabase(){ } } class Address{ private String doorNumber; private String streetName; private String cityName; private String districtName; private String stateName; private String countryName; private long pinCode; }

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  • Access DB Transaction Insert limit

    - by user986363
    Is there a limit to the amount of inserts you can do within an Access transaction before you need to commit or before Access/Jet throws an error? I'm currently running the following code in hopes to determine what this maximum is. OleDbConnection cn = new OleDbConnection( @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\temp\myAccessFile.accdb;Persist Security Info=False;"); try { cn.Open(); oleCommand = new OleDbCommand("BEGIN TRANSACTION", cn); oleCommand.ExecuteNonQuery(); oleCommand.CommandText = "insert into [table1] (name) values ('1000000000001000000000000010000000000000')"; for (i = 0; i < 25000000; i++) { oleCommand.ExecuteNonQuery(); } oleCommand.CommandText = "COMMIT"; oleCommand.ExecuteNonQuery(); } catch (Exception ex) { } finally { try { oleCommand.CommandText = "COMMIT"; oleCommand.ExecuteNonQuery(); } catch{} if (cn.State != ConnectionState.Closed) { cn.Close(); } } The error I received on a production application when I reached 2,333,920 inserts in a single uncommited transaction was: "File sharing lock count exceeded. Increase MaxLocksPerFile registry entry". Disabling transactions fixed this problem.

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  • Producer consumer with qualifications

    - by tgguy
    I am new to clojure and am trying to understand how to properly use its concurrency features, so any critique/suggestions is appreciated. So I am trying to write a small test program in clojure that works as follows: there 5 producers and 2 consumers a producer waits for a random time and then pushes a number onto a shared queue. a consumer should pull a number off the queue as soon as the queue is nonempty and then sleep for a short time to simulate doing work the consumers should block when the queue is empty producers should block when the queue has more than 4 items in it to prevent it from growing huge Here is my plan for each step above: the producers and consumers will be agents that don't really care for their state (just nil values or something); i just use the agents to send-off a "consumer" or "producer" function to do at some time. Then the shared queue will be (def queue (ref [])). Perhaps this should be an atom though? in the "producer" agent function, simply (Thread/sleep (rand-int 1000)) and then (dosync (alter queue conj (rand-int 100))) to push onto the queue. I am thinking to make the consumer agents watch the queue for changes with add-watcher. Not sure about this though..it will wake up the consumers on any change, even if the change came from a consumer pulling something off (possibly making it empty) . Perhaps checking for this in the watcher function is sufficient. Another problem I see is that if all consumers are busy, then what happens when a producer adds something new to the queue? Does the watched event get queued up on some consumer agent or does it disappear? see above I really don't know how to do this. I heard that clojure's seque may be useful, but I couldn't find enough doc on how to use it and my initial testing didn't seem to work (sorry don't have the code on me anymore)

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  • Using application roles with DataReader

    - by Shahar
    I have an application that should use an application role from the database. I'm trying to make this work with queries that are actually run using Subsonic (2). To do this, I created my own DataProvider, which inherits from Subsonic's SqlDataProvider. It overrides the CreateConnection function, and calls sp_appsetrole to set the application role after the connection is created. This part works fine, and I'm able to get data using the application role. The problem comes when I try to unset the application role. I couldn't find any place in the code where my provider is called after the query is done, so I tried to add my own, by changing SubSonic code. The problem is that Subsonic uses a data reader. It loads data from the data reader, and then closes it. If I unset the application role before the data reader is closed, I get an error saying: There is already an open DataReader associated with this Command which must be closed first. If I unset the application role after the data reader is closed, I get an error saying ExecuteNonQuery requires an open and available Connection. The connection's current state is closed. I can't seem to find a way to close the data reader without closing the connection.

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  • How to send Event signal through Processes - C

    - by Jamie Keeling
    Hello all! I have an application consisting of two windows, one communicates to the other and sends it a struct constaining two integers (In this case two rolls of a dice). I will be using events for the following circumstances: Process a sends data to process b, process b displays data Process a closes, in turn closing process b Process b closes a, in turn closing process a I have noticed that if the second process is constantly waiting for the first process to send data then the program will be just sat waiting, which is where the idea of implementing threads on each process occurred and I have started to implement this already. The problem i'm having is that I don't exactly have a lot of experience with threads and events so I'm not sure of the best way to actually implement what I want to do. I'm trying to work out how the other process will know of the event being fired so it can do the tasks it needs to do, I don't understand how one process that is separate from another can tell what the states the events are in especially as it needs to act as soon as the event has changed state. Thanks for any help Edit: I can only use the Create/Set/Open methods for events, sorry for not mentioning it earlier.

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  • Returning c_str from a function

    - by user199421
    This is from a small library that I found online: const char* GetHandStateBrief(const PostFlopState* state) { static std::ostringstream out; ... rest of the function ... return out.str().c_str() Now in my code I am doing this: const char *d = GetHandStateBrief(&post); std::cout<< d << std::endl; Now, at first d contained garbage. I then realized that the c string I am getting from the function is destroyed when the function returns because std::ostringstream is allocated on the stack. So I added: return strdup( out.str().c_str()); And now I can get the text I need from the function. I have two questions: 1) Am I understanding this correctly? 2) I later noticed that the ostringstream was was allocated with static storage. Doesn't that mean that the object is supposed to stay in memory until the program terminates? and if so , then why can't I access the string?

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  • Update Datatable and DatagridView with database Changes by Timer

    - by aleroot
    Scenario : i have a database table that is being updated frequently by some services. I have a c# Winforms Application that load this table in a datagridview by binding a datatable as Datasource, then i whant to add a Timer that every 10 seconds update a the content of a datatable with the last changes in the database table ... I don't need to update a database with the datatable changes, but i need to update datatable with the last changes in the database table, that is the inverse of the usually.... Is there a way to do that ? What is the best way ? i've tried with this code : private void ServiceTimer_Tick(object state) { OdbcConnection oCon = new OdbcConnection(); oCon.ConnectionString = ConnectionStrings; OdbcDataAdapter dp = new OdbcDataAdapter("SELECT * FROM table", oCon); dsProva.Tables.Clear(); dp.Fill(dsProva,"table"); dataGridViewMessaggi.DataSource = dsProva.Tables["table"]; dataGridViewMessaggi.Refresh(); } But every Timer Tick i lost the selection in DatagridView and Current Row .... Is There a better solution ?

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  • Fading out everything but (this) - while honoring a click()

    - by Kasper Lewau
    I'm trying to achieve a fading navigation system, where everything in the nav but the element being hovered will fade out to say, 0.3 opacity. At the same time, I want clicks to have a greater "value", so as to not fade out a clicked element (or in this case, the active subpage).. That didn't make much sense to me either, I'll just post the code I have. <nav id="main"> <ul> <li> <a>work</a> </li> <li> <a>about me</a> </li> <li> <a>contact</a> </li> </ul> </nav> And the script that makes it sparkle: var nava = "nav#main ul li a"; $(nava).hover(function(){ $(nava).not(this).removeClass().addClass("inactive"); $(this).addClass("active"); }); $(nava).click(function(){ $(this).removeClass().addClass("active"); }); }); And the classes / css(less): .inactive{color:@color2; border-bottom:0 solid #000;} .active{color:@color1; border-bottom:1px solid #000;} nav#main ul li a{color:@color1;} Basically the hover states take priority over the click, which I do not want to happen. Ideally I'd like for all of the anchor elements to revert to its original state whenever you hover out from the unordered list holding it all. If anyone has some pointers on this it'd be greatly appreciated. Cheers!

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  • Node & Redis: Crucial Design Issues in Production Mode

    - by Ali
    This question is a hybrid one, being both technical and system design related. I'm developing the backend of an application that will handle approx. 4K request per second. We are using Node.js being super fast and in terms of our database struction we are using MongoDB, with Redis being a layer between Node and MongoDB handling volatile operations. I'm quite stressed because we are expecting concurrent requests that we need to handle carefully and we are quite close to launch. However I do not believe I've applied the correct approach on redis. I have a class Student, and they constantly change stages(such as 'active', 'doing homework','in lesson' etc. Thus I created a Redis DB for each state. (1 for being 'active', 2 for being 'doing homework'). Above I have the structure of the 'active' students table; xa5p - JSON stringified object #1 pQrW - JSON stringified object #2 active_student_table - {{studentId:'xa5p'}, {studentId:'pQrW'}} Since there is no 'select all keys method' in Redis, I've been suggested to use a set such that when I run command 'smembers' I receive the keys and later on do 'get' for each id in order to find a specific user (lets say that age older than 15). I've been also suggested that in fact I used never use keys in production mode. My question is, no matter how 'conceptual' it is, what specific things I should avoid doing in Node & Redis in production stage?. Are they any issues related to my design? Students must be objects and I sure can list them in a list but I haven't done yet. Is it that crucial in production stage?

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  • Django: Paginator + raw SQL query

    - by Silver Light
    Hello! I'm using Django Paginator everywhere on my website and even wrote a special template tag, to make it more convenient. But now I got to a state, where I need to make a complex custom raw SQL query, that without a LIMIT will return about 100K records. How can I use Django Pagintor with custom query? Simplified example of my problem: My model: class PersonManager(models.Manager): def complicated_list(self): from django.db import connection #Real query is much more complex cursor.execute("""SELECT * FROM `myapp_person`"""); result_list = [] for row in cursor.fetchall(): result_list.append(row[0]); return result_list class Person(models.Model): name = models.CharField(max_length=255); surname = models.CharField(max_length=255); age = models.IntegerField(); objects = PersonManager(); The way I use pagintation with Django ORM: all_objects = Person.objects.all(); paginator = Paginator(all_objects, 10); try: page = int(request.GET.get('page', '1')) except ValueError: page = 1 try: persons = paginator.page(page) except (EmptyPage, InvalidPage): persons = paginator.page(paginator.num_pages) This way, Django get very smart, and adds LIMIT to a query when executing it. But when I use custom manager: all_objects = Person.objects.complicated_list(); all data is selected, and only then python list is sliced, which is VERY slow. How can I make my custom manager behave similar like built in one?

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  • Return latitude/longitude based on entered address

    - by Don
    I'm building a php based application for a client to enter in addresses for their customers' buildings. They'd like the ability to view the location on a map (either as individuals or grouped in a city search). What I'm trying to accomplish is a lookup once the address is entered into a form that populates the database, so after they enter in the addresss, city, state, zip (these are all US locations) they could click a "get lat/long info" link/button that would check to make sure the data is complete, then would lookup the address and return the latitude/longitude into the appropriate form fields. Then the form could be submitted to store the info, and I could later just pull the lat/long when plotting on a map. 1) Does this make sense, or would I be better off just doing the lookup when it's time to plot it? 2) Does anyone have any pointers to solve this problem? I've seen some of the Google/Yahoo API's but it looks like this is more based on the plotting a point part. I may be able to modify it to suit my needs, but I'm just trying to cut some research time posting here with the hopes one of you may have a more direct route. I'll RTFM if I have to... Thanks, D.

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