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• Building a custom CMS, how to handle page settings?

  - by davidosomething

  Not a coldfusion specific question so answer however you can. I've inherited a ColdFusion project where at the top of every page various page-setting specific variables are set, such as: <cfset request.page.title = "Example Page"> <cfset request.page.machineTitle = "example_page"> <cfset request.page.isJQueryEnabled = 1> <cfset request.page.showNavigation = 1> <cfset request.page.SWFObjectVersion = 2.2> I'm thinking about creating a database table with just integer page_id varchar key varchar value I'd reduce the variables at the top of every page to just the page id, and then call the DB for the correct settings. Is this a good idea? I hate reinventing the wheel, but this is a really big project that would require many months for a full content migration to a CMS. What are the current practices for storing page settings? (e.g., what does WordPress do? Drupal? etc.)

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• Web framework with JasperReports integration?

  - by Dave Jarvis

  What web development frameworks natively support JasperReports? Consider the following form as an example: <form name="report" method="post"> <input type="hidden" name="REPORT_PATH" value="reports/Names" /> <input type="hidden" name="REPORT_FILE" value="List" /> <input type="hidden" name="REPORT_FORMAT" value="pdf" /> <input type="hidden" name="REPORT_EMBED" value="false" /> Name: <input type="text" name="report_Name" value="" /><br /> Date: <input type="text" name="report_Date" value="" /><br /> <input type="submit" name="View" value="View" /> </form> The framework would pass the report_ parameters to JasperReports, which in turn runs reports/Names/List.jasper, and then sends a PDF attachment to the browser. In general: Ability to configure report (i.e., the hidden REPORT_ variables) Web FORM for setting report parameters (i.e., the report_ variables) Framework handles configuring database connection, report execution, etc. I don't care about the technical minutia on how the integration works. The example above is just one possibility of many.

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• Can I compare a template variable to an integer in Django/App Engine templates?

  - by matt b

  Using Django templates in Google App Engine (on Python), is it possible to compare a template variable to an integer in an {% if %} block? views.py: class MyHandler(webapp.RequestHandler): def get(self): foo_list = db.GqlQuery(...) ... template_values['foos'] = foo_list template_values['foo_count'] = len(foo_list) handler.response.out.write(template.render(...)) My template: {% if foo_count == 1 %} There is one foo. {% endif %} This blows up with 'if' statement improperly formatted. What I was attempting to do in my template was build a simple if/elif/else tree to be grammatically correct to be able to state #foo_count == 0: There are no foos. #foo_count == 1: There is one foo. #else: There are {{ foos|length }} foos. Browsing the Django template documents (this link provided in the GAE documentation appears to be for versions of Django far newer than what is supported on GAE), it appears as if I can only actually use boolean operators (if in fact boolean operators are supported in this older version of Django) with strings or other template variables. Is it not possible to compare variables to integers or non-strings with Django templates? I'm sure there is an easy way to workaround this - built up the message string on the Python side rather than within the template - but this seems like such a simple operation you ought to be able to handle in a template. It sounds like I should be switching to a more advanced templating engine, but as I am new to Django (templates or any part of it), I'd just like some confirmation first.

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• How do I use a variable within an extended class public variable

  - by Gerry Humphrey

  Have a class that I am using, I am overriding variables in the class to change them to what values I need, but I also not sure if or how to handle an issue. I need to add a key that is generated to each of this URLs before the class calls them. I cannot modify the class file itself. use Theme/Ride class ETicket extends Ride { public $key='US20120303'; // Not in original class public $accessURL1 = 'http://domain.com/keycheck.php?key='.$key; public $accessURL2 = 'http://domain.com/keycheck.php?key='.$key; } I understand that you cannot use a variable in the setting of the public class variables. Just not sure what would be the way to actually do something like this in the proper format. My OOP skills are weak. I admit it. So if someone has a suggestion on where I could read up on it and get a clue, it would be appreciated as well. I guess I need OOP for Dummies. =/

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• accessing a method from a button within a class?

  - by flo

  #import "GameObject.h" #import "Definitions.h" @implementation GameObject @synthesize owner; @synthesize state; @synthesize mirrored; @synthesize button; @synthesize switcher; - (id) init { if ( self = [super init] ) { [self setOwner: EmptyField]; button = [UIButton buttonWithType:UIButtonTypeCustom]; [self setSwitcher: FALSE]; } return self; } - (UIButton*) display{ button.frame = CGRectMake(0, 0, GO_Width, GO_Height); [button setBackgroundImage:[UIImage imageNamed:BlueStone] forState:UIControlStateNormal]; [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside]; return button; } -(void)buttonPressed:(id) sender { //... } } - (void) dealloc { [super dealloc]; } @end Hi! i would like to know if the above is possible somehow within a class (in my case it is called GameObject) or if i HAVE to have the button call a methode in the viewcontroller... the above results with the app crashing. i would call display within a loop on the viewcontroller and id like to change some of the GameObjects instance variables within buttonPressed. Also id like to change some other stuff by calling some other methods from within buttonPressed but i think that will be the lesser of my problems ;) also id like to know how i can pass some variables to the buttonPressed method... cant find it anywhere :( help on this one would be much appreciated ;) thanks flo

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• From where starts the process' memory space and where does it end?

  - by nhaa123

  Hi, I'm trying to dump memory from my application where the variables lye. Here's the function: void MyDump(const void *m, unsigned int n) { const unsigned char *p = reinterpret_cast<const unsigned char *(m); char buffer[16]; unsigned int mod = 0; for (unsigned int i = 0; i < n; ++i, ++mod) { if (mod % 16 == 0) { mod = 0; std::cout << " | "; for (unsigned short j = 0; j < 16; ++j) { switch (buffer[j]) { case 0xa: case 0xb: case 0xd: case 0xe: case 0xf: std::cout << " "; break; default: std::cout << buffer[j]; } } std::cout << "\n0x" << std::setfill('0') << std::setw(8) << std::hex << (long)i << " | "; } buffer[i % 16] = p[i]; std::cout << std::setw(2) << std::hex << static_cast<unsigned int(p[i]) << " "; if (i % 4 == 0 && i != 1) std::cout << " "; } } Now, how can I know from which address starts my process memory space, where all the variables are stored? And how do I now, how long the area is? For instance: MyDump(0x0000 /* <-- Starts from here? */, 0x1000 /* <-- This much? */); Best regards, nhaa123

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• Using Parameter Values In SQL Statement

  - by Dangerous

  I am trying to write a database script (SQL SERVER 2008) which will copy information from database tables on one server to corresponding tables in another database on a different server. I have read that the correct way to do this is to use a sql statement in a format similar to the following: INSERT INTO <linked_server>.<database>.<owner>.<table_name> SELECT * FROM <linked_server>.<database>.<owner>.<table_name> As there will be several tables being copied, I would like to declare variables at the top of the script to allow the user to specify the names of each server and database that are to be used. These could then be used throughout the script. However, I am not sure how to use the variable values in the actual SQL statements. What I want to achieve is something like the following: DECLARE @SERVER_FROM AS NVARCHAR(50) = 'ServerFrom' DECLARE @DATABASE_FROM AS NVARCHAR(50) = 'DatabaseTo' DECLARE @SERVER_TO AS NVARCHAR(50) = 'ServerTo' DECLARE @DATABASE_TO AS NVARCHAR(50) = 'DatabaseTo' INSERT INTO @SERVER_TO.@DATABASE_TO.dbo.TableName SELECT * FROM @SERVER_FROM.@DATABASE_FROM.dbo.TableName ... How should I use the @ variables in this code in order for it to work correctly? Additionally, do you think my method above is correct for what I am trying to achieve and should I be using NVARCHAR(50) as my variable type or something else? Thanks

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• How do you store accented characters coming from a web service into a database?

  - by Thierry Lam

  I have the following word that I fetch via a web service: André From Python, the value looks like: "Andr\u00c3\u00a9". The input is then decoded using json.loads: >>> import json >>> json.loads('{"name":"Andr\\u00c3\\u00a9"}') >>> {u'name': u'Andr\xc3\xa9'} When I store the above in a utf8 MySQL database, the data is stored like the following using Django: SomeObject.objects.create(name=u'Andr\xc3\xa9') Querying the name column from a mysql shell or displaying it in a web page gives: André The web page displays in utf8: <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> My database is configured in utf8: mysql> SHOW VARIABLES LIKE 'collation%'; +----------------------+-----------------+ | Variable_name | Value | +----------------------+-----------------+ | collation_connection | utf8_general_ci | | collation_database | utf8_unicode_ci | | collation_server | utf8_unicode_ci | +----------------------+-----------------+ 3 rows in set (0.00 sec) mysql> SHOW VARIABLES LIKE 'character_set%'; +--------------------------+----------------------------+ | Variable_name | Value | +--------------------------+----------------------------+ | character_set_client | utf8 | | character_set_connection | utf8 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | utf8 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /usr/share/mysql/charsets/ | +--------------------------+----------------------------+ 8 rows in set (0.00 sec) How can I retrieve the word André from a web service, store it properly in a database with no data loss and display it on a web page in its original form?

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• Why is this JLabel continuously repainting?

  - by Morinar

  I've got an item that appears to continuously repaint when it exists, causing the CPU to spike whenever it is in any of my windows. It directly inherits from a JLabel, and unlike the other JLabels on the screen, it has a red background and a border. I have NO idea why it would be different enough to continuously repaint. The callstack looks like this: Thread [AWT-EventQueue-1] (Suspended (breakpoint at line 260 in sItem)) sItem.paint(Graphics) line: 260 sItem(JComponent).paintToOffscreen(Graphics, int, int, int, int, int, int) line: 5124 RepaintManager$PaintManager.paintDoubleBuffered(JComponent, Image, Graphics, int, int, int, int) line: 1475 RepaintManager$PaintManager.paint(JComponent, JComponent, Graphics, int, int, int, int) line: 1406 RepaintManager.paint(JComponent, JComponent, Graphics, int, int, int, int) line: 1220 sItem(JComponent)._paintImmediately(int, int, int, int) line: 5072 sItem(JComponent).paintImmediately(int, int, int, int) line: 4882 RepaintManager.paintDirtyRegions(Map<Component,Rectangle>) line: 803 RepaintManager.paintDirtyRegions() line: 714 RepaintManager.seqPaintDirtyRegions() line: 694 [local variables unavailable] SystemEventQueueUtilities$ComponentWorkRequest.run() line: 128 InvocationEvent.dispatch() line: 209 summitEventQueue(EventQueue).dispatchEvent(AWTEvent) line: 597 summitEventQueue(SummitHackableEventQueue).dispatchEvent(AWTEvent) line: 26 summitEventQueue.dispatchEvent(AWTEvent) line: 62 EventDispatchThread.pumpOneEventForFilters(int) line: 269 EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: 184 EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: 174 EventDispatchThread.pumpEvents(int, Conditional) line: 169 EventDispatchThread.pumpEvents(Conditional) line: 161 EventDispatchThread.run() line: 122 [local variables unavailable] It basically just continually hits that over and over again as fast as I can press continue. The code that is "unique" to this particular label looks approximately like this: bgColor = OurColors.clrWindowTextAlert; textColor = Color.white; setBackground(bgColor); setOpaque(true); setSize(150, getHeight()); Border border_warning = BorderFactory.createCompoundBorder( BorderFactory.createMatteBorder(1, 1, 1, 1, OurColors.clrXBoxBorder), Global.border_left_margin); setBorder(border_warning); It obviously does more, but that particular block only exists for these labels that are causing the spike/continuous repaint. Any ideas why it would keep repainting this particular label?

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• Creating a simple JQuery tooltip?

  - by Mike El Panther

  Has anybody here got any experience in creating simple tooptips using JQuery? I have created a table: <tr id="mon_Section"> <td id="day_Title">Monday</td>` <td id="mon_Row" onmousemove="calculate_Time(event)"></td> </tr>` the function "calculate_Time" will be called and this gets the X position of the mouse cursor and from the value, uses IF and ELSE-IF statements to calculate the values of other variables i have created: var mon_Pos; var hour; var minute; var orig; var myxpos; function calculate_Time(event) { myxpos = event.pageX; myxpos = myxpos-194; if (myxpos<60) { orig = myxpos; minute = myxpos; hour = 07; } else if (myxpos>=60 && myxpos<120) { orig = myxpos; minute=myxpos-60; hour=08; } } How do i go about creating a stylized tooltip containing the Hour and Minute variables that i created, I need the tooltip to be updated everytime the X position of the cursor changes. I know that with myxpos variable does change whenever the mouse is moved because i tried it out using an alert(myxpos) and as expected, if the mouse moves, a new alert box popups with a new value. I just cant work out how to place that value in a tooltip?

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• How can I optimize retrieving lowest edit distance from a large table in SQL?

  - by Matt

  Hey, I'm having troubles optimizing this Levenshtein Distance calculation I'm doing. I need to do the following: Get the record with the minimum distance for the source string as well as a trimmed version of the source string Pick the record with the minimum distance If the min distances are equal (original vs trimmed), choose the trimmed one with the lowest distance If there are still multiple records that fall under the above two categories, pick the one with the highest frequency Here's my working version: DECLARE @Results TABLE ( ID int, [Name] nvarchar(200), Distance int, Frequency int, Trimmed bit ) INSERT INTO @Results SELECT ID, [Name], (dbo.Levenshtein(@Source, [Name])) As Distance, Frequency, 'False' As Trimmed FROM MyTable INSERT INTO @Results SELECT ID, [Name], (dbo.Levenshtein(@SourceTrimmed, [Name])) As Distance, Frequency, 'True' As Trimmed FROM MyTable SET @ResultID = (SELECT TOP 1 ID FROM @Results ORDER BY Distance, Trimmed, Frequency) SET @Result = (SELECT TOP 1 [Name] FROM @Results ORDER BY Distance, Trimmed, Frequency) SET @ResultDist = (SELECT TOP 1 Distance FROM @Results ORDER BY Distance, Trimmed, Frequency) SET @ResultTrimmed = (SELECT TOP 1 Trimmed FROM @Results ORDER BY Distance, Trimmed, Frequency) I believe what I need to do here is to.. Not dumb the results to a temporary table Do only 1 select from `MyTable` Setting the results right in the select from the initial select statement. (Since select will set variables and you can set multiple variables in one select statement) I know there has to be a good implementation to this but I can't figure it out... this is as far as I got: SELECT top 1 @ResultID = ID, @Result = [Name], (dbo.Levenshtein(@Source, [Name])) As distOrig, (dbo.Levenshtein(@SourceTrimmed, [Name])) As distTrimmed, Frequency FROM MyTable WHERE /* ... yeah I'm lost */ ORDER BY distOrig, distTrimmed, Frequency Any ideas?

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• Natural problems to solve using closures

  - by m.u.sheikh

  I have read quite a few articles on closures, and, embarassingly enough, I still don't understand this concept! Articles explain how to create a closure with a few examples, but I don't see any point in paying much attention to them, as they largely look contrived examples. I am not saying all of them are contrived, just that the ones I found looked contrived, and I dint see how even after understanding them, I will be able to use them. So in order to understand closures, I am looking at a few real problems, that can be solved very naturally using closures. For instance, a natural way to explain recursion to a person could be to explain the computation of n!. It is very natural to understand a problem like computing the factorial of a number using recursion. Similarly, it is almost a no-brainer to find an element in an unsorted array by reading each element, and comparing with the number in question. Also, at a different level, doing Object-oriented programming also makes sense. So I am trying to find a number of problems that could be solved with or without closures, but using closures makes thinking about them and solving them easier. Also, there are two types to closures, where each call to a closure can create a copy of the environment variables, or reference the same variables. So what sort of problems can be solved more naturally in which of the closure implementations?

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• C ] How can I handle weird errors from calculating acos / sin / atan2?

  - by Phrixus

  Has anyone seen this weird value while handling sin / cos/ tan / acos.. math stuff? ===THE WEIRD VALUE=== -1.#IND00 ===================== void inverse_pos(double x, double y, double& theta_one, double& theta_two) { // Assume that L1 = 350 and L2 = 250 double B = sqrt(x*x + y*y); double angle_beta = atan2(y, x); double angle_alpha = acos((L2*L2 - B*B - L1*L1) / (-2*B*L1)); theta_one = angle_beta + angle_alpha; theta_two = atan2((y-L1*sin(theta_one)), (x-L1*cos(theta_one))); } This is the code I was working on. In a particular condition - like when x & y are 10 & 10, this code stores -1.#IND00 into theta_one & theta_two. It doesn't look like either characters or numbers :( Without a doubt, atan2 / acos / stuff are the problems. But the problem is, try and catch doesn't work either cuz those double variables have successfully stored some values in them. Moreover, the following calculations never complain about it and never break the program! I'm thinking of forcing to use this value somehow and make the entire program crash... So that I can catch this error.. Except for that idea, I have no idea how I should check whether these theta_one and theta_two variables have stored this crazy values. Any good ideas? Thank you in advance..

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• how to implement enhanced session handling in PHP

  - by praksant

  Hi, i'm working with sessions in PHP, and i have different applications on single domain. Problem is, that cookies are domain specific, and so session ids are sent to any page on single domain. (i don't know if there is a way to make cookies work in different way). So Session variables are visible in every page on this domain. I'm trying to implement custom session manager to overcome this behavior, but i'm not sure if i'm thinking about it right. I want to completely avoid PHP session system, and make a global object, which would store session data and on the end of script save it to database. On first access i would generate unique session_id and create a cookie On the end of script save session data with session_id, timestamps for start of session and last access, and data from $_SERVER, such as REMOTE_ADDR, REMOTE_PORT, HTTP_USER_AGENT. On every access chceck database for session_id sent in cookie from client, check IP, Port and user agent (for security) and read data into session variable (if not expired). If session_id expired, delete from database. That session variable would be implemented as singleton (i know i would get tight coupling with this class, but i don't know about better solution). I'm trying to get following benefits: Session variables invisible in another scripts on the same server and same domain Custom management of session expiration Way to see open sessions (something like list of online users) i'm not sure if i'm overlooking any disadvantages of this solution. Is there any better way? Thank you!!

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• How to cope with null results in SQL Tasks that return single rows in SSIS 2005?

  - by JSacksteder

  In a dataflow task, I can slip a rowcount into the processing flow and place the count into a variable. I can later use that variable to conditionally perform some other work if the rowcount was 0. This works well for me, but I have no corresponding strategy for sql tasks expected to return a single row. In that event, I'm returning those values into variables. If the lookup produces no rows, the sql task fails when assigning values into those variables. I can branch on that component failing, but there's a side effect of that - if I'm running the job as a SQL server agent job step, the step returns DTSER_FAILURE, causing the step to fail. I can tell the sql agent to disregard the step failure, but then I won't know if I have a legitimate error in that step. This seems harder than it should be. The only strategy I can think of is to run the same query with a count(*) aggregate and test if that returns a number 0 and if so running the query again without the count. That's ugly because I have the same query in two places that I need to keep in sync. Is there a better way?

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• Showing latex commands in text string using mathjax

  - by robezy

  I have a text string, for ex. 'A vehicle travels from A to B, distance {$d} km at constant speed. While returning back to A on same path it {$variation} its speed by {$v} km/hr. The total time of journey is {$t} hours. Find the original speed of vehicle.' The variables in the curly brackets are to be replaced by appropriate latex equation. I'm using php's preg_replace to replace the variables with latex commands. Unfortunately, my latex commands are coming as it is. It is not processed by mathjax. For ex, above text becomes A vehicle travels from A to B, distance 1 km at constant speed. While returning back to A on same path it increased its speed by (\frac{3}{2}) km/hr. The total time of journey is 1 hours. Find the original speed of vehicle. The frac is show as it is. What is wrong here? Please ask me if you need any more info. Thanks

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• charsets in MySQL replication

  - by niklassaers

  Hi guys, What can I do to ensure that replication will use latin1 instead of utf-8? I'm migrating between an MySQL 5.1.22 server (master) on a Linux system and a MySQL 5.1.42 server (slave) on a FreeBSD system. My replication works well, but when non-ascii characters are in my varchars, they turn "weird". The Linux/MySQL-5.1.22 shows the following character set variables: character_set_client=latin1 character_set_connection=latin1 character_set_database=latin1 character_set_filesystem=binary character_set_results=latin1 character_set_server=latin1 character_set_system=utf8 character_sets_dir=/usr/share/mysql/charsets/ collation_connection=latin1_swedish_ci collation_database=latin1_swedish_ci collation_server=latin1_swedish_ci While the FreeBSD shows character_set_client=utf8 character_set_connection=utf8 character_set_database=utf8 character_set_filesystem=binary character_set_results=utf8 character_set_server=utf8 character_set_system=utf8 character_sets_dir=/usr/local/share/mysql/charsets/ collation_connection=utf8_general_ci collation_database=utf8_general_ci collation_server=utf8_general_ci Setting any of these variables from the MySQL CLI has no effect, and setting them in my.cnf or at the command line makes the server not start. Of course, both servers have the tables in question created the same way, in this case with DEFAULT CHARSET=latin1. Let me give you an example: CREATE TABLE `test` ( `test` varchar(5) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 When I on the master do, in a Latin1 terminal, "INSERT INTO test VALUES ('æøå')", this becomes on the slave, when I select it from a Latin1 based terminal +--------+ | test | +--------+ | æøå | +--------+ On a UTF-8 based terminal on the replication slave, test contains: +--------+ | test | +--------+ | æøå | +--------+ So my conclusion is that it is converted to utf8, even though the table definition is latin1. Is this a correct conclusion? Of course, on the master, in a latin1 terminal, it still says: +------+ | test | +------+ | æøå | +------+ Since both system character sets are utf-8, if I set both terminals to utf-8 and do again "INSERT INTO test VALUES ('æøå')" on the master with a utf-8 terminal, on the slave with utf-8 I get: +------------+ | test | +------------+ | æøà | +------------+ If my conclusion is correct, all my replicated data is converted to utf8 (if it is utf8, it is treated as latin1 and converted to utf8), while all the old data in the table is, as the CREATE TABLE suggests, latin1. I'd love to convert it all to utf-8 if it weren't for the fact that legacy applications rely on it being latin1, so I need to keep it in latin1 while they still exist. What can I do to ensure that the replication reads latin1, treats it as latin1 and writes it on the slave as latin1? Cheers Nik

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• Why is debugging better in an IDE?

  - by Bill Karwin

  I've been a software developer for over twenty years, programming in C, Perl, SQL, Java, PHP, JavaScript, and recently Python. I've never had a problem I could not debug using some careful thought, and well-placed debugging print statements. I respect that many people say that my techniques are primitive, and using a real debugger in an IDE is much better. Yet from my observation, IDE users don't appear to debug faster or more successfully than I can, using my stone knives and bear skins. I'm sincerely open to learning the right tools, I've just never been shown a compelling advantage to using visual debuggers. Moreover, I have never read a tutorial or book that showed how to debug effectively using an IDE, beyond the basics of how to set breakpoints and display the contents of variables. What am I missing? What makes IDE debugging tools so much more effective than thoughtful use of diagnostic print statements? Can you suggest resources (tutorials, books, screencasts) that show the finer techniques of IDE debugging? Sweet answers! Thanks much to everyone for taking the time. Very illuminating. I voted up many, and voted none down. Some notable points: Debuggers can help me do ad hoc inspection or alteration of variables, code, or any other aspect of the runtime environment, whereas manual debugging requires me to stop, edit, and re-execute the application (possibly requiring recompilation). Debuggers can attach to a running process or use a crash dump, whereas with manual debugging, "steps to reproduce" a defect are necessary. Debuggers can display complex data structures, multi-threaded environments, or full runtime stacks easily and in a more readable manner. Debuggers offer many ways to reduce the time and repetitive work to do almost any debugging tasks. Visual debuggers and console debuggers are both useful, and have many features in common. A visual debugger integrated into an IDE also gives you convenient access to smart editing and all the other features of the IDE, in a single integrated development environment (hence the name).

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• How is a referencing environment generally implemented for closures?

  - by Alexandr Kurilin

  Let's say I have a statically/lexically scoped language with deep binding and I create a closure. The closure will consist of the statements I want executed plus the so called referencing environment, or, to quote this post, the collection of variables which can be used. What does this referencing environment actually look like implementation-wise? I was recently reading about ObjectiveC's implementation of blocks, and the author suggests that behind the scenes you get a copy of all of the variables on the stack and also of all the references to heap objects. The explanation claims that you get a "snapshot" of the referencing environment at the point in time of the closure's creation. Is that more or less what happens, or did I misread that? Is anything done to "freeze" a separate copy of the heap objects, or is it safe to assume that if they get modified between closure creation and the closure executing, the closure will no longer be operating on the original version of the object? If indeed there's copying being made, are there memory usage considerations in situations where one might want to create plenty of closures and store them somewhere? I think that misunderstanding of some of these concepts might lead to tricky issues like the ones Eric Lippert mentions in this blog post. It's interesting because you'd think that it wouldn't make sense to keep a reference to a value type that might be gone by the time the closure is called, but I'm guessing that in C# the compiler will figure out that the variable is needed later and put it into the heap instead. It seems that in most memory-managed languages everything is a reference and thus ObjectiveC is a somewhat unique situation with having to deal with copying what's on the stack.

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• Django: How can I identify the calling view from a template?

  - by bryan

  Short version: Is there a simple, built-in way to identify the calling view in a Django template, without passing extra context variables? Long (original) version: One of my Django apps has several different views, each with its own named URL pattern, that all render the same template. There's a very small amount of template code that needs to change depending on the called view, too small to be worth the overhead of setting up separate templates for each view, so ideally I need to find a way to identify the calling view in the template. I've tried setting up the views to pass in extra context variables (e.g. "view_name") to identify the calling view, and I've also tried using {% ifequal request.path "/some/path/" %} comparisons, but neither of these solutions seems particularly elegant. Is there a better way to identify the calling view from the template? Is there a way to access to the view's name, or the name of the URL pattern? Update 1: Regarding the comment that this is simply a case of me misunderstanding MVC, I understand MVC, but Django's not really an MVC framework. I believe the way my app is set up is consistent with Django's take on MVC: the views describe which data is presented, and the templates describe how the data is presented. It just happens that I have a number of views that prepare different data, but that all use the same template because the data is presented the same way for all the views. I'm just looking for a simple way to identify the calling view from the template, if this exists. Update 2: Thanks for all the answers. I think the question is being overthought -- as mentioned in my original question, I've already considered and tried all of the suggested solutions -- so I've distilled it down to a "short version" now at the top of the question. And right now it seems that if someone were to simply post "No", it'd be the most correct answer :) Update 3: Carl Meyer posted "No" :) Thanks again, everyone.

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• BASH echo write mysql input

  - by jmituzas

  Have a bash menu where variables write to file for mysql input. heres what I have: echo "CREATE DATABASE '$mysqldbn'; #GRANT ALL PRIVILEGES ON *.* TO '$mysqlu'@'$myhost' IDENTIFIED BY '$mysqlup' WITH GRANT OPTION; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON '$mysqldbn'.* TO '$mysqlu'@'$myhost' IDENTIFIED BY '$mysqlup'; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON '$mysqldbn'.* TO '$mysqlu'@'$myip' IDENTIFIED BY '$mysqlup'; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON '$mysqldbn'.* TO '$mysqlu'@'localhost' IDENTIFIED BY '$mysqlup'; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES< LOCK TABLES on '$mysqldbn'.* TO '$mysqlu'@'$rip' IDENTIFIED BY '$mysqlup';" > nmysql.db mysql -u root -p$mypass < nmysql.db problem is to get variables to show I had to put them in single quotes, the single quotes show up as I want for instances like '$mysqlu'@'localhost'. But how can I remove the quotes and still get to use the variable in the instance like, CREATE DATABASE '$mysqldbn' ? Double quotes wont work either, I am at a loss. Thanks in advance, Joe

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• Partial template specialization for more than one typename

  - by Matt Joiner

  In the following code, I want to consider functions (Ops) that have void return to instead be considered to return true. The type Retval, and the return value of Op are always matching. I'm not able to discriminate using the type traits shown here, and attempts to create a partial template specialization based on Retval have failed due the presence of the other template variables, Op and Args. How do I specialize only some variables in a template specialization without getting errors? Is there any other way to alter behaviour based on the return type of Op? template <typename Retval, typename Op, typename... Args> Retval single_op_wrapper( Retval const failval, char const *const opname, Op const op, Cpfs &cpfs, Args... args) { try { CallContext callctx(cpfs, opname); Retval retval; if (std::is_same<bool, Retval>::value) { (callctx.*op)(args...); retval = true; } else { retval = (callctx.*op)(args...); } assert(retval != failval); callctx.commit(cpfs); return retval; } catch (CpfsError const &exc) { cpfs_errno_set(exc.fserrno); LOGF(Info, "Failed with %s", cpfs_errno_str(exc.fserrno)); } return failval; }

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• segmentation fault in file operations in c

  - by mekasperasky

  #include<stdio.h> /* this is a lexer which recognizes constants , variables ,symbols, identifiers , functions , comments and also header files . It stores the lexemes in 3 different files . One file contains all the headers and the comments . Another file will contain all the variables , another will contain all the symbols. */ int main() { int i; char a,b[20],c; FILE *fp1; fp1=fopen("source.txt","r"); //the source file is opened in read only mode which will passed through the lexer //now lets remove all the white spaces and store the rest of the words in a file if(fp1==NULL) { perror("failed to open source.txt"); //return EXIT_FAILURE; } i=0; while(1) { a=fgetc(fp1); if(a !="") { b[i]=a; } else { fprintf(fp1, "%.20s\n", b); i=0; continue; } i=i+1; /*Switch(a) { case EOF :return eof; case '+':sym=sym+1; case '-':sym=sym+1; case '*':sym=sym+1; case '/':sym=sym+1; case '%':sym=sym+1; case ' */ } return 0; } how does this code end up in segmentation fault?

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• Drupal theme preprocess function - primary links and suckerfish menus

  - by slimcady

  I have a preprocess function that works fine when the menu is single level list. However I would like it to work w/ suckerfish menus. I want to add a class to the top level menu item so that I can style it. This is the code I used for the single level menu: function cti_flex_preprocess_page(&$vars, $hook) { // Make a shortcut for the primary links variables $primary_links = $vars['primary_links']; // Loop thru the menu, adding a new class for CSS selectors $i = 1; foreach ($primary_links as $link => $attributes){ // Append the new class to existing classes for each menu item $class = $attributes['attributes']['class'] . " item-$i"; // Add revised classes back to the primary links temp variable $primary_links[$link]['attributes']['class'] = $class; $link['title'] = '<span class="hide">' . check_plain($link['title']) . '</span>'; $i++; } // end the foreach loop // reset the variable to contain the new markup $vars['primary_links'] = $primary_links; } I've been trying to use the menu_tree() function to no avail, for example: function cti_flex_preprocess_page(&$vars, $hook) { // Make a shortcut for the primary links variables $primary_links = $vars['primary_links']; // Loop thru the menu, adding a new class for CSS selectors $i = 1; foreach ($primary_links as $link => $attributes){ // Append the new class to existing classes for each menu item $class = $attributes['attributes']['class'] . " item-$i"; // Add revised classes back to the primary links temp variable $primary_links[$link]['attributes']['class'] = $class; $link['title'] = '<span class="hide">' . check_plain($link['title']) . '</span>'; $i++; } // end the foreach loop // reset the variable to contain the new markup $vars['primary_links_tree'] = menu_tree(variable_get('menu_primary_links_source', '$primary_links')); } Any ideas would be greatly appreciated.

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• Slope requires a real as parameter 2?

  - by Dave Jarvis

  Question How do you pass the correct value to udf_slope's second parameter type? Attempts CAST(Y.YEAR AS FLOAT), but that failed (SQL error). Y.YEAR + 0.0, but that failed, too (see error message). slope(D.AMOUNT, 1.0), failed as well Error Message Using udf_slope fails due to: Can't initialize function 'slope'; slope() requires a real as parameter 2 Code SELECT D.AMOUNT, Y.YEAR, slope(D.AMOUNT, Y.YEAR + 0.0) as SLOPE, intercept(D.AMOUNT, Y.YEAR + 0.0) as INTERCEPT FROM YEAR_REF Y, DAILY D Here, D.AMOUNT is a FLOAT and Y.YEAR is an INTEGER. Create Function The slope function was created as follows: CREATE AGGREGATE FUNCTION slope RETURNS REAL SONAME 'udf_slope.so'; Function Signature From udf_slope.cc: double slope( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* is_error ) Example Usages Reading the fine manual reveals: UDF intercept() Calculates the intercept of the linear regression of two sets of variables. Function name intercept Input parameter(s) 2 (dependent variable: REAL, independent variable: REAL) Examples SELECT intercept(income,age) FROM customers UDF slope() Calculates the slope of the linear regression of two sets of variables. Function name slope Input parameter(s) 2 (dependent variable: REAL, independent variable: REAL) Examples SELECT slope(income,age) FROM customers Thoughts? Thank you!

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