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  • What's the difference between => , ()=>, and Unit=>

    - by Malvolio
    I'm trying to represent a function that takes no arguments and returns no value (I'm simulating the setTimeout function in JavaScript, if you must know.) case class Scheduled(time : Int, callback : => Unit) doesn't compile, saying " `val' parameters may not be call-by-name" case class Scheduled(time : Int, callback : () => Unit) compiles, but has to be invoked strangely, instead of Scheduled(40, { println("x") } ) I have to do this Scheduled(40, { () => println("x") } ) What also works is class Scheduled(time : Int, callback : Unit => Unit) but is invoked in an even-less-sensible way Scheduled(40, { x : Unit => println("x") } ) (What would a variable of type Unit be?) What I want of course is a constructor that can be invoke the way I would invoke it if it were an ordinary function: Scheduled(40, println("x") ) Give baby his bottle!

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  • Switching from php to python

    - by ts
    Hello I am trying to make a list of things which can be difficult/surprising to someone who is changing language from PHP to Python. so far i have rather short list: forget require / include, learn import (this was most difficult to me - to understand package - module - class - object hierarchy and its mapping to filesystem) you can't just upload file on server to have webpage (-mod_python, wsgi etc) learn the python way for use variable class names (new $class() vs import + getattr) / operator in python 2.x and all float-related horrors those were difficult to me, it takes few days before mind adapts a new paradigm after i found that there is few other areas which could be challenging for someone with (too) many years of php: everything is an object you have to live with exceptions array vs list, set, dictionary, tuple ... learn (effective) list comprehensions learn generators any other ideas / personal experiences ?

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  • how to use constants in SQL CREATE TABLE?

    - by kchiu
    Hi, I have 3 SQL tables, defined as follows: CREATE TABLE organs( abbreviation VARCHAR(16), -- ... other stuff ); CREATE TABLE blocks( abbreviation VARCHAR(16), -- ... other stuff ); CREATE TABLE slides( title VARCHAR(16), -- ... other stuff ); The 3 fields above all use VARCHAR(16) because they're related and have the same length restriction. Is there a (preferably portable) way to put '16' into a constant / variable and reference that instead in CREATE TABLE? eg. something like this would be nice: CREATE TABLE slides( title VARCHAR(MAX_TITLE_LENGTH), -- ... other stuff ); I'm using PostgreSQL 8.4. thanks a lot, and Happy New Year! cheers.

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  • Subtype polymorphism and arrays

    - by user133466
    Computer[] labComputers = new Computer[10]; with public class Computer { ... void toString(){ // print computer specs } } public class Notebook extends Computer{ ... void toString(){ // print computer specs + laptop color } } each subscripted variable labComputers[i] can reference either a Computer object or a Notebook object because Notebook is a subclass of Computer. For the method call labComputers[i].toString(), polymorphism ensures that the correct toString method is called. I wonder what if we do Notebook[] labComputers = new Notebook[10]; what kind or error would I get if I reference with Computer object and a Notebook object

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  • files get uploaded just before they get cancelled

    - by user1763986
    Got a little situation here where I am trying to cancel a file's upload. What I have done is stated that if the user clicks on the "Cancel" button, then it will simply remove the iframe so that it does not go to the page where it uploads the files into the server and inserts data into the database. Now this works fine if the user clicks on the "Cancel" button in quickish time the problem I have realised though is that if the user clicks on the "Cancel" button very late, it sometimes doesn't remove the iframe in time meaning that the file has just been uploaded just before the user has clicked on the "Cancel" button. So my question is that is there a way that if the file does somehow get uploaded before the user clicks on the "Cancel" button, that it deletes the data in the database and removes the file from the server? Below is the image upload form: <form action="imageupload.php" method="post" enctype="multipart/form-data" target="upload_target_image" onsubmit="return imageClickHandler(this);" class="imageuploadform" > <p class="imagef1_upload_process" align="center"> Loading...<br/> <img src="Images/loader.gif" /> </p> <p class="imagef1_upload_form" align="center"> <br/> <span class="imagemsg"></span> <label>Image File: <input name="fileImage" type="file" class="fileImage" /></label><br/> <br/> <label class="imagelbl"><input type="submit" name="submitImageBtn" class="sbtnimage" value="Upload" /></label> </p> <p class="imagef1_cancel" align="center"> <input type="reset" name="imageCancel" class="imageCancel" value="Cancel" /> </p> <iframe class="upload_target_image" name="upload_target_image" src="#" style="width:0px;height:0px;border:0px;solid;#fff;"></iframe> </form> Below is the jquery function which controls the "Cancel" button: $(imageuploadform).find(".imageCancel").on("click", function(event) { $('.upload_target_image').get(0).contentwindow $("iframe[name='upload_target_image']").attr("src", "javascript:'<html></html>'"); return stopImageUpload(2); }); Below is the php code where it uploads the files and inserts the data into the database. The form above posts to this php page "imageupload.php": <body> <?php include('connect.php'); session_start(); $result = 0; //uploads file move_uploaded_file($_FILES["fileImage"]["tmp_name"], "ImageFiles/" . $_FILES["fileImage"]["name"]); $result = 1; //set up the INSERT SQL query command to insert the name of the image file into the "Image" Table $imagesql = "INSERT INTO Image (ImageFile) VALUES (?)"; //prepare the above SQL statement if (!$insert = $mysqli->prepare($imagesql)) { // Handle errors with prepare operation here } //bind the parameters (these are the values that will be inserted) $insert->bind_param("s",$img); //Assign the variable of the name of the file uploaded $img = 'ImageFiles/'.$_FILES['fileImage']['name']; //execute INSERT query $insert->execute(); if ($insert->errno) { // Handle query error here } //close INSERT query $insert->close(); //Retrieve the ImageId of the last uploded file $lastID = $mysqli->insert_id; //Insert into Image_Question Table (be using last retrieved Image id in order to do this) $imagequestionsql = "INSERT INTO Image_Question (ImageId, SessionId, QuestionId) VALUES (?, ?, ?)"; //prepare the above SQL statement if (!$insertimagequestion = $mysqli->prepare($imagequestionsql)) { // Handle errors with prepare operation here echo "Prepare statement err imagequestion"; } //Retrieve the question number $qnum = (int)$_POST['numimage']; //bind the parameters (these are the values that will be inserted) $insertimagequestion->bind_param("isi",$lastID, 'Exam', $qnum); //execute INSERT query $insertimagequestion->execute(); if ($insertimagequestion->errno) { // Handle query error here } //close INSERT query $insertimagequestion->close(); ?> <!--Javascript which will output the message depending on the status of the upload (successful, failed or cancelled)--> <script> window.top.stopImageUpload(<?php echo $result; ?>, '<?php echo $_FILES['fileImage']['name'] ?>'); </script> </body> UPDATE: Below is the php code "cancelimage.php" where I want to delete the cancelled file from the server and delete the record from the database. It is set up but not finished, can somebody finish it off so I can retrieve the name of the file and it's id using $_SESSION? <?php // connect to the database include('connect.php'); /* check connection */ if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); die(); } //remove file from server unlink("ImageFiles/...."); //need to retrieve file name here where the ... line is //DELETE query statement where it will delete cancelled file from both Image and Image Question Table $imagedeletesql = " DELETE img, img_q FROM Image AS img LEFT JOIN Image_Question AS img_q ON img_q.ImageId = img.ImageId WHERE img.ImageFile = ?"; //prepare delete query if (!$delete = $mysqli->prepare($imagedeletesql)) { // Handle errors with prepare operation here } //Dont pass data directly to bind_param store it in a variable $delete->bind_param("s",$img); //execute DELETE query $delete->execute(); if ($delete->errno) { // Handle query error here } //close query $delete->close(); ?> Can you please provide an sample code in your answer to make it easier for me. Thank you

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  • Isotope active class when using select menu

    - by Michael
    I am using Metafizzy's Isotope plugin and have it set up to filter using a select menu as seen here: http://jsfiddle.net/trewknowledge/jJZEN/ $(function() { var $container = $('#container'), $select = $('#filters select'); $container.isotope({ itemSelector: '.item' }); $select.change(function() { var filters = $(this).val(); ; $container.isotope({ filter: filters }); }); });? What I am trying to figure out is how I would add a highlight/active class to the selected elements when the filters variable is already being used.

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  • mysql result for pagination

    - by Reteras Remus
    The query is: SELECT * FROM `news` ORDER BY `id` LIMIT ($curr_page * 5), ( ($curr_page * 5) + 5 ) Where $curr_page is a php variable which is getting a value from $_GET['page'] I want to make a pagination (5 news on each page), but I don't know why the mysql is returning me extra values. On the first page the result ok: $curr_page = 0 The query would be: SELECT * FROM `news` ORDER BY `id` LIMIT 0, 5 But on the second page, the result from the query is adding extra news, 10 instead of 5. The query on the second page: SELECT * FROM `news` ORDER BY `id` LIMIT 5, 10 Whats wrong? Why the result has 10 values instead of 5? Thank you!

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  • mysql_real_escape_string & slashes (again, oh yes)

    - by Fizzadar
    Righto, firstly magic quotes & runtime are disabled correctly in php.ini, and confirmed by phpinfo(). PHP version: 5.3.4 MySQL version: 5.1.52 I'm only use mysql_real_escape_string on the data, after htmlspecialchars and a trim, that's all the data cleaning on the variable. Yet, when I submit a single quote, the slash remains in the database. When running mysql_query I'm using "' . $var . '", although in the past this hasn't changed anything (could be due to the double quotes?). Any ideas? and please don't tell me about PDO/prepared statements, I'm aware of them and I have my reasons for doing it this way. Thanks!

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  • How to remove [^a-z\s] in C++

    - by Steven
    So far I have: int SimplifyText(char chars[], int length) { //To lower for(int i=0; i<length; i++) { chars[i] = tolower(chars[i]); } This function simplifies the text in the first argument which is an array containing the number of characters as given in the second argument The requirements are: tolower all remove all non-alpha characters replace multiple whitespace by one blank. Any leading whitespace at the beginning of the array should be removed completely. The resulting number of characters should be returned as the value of the function. And the annoying part: Another array cannot appear in the function Cannot use strings, only char arrays. Cannot using G++'s extension for setting an array size using a variable. Oh and can't use regex :) I'm stuck with this, any help would be great. :)

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  • What is a good rule for when to prepend members with 'this' (C#)?

    - by RichAmberale
    If I am accessing a member field, property, or method, I'm never sure when I should prepend it with 'this'. I am not asking about cases where it is required, like in the case where a local variable has the same name. I am talking about cases where the meaning is exactly the same. Which is more readable? Are there any standards, best practices, or rules of thumb I should be following? Should it just be consistent throughout a class, or an entire code base?

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  • Using PHP to grab the absolute URL of the script?

    - by Rob
    Basically, I want my script to output its absolute URL, but I don't want to statically program it into the script. For example, if my current URL is http://example.com/script.php I want to be able to store it as a variable, or echo it. i.e. $url = http://example.com/script.php; But if I move the script to a different server/domain, I want it to automatically adjust to that, i.e. $url = http://example2.com/newscript.php; But I have no idea how to go about doing this. Any ideas?

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  • Catch a generic exception in Java?

    - by Alex Baranosky
    We use JUnit 3 at work and there is no ExpectedException annotation. I wanted to add a utility to our code to wrap this: try { someCode(); fail("some error message"); } catch (SomeSpecificExceptionType ex) { } So I tried this: public static class ExpectedExceptionUtility { public static <T extends Exception> void checkForExpectedException(String message, ExpectedExceptionBlock<T> block) { try { block.exceptionThrowingCode(); fail(message); } catch (T ex) { } } } However, Java cannot use generic exception types in a catch block, I think. How can I do something like this, working around the Java limitation? Is there a way to check that the ex variable is of type T?

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  • How could I compare these database values in PHP?

    - by Dan
    So a user selects from a drop down list a value. I take this value, put it into a variable, then select from the database the ID value of that table A holding the selected value also. So now I'm trying to use that ID value to get to a many-to-many relationship table that has the selected value from table A to a different table B. The many-to-many relationship table has both IDs. How can I compare this using PHP? So it would be like: $A = $_POST['a']; $sql = "SELECT a, aID from TABLEA WHERE a = $A"; What do I do then to compare the aID with the many-to-many relationships table, then get the other ID in that table and then take that ID to get values from table B?

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  • Is new int[10]() valid c++?

    - by Naveen
    While trying to answer this question I found that the code int* p = new int[10](); compiles fine with VC9 compiler and initializes the integers to 0. So my questions are: First of all is this valid C++ or is it a microsoft extension? Is it guaranteed to initialize all the elements of the array? Also, is there any difference if I do new int; or new int();? Does the latter guarantee to initialize the variable?

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  • How does * work in Python

    - by Deqing
    Just switched from C++ to Python, and found that sometimes it is a little hard to understand ideas behind Python. I guess, a variable is a reference to the real object. For example, a=(1,2,5) meaning a - (1,2,5), so if b=a, then b and a are 2 references pointing to the same (1,2,5). It is a little like pointers in C/C++. If I have: def foo(a,b,c): print a,b,c a=(1,3,5) foo(*a) What does * mean here? Looks like it expands tuple a to a[0], a[1] and a[2]. But why print(*a) is not working while print(a[0],a[1],a[2]) works fine?

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  • .NET Garbage Collection behavior (with DataTable)

    - by gmac
    I am wonder why after creating a very simple DataTable and then setting it to null why Garbage Collection does not clear out all the memory used by that DataTable. Here is an example. The variable Before should be equal to Removed but it is not. { long Before = 0, After = 0, Removed = 0, Collected = 0; Before = GC.GetTotalMemory(true); DataTable dt = GetSomeDataTableFromSql(); After = GC.GetTotalMemory(true); dt = null; Removed = GC.GetTotalMemory(true); GC.Collect(); Collected = GC.GetTotalMemory(true); } Gives the following results. Before = 388116 After = 731248 Removed = 530176 Collected = 530176

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  • Java synchronizing static list ?

    - by JavaUser
    Hi, In a Java class , i am having a static list so this list is shared across all the objects of this class.The business logic in this class will run periodically which is invoked by some method with out passing instance parameters.Now I want to invoke this run method based on the list(I will add some vales into this list based on JMS) ,this list may empty sometimes and after finishing the run , i am emptying this list.Now my question is , whether I need to synchronize this list or not? Also let me know is there any other way to pass value in one object instance(Thread1) to other object instance (Thread2) other than having Static variable(static list)? Thx

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  • Why does Generic class signature requires specifying new() if type T needs instantiation ?

    - by this. __curious_geek
    I'm writing a Generic class as following. public class Foo<T> : where T : Bar, new() { public void MethodInFoo() { T _t = new T(); } } As you can see the object(_t) of type T is instantiated at run-time. To support instantiation of generic type T, language forces me to put new() in the class signature. I'd agree to this if Bar is an abstract class but why does it need to be so if Bar standard non-abstract class with public parameter-less constructor. compiler prompts following message if new() is not found. Cannot create an instance of the variable type 'T' because it does not have the new() constraint

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  • grabbing text in div with jquery

    - by vick
    <a class="source" href="jquery-lead.php?source=<?=$src;?>">3</a> <script type="text/javascript"> $("a.source").live('click', function() { $("#results").load( $(this).attr('href') ); return false; }); </script> I am able to pass $src variable to my php script, but I also want to pass whatever is in the tag. In this case "3", this is going to be a pagination..

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  • How do you know how much space an NSString (using default font) will occupy on a UITableView section

    - by paul_sns
    Basically I want to copy the behavior in iPhone's Calendar where the day of week (Mon, Tue, Wed) is on the left side of the table's section header (left justified) while the formatted date (Apr 1, 2010, May 1, 2010) based on locale is on the right side of the table's section header (right justified). I was thinking of inserting a variable amount of space in between the day of week and formatted date but I first need to know the actual space consumed by the text on both sides to figure out how much space to add. Hope to hear your thoughts on this. Thanks.

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  • Rails: saving a string on an object -- syntax problem?

    - by Veep
    Hey there, I am trying to write a simple function to clean a filename string and update the object. When I save a test string it works, but when I try to save the string variable I've created, nothing happens. But when I return the string, the output seems to be correct! What am I missing? def clean_filename clean_name = filename clean_name.gsub! /^.*(\\|\/)/, '' clean_name.gsub! /[^A-Za-z0-9\.\-]/, '_' clean_name.gsub!(/\_+/, ' ') #update_attribute(:filename, "test") #<-- correctly sets filename to test #update_attribute(:filename, clean_name) #<-- no effect????? WTF #return clean_name <-- seems to returns the correct string end Thank you very much.

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  • Wordpress Custom Type permalink containing Taxonomy slug

    - by treznik
    I'm trying to create a permalink pattern for a Custom Type, that includes one of its taxonomies. The taxonomy name is known from the start (so I'm not trying to add or mix all of its taxonomies, just a specific one), but the value will by dynamic, of course. Normally, the Custom Type permalink is built using the rewrite arg with the slug param, but I don't see how I could add a dynamic variable in there. http://codex.wordpress.org/Function_Reference/register_post_type I'm guessing a custom solution is required, but I'm not sure what the best unintrusive approach would be. Is there a known practice for this or has anyone built something similar recently? I'm using WP 3.2.1 btw.

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  • Run command with no terminal output

    - by Insomaniacal
    Hello, I've searched around online, but can't find the answer to my question. What I want to do is run a command in pythong, using the subprocess module, and store the output in a variable. However, I do not want the command's output to be printed to the terminal. For this code: def storels(): a = subprocess.Popen("ls",shell=True) storels() I get the directory listing in the terminal, instead of having it stored in a. I've also tried def storels(): subprocess.Popen("ls > tmp",shell=True) a = open("./tmp") [Rest of Code] storels() This also prints the output of ls to my terminal. I've even tried this command with the somewhat dated os.system method, since running "ls tmp" in the terminal doesn't print ls to the terminal at all, but stores it in tmp. However, the same thing happens. I'm using python 2.6. Any suggestions? Thanks in advance!

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  • Sql server Stored Procedure

    - by user177883
    I m passing a variable to stored procedure, i want the proc to make a look up to another table and get the primary key of the table and insert that value to the table. Table A: pk_id int, user varchar Table B: userKey int When i invoke sp_howto, and pass user to it, i want to it to get the pk_id from table A and insert it to table B userKey. @res = select userKey from TableA where user=@user insert into tableB (userKey) values (@res) Does this work? and what if I have many keys I want to populate like this?

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  • Is there a method to retrieve the file name of a class?

    - by Dran Dane
    Hello Is there a method to retrieve the file name of a class? Specifically I would like to create a static method (CreateLink) in a base class (BasePage) to automatically return the path and filename of the page called. I code in .C# ASP.NET private const string TEMPLATE = "~/One.aspx"; public static HyperLink CreateLink() { HyperLink link = new HyperLink(); link.Text = "Click here"; link.NavigateUrl = String.Format(TEMPLATE); return link; } Is it possible to avoid the use of TEMPLATE hardcoded variable? Is it possible to retrieve the One.aspx path from file name and location?

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