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• Would popup blockers stop a URL which pops up only when the user clicked on something?

  - by tomeaton

  I'm currently building a web application that can can track a users actions on a particular website and pop a URL if the user takes certain actions, such as: first click, responding to a question by clicking yes / no, clicking a submit button, or exiting the site. It is important that these URLs are served to the user and are not blocked by pop-up blockers. It is my understanding that there are certain exceptions within the major internet browsers that allow pop-ups if they are served based on some user action, rather than serving an unsolicited pop? Is this true? How do I design this web application so that it can serve these pops (and not have them blocked).

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• casting char* to char**

  - by blue_whale

  I am having a tough time understanding the following piece of code: int stride = 512; int max_len = 1024 * stride; char *addr = (char *)malloc(max_len); for (int i=stride; i<max_len; i += stride) *(char **)&addr[i-stride] = (char*)&addr[i]; *(char **)&addr[i-stride] = (char*)&addr[0]; Looking at the code it seems this is trying to create some kind of circular link list. But I have no clue what those casts are actually doing.

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• Calling finish() After Starting a New Activity

  - by stormin986

  The first Activity that loads in my application is an initialization activity, and once complete it loads a new Activity. I want to ensure if the user presses 'Back' they go straight to the Launcher, and not the initialization screen. Side note, is this even the best approach, or would this be better done with some kind of Intent Flag? Is it correct to call finish() after calling startActivity() on the new activity? onCreate() { ... startActivity(new Intent(this, NextActivity.class)); finish(); ... } I'm still taking in the whole 'Message Queue' method of doing things in Android, and my assumption is that calling startActivity() and then finish() from my first Activity's onCreate() will log each respective message in the message queue, but finish execution of onCreate() before moving on to starting the next Activity and finishing my first one. Is this a correct understanding?

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• Perform tasks with delay, without delaying web response (ASP.NET)

  - by Tomas Lycken

  I'm working on a feature that needs to send two text messages with a 30 second delay, and it is crucial that both text messages are sent. Currently, this feature is built with ajax requests, that are sent with a 30 second javascript delay, but since this requires the user to have his browser open and left on the same page for at least 30 seconds, it is not a method I like. Instead, I have tried to solve this with threading. This is what I've done: Public Shared Sub Larma() Dim thread As New System.Threading.Thread(AddressOf Larma_Thread) thread.Start() End Sub Private Shared Sub Larma_Thread() StartaLarm() Thread.Sleep(1000 * 30) StoppaLarm() End Sub A web handler calls Larma(), and StartaLarm() and StoppaLarm() are the methods that send the first and second text messages respectively. However, I only get the first text message delivered - the second is never sent. Am I doing something wrong here? I have no deep understanding of how threading works in ASP.NET, so please let me know how to accomplish this.

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• Why is rails called a dsl?

  - by b_ayan

  Recently, when I tried to explain why Rails is a DSL to an intern at my organisation, I was not able to articulate my reasonings to the effect I would like to. Maybe I do not understand the space well enough to teach the nuances. Redirecting him to Martin Fowler' article or the google ranked one InfoQ or other material has not helped much either. Can some explain why Rails is a DSL with an example / parallel situation which is not voodoo stuff for someone who is fairly new to the world of code? Understanding the ideology might also help in elaborating the intricacies of the rails ecosystem?

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• Mod_rewrite trouble: Want to direct from ?= to a flat link, nothing seems to work.

  - by Davezatch

  I have a site that currently serves results as example.com/index.php?show=foo and I'd like it to read example.com/show/foo. My understanding is this would make them visible to search engine robots, and it seems a much simpler way to do this than to create a couple hundred html files... I've tried the following .htaccess code: Options +FollowSymLinks RewriteEngine on RewriteRule ^show/(.*)$ index.php?show=$1 [NC,L] No dice. Also tried this, which I found on another stack overflow question: <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^([0-9A-Za-z]+)/?$ /index.php?show=$1 [L] </IfModule> Any ideas on what I'm missing here?

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• Beginning Programmer Interested in Android - Should I Start with Java?

  - by Hudey

  I'm a beginner in programming. My experience so far is only in Actionscript 2 and 3. So I have a basic understanding of declaring variables, loops, arrays, if/then, do/while... I'm wanting to move to developing for Android phones so I'm wondering what suggestions people have for where to go next. Should I jump right to Android? Start with a 'beginning Java' approach? Or should I go some other route to beef up my knowledge of OOP concepts before launching into Android? I have my Dev environment set up and completed the Hello Android tutorial and I'm just wondering if I am going to be in over my head quickly?

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• What is the complexity of this c function

  - by Bunny Rabbit

  what is the complexity of the following c Function ? double foo (int n) { int i; double sum; if (n==0) return 1.0; else { sum = 0.0; for (i =0; i<n; i++) sum +=foo(i); return sum; } } Please don't just post the complexity can you help me in understanding how to go about it . EDIT: It was an objective question asked in an exam and the Options provided were 1.O(1) 2.O(n) 3.O(n!) 4.O(n^n)

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• Updating external Flex components from an action

  - by Scott

  Hello, I'm new to Flex and am having trouble understanding Events. I think Events are what I want to use for my situation. I have 2 components, addUser.mxml and listUsers.mxml. I access these from a ViewStack in my main application. When I load listUsers.mxml it shows a list of current users in a datagrid via a HTTPService call. When I add a user using the form on addUser.mxml I would like the datagrid in listUsers.mxml to refresh when I return to that view to show the new user. I've tried several different things with addEventListener and dispatchEvent but can't seem to get it working. Can someone help me with this logic?

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• Delayed evaluation in Clojure

  - by StackedCrooked

  I'm having some trouble understanding how the delay macro works in Clojure. It doesn't seem to do what expect it to do (that is: delaying evaluation). As you can see in this code sample: ; returns the current time (defn get-timestamp [] (.getTime (java.util.Date.))) ; var should contain the current timestamp after calling "force" (def current-time (delay (get-timestamp))) However, calling current-time in the REPL appears to immediately evaluate the expression, even without having used the force macro: user=> current-time #<Delay@19b5217: 1276376485859> user=> (force current-time) 1276376485859 Why was the evaluation of get-timestamp not delayed until the first force call?

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• [CakePHP] Pagination after inserting or updateing record

  - by user198003

  one more question related with cakephp... let's say that i have 20+ records in my table. they are sorted by some criteria, ie. by title. and on a list view, i have a list of 10 records, with available pagination. how can i achieve that when i insert new record, to be redirected to proper page, where i can see record that is just was insterted? how can i get information on which page i have to be redirected? hope my question is enough clear for understanding... tnx in adv!

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• c# event and delegate question

  - by user359562

  I want to detach the custom event but could not detach. Please find below I am using -= to detach the event. I assume after this, TextChanged2 method should not be invoked as I have unregistered the event. Let me know if my understanding is wrong. public delegate void TextChangedEventHandler1(object sender, TextBoxargs ta); public event TextChangedEventHandler1 TextChanged1; private void textBox1_TextChanged(object sender, EventArgs e) { this.TextChanged1 -= new TextChangedEventHandler1(TextChanged2); TextChanged2(sender, e); } public void TextChanged2(object sender, EventArgs e) { textBox1.Text = textBox1.Text.ToUpper(); }

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• Getting all matches for a regexp on clojure

  - by Deleteman

  I'm trying to parse an HTML file and get all href's inside it. So far, the code I'm using is: (map #(println (str "Match: " %)) (re-find #"(?sm)href=\"([a-zA-Z.:/]+)\"" str_response)) str_response being the string with the HTML code inside it. According to my basic understanding of Clojure, that code should print a list of matches, but so far, no luck. It doens't crash, but it doens't match anything either. I've tried using re-seq instead of re-find, but with no luck. Any help? Thanks!

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• Java/Swing: JTable.rowAtPoint doesn't work correctly for points outside the table?

  - by Jason S

  I have this code to get a row from a JTable that is generated by a DragEvent for a DropTarget in some component C which may or may not be the JTable: public int getRowFromDragEvent(DropTargetDragEvent event) { Point p = event.getLocation(); if (event.getSource() != this.table) { SwingUtilities.convertPointToScreen(p, event.getDropTargetContext().getComponent()); SwingUtilities.convertPointFromScreen(p, this.table); if (!this.table.contains(p)) { System.out.println("outside table, would be row "+this.table.rowAtPoint(p)); } } return this.table.rowAtPoint(p); } The System.out.println is just a hack right now. What I'm wondering, is why the System.out.println doesn't always print "row -1". When the table is empty it does, but if I drag something onto the table's header row, I get the println with "row 0". This seems like a bug... or am I not understanding how rowAtPoint() works?

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• ASP.NET MVC vs. Jquery/AJAX (Where to draw the dividing line?)

  - by punkouter

  I am learning MVC and I understand the basics now. It is very good for CRUD pages and has built in HTTP methods to post/get edits/updates. That is nice. This is all very testable by just creating a new controller and testing it. But I was thinking about other web page scenerios when using MVC. What about a page that has 2 listboxes that you add/remove users with. (A button will move the user from one listbox to another) This would be done using Jquery/Javascript... But then what happens to testing? How do you test adding/removing users from a listbox like that example? It seems to me the more jquery you use the less testable the page becomes right? When you get beyond basic forms being filled out then you need to use something more than the standard MVC pages. What is the correct philosophy on this on when am I not understanding ?

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• Setting a form field's valule during validation

  - by LaundroMat

  Hi, I read about this issue already, but I'm having trouble understanding why I can't change the value of a form's field during validation. I have a form where a user can enter a decimal value. This value has to be higher than the initial value of the item the user is changing. During clean(), the value that was entered is checked against the item's previous value. I would like to be able to re-set the form field's value to the item's initial value when a user enters a lower value. Is this possible from within the clean() method, or am I forced to do this in the view? Somehow, it doesn't feel right to do this in the view... (To make matters more complicated, the form's fields are built up dynamically, meaning I have to override the form's clean() method instead of using the clean_() method). Thanks in advance!

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• Optimal strategy to make a C++ hash table, thread safe

  - by Ajeet

  (I am interested in design of implementation NOT a readymade construct that will do it all.) Suppose we have a class HashTable (not hash-map implemented as a tree but hash-table) and say there are eight threads. Suppose read to write ratio is about 100:1 or even better 1000:1. Case A) Only one thread is a writer and others including writer can read from HashTable(they may simply iterate over entire hash table) Case B) All threads are identical and all could read/write. Can someone suggest best strategy to make the class thread safe with following consideration 1. Top priority to least lock contention 2. Second priority to least number of locks My understanding so far is thus : One BIG reader-writer lock(semaphore). Specialize the semaphore so that there could be eight instances writer-resource for case B, where each each writer resource locks one row(or range for that matter). (so i guess 1+8 mutexes) Please let me know if I am thinking on the correct line, and how could we improve on this solution.

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• variable scope in statement blocks

  - by fearofawhackplanet

  for (int i = 0; i < 10; i++) { Foo(); } int i = 10; // error, 'i' already exists ---------------------------------------- for (int i = 0; i < 10; i++) { Foo(); } i = 10; // error, 'i' doesn't exist By my understanding of scope, the first example should be fine. The fact neither of them are allowed seems even more odd. Surely 'i' is either in scope or not. Is there something non-obvious about scope I don't understand which means the compiler genuinely can't resolve this? Or is just a case of nanny-state compilerism?

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• Why do these seemingly similar queries have such drastically different run times?

  - by Jherico

  I'm working with an oracle DB trying to tune some queries and I'm having trouble understanding why working a particular clause in a particular way has such a drastic impact on the query performance. Here is a performant version of the query I'm doing select * from ( select a.*, rownum rn from ( select * from table_foo ) a where rownum < 3 ) where rn >= 2 The same query by replacing the last two lines with this ) a where rownum >=2 rownum < 3 ) performs horribly. Several orders of magnitude worse ) a where rownum between 2 and 3 ) also performs horribly. I don't understand the magic from the first query and how to apply it to further similar queries.

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• Using a database with C#

  - by Mike

  I have been trying to do something that I think would be really easy but have never used C# before and am having trouble with the details. I simple want to use a sql database with Visual C# Express 2008. For testing purposes I have a datagrid on my form that can reflect changes to the db. If i use this: codesTableAdapter.Fill(dataSet1.codes); The datagrid(dataset) will fill with the info from the sql database. If i then do something like this: codesTableAdapter.InsertQuery(txtCode.Text,txtName.Text); codesTableAdapter.Fill(dataSet1.codes); codesTableAdapter.Update(dataSet1); dataSet1.AcceptChanges(); The datagrid reflects the changes but if close the program and go to the database the changes are not there. When I open the program again the changes are not there. I have a feeling this isn't too clear as my understanding here is very low so please let me know what other info is needed. Thanks

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• What is this VB6 method doing?

  - by Craig

  We are converting a VB6 application to C# (4.0). and have come across a method in VB6 that we're battling to understand. Public Sub SaveToField(fldAttach As ADODB.Field) Dim bData() As Byte Dim nSize As Long nSize = Len(m_sEmail) bData = LngToByteArray(nSize) fldAttach.AppendChunk bData If nSize > 0 Then bData = StringToByteArray(m_sEmail) fldAttach.AppendChunk bData End If nSize = Len(m_sName) bData = LngToByteArray(nSize) fldAttach.AppendChunk bData If nSize > 0 Then bData = StringToByteArray(m_sName) fldAttach.AppendChunk bData End If bData = LngToByteArray(m_nContactID) fldAttach.AppendChunk bData End Sub It seems like it's doing some binary file copy type thing, but I'm not quite understanding. Could someone explain so that we can rewrite it?

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• git destroyed my changes

  - by mare

  I made a commit of my repository a week ago but never actually pushed it to the remote at github, which I did today. However, in the time from my commit I made many changes to the source. But just the initial commit was pushed to remote and while doing it, it also overwrote my local files. What can I do to get back my current files?? For better understanding, this is what I've done: Created new VS project and created a new git repository in it, Performed an initial scan, stage and commit but without adding a remote and performing a push, Worked on files for a week, (Today) Forgot to perform rescan, new stage and commit and just created new GitHub repository and performed this: git remote add origin [email protected]:myaccount/webshop.git git push origin master Now the files in GitHub repository are the ones from inital commit and those were also copied over my current files, so I'm in the initial commit stage now locally too, which is awful. Help appreciated

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• Is it possible (and if so how) to delete a zookeeper node with apache camel?

  - by b_habegger

  I am looking into using Zookeeper to synchronized distributed Camel instances. In doing so it seems that there is not possibility to delete a znode from Zookeeper from Camel (I imagined some sort of producer operation). A look at the components source seems to confirm this. (I didn't find any code explicitely requesting a node removal). Am I missing something ? When would a node created via Camel (in my case EPHEMERAL) be deleted ? Maybe I am miss understanding something with zookeeper ?

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• How do database servers decide which order to return rows without any "order by" statements?

  - by Chris

  Kind of a whimsical question, always something I've wondered about and I figure knowing why it does what it does might deepen my understanding a bit. Let's say I do "SELECT TOP 10 * FROM TableName". In short timeframes, the same 10 rows come back, so it doesn't seem random. They weren't the first or last created. In my massive sample size of...one table, it isn't returning the min or max auto-incrementing primary key value. I also figure the problem gets more complex when taking joins into account. My database of choice is MSSQL, but I figure this might be an interesting question regardless of the platform.

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• Control.Invoke() vs. Control.BeginInvoke()

  - by user590088

  First of all, I would like to apologize for my bad grammar since English is not my native tongue. This is my understanding: Control.Invoke(delegated_method) // Executes on the thread wich the control was created on witch holds its handle ,typically this would be the main thread of a winform application . Control.BeginInvoke(delegated_method // Executes asynchronously on a threadPool Thread . According to MSDN, it says Executes a delegate asynchronously on the thread that the control's underlying handle was created on. My QUESTION : Am I to understand that beginInvoke treats the main thread in this matter as it would the thread pool, and execute the delegated method on the main thread when it "gets a chance" ? Another question which is raised, is it possible to create a control not on the main thread ? if so could someone give me an example?

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