Search Results

Search found 7740 results on 310 pages for 'book reader'.

Page 280/310 | < Previous Page | 276 277 278 279 280 281 282 283 284 285 286 287  | Next Page >

  • "'Objects' may not respond to 'functions'" warnings.

    - by Andrew
    Hello all, for the last couple of weeks I've finally gotten into Obj-C from regular C and have started my first app. I've watched tutorials and read through a book along with a lot of webpages, but I know I've only just begun. Anyway, for most of the night and this morning, I've been trying to get this code to work, and now that it will compile, I have a few warnings. I've searched and found similar problems with solutions, but still no dice. What I'm trying to do is put an array made from a txt document into the popup list in a combo box. AwesomeBoxList.h: #import <Cocoa/Cocoa.h> @interface AwesomeBoxList : NSObject { IBOutlet NSComboBox *ComboBoz; } -(NSArray *) getStringzFromTxtz; - (void) awesomeBoxList; @end AwesomeBoxList.m: #import "AwesomeBoxList.h" @implementation AwesomeBoxList -(NSArray *)getStringzFromTxtz { ... return combind; } - (void) awesomeBoxList { [ComboBoz setUsesDataSource:YES]; [ComboBoz setDataSource: [ComboBoz getStringzFromTxtz]: //'NSComboBox' may not respond to 'getStringzFromTxtz' [ComboBoz comboBox:(NSComboBox *)ComboBoz objectValueForItemAtIndex: [ComboBoz numberOfItemsInComboBox:(NSComboBox *)ComboBoz]]]; /*'NSComboBox' may not respond to '-numberOfItemsInComboBox:' 'NSComboBox' may not respond to '-comboBox:objectValueForItemAtIndex:' 'NSComboBox' may not respond to '-setDataSource:' */ } @end So, with all of these errors and my still shallow knowledge of Obj-C, I must be making some sort of n00b mistake. Thanks for the help.

    Read the article

  • Programming texts and reference material for my Kindle DX, creating the ultimate reference device?

    - by mwilliams
    (Revisiting this topic with the release of the Kindle DX) Having owned both generation Kindle readers and now getting a Kindle DX; I'm very excited for true PDF handling on an e-ink device! An image of _Why's book on my Kindle (from my iPhone). This gives me a device capable of storing hundreds of thousands of pages that are full text search capable in the form factor of a magazine. What references (preferably PDF to preserve things such as code samples) would you recommend? Ultimately I would like reference material for every modern and applicable programming language (C, C++, Objective-C, Python, Ruby, Java, .NET (C#, Visual Basic, ASP.NET), Erlang, SQL references) as well as general programming texts and frameworks (algorithms, design patterns, theory, Rails, Django, Cocoa, ORMs, etc) and anything else that could be thought of. With so many developers here using such a wide array of languages, as a professional in your particular field, what books or references would you recommend to me for my Kindle? Creative Commons material a plus (translate that to free) as well as the material being in the PDF file format. File size is not an issue. If this turns out to be a success, I will update with a follow-up with a compiled list generated from all of the answers. Thanks for the assistance and contributing! UPDATE I have been using the Kindle DX a lot now for technical books. Check out this blog post I did for high resolution photos of different material: http://www.matthewdavidwilliams.com/2009/06/12/technical-document-pdfs-on-the-kindle-dx/

    Read the article

  • ActionListener isn't Implementing

    - by Nick Gibson
    JFrameWithPanel is not abstract and does not override abstract method actionPerformed(java.awt.event.ActionEvent) in java.awt.event.ActionListener public class JFrameWithPanel extends JFrame implements ActionListener I Don't get this code. Book and Java site tells me this is the syntax for the method, but again this error shows up constantly. import javax.swing.*; import javax.swing.JOptionPane; import java.awt.*; import java.awt.event.*; import java.lang.Math.*; import java.lang.Integer.*; import java.util.*; import java.util.Random; import java.io.*; import java.text.*; import java.text.DecimalFormat.*; public class JFrameWithPanel extends JFrame implements ActionListener { JButton button = new JButton("Exit"); public JFrameWithPanel() { super("JFrame with Panel"); JComboBox packageChoice = new JComboBox(); packageChoice.addItem("A+ Certification"); packageChoice.addItem("Network+ Certification "); packageChoice.addItem("Security+ Certifictation"); packageChoice.addItem("CIT Full Test Package"); packageChoice.addActionListener(this); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel pane = new JPanel(); pane.add(button); pane.add(packageChoice); setContentPane(pane); setSize(200,100); setVisible(true); } } then later public class CreateJFrameWithPanel { public static void main(String[] args) { JFrameWithPanel panel = new JFrameWithPanel(); } }

    Read the article

  • Strange data swapping error occurs when I attempt to update rows in my table from another table in m

    - by Wesley
    So I have a table of data that is 10,000 lines long. Several of the columns in the table simply describe information about one of the columns, meaning, that only one column has the content, and the rest of the columns describe the location of the content (its for a book). Right now, only 6,000 of the 10,000 rows' content column is filled with its content. Rows 6-10,000's content column simply says null. I have another table in the db that has the content for rows 6,000-10,000, with the correct corresponding primary key which would (seemingly) make it easy to update the 10,000 row table. I have been trying an update query such as the following: UPDATE table(10,000) SET content_column = (SELECT content FROM table(6,000-10,000) WHERE table(10,000).id = table(6-10,000.id) Which kind of works, the only problem is that it pulls in the data from the second table just fine, but it replaces the existing content column with null. So rows 1-6,000's content column become null, and rows 6-10,000's content column have the correct values...Pretty strange I thought anyway. Does anybody have any thoughts about where I am going wrong? If you could show me a better sql query, I would appreciate it! Thanks

    Read the article

  • How do I load PersistentDocuments into the same window

    - by Brad Stone
    I want to open NSPersistentDocuments and load them into the same window one at a time. I'm almost there but missing some steps. Hopefully someone can help me. I have a few saved documents on the hard drive. On launch my app opens to an untitled NSPersistentDocument and creates a separate NSWindowController. When I press the button to load file 1 off the hard drive the data appears in the fields but two things are wrong that I can see: 1) changing the data doesn't make the document dirty 2) choosing save updates the persistentstore (I know this because when I open the file again I see the changes) but I get an error: +entityForName: could not locate an NSManagedObjectModel for entity name 'Book' Here's my code which is in the WindowController that was launched initially with the untitled document. This code isn't perfect. For example, I know I should processPendingChanges and save the current doc before I load the new one. This is test code to try to get over this hurdle. - (IBAction)newBookTwo:(id)sender { NSDocumentController *dc = [NSDocumentController sharedDocumentController]; NSURL *url = [NSURL fileURLWithPath:[@"~/Desktop/File 2.binary" stringByExpandingTildeInPath]]; NSError *error; MainWindowDocument *thisDoc = [dc openDocumentWithContentsOfURL:url display:NO error:&error]; [self setDocument:thisDoc]; [self setManagedObjectContext:[thisDoc managedObjectContext]]; } Thanks!

    Read the article

  • Doubly Linked Lists Implementation

    - by user552127
    Hi All, I have looked at most threads here about Doubly linked lists but still unclear about the following. I am practicing the Goodrich and Tamassia book in Java. About doubly linked lists, please correct me if I am wrong, it is different from a singly linked list in that a node could be inserted anywhere, not just after the head or after the tail using both the next and prev nodes available, while in singly linked lists, this insertion anywhere in the list is not possible ? If one wants to insert a node in a doubly linked list, then the default argument should be either the node after the to-be inserted node or node before the to-be inserted node ? But if this is so, then I don't understand how to pass the node before or after. Should we be displaying all nodes that were inserted till now and ask the user to select the node before or after which some new node is to be inserted ? My doubt is how to pass this default node. Because I assume that will require the next and prev nodes of these nodes as well. For e.g, Head<-A<-B<-C<-D<-E<-tail If Z is the new node to be inserted after say D, then how should node D be passed ? I am confused with this though it seems pretty simple to most. But pl do explain. Thanks, Sanjay

    Read the article

  • LINQ-to-SQL - Join, Count

    - by ile
    I have following query: var result = ( from role in db.Roles join user in db.Users on role.RoleID equals user.RoleID where user.CreatedByUserID == userID orderby user.FirstName ascending select new UserViewModel { UserID = user.UserID, PhotoID = user.PhotoID.ToString(), FirstName = user.FirstName, LastName = user.LastName, FullName = user.FirstName + " " + user.LastName, Email = user.Email, PhoneNumber = user.Phone, AccessLevel = role.Name }); Now, I need to modify this query... Other table I have is table Deals. I would like to count how many deals user created last month and last year. I tried something like this: var result = ( from role in db.Roles join user in db.Users on role.RoleID equals user.RoleID //join dealsYear in db.Deals on date.Year equals dealsYear.DateCreated.Year join dealsYear in ( from deal in db.Deals group deal by deal.DateCreated into d select new { DateCreated = d.Key, dealsCount = d.Count() } ) on date.Year equals dealsYear.DateCreated.Year into dYear join dealsMonth in ( from deal in db.Deals group deal by deal.DateCreated into d select new { DateCreated = d.Key, dealsCount = d.Count() } ) on date.Month equals dealsMonth.DateCreated.Month into dMonth where user.CreatedByUserID == userID orderby user.FirstName ascending select new UserViewModel { UserID = user.UserID, PhotoID = user.PhotoID.ToString(), FirstName = user.FirstName, LastName = user.LastName, FullName = user.FirstName + " " + user.LastName, Email = user.Email, PhoneNumber = user.Phone, AccessLevel = role.Name, DealsThisYear = dYear, DealsThisMonth = dMonth }); but here is even syntax not correct. Any idea? Btw, is there any good book of LINQ to SQL with examples?

    Read the article

  • 3D and AI basics. The foundation before the coding.

    - by Allan
    Hi, everyone. (If you have the time and patience:) I've recently made the decision to study programming seriously and I'm about to order TAOCP and Concrete Mathematics to begin my studies (please don't get caught up on this). I'm very much interested in learning and understanding how 3D works but I'm aware that if I plan to do it right there's still a long walk before I get to actually play with 3D coding. Now to the question.. (tl;dr) Excluding programming itself, what disciplines do I have to be familiar with to code 3D? What kinds of mathematics? Physics? What else? What books do you recommend on such subjects? Now read it all again but replacing "3D" with "AI". Please don't recommend computer-specific books. The question is about the foundation to be learned before using the machine. Also, if possible, please keep the list brief; I plan to order one book on each subject but no more than that for now. Excuse me for any English mistakes, it's not my first language. Thank you.

    Read the article

  • C++ - Need to learn some basics in a short while

    - by Rubys
    For reasons I will spare you, I have two weeks to learn some C++. I can learn alone just fine, but I need a good source. I don't think I have time to go through an entire book, and so I need some cliff notes, or possibly specific chapters/specialized resources I need to look up. I know my Asm/C/C# well, and so anything inherited from C, or any OOP is not needed. What I do need is some sources on the following subjects(I have a page that specifies what is needed, this is basically it, but I trimmed what I know): new/delete in C++ (as opposed to C#). Overloading cin/cout. Constructor, Destructor and MIL. Embedded Objects. References. Templates. If you feel some basic C++ concept that is not shared with C/C# is not included on this list, feel free to enter those as well. But the above subjects are the ones I'm supposed to roughly know in two week's time. Any help would be appreciated, thanks.

    Read the article

  • How to get a debug flow of execution in C++

    - by Rich
    Hi, I work on a global trading system which supports many users. Each user can book,amend,edit,delete trades. The system is regulated by a central deal capture service. The deal capture service informs all the user of any updates that occur. The problem comes when we have crashes, as the production environment is impossible to re-create on a test system, I have to rely on crash dumps and log files. However this doesn't tell me what the user has been doing. I'd like a system that would (at the time of crashing) dump out a history of what the user has been doing. Anything that I add has to go into the live environment so it can't impact performance too much. Ideas wise I was thinking of a MACRO at the top of each function which acted like a stack trace (only I could supply additional user information, like trade id's, user dialog choices, etc ..) The system would record stack traces (on a per thread basis) and keep a history in a cyclic buffer (varying in size, depending on how much history you wanted to capture). Then on crash, I could dump this history stack. I'd really like to hear if anyone has a better solution, or if anyone knows of an existing framework? Thanks Rich

    Read the article

  • HMAC URLs instead of login?

    - by Tres
    In implementing my site (a Rails site if it makes any difference), one of my design priorities is to relieve the user of the need to create yet another username and password while still providing useful per-user functionality. The way I am planning to do this is: User enters information on the site. Information is associated with the user via server-side session. User completes entering information, server sends an access URL via e-mail to the user roughly in the form of: http://siteurl/<user identifier>/<signature: HMAC(secret + salt + user identifier)> User clicks URL, site looks up user ID and salt and computes the HMAC with the server-stored secret and authenticates if the computed HMAC and signature match. My question is: is this a reasonably secure way to accomplish what I'm looking to do? Are there common attacks that would render it useless? Is there a compelling reason to abandon my desire to avoid a username/password? Is there a must-read book or article on the subject? Note that I'm not dealing with credit card numbers or anything exceedingly private, but I would still like to keep the information reasonably secure.

    Read the article

  • Is it bad practise to initialise fields outside of an explicit constructor

    - by MrTortoise
    So its monday and we are arguing about coding practises. The examples here are a litttle too simple, but the real deal has several constructors. In order to initialise the simple values (eg dates to their min value) I have moved the code out of the constructors and into the field definitions. public class ConstructorExample { string _string = "John"; } public class ConstructorExample2 { string _string; public ConstructorExample2() { _string = "John"; } } How should it be done by the book. I tend to be very case by case and so am maybe a little lax abotu this kind of thing. However i feel that accams razor tells me to move the initialisation out of multiple constructors. Of course I could always move this shared initialisation into a private method. The question is essentially ... is initialising fields where they are defined as opposed to the constructor bad in any way? The argument I am facing is one of error handling, but i do not feel it is relevant as there are no possible exceptions that won't be picked up at compile time.

    Read the article

  • pyPDF - Retrieve page numbers from document

    - by SquidneyPoitier
    At the moment I'm looking into doing some PDF merging with pyPdf, but sometimes the inputs are not in the right order, so I'm looking into scraping each page for its page number to determine the order it should go in (e.g. if someone split up a book into 20 10-page PDFs and I want to put them back together). I have two questions - 1.) I know that sometimes the page number is stored in the document data somewhere, as I've seen PDFs that render on Adobe as something like [1243] (10 of 150), but I've read documents of this sort into pyPDF and I can't find any information indicating the page number - where is this stored? 2.) If avenue #1 isn't available, I think I could iterate through the objects on a given page to try to find a page number - likely it would be its own object that has a single number in it. However, I can't seem to find any clear way to determine the contents of objects. If I run: pdf.getPage(0).getContents() This usually either returns: {'/Filter': '/FlateDecode'} or it returns a list of IndirectObject(num, num) objects. I don't really know what to do with either of these and there's no real documentation on it as far as I can tell. Is anyone familiar with this kind of thing that could point me in the right direction?

    Read the article

  • Need help extrapolating Java code

    - by Berlioz
    If anyone familiar with Rebecca Wirfs-Brock, she has a piece of Java code found in her book titled, Object Design: Roles, Responsibilities, and Collaborations. Here is the quote Applying Double Dispatch to a Specific Problem To implement the game Rock, Paper, Scissors we need to write code that determines whether one object “beats” another. The game has nine possible outcomes based on the three kinds of objects. The number of interactions is the cross product of the kinds of objects. Case or switch statements are often governed by the type of data that is being operated on. The object-oriented language equivalent is to base its actions on the class of some other object. In Java, it looks like this Here is the piece of Java code on page 16 ' import java.util.*; import java.lang.*; public class Rock { public static void main(String args[]) { } public static boolean beats(GameObject object) { if (object.getClass.getName().equals("Rock")) { result = false; } else if (object.getClass.getName().equals("Paper")) { result = false; } else if(object.getClass.getName().equals("Scissors")) { result = true; } return result; } }' ===This is not a very good solution. First, the receiver needs to know too much about the argument. Second, there is one of these nested conditional statements in each of the three classes. If new kinds of objects could be added to the game, each of the three classes would have to be modified. Can anyone share with me how to get this "less than optimal" piece of code to work in order to see it 'working'. She proceeds to demonstrate a better way, but I will spare you. Thanks

    Read the article

  • error catching exception while System.out.print

    - by user1702633
    I have 2 classes, one that implements a double lookup( int i); and one where I use that lookup(int i) in solving a question, or in this case printing the lookup values. This case is for an array. So I read the exception documentation or google/textbook and come with the following code: public double lookup(int i) throws Exception { if( i > numItems) throw new Exception("out of bounds"); return items[i]; } and take it over to my class and try to print my set, where set is a name of the object type I define in the class above. public void print() { for (int i = 0; i < set.size() - 1; i++) { System.out.print(set.lookup(i) + ","); } System.out.print(set.lookup(set.size())); } I'm using two print()'s to avoid the last "," in the print, but am getting an unhandled exception Exception (my exception's name was Exception) I think I have to catch my exception in my print() but cannot find the correct formatting online. Do I have to write catch exception Exception? because that gives me a syntax error saying invalid type on catch. Sources like http://docs.oracle.com/javase/tutorial/essential/exceptions/ are of little help to me, I'm can't seem to grasp what the text is telling me. I'm also having trouble finding sources with multiple examples where I can actually understand the coding in the examples. so could anybody give me a source/example for the above catch phrase and perhaps a decent source of examples for new Java programmers? my book is horrendous and I cannot seem to find an understandable example for the above catch phrase online.

    Read the article

  • mysql get table based on common column between two tables

    - by Zentdayn
    while trying to learn sql i came across "Learn SQL The Hard Way" and i started reading it. Everything was going fine then i thought ,as a way to practice, to make something like given example in the book (example consists in 3 tables pet,person,person_pet and the person_pet table 'links' pets to their owners). I made this: report table +----+-------------+ | id | content | +----+-------------+ | 1 | bank robbery| | 2 | invalid | | 3 | cat on tree | +----+-------------+ notes table +-----------+--------------------+ | report_id | content | +-----------+--------------------+ | 1 | they had guns | | 3 | cat was saved | +-----------+--------------------+ wanted result +-----------+--------------------+---------------+ | report_id | report_content | report_notes | +-----------+--------------------+---------------+ | 1 | bank robbery | they had guns | | 2 | invalid | null or '' | | 3 | cat on tree | cat was saved | +-----------+--------------------+---------------+ I tried a few combinations but no success. My first thought was SELECT report.id,report.content AS report_content,note.content AS note_content FROM report,note WHERE report.id = note.report_id but this only returns the ones that have a match (would not return the invalid report). after this i tried adding IF conditions but i just made it worse. My question is, is this something i will figure out after getting past basic sql or can this be done in simple way? Anyway i would appreciate any help, i pretty much lost with this. Thank you. EDIT: i have looked into related questions but havent yet found one that solves my problem. I probably need to look into other statements such as join or something to sort this out.

    Read the article

  • User Defined Conversions in C++

    - by wash
    Recently, I was browsing through my copy of the C++ Pocket Reference from O'Reilly Media, and I was surprised when I came across a brief section and example regarding user-defined conversion for user-defined types: #include <iostream> class account { private: double balance; public: account (double b) { balance = b; } operator double (void) { return balance; } }; int main (void) { account acc(100.0); double balance = acc; std::cout << balance << std::endl; return 0; } I've been programming in C++ for awhile, and this is the first time I've ever seen this sort of operator overloading. The book's description of this subject is somewhat brief, leaving me with a few unanswered questions about this feature: Is this a particularly obscure feature? As I said, I've been programming in C++ for awhile and this is the first time I've ever come across this. I haven't had much luck finding more in-depth material regarding this. Is this relatively portable? (I'm compiling on GCC 4.1) Can user-defined conversions to user defined types be done? e.g. operator std::string () { /* code */ }

    Read the article

  • Using Enum in Hibernate causes select followed by an update statement

    - by Leonardo
    Hi all, I have a mapped entity wich has an enum property. By loking at log file, whenever I run a select statement on such entity, the result is an immediately following update. For example if my result set contains 100 records, then I have: [INFO org... select...] [INFO org... update... where id=?] [INFO org... update... where id=?] .... repeated 100 times If I mark the property as update=false the problem disappear. The enum is assigned trough an enum converter class, which I copied from a well known book. So I don't know if I just copy and paste the code. Here it is how is declared on hbm file. <typedef class="mypackage.HbnEnumConverter" name="the_type"> <param name="enumClassname">mypackage.TheType</param> </typedef> Can you point out a direction to investigate this ? Beside, what are the consequences of having update=false on hibernate field ? thanks

    Read the article

  • How to create anroid to send to work in my place?

    - by aj-sin-dhal
    Hi I would like to create a life like android/robot to send to work in my place. Requirements 1) People should not be able to tell the difference between me and the android. My first attempt may not be perfect but I can tell people that its my twin that was dropped on its head while we were growing up. 2) Should have the same weight as me so it won't crush small children if it falls over. By small children I mean those above 7 years old. Those below 7 can easily be crushed by a normal human adult so it is not important to consider that special case. 3) Should run on linux. I have a tight budget and cannot afford to pay for any propreitary operating system. Will consider writing my own operating system if this is the best way to go. I am reading "The design of the unix operating system" by Maurice J. Bach currently. That should be useful. I also have an old copy of the dragon book. What other books should I read? I would like to finish this by monday if possible. I don't like working on mondays. I have made a start and have picked some clothes and shoes for my android worker. Any help will be appreciated. This is a serious question. AJ

    Read the article

  • Strange Access Denied warning when running the simplest C++ program.

    - by DaveJohnston
    I am just starting to learn C++ (coming from a Java background) and I have come across something that I can't explain. I am working through the C++ Primer book and doing the exercises. Every time I get to a new exercise I create a new .cpp file and set it up with the main method (and any includes I think I will need) e.g.: #include <list> #include <vector> int main(int argc, char **args) { } and just to make sure I go to the command prompt and compile and run: g++ whatever.cpp a.exe Normally this works just fine and I start working on the exercise, but I just did it and got a strange error. It compiles fine, but when I run it it says Access Denied and AVG pops up telling me that a threat has been detected 'Trojan Horse Generic 17.CKZT'. I tried compiling again using the Microsoft Compiler (cl.exe) and it runs fines. So I went back, and added: #include <iostream> compiled using g++ and ran. This time it worked fine. So can anyone tell me why AVG would report an empty main method as a trojan horse but if the iostream header is included it doesn't?

    Read the article

  • How to combine two separate unrelated Git repositories into one with single history timeline

    - by Antony
    I have two unrelated (not sharing any ancestor check in) Git repositories, one is a super repository which consists a number of smaller projects (Lets call it repository A). Another one is just a makeshift local Git repository for a smaller project (lets call it repository B). Graphically, it would look like this A0-B0-C0-D0-E0-F0-G0-HEAD (repo A) A0-B0-C0-D0-E0-F0-G0-HEAD (remote/master bare repo pulled & pushed from repo A) A1-B1-C1-D1-E1-HEAD (repo B) Ideally, I would really like to merge repo B into repo A with a single history timeline. So it would appear that I originally started project in repo A. Graphically, this would be the ideal end result A0-A1-B1-B0-D1-C0-D0-E0-F0-G0-E1-H(from repo B)-HEAD (new repo A) A0-A1-B1-B0-D1-C0-D0-E0-F0-G0-E1-H(from repo B)-HEAD (remote/master bare repo pulled & pushed from repo A) I have been doing some reading with submodules and subtree (Pro Git is a pretty good book by the way), but both of them seem to cater solution towards maintaining two separate branch with sub module being able to pull changes from upstream and subtree being slightly less headache. Both solution require additional and specialized git commands to handle check ins and sync between master and sub tree/module branch. Both solution also result in multiple time-lines (with --squash you even get 3 timelines with subtree). The closest solution from SO seems to talk about "graft", but is that really it? The goal is to have a single unified repository where I can pull/push check-ins, so that there are no more repo B, just repo A in the end.

    Read the article

  • Is this state-of-the-art Ajax/jQuery, or should I do it differently?

    - by AP257
    Hi everyone: I'm using Ajax and jQuery to do some cool client-side stuff. Basically, if the user chooses a subject from a from a drop-down list, I want to auto-populate the page with a set of book details. However, I've built the Ajax from Google results and bits of string. I don't know if what I've done is up-to-date, or whether there are now much neater ways of doing it! Here's what I have: can it be improved? $("#subjectlist").change(function() { if (window.XMLHttpRequest) { xmlhttp=new XMLHttpRequest(); } else { xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { var book_details = eval(xmlhttp.responseText); alert(book_details[0]["url"]); // To be added: extra code to populate HTML results. document.getElementById("book_results").innerHTML=xmlhttp.responseText; } } xmlhttp.open("GET","/subject_json/?id=" + $("#subjectlist").val(),true); xmlhttp.send(); }); Thanks for any advice!

    Read the article

  • Strange results about C++11 memory model (Relaxed ordering)

    - by Dancing_bunny
    I was testing the example in the memory model of the Anthony Williams's book "C++ Concurrency" #include<atomic> #include<thread> #include<cassert> std::atomic_bool x,y; std::atomic_int z; void write_x_then_y() { x.store(true, std::memory_order_relaxed); y.store(true, std::memory_order_relaxed); } void read_y_then_x() { while(!y.load(std::memory_order_relaxed)); if(x.load(std::memory_order_relaxed)) { ++z; } } int main() { x = false; y = false; z = 0; std::thread a(write_x_then_y); std::thread b(read_y_then_x); a.join(); b.join(); assert(z.load()!=0); } According to the explanation, relaxed operations on difference variables (here x and y) can be freely reordered. However, I repeated running the problem for more than several days. I never hit the situation that the assertion (assert(z.load()!=0);) fires. I just use the default optimization and compile the code using g++ -std=c++11 -lpthread dataRaceAtomic.cpp Does anyone actually try it and hit the assertion? Could anyone give me an explanation about my test results? BTW, I also tried the version without using the atomic type, I got the same result. Currently, both programs are running healthily. Thanks.

    Read the article

  • Selective replication with CouchDB

    - by FRotthowe
    I'm currently evaluating possible solutions to the follwing problem: A set of data entries must be synchonized between multiple clients, where each client may only view (or even know about the existence of) a subset of the data. Each client "owns" some of the elements, and the decision who else can read or modify those elements may only be made by the owner. To complicate this situation even more, each element (and each element revision) must have an unique identifier that is equal for all clients. While the latter sounds like a perfect task for CouchDB (and a document based data model would fit my needs perfectly), I'm not sure if the authentication/authorization subsystem of CouchDB can handle these requirements: While it should be possible to restict write access using validation functions, there doesn't seem to be a way to authorize read access. All solutions I've found for this problem propose to route all CouchDB requests through a proxy (or an application layer) that handles authorization. So, the question is: Is it possible to implement an authorization layer that filters requests to the database so that access is granted only to documents that the requesting client has read access to and still use the replication mechanism of CouchDB? Simplified, this would be some kind of "selective replication" where only some of the documents, and not the whole database is replicated. I would also be thankful for directions to some detailed information about how replication works. The CouchDB wiki and even the "Definite Guide" Book are not too specific about that.

    Read the article

  • uploading database file in assets not returning a record

    - by Alexander
    I have a problem with a database file not being read I have added the database file in assets called mydb but when i run my code it says its not being located. It is calling this toast Toast.makeText(this, "No contact found", Toast.LENGTH_LONG).show(); This is being called because no records are being returned. This is an example form Android Application Development book. public class DatabaseActivity extends Activity { /** Called when the activity is first created. */ TextView quest, response1, response2; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); TextView quest = (TextView) findViewById(R.id.quest); try { String destPath = "/data/data/" + getPackageName() + "/databases/MyDB"; File f = new File(destPath); if (!f.exists()) { CopyDB( getBaseContext().getAssets().open("mydb"), new FileOutputStream(destPath)); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } DBAdapter db = new DBAdapter(this); //---get a contact--- db.open(); Cursor c = db.getContact(2); if (c.moveToFirst()) DisplayContact(c); else Toast.makeText(this, "No contact found", Toast.LENGTH_LONG).show(); db.close(); } public void CopyDB(InputStream inputStream, OutputStream outputStream) throws IOException { //---copy 1K bytes at a time--- byte[] buffer = new byte[1024]; int length; while ((length = inputStream.read(buffer)) > 0) { outputStream.write(buffer, 0, length); } inputStream.close(); outputStream.close(); } public void DisplayContact(Cursor c) { quest.setText(String.valueOf(c.getString(1))); //quest.setText(String.valueOf("this is a text string")); } }

    Read the article

< Previous Page | 276 277 278 279 280 281 282 283 284 285 286 287  | Next Page >