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  • How to call Ajax function recursively.

    - by MAS1
    Hi guys, I want to know how to call Ajax function Recursively. My ajax code is like this, <html> <head> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript"> var step='1'; $.ajax ( { url: 'test1.php', data: {step: step}, success: function(output) { step=eval(output); alert(step); } } ); </script> </head> </html> And php code is like this <?php function writeName() { echo "step=2"; } function ReadName() { echo "In Read Name Function"; } if(isset($_REQUEST['step']) && !empty($_REQUEST['step'])) { $step = $_REQUEST['step']; switch($step) { case '1' : writeName(); break; case '2' : ReadName(); break; default : echo "Empty String"; } } ?> first time this function is get called with value of step variable equal to 1 and Function Write name modified it as 2. Now i want to call this Ajax function with Step variable value equal to 2. So that 2nd php function gets called.

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  • Form is submitting when the page loads

    - by RailAddict
    I have a really simple Rails app. Basically an article with comments. I want the article page to show the article, comments underneath and then a textbox to write a comment and a submit button to submit it. I got it all working except for one (big) problem. When the page loads.. example.com/article/1 a blank comment is submitted to the database. I fixed that by including "validates_presence_of :body" in the Comment model. But that results in the following image when the page loads: This is my code by the way: def show @place = Article.find(params[:id]) @comment = Article.find(params[:id]).comments.create(params[:comment]) respond_to do |format| format.html # show.html.erb format.xml { render :xml => @article } end end and <% form_for([@article, @comment]) do |f| %> <p> <%= f.label :commenter %><br /> <%= f.text_field :commenter %> </p> <p> <%= f.label :body %><br /> <%= f.text_area :body %> </p> <p> <%= f.submit "Create" %> </p> <% end %>

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  • How do I read the manifest file for a webapp running in apache tomcat?

    - by Nik Reiman
    I have a webapp which contains a manifest file, in which I write the current version of my application during an ant build task. The manifest file is created correctly, but when I try to read it in during runtime, I get some strange side-effects. My code for reading in the manifest is something like this: InputStream manifestStream = Thread.currentThread() .getContextClassLoader() .getResourceAsStream("META-INFFFF/MANIFEST.MF"); try { Manifest manifest = new Manifest(manifestStream); Attributes attributes = manifest.getMainAttributes(); String impVersion = attributes.getValue("Implementation-Version"); mVersionString = impVersion; } catch(IOException ex) { logger.warn("Error while reading version: " + ex.getMessage()); } When I attach eclipse to tomcat, I see that the above code works, but it seems to get a different manifest file than the one I expected, which I can tell because the ant version and build timestamp are both different. Then, I put "META-INFFFF" in there, and the above code still works! This means that I'm reading some other manifest, not mine. I also tried this.getClass().getClassLoader().getResourceAsStream(...) But the result was the same. What's the proper way to read the manifest file from inside of a webapp running in tomcat? Edit: Thanks for the suggestions so far. Also, I should note that I am running tomcat standalone; I launch it from the command line, and then attach to the running instance in Eclipse's debugger. That shouldn't make a difference, should it?

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  • C#, create virtual directory on remote system

    - by sankar
    The following code create only virtual directory on local system , but i need to create on remote sytem ..help me.. Thanks, Sankar DirectoryEntry iisServer; string VirDirSchemaName = "IIsWebVirtualDir"; public DirectoryEntry Connect() { try { if (txtPath.Text.ToLower().Trim() == "localhost") iisServer = new DirectoryEntry("IIS://" + txtPath.Text.Trim() + "/W3SVC/1/Root"); else iisServer = new DirectoryEntry("IIS://" + txtPath.Text + "/Schema/AppIsolated", "XYZ", "xyz"); iisServer.Dispose(); } catch (Exception e) { throw new Exception("Could not connect to: " + txtPath.Text.Trim(), e); } return iisServer; } public void CreateVirtualDirectory(DirectoryEntry iisServer) { DirectoryEntry folderRoot = new DirectoryEntry("IIS://" + txtPath.Text + "/W3SVC/1/Root", "XYZ", "xyz"); folderRoot.RefreshCache(); folderRoot.CommitChanges(); try { DirectoryEntry newVirDir = folderRoot.Children.Add(txtName.Text, VirDirSchemaName); newVirDir.CommitChanges(); newVirDir.Properties["AccessRead"].Add(true); newVirDir.Properties["Path"].Add(@"\\abc\abc"); newVirDir.Invoke("AppCreate", true); newVirDir.CommitChanges(); folderRoot.CommitChanges(); newVirDir.Close(); folderRoot.CommitChanges(); } catch (Exception e) { throw new Exception("Error! Virtual Directory Not Created", e); } } protected void btnCreate_Click(object sender, EventArgs e) { try { CreateVirtualDirectory(Connect()); } catch (Exception ex) { Response.Write(ex.Message); } } protected void Page_Load(object sender, EventArgs e) { }

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  • Cloud-aware programming and help choosing a good framework

    - by Shoaibi
    How can i write a cloud-aware application? e.g. an application that takes benefit of being deployed on cloud. Is it same as an application that runs or a vps/dedicated server? if not then what are the differences? are there any design changes? What are the procedures that i need to take if i am to migrate an application to cloud-aware? Also i am about to implement a web application idea which would need features like security, performance, caching, and more importantly free. I have been comparing some frameworks and found that django has least RAM/CPU usage and works great in prefork+threaded mode, but i have also read that django based sites stop to respond with huge load of connections. Other frameworks that i have seen/know are Zend, CakePHP, Lithium/Cake3, CodeIgnitor, Symfony, Ruby on Rails.... So i would leave this to your opinion as well, suggest me a good free framework based on my needs. Finally thanks for reading the essay ;)

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  • Adding custom valiadtion to ASP.NET controls

    - by Brian
    We're trying to build a simple asp control for some clients where they can just drop in a single block - i.e. <captcha:CaptchaControl ID="CaptchaControl1" runat="server" Server="http://localhost:51947/" /> and have it render the control. The catch is that I can't get this to include custom validation. Right now I'm using the RenderContents function to display the layout of the control itself as well as hook it up the to Javascript. The problem is that I don't know how to get custom validation to fire when used as part of a control. protected override void RenderContents(HtmlTextWriter output) { output.Write(@" <script type=""text/javascript"" src=""http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js""></script> <link rel=""stylesheet"" type=""text/css"" href=""/Layout/CaptchaLayout.css"" /> //etc <asp:Textbox id=""text1"" runat=""server"" text=""""></asp:Textbox> <asp:CustomValidator id=""CustomValidator2"" runat=""server"" ControlToValidate = ""text1"" ErrorMessage = ""You must enter at least 8 characters!"" ClientValidationFunction=""validateLength"" > </asp:CustomValidator>" ); } Any suggestions for a better way to do this?

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  • Is there a Standard or Best Practice for Perl Programs, as opposed to Perl Modules?

    - by swestrup
    I've written any number of perl modules in the past, and more than a few stand-alone perl programs, but I've never released a multi-file perl program into the wild before. I have a perl program that is almost at the beta stage and is going to be released open source. It requires a number of data files, as well as some external perl modules -- some I've written myself, and some from CPAN -- that I'll have to bundle with it so as to ensure that someone can just download my program and install it without worrying about hunting for obscure modules. So, it sounds to me like I need to write an installer to copy all the files to standard locations so that a user can easily install everything. The trouble is, I have no idea what the standard practice would be for this. I have found lots of tutorials on perl module standards, but none on perl program standards. Does anyone have any pointers to standard paths, installation proceedures, etc, for perl programs? This is going to be complicated by the fact that the program is multi-platform. I've been testing it in Linux, but its designed to work equally well in Windows.

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  • Java Error beeping

    - by user1281385
    Im working on a Chat client that i didnt write the bulk of the code for. It works fine however when someone sends a message it beeps (system error beep) when using Java 7. Java 6 and below doesn't have this beep. I cant seem to find whats causing the beep is there any way to find it ? I dont think its calling beep as i have public class nobeep extends sun.awt.windows.WToolkit { @Override public void beep() { System.out.println("tried to beep"); new Exception().printStackTrace(); } } and then called System.setProperty("awt.toolkit", "nobeep"); in the main method. Using the method to send a beep doesnt make it beep. Its only when sent normally. Is there a quick way to track down the cause of the beep ? Edit: After looking in the bugs database - its confirmed. http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7194469 I know it says no work around but is there one (java not c++) or just wait until update 8 ?

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  • Lua Alien Module - Trouble using WriteProcessMemory function, unsure on types (unit32)

    - by jefferysanders
    require "alien" --the address im trying to edit in the Mahjong game on Win7 local SCOREREF = 0x0744D554 --this should give me full access to the process local ACCESS = 0x001F0FFF --this is my process ID for my open window of Mahjong local PID = 1136 --function to open proc local op = alien.Kernel32.OpenProcess op:types{ ret = "pointer", abi = "stdcall"; "int", "int", "int"} --function to write to proc mem local wm = alien.Kernel32.WriteProcessMemory wm:types{ ret = "long", abi = "stdcall"; "pointer", "pointer", "pointer", "long", "pointer" } local pRef = op(ACCESS, true, PID) local buf = alien.buffer("99") -- ptr,uint32,byte arr (no idea what to make this),int, ptr print( wm( pRef, SCOREREF, buf, 4, nil)) --prints 1 if success, 0 if failed So that is my code. I am not even sure if I have the types set correctly. I am completely lost and need some guidance. I really wish there was more online help/documentation for alien, it confuses my poor brain. What utterly baffles me is that it WriteProcessMemory will sometimes complete successfully (though it does nothing at all, to my knowledge) and will also sometimes fail to complete successfully. As I've stated, my brain hurts. Any help appreciated.

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  • Delete all rows that do not have the value: Criteria 1 or Criteria 2 or Criteria 3 in Column D --> Using VBA Macro for excel

    - by JDS
    I am new to Macro's/VBA and cannot seem to figure out how to do this action for multiple criteria. I am trying to Delete all rows that do not have the value: Identify Fail or Identify Success in Column D. I write the following code and it works for one criteria "Identify Fail": '***********************************************' Sub DeleteRows() 'Action 1 --> Delete all Rows without Identify Fail in column D' Application.ScreenUpdating = False For i = Range("D" & Rows.Count).End(xlUp).Row To 1 Step -1 If Range("D" & i).Value <> "Identify Fail" Then Rows(i).Delete shift:=xlUp Next i Application.ScreenUpdating = True End Sub '***********************************************' Once I try to add 'OR' with another criteria it does not work: '***********************************************' Sub DeleteRows() 'Action 1 --> Delete all Rows without Identify Fail in column D' Application.ScreenUpdating = False For i = Range("D" & Rows.Count).End(xlUp).Row To 1 Step -1 If Range("D" & i).Value <> "Identify Fail" Or "Identify Success" Then Rows(i).Deleteshift:=xlUp Next i Application.ScreenUpdating = True End Sub '***********************************************' Any suggestions would be appreciated as I have been scouring this website and have not found an efficient code that will do the trick.

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  • Simple, fast SQL queries for flat files.

    - by plinehan
    Does anyone know of any tools to provide simple, fast queries of flat files using a SQL-like declarative query language? I'd rather not pay the overhead of loading the file into a DB since the input data is typically thrown out almost immediately after the query is run. Consider the data file, "animals.txt": dog 15 cat 20 dog 10 cat 30 dog 5 cat 40 Suppose I want to extract the highest value for each unique animal. I would like to write something like: cat animals.txt | foo "select $1, max(convert($2 using decimal)) group by $1" I can get nearly the same result using sort: cat animals.txt | sort -t " " -k1,1 -k2,2nr And I can always drop into awk from there, but this all feels a bit awkward (couldn't resist) when a SQL-like language would seem to solve the problem so cleanly. I've considered writing a wrapper for SQLite that would automatically create a table based on the input data, and I've looked into using Hive in single-processor mode, but I can't help but feel this problem has been solved before. Am I missing something? Is this functionality already implemented by another standard tool? Halp!

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  • SSL with private key on an HSM

    - by Jason
    I have a client-server architecture in my application that uses SSL. Currently, the private key is stored in CAPI's key store location. For security reasons, I'd like to store the key in a safer place, ideally a hardware signing module (HSM) that is built for this purpose. Unfortunately, with the private key stored on such a device, I can't figure out how to use it in my application. On the server, I am simply using the SslStream class and the AuthenticateAsServer(...) call. This method takes an X509Certificate object that has its private key loaded, but since the private key is stored in a secure (e.g. non exportable) location on the HSM, I don't know how to do this. On the client, I am using an HttpWebRequest object and then using the ClientCertificates property to add my client authentication certificate, but I have the same problem here: how do I get the private key? I know there are some HSMs that act as SSL accelerators but I don't really need an accelerator. Also, these products tend to have special integration with web servers such as IIS and Apache which I'm not using. Any ideas? The only thing I can think of would be to write my own SSL library that would allow me to hand off the signing portion of the transaction to the HSM, but this seems like a huge amount of work.

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  • C# StreamReader.EndOfStream produces IOException

    - by Ziplin
    I'm working on an application that accepts TCP connections and reads in data until an </File> marker is read and then writes that data to the filesystem. I don't want to disconnect, I want to let the client sending the data to do that so they can send multiple files in one connection. I'm using the StreamReader.EndOfStream around my outter loop, but it throws an IOException when the client disconnects. Is there a better way to do this? private static void RecieveAsyncStream(IAsyncResult ar) { TcpListener listener = (TcpListener)ar.AsyncState; TcpClient client = listener.EndAcceptTcpClient(ar); // init the streams NetworkStream netStream = client.GetStream(); StreamReader streamReader = new StreamReader(netStream); StreamWriter streamWriter = new StreamWriter(netStream); while (!streamReader.EndOfStream) // throws IOException { string file= ""; while (file!= "</File>" && !streamReader.EndOfStream) { file += streamReader.ReadLine(); } // write file to filesystem } listener.BeginAcceptTcpClient(RecieveAsyncStream, listener); }

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  • How to make a model instance read-only after saving it once?

    - by Ryszard Szopa
    One of the functionalities in a Django project I am writing is sending a newsletter. I have a model, Newsletter and a function, send_newsletter, which I have registered to listen to Newsletter's post_save signal. When the newsletter object is saved via the admin interface, send_newsletter checks if created is True, and if yes it actually sends the mail. However, it doesn't make much sense to edit a newsletter that has already been sent, for the obvious reasons. Is there a way of making the Newsletter object read-only once it has been saved? Edit: I know I can override the save method of the object to raise an error or do nothin if the object existed. However, I don't see the point of doing that. As for the former, I don't know where to catch that error and how to communicate the user the fact that the object wasn't saved. As for the latter, giving the user false feedback (the admin interface saying that the save succeded) doesn't seem like a Good Thing. What I really want is allow the user to use the Admin interface to write the newsletter and send it, and then browse the newsletters that have already been sent. I would like the admin interface to show the data for sent newsletters in an non-editable input box, without the "Save" button. Alternatively I would like the "Save" button to be inactive.

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  • need help passing multiple variables from foreach loop to test in switch case statement

    - by Brad
    $list_of_groups = array("FACULTY","STAFF"); foreach ($list_of_groups as $i => $group) { $user_in_group = $adldap->user_ingroup($username,$group); print "<h2>Group: ".$group." user in group? ".$user_in_group."</h2>"; // if 1, means yes } Need to print run the appropriate function based on what returns true. There are user's that are members of both FACULTY and STAFF groups, so I want to check for those users and display the appropriate content for them. So if the user is both faculty and staff, then display this, if they are only of staff, display that, same for faculty, might not make sense, but I will write out some code "in theory" that will help you understand what I am trying to do switch(Get group membership of user) { case "FACULTY": print "Faculty group member"; break; case "STAFF": print "Staff group member"; break; case "FACULTY and STAFF": print "Member of both faculty and staff"; break; } I am unsure on how it will check if they are members of both groups and run that thru the case statement to display the appropriate message. The foreach look currently runs thru every group the user belongs to, prints out the ones from the $list_of_groups and the number 1 to the right of it, signifying they belong to it. The problem I have is trying to use that information to run thru the case statement, I am unsure of how to go about that. This is what it prints out for the user currently passed thru the foreach loop: Group: FACULTY user in group? 1 Group: STAFF user in group? 1 Any help is appreciated.

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  • Looking for a .Net ORM

    - by SLaks
    I'm looking for a .Net 3.5 ORM framework with a rather unusual set of requirements: I need to create and alter tables at runtime with schemas defined by my end-users. (Obviously, that wouldn't be strongly-typed; I'm looking for something like a DataTable there) I also want regular strongly-typed partial classes for rows in non-dynamic tables, with custom validation and other logic. (Like normal ORMs) I want to load the entire database (or some entire tables) once, and keep it in memory throughout the life of the (WinForms) GUI. (I have a shared SQL Server with a relatively slow connection) I also want regular LINQ support (like LINQ-to-SQL) for ASP.Net on the shared server (which has a fast connection to SQL Server) In addition to SQL Server, I also want to be able to use a single-file database that would support XCopy deployment (without installing SQL CE on the end-user's machine). (Probably Access or SQLite) Finally, it has to be free (unless it's OpenAccess) I'll probably have to write it myself, as I don't think there is an existing ORM that meets these requirements. However, I don't want to re-invent the wheel if there is one, hence this question. I'm using VS2010, but I don't know when my webhost (LFC) will upgrade to .Net 4.0

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  • Python: How to execute a SQL file or command

    - by Mestika
    Hi, I have this Python script: import sys import getopt import timeit import random import os import re import ibm_db import time from string import maketrans runs=5 queries=50 file = open("results.txt", "a") for r in range(5): print "Run %s\n" % r os.system("python reads.py -r1 -pquery1.sql -q50 -sespec") file.write('END QUERY READ 01') file.close() os.system("python query_read_02.py") Everything here is working, it is creating the results.txt file, it run the os.system("python reads.py...") file and that file is doing everything it's suppose to, but the problem comes when go and run the query_read_02.py file. In this file, it should execute a SQL command or a SQL file on my database, so I can create an index and see what the performance of that input is, but how do i do it? I create the connection to the database in the reads.py file, but it's hard to create the queries in there because I doesn't keep track of which file it has reached, it just execute commands from what the parameters are. I hope I've explained myself clear enough, otherwise please let me know. I just want to execute a SQL command or file which each query_read_0x.py file. Sincerely Mestika

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  • Bypassing confirmation prompt of an external process

    - by Alidad
    How can I convert this Perl code to Groovy? How to bypass confirmation prompts of an external process? I am trying to convert a Perl script to Groovy. The program is loading/delete maestro (job scheduling) jobs automatically. The problem is the delete command will prompt for confirmation (Y/N) on every single job that it finds. I tried the process execute in groovy but will stop at the prompts. The Perl script is writing bunch of Ys to the stream and print it to the handler( if I understood it correctly) to avoid stopping. I am wondering how to do the same thing in Groovy ? Or any other approach to execute a command and somehow write Y on every confirmation prompt. Perl Script: $maestrostring=""; while ($x < 1500) { $maestrostring .= "y\n"; $x++; } # delete the jobs open(MAESTRO_CMD, "|ssh mserver /bin/composer delete job=pserver#APPA@") print MAESTRO_CMD $maestrostring; close(MAESTRO_CMD); This is my groovy code so far: def deleteMaestroJobs (){ ... def commandSched ="ssh $maestro_server /bin/composer delete sched=$primary_server#$app_acronym$app_level@" def commandJobs ="ssh $maestro_server /bin/composer delete job=$primary_server#$app_acronym$app_level@" try { executeCommand commandJobs } catch (Exception ex ){ throw new Exception("Error executing the Maestro Composer [DELETE]") } try { executeCommand commandSched } catch (Exception ex ){ throw new Exception("Error executing the Maestro Composer [DELETE]") } } def executeCommand(command){ def process = command.execute() process.withWriter { writer -> 1500.times {writer.println 'Y' } } process.consumeProcessOutput(System.out, System.err) process.waitFor() }

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  • Log4net Logging Problem : Very simple file appender logging not working

    - by contactmatt
    Here's my web.config information <configSections> <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/> </configSections> <log4net> <root> <level value="ALL" /> </root> <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender"> <file value="c:\temp\log-file.txt" /> <appendToFile value="true" /> <rollingStyle value="Size" /> <maxSizeRollBackups value="10" /> <maximumFileSize value="1MB" /> <staticLogFileName value="true" /> <layout type="log4net.Layout.SimpleLayout" /> </appender> </log4net> ... Here's the code that initalizes the logger protected void SendMessage() { log4net.Config.XmlConfigurator.Configure(); ILog log = LogManager.GetLogger(typeof(Contact)); ... log.Info("here we go!"); log.Debug("debug afasf"); ... } it doesn't work, no matter what I seem to do. I am referencing the 'log4net.dll' correctly, and by debugging the application i can see that the log object is getting initiated properly. This is a asp.net 3.5 framework web project. Any ideas/suggestions? I thought originally this error may be due to a file write permission constraint, but that doesn't seem to be the case (or so I think).

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  • BizTalk SMTP Message Part Getting XML Encoding

    - by alram
    I have a email multi-part message which I am using to send failed message routing from the messagebox to a business users mailbox. Email{ Body - RawString; OriginalMessage - string}; The original message gets set from the received message that activates the orchestration. For example assume the original failed message is from a Flat file that failed disassembly with the contents: Order,1,2,3,4,5,<6>, I set the message using: Email.OriginalMessage = MyUtil.XlangMsgToStringMethod(FailedMessage);// XmlDocument type, this can be malformed xml, valid xml, or flat file that fails in disassembler. I can then write to the event log to test whats in Email.OriginalMessage: System.Diagnostics.EventLog.WriteEntry("BizTalk Server 2006", Email.OriginalMessage, Information); // This displays the correct original message "Order, 1,2,3,4,5,<6," When the email is delivered using a SMTP server and a dynamic send port, with the attachment set to text/plain mime type, the original message gets xml encoding escaped and wrapped in xml: <?xml version="1.0"?> <string>Order, 1,2,3,4,5,&lt;6&gt;,</string> Any ideas why? The SMTP port has passthrutransmit as pipeline. Thanks.

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  • PHP, We have sessions, and cookies....I love cookies, but they are blowing my mind right now.

    - by Matt
    I am not sure how to go about accessing the variable I need to set on a cookie... I was thinking about using the $_POST global but I dont know how based on my design if it will work. I am using a master page type design seperating index.php from my function includes and database information and individual pages (that will be returned to an include in index.php based on a $_GET) Okay so back to my question. What is the most efficient way to set a cookie on a design that has a main page that everything will branch from. How would I pull the value. Is $_POST a good enough way to go about it? Also...by saying it must be the first thing sent...does that mean I cannot run any serverside scripts before that? I could definately utilize a login query I think but I dont want to write code just to be dissapointed based on my lack of time and knowledge. I did search for answers...I know this most likely feels like a generic question that could be answered in a difference place...but I know I will get an accurate and professional answer here...so I dont want to bet on the half answers I found otherwise. Of course I will sanitize everything and not store any sensitive information (passwords,address,phone,or anything really for that matter besides some kind of session ID and the username) If this is confusing I am sorry but I am on a gov computer...and they lock these tighter than ft knox...so getting my code on here will be a chore until I get back to my room. Thanks, Matt

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  • Java: volatile guarantees and out-of-order execution

    - by WizardOfOdds
    Note that this question is solely about the volatile keyword and the volatile guarantees: it is not about the synchronized keyword (so please don't answer "you must use synchronize" for I don't have any issue to solve: I simply want to understand the volatile guarantees (or lack of guarantees) regarding out-of-order execution). Say we have an object containing two volatile String references that are initialized to null by the constructor and that we have only one way to modify the two String: by calling setBoth(...) and that we can only set their references afterwards to non-null reference (only the constructor is allowed to set them to null). For example (it's just an example, there's no question yet): public class SO { private volatile String a; private volatile String b; public SO() { a = null; b = null; } public void setBoth( @NotNull final String one, @NotNull final String two ) { a = one; b = two; } public String getA() { return a; } public String getB() { return b; } } In setBoth(...), the line assigning the non-null parameter "a" appears before the line assigning the non-null parameter "b". Then if I do this (once again, there's no question, the question is coming next): if ( so.getB() != null ) { System.out.println( so.getA().length ); } Am I correct in my understanding that due to out-of-order execution I can get a NullPointerException? In other words: there's no guarantee that because I read a non-null "b" I'll read a non-null "a"? Because due to out-of-order (multi)processor and the way volatile works "b" could be assigned before "a"? volatile guarantees that reads subsequent to a write shall always see the last written value, but here there's an out-of-order "issue" right? (once again, the "issue" is made on purpose to try to understand the semantics of the volatile keyword and the Java Memory Model, not to solve a problem).

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  • Read-only view of a Java list with more general type parameter

    - by Michael Rusch
    Suppose I have class Foo extends Superclass. I understand why I can't do this: List<Foo> fooList = getFooList(); List<Superclass> supList = fooList; But, it would seem reasonable for me to do that if supList were somehow "read-only". Then, everything would be consistent as everything that would come out of an objList would be a Foo, which is a Superclass. I could probably write a List implementation that would take an underlying list and a more general type parameter, and would then return everything as the more general type instead of the specific type. It would work like the return of Collections.unmodifiableList() except that the type would be made more general. Is there an easier way? The reason I'm considering doing this is that I am implementing an interface that requires that I return an (unmodifiable) List<Superclass>, but internally I need to use Foos, so I have a List<Foo>. I can't just cast.

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  • Invalidating Memcached Keys on save() in Django

    - by Zack
    I've got a view in Django that uses memcached to cache data for the more highly trafficked views that rely on a relatively static set of data. The key word is relatively: I need invalidate the memcached key for that particular URL's data when it's changed in the database. To be as clear as possible, here's the meat an' potatoes of the view (Person is a model, cache is django.core.cache.cache): def person_detail(request, slug): if request.is_ajax(): cache_key = "%s_ABOUT_%s" % settings.SITE_PREFIX, slug # Check the cache to see if we've already got this result made. json_dict = cache.get(cache_key) # Was it a cache hit? if json_dict is None: # That's a negative Ghost Rider person = get_object_or_404(Person, display = True, slug = slug) json_dict = { 'name' : person.name, 'bio' : person.bio_html, 'image' : person.image.extra_thumbnails['large'].absolute_url, } cache.set(cache_key) # json_dict will now exist, whether it's from the cache or not response = HttpResponse() response['Content-Type'] = 'text/javascript' response.write(simpljson.dumps(json_dict)) # Make sure it's all properly formatted for JS by using simplejson return response else: # This is where the fully templated response is generated What I want to do is get at that cache_key variable in it's "unformatted" form, but I'm not sure how to do this--if it can be done at all. Just in case there's already something to do this, here's what I want to do with it (this is from the Person model's hypothetical save method) def save(self): # If this is an update, the key will be cached, otherwise it won't, let's see if we can't find me try: old_self = Person.objects.get(pk=self.id) cache_key = # Voodoo magic to get that variable old_key = cache_key.format(settings.SITE_PREFIX, old_self.slug) # Generate the key currently cached cache.delete(old_key) # Hit it with both barrels of rock salt # Turns out this doesn't already exist, let's make that first request even faster by making this cache right now except DoesNotExist: # I haven't gotten to this yet. super(Person, self).save() I'm thinking about making a view class for this sorta stuff, and having functions in it like remove_cache or generate_cache since I do this sorta stuff a lot. Would that be a better idea? If so, how would I call the views in the URLconf if they're in a class?

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  • JSON.Net and Linq

    - by user1745143
    I'm a bit of a newbie when it comes to linq and I'm working on a site that parses a json feed using json.net. The problem that I'm having is that I need to be able to pull multiple fields from the json feed and use them for a foreach block. The documentation for json.net only shows how to pull just one field. I've done a few variations after checking out the linq documentation, but I've not found anything that works best. Here's what I've got so far: WebResponse objResponse; WebRequest objRequest = HttpWebRequest.Create(url); objResponse = objRequest.GetResponse(); using (StreamReader reader = new StreamReader(objResponse.GetResponseStream())) { string json = reader.ReadToEnd(); JObject rss = JObject.Parse(json); var postTitles = from p in rss["feedArray"].Children() select (string)p["item"], //These are the fields I need to also query //(string)p["title"], (string)p["message"]; //I've also tried this with console.write and labeling the field indicies for each pulled field foreach (var item in postTitles) { lbl_slides.Text += "<div class='slide'><div class='slide_inner'><div class='slide_box'><div class='slide_content'></div><!-- slide content --></div><!-- slide box --></div><div class='rotator_photo'><img src='" + item + "' alt='' /></div><!-- rotator photo --></div><!-- slide -->"; } } Has anyone seen how to pull multiple fields from a json feed and use them as part of a foreach block (or something similar?

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