Search Results

Search found 17501 results on 701 pages for 'stored functions'.

Page 585/701 | < Previous Page | 581 582 583 584 585 586 587 588 589 590 591 592  | Next Page >

• Using function arguments to dynamically generate a query

  - by Varun

  I am working on an issue management system, developed in PHP/MySQL. It requires search functionality, where the user will mention the search parameters and based on these parameters the system will return the result set. To solve this I am trying to write a function and all the user selected parameters are passed as arguments. Based on the arguments I will dynamically generate the query. Sample Query: select * from tickets inner join ticket_assigned_to on tickets.id=ticket_assigned_to.ticket_id where tickets.project_id= in ('') and tickets.status in ('') and ticket_assigned_to.user_id in ('') and tickets.reporter_user_id='' and tickets.operator_user_id in ('') and tickets.due_date between '' and '' and tickets.ts_created between '' and ''; I also need to handle cases where the arguments can be ORed or ANDed in the query. For example: select * from tickets inner join ticket_assigned_to on tickets.id=ticket_assigned_to.ticket_id where tickets.project_id= in ('') and tickets.status in ('') or tickets.due_date = '' or tickets.ts_created between '' and ''; I am also planning to use the same function at other places in the project also. Like to display all the tickets of a user or all tickets created between given dates and so on... How to handle this situation? Should I go with a single function which handles all this or numerous small functions? Need guidance here.

  Read the article

• Updating section in ConfigParser (or an alternative)

  - by lyrae

  I am making a plugin for another program and so I am trying to make thing as lightweight as possible. What i need to do is be able to update the name of a section in the ConfigParser's config file. [project name] author:john doe email: [email protected] year: 2010 I then have text fields where user can edit project's name, author, email and year. I don't think changing [project name] is possible, so I have thought of two solutions: 1 -Have my config file like this: [0] projectname: foobar author:john doe email: [email protected] year: 2010 that way i can change project's name just like another option. But the problem is, i would need the section # to be auto incremented. And to do this i would have to get every section, sort of, and figure out what the next number should be. The other option would be to delete the entire section and its value, and re-add it with the updated values which would require a little more work as well, such as passing a variable that holds the old section name through functions, etc, but i wouldn't mind if it's faster. Which of the two is best? or is there another way? I am willing to go with the fastest/lightweight solution possible, doesn't matter if it requires more work or not.

  Read the article

• Having trouble parsing XML with jQuery

  - by Jack

  Hi Guys, I'm trying to parse some XML data using jQuery, and as it stands I have extracted the 'ID' attribute of the required nodes and stored them in an array, and now I want to run a loop for each array member and eventually grab more attributes from the notes specific to each ID. The problem currently is that once I get to the 'for' loop, it isn't looping, and I think I may have written the xml path data incorrectly. It runs once and I recieve the 'alert(arrayIds.length);' only once, and it only loops the correct amount of times if I remove the subsequent xml path code. Here is my function: var arrayIds = new Array(); $(document).ready(function(){ $.ajax({ type: "GET", url: "question.xml", dataType: "xml", success: function(xml) { $(xml).find("C").each(function(){ $("#attr2").append($(this).attr('ID') + "<br />"); arrayIds.push($(this).attr('ID')); }); for (i=0; i<arrayIds.length; i++) { alert(arrayIds.length); $(xml).find("C[ID='arrayIds[i]']").(function(){ // pass values alert('test'); }); } } }); }); Any ideas?

  Read the article

• DotNetOpeId - Using OpenIdButton for Google Apps

  - by JediPotPie

  I am an ASP.NET newbie and I am trying to design an OpenID/SSO system for an internal web application. The web application is pretty simple and the authentication is currently being managed by a database with usernames and passwords. I want to replace the existing accounts stored in the database with Google Apps accounts. I have downloaded the latest DotNetOpenAuth-3.4.3.10103 package and got the OpenIdRelyingPartyWebForms sample up and running on IIS. I have built my own login page using just a OpenIdButton object that points to a development Google domain. The button seems to work fine in FireFox, at least it is forwarding me to the Google Apps login, but nothing happens when I load the same page in IE. When I click the Google button, nothing happens, zip. The same is true for the Yahoo button in the login.aspx page given in the sample. Here is the .aspx code I am using... <rp:OpenIdButton runat="server" ImageUrl="http://www.google.com/accounts/google_transparent.gif" Text="Login with Google!" ID="googleLoginButton" Identifier="https://www.google.com/accounts/o8/site-xrds?hd=dev.connexcloud.com" />

  Read the article

• What's the best way to store Logon User information for Web Application?

  - by Morgan Cheng

  I was once in a project of web application developed on ASP.NET. For each logon user, there is an object (let's call it UserSessionObject here) created and stored in RAM. For each HTTP request of given user, matching UserSessoinObject instance is used to visit user state information and connection to database. So, this UserSessionObject is pretty important. This design brings several problems found later: 1) Since this UserSessionObject is cached in ASP.NET memory space, we have to config load balancer to be sticky connection. That is, HTTP request in single session would always be sent to one web server behind. This limit scalability and maintainability. 2) This UserSessionObject is accessed in every HTTP request. To keep the consistency, there is a exclusive lock for the UserSessionObject. Only one HTTP request can be processed at any given time because it must to obtain the lock first. The performance and response time is affected. Now, I'm wondering whether there is better design to handle such logon user case. It seems Sharing-Nothing-Architecture helps. That means long user info is retrieved from database each time. I'm afraid that would hurt performance. Is there any design pattern for long user web app? Thanks.

  Read the article

• Ruby syntax error: unexpected $end, expecting keyword_end

  - by user2839246

  I am supposed to: Capitalize the first letter of string. Capitalize every word except articles (the, a, an), conjunctions (and), and prepositions (in). Capitalize i (as in "I am male."). Specify the first word of a string (I actually have no idea what this means. I'm trying to run the spec file to test other functions). Here's my code: class Book def initialize(string) title(string) end def title(string) arts_conjs_preps = %w{ a an the and but or nor for yet so although because since unless despite in to } array = string.downcase.split array.each do |word| if (word == array[0] || word == "i") then word = word.capitalize if arts_conjs_preps !include?(word) then word = word.capitalize end puts array.join(' ') end end puts Book.new("inferno") Ruby says I'm messing up at: puts Book.new("inferno") <--(right after the last line of code) I get exactly the same error message with this test code: def title(string) array = string.downcase.split array.each do |word| if word == array[0] then word = word.capitalize end array.join(' ') end puts title("dante's inferno") The only other Stack Overflow thread regarding this particular syntax error that did not suggest trailing or missing ends or .s as the root of the problem is here. The last comment recommends deleting and recreating the gemset, Which sounds scary. And I'm not sure how to do. Any thoughts? Simple solution? Resources to help? Solution class Book def initialize(string) title(string) end def title(string) arts_conjs_preps = %w{ a an the and but or nor for yet so although because since unless despite of in to } array = string.downcase.split title = array.map do |word| if (word == array[0] || word == "i") || !arts_conjs_preps.include?(word) word = word.capitalize else word end end puts title.join(' ') end end Book.new("dante's the inferno")

  Read the article

• SQLAlchemy Custom Type Which Contains Multiple Columns

  - by Kekoa

  I would like to represent a datatype as a single column in my model, but really the data will be stored in multiple columns in the database. I cannot find any good resources on how to do this in SQLAlchemy. I would like my model to look like this(this is a simplified example using geometry instead of my real problem which is harder to explain): class 3DLine(DeclarativeBase): start_point = Column(my.custom.3DPoint) end_point = Column(my.custom.3DPoint) This way I could assign an object with the (x, y, z) components of the point at once without setting them individually. If I had to separate each component, this could get ugly, especially if each class has several of these composite objects. I would combine the values into one encoded field except that I need to query each value separately at times. I was able to find out how to make custom types using a single column in the documentation. But there's no indication that I can map a single type to multiple columns. I suppose I could accomplish this by using a separate table, and each column would be a foreign key, but in my case I don't think it makes sense to have a one to one mapping for each point to a separate table, and this still does not give the ability to set the related values all at once.

  Read the article

• Best practices for encrypting continuous/small UDP data

  - by temp

  Hello everyone, I am having an application where I have to send several small data per second through the network using UDP. The application need to send the data in real-time (no waiting). I want to encrypt these data and insure that what I am doing is as secure as possible. Since I am using UDP, there is no way to use SSL/TLS, so I have to encrypt each packet alone since the protocol is connectionless/unreliable/unregulated. Right now, I am using a 128-bit key derived from a passphrase from the user, and AES in CBC mode (PBE using AES-CBC). I decided to use a random salt with the passphrase to derive the 128-bit key (prevent dictionary attack on the passphrase), and of course use IVs (to prevent statistical analysis for packets). However I am concerned about few things: Each packet contains small amount of data (like a couple of integer values per packet) which will make the encrypted packets vulnerable to known-plaintext attacks (which will result in making it easier to crack the key). Also, since the encryption key is derived from a passphrase, this will make the key space way less (I know the salt will help, but I have to send the salt through the network once and anyone can get it). Given these two things, anyone can sniff and store the sent data, and try to crack the key. Although this process might take some time, once the key is cracked all the stored data will be decrypted, which will be a real problem for my application. So my question is, what is the best practices for sending/encrypting continuous small data using a connectionless protocol (UDP)? Is my way the best way to do it? ...flowed? ...Overkill? ... Please note that I am not asking for a 100% secure solution, as there is no such thing. Cheers

  Read the article

• How to encapsulate a WinAPI application into a C++ class

  - by Semen Semenych

  There is a simple WinAPI application. All it does currently is this: register a window class register a tray icon with a menu create a value in the registry in order to autostart and finally, it checks if it's unique using a mutex As I'm used to writing code mainly in C++, and no MFC is allowed, I'm forced to encapsulate this into C++ classes somehow. So far I've come up with such a design: there is a class that represents the application it keeps all the wndclass, hinstance, etc variables, where the hinstance is passed as a constructor parameter as well as the icmdshow and others (see WinMain prototype) it has functions for registering the window class, tray icon, reigstry information it encapsulates the message loop in a function In WinMain, the following is done: Application app(hInstance, szCmdLIne, iCmdShow); return app.exec(); and the constructor does the following: registerClass(); registerTray(); registerAutostart(); So far so good. Now the question is : how do I create the window procedure (must be static, as it's a c-style pointer to a function) AND keep track of what the application object is, that is, keep a pointer to an Application around. The main question is : is this how it's usually done? Am I complicating things too much? Is it fine to pass hInstance as a parameter to the Application constructor? And where's the WndProc? Maybe WndProc should be outside of class and the Application pointer be global? Then WndProc invokes Application methods in response to various events.

  Read the article

• Am I understanding premature optimization correctly?

  - by Ed Mazur

  I've been struggling with an application I'm writing and I think I'm beginning to see that my problem is premature optimization. The perfectionist side of me wants to make everything optimal and perfect the first time through, but I'm finding this is complicating the design quite a bit. Instead of writing small, testable functions that do one simple thing well, I'm leaning towards cramming in as much functionality as possible in order to be more efficient. For example, I'm avoiding multiple trips to the database for the same piece of information at the cost of my code becoming more complex. One part of me wants to just not worry about redundant database calls. It would make it easier to write correct code and the amount of data being fetched is small anyway. The other part of me feels very dirty and unclean doing this. :-) I'm leaning towards just going to the database multiple times, which I think is the right move here. It's more important that I finish the project and I feel like I'm getting hung up because of optimizations like this. My question is: is this the right strategy to be using when avoiding premature optimization?

  Read the article

• Function behaviour on shell(ksh) script

  - by footy

  Here are 2 different versions of a program: this Program: #!/usr/bin/ksh printmsg() { i=1 print "hello function :)"; } i=0; echo I printed `printmsg`; printmsg echo $i Output: # ksh e I printed hello function :) hello function :) 1 and Program: #!/usr/bin/ksh printmsg() { i=1 print "hello function :)"; } i=0; echo I printed `printmsg`; echo $i Output: # ksh e I printed hello function :) 0 The only difference between the above 2 programs is that printmsg is 2times in the above program while printmsg is called once in the below program. My Doubt arises here: To quote Be warned: Functions act almost just like external scripts... except that by default, all variables are SHARED between the same ksh process! If you change a variable name inside a function.... that variable's value will still be changed after you have left the function!! But we can clearly see in the 2nd program's output that the value of i remains unchanged. But we are sure that the function is called as the print statement gets the the output of the function and prints it. So why is the output different in both?

  Read the article

• Avoiding seasonality assumption for stl() or decompose() in R

  - by user303922

  Hello everybody, I have high frequency commodity price data that I need to analyze. My objective is to not assume any seasonal component and just identify a trend. Here is where I run into problems with R. There are two main functions that I know of to analyze this time series: decompose() and stl(). The problem is that they both take a ts object type with a frequency parameter greater than or equal to 2. Is there some way I can assume a frequency of 1 per unit time and still analyze this time series using R? I'm afraid that if I assume frequency greater than 1 per unit time, and seasonality is calculated using the frequency parameter, then my forecasts are going to depend on that assumption. names(crude.data)=c('Date','Time','Price') names(crude.data) freq = 2 win.graph() plot(crude.data$Time,crude.data$Price, type="l") crude.data$Price = ts(crude.data$Price,frequency=freq) I want frequency to be 1 per unit time but then decompose() and stl() don't work! dim(crude.data$Price) decom = decompose(crude.data$Price) win.graph() plot(decom$random[2:200],type="line") acf(decom$random[freq:length(decom$random-freq)]) Thank you.

  Read the article

• How to globalize ASP.NET MVC views (decimal separators in particular)?

  - by Pawel Krakowiak

  I'm working with the NerdDinner sample application and arrived at the section which deals with the Virtual Earth map. The application stores some values for the longitude and latitude. Unfortunately on my system floating point numbers are stored with a comma as the decimal separator, not a dot like in the US. So if I have a latitude of 47.64 it's retrieved and displayed as 47,64. Because that value is passed in a function call to the Virtual Earth API it fails at that point (e.g. JavaScript API expects 47.64, -122.13, but gets 47,64, -122,13). I need to make sure that the application always uses dots. In a WebForms app I would have a common class which overrides the System.Web.UI.Page.InitializeCulture() method and I would be inheriting my pages from that class. I am not sure about how to do the same with MVC. Do I need a customized ViewPage or something? Is there an easy way to solve this? Examples?

  Read the article

• Need to exclude results in a MySQL query where two table fields are not of certain values (brain far

  - by DondeEstaMiCulo

  I don't know if I'm just burnt out and can't think, or what... But I can't seem to make this work right... (We're using MySQL 5.1...) I have two tables which have some transactional stuff stored in them. There will be many records per user_id in each table. Table1 and Table2 have a one-to-one relationship with each other. I want to pull records from both tables, but I want to exclude records which have certain values in both tables. I don't care if they both don't have these values, or if just one does, but both tables should not have both values. (Does this make any sense? lol) For example: SELECT t1.id, t1.type, t2.name FROM table1 t1 INNER JOIN table2 t2 ON table.xid = table2.id WHERE t1.user_id = 100 AND (t1.type != 'FOO' AND t2.name != 'BAR') So t1.type is type ENUM with about 10 different options, and t2.name is also type ENUM with 2 options. My expected results would look a little like: 1, FOO, YUM 2, BOO, BAR 3, BOO, YUM But instead, all I'm getting is: 3, BOO, YUM Because it's filtering out all records which has 'FOO' as the type, and 'BAR' as the name. I keep waiting for that D'oh! moment where it hits me and I feel like an idiot for not realizing what I'm doing wrong. But it hasn't come. And I still feel like an idiot, lol. I appreciate any light any of you can shed on this! Many thanks in advance for the help!

  Read the article

• Enumeration trouble: redeclared as different kind of symbol

  - by Matt

  Hello all. I am writing a program that is supposed to help me learn about enumeration data types in C++. The current trouble is that the compiler doesn't like my enum usage when trying to use the new data type as I would other data types. I am getting the error "redeclared as different kind of symbol" when compiling my trangleShape function. Take a look at the relevant code. Any insight is appreciated! Thanks! (All functions are their own .cpp files.) header file #ifndef HEADER_H_INCLUDED #define HEADER_H_INCLUDED #include <iostream> #include <iomanip> using namespace std; enum triangleType {noTriangle, scalene, isoceles, equilateral}; //prototypes void extern input(float&, float&, float&); triangleType extern triangleShape(float, float, float); /*void extern output (float, float, float);*/ void extern myLabel(const char *, const char *); #endif // HEADER_H_INCLUDED main function //8.1 main // this progam... #include "header.h" int main() { float sideLength1, sideLength2, sideLength3; char response; do //main loop { input (sideLength1, sideLength2, sideLength3); triangleShape (sideLength1, sideLength2, sideLength3); //output (sideLength1, sideLength2, sideLength3); cout << "\nAny more triangles to analyze? (y,n) "; cin >> response; } while (response == 'Y' || response == 'y'); myLabel ("8.1", "2/11/2011"); return 0; } triangleShape shape # include "header.h" triangleType triangleShape(sideLenght1, sideLength2, sideLength3) { triangleType triangle; return triangle; }

  Read the article

• How to restrict date range of a jquery datepicker by giving two dates?

  - by Harie

  I am having two dates that is stored in db and am selecting it using $.ajax() and what i need is to show the datepicker values between the dates I selected from db. Here is my code for it.But it is not working properly function setDatePickerSettings(isFisc) { var fSDate, fEDate; $.ajax({ type: "POST", url: '../Asset/Handlers/AjaxGetData.ashx?fisc=1', success: function(data) { alert(data); var res = data.split("--");//data will be 4/4/2010 12:00:00--5/4/2011 12:00:00 var sDate = res[0].split(getSeparator(res[0])); alert("Separator " + getSeparator(res[1]) + " Starts " + sDate); var eDate = res[1].split(getSeparator(res[1])); alert("End " + eDate); alert("sub " + sDate[0]); fSDate = new Date(sDate[2].substring(0, 4), sDate[0], sDate[1]); alert("Starts " + fSDate.substring(0, 4)); fEDate = new Date(eDate[2].substring(0, 4), eDate[0], eDate[1]); alert("eND " + fEDate.toString()); } }); var dtSettings = { changeMonth: true, changeYear: true, showOn: 'both', buttonImage: clientURL + 'images/calendar.png', buttonImageOnly: true, showStatus: true, showOtherMonths: false, dateFormat: 'dd/mm/yy', minDate:fSDate, //assigning startdate maxDate:fEDate //assigning enddate }; return dtSettings; } Pls provide some solution. I need the datetime picker which requires values between that range. Thanks in advance

  Read the article

• Long running method causing race condition

  - by keeleyt83

  Hi, I'm relatively new with hibernate so please be gentle. I'm having an issue with a long running method (~2 min long) and changing the value of a status field on an object stored in the DB. The pseudo-code below should help explain my issue. public foo(thing) { if (thing.getStatus() == "ready") { thing.setStatus("finished"); doSomethingAndTakeALongTime(); } else { // Thing already has a status of finished. Send the user back a message. } } The pseudo-code shouldn't take much explanation. I want doSomethingAndTakeALongTime() to run, but only if it has a status of "ready". My issue arises whenever it takes 2 minutes for doSomethingAndTakeALongTime() to finish and the change to thing's status field doesn't get persisted to the database until it leaves foo(). So another user can put in a request during those 2 minutes and the if statement will evaluate to true. I've already tried updating the field and flushing the session manually, but it didn't seem to work. I'm not sure what to do from here and would appreciate any help. PS: My hibernate session is managed by spring.

  Read the article

• Which function pair in QString to use for converting to/from std::string?

  - by Noah Roberts

  I'm working on a project that we want to use Unicode and could end up in countries like Japan, etc... We want to use std::string for the underlying type that holds string data in the data layer (see Qt, MSVC, and /Zc:wchar_t- == I want to blow up the world as to why). The problem is that I'm not completely sure which function pair (to/from) to use for this and be sure we're 100% compatible with anything the user might enter in the Qt layer. A look at to/fromStdString indicates that I'd have to use setCodecForCStrings. The documentation for that function though indicates that I wouldn't want to do this for things like Japanese. This is the set that I'd LIKE to use though. Does someone know enough to explain how I'd set this up if it's possible? The other option that looks like I could be pretty sure of it working is the to/fromUTF8 functions. Those would require a two step approach though so I'd prefer the other if possible. Is there anything I've missed?

  Read the article

• Get part of array string

  - by user1560295

  Hello my output PHP code is : Array ( [country] => BG - Bulgaria ) ... and he comes from here : <?php $ip = $_SERVER['REMOTE_ADDR']; print_r(geoCheckIP($ip)); //Array ( [domain] => dslb-094-219-040-096.pools.arcor-ip.net [country] => DE - Germany [state] => Hessen [town] => Erzhausen ) //Get an array with geoip-infodata function geoCheckIP($ip) { //check, if the provided ip is valid if(!filter_var($ip, FILTER_VALIDATE_IP)) { throw new InvalidArgumentException("IP is not valid"); } //contact ip-server $response=@file_get_contents('http://www.netip.de/search?query='.$ip); if (empty($response)) { throw new InvalidArgumentException("Error contacting Geo-IP-Server"); } //Array containing all regex-patterns necessary to extract ip-geoinfo from page $patterns=array(); $patterns["country"] = '#Country: (.*?)&nbsp;#i'; //Array where results will be stored $ipInfo=array(); //check response from ipserver for above patterns foreach ($patterns as $key => $pattern) { //store the result in array $ipInfo[$key] = preg_match($pattern,$response,$value) && !empty($value[1]) ? $value[1] : ''; } return $ipInfo; } ?> How can I get ONLY the name of the Country like in my case "Bulgaria"? I think it will happen with preg_replace or substr but i dont know what is the better solution now.

  Read the article

• Appengine JDO dataclasses to python model

  - by M.A. Cape

  Does anyone have tried to implement an app in GAE having both java and python? I have an existing app and my front end is in java. Now I want to use the existing datastore to be interfaced by python. My problem is i don't know how to define the relationships and model that would be equivalent to the one in java. I have tried the one-to-many relationship in python but when stored in the datastore, the fields are different than the one-to-many of java. My data classes are as follows. //one-to-many owned Parent Class public class Parent{ @PrimaryKey @Persistent private String unitID; //some other fields... @Persistent @Order(extensions = @Extension(vendorName="datanucleus", key="list-ordering", value="dateCreated desc")) private List <Child> child; //methods & constructors were omitted } Child public class Child{ @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Key uId; @Persistent private String name; /* etc... */ }

  Read the article

• Memcache error: Failed reading line from stream (0) Array

  - by daviddripps

  I get some variation of the following error when our server gets put under any significant load. I've Googled for hours about it and tried everything (including upgrading to the latest versions and clean installs). I've read all the posts about it here on SA, but can't figure it out. A lot of people are having the same problem, but no one seems to have a definitive answer. Any help would be greatly appreciated. Thanks in advance. Fatal error: Uncaught exception 'Zend_Session_Exception' with message 'Zend_Session::start() - /var/www/trunk/library/Zend/Cache/Backend/Memcached.php(Line:180): Error #8 Memcache::get() [memcache.get]: Server localhost (tcp 11211) failed with: Failed reading line from stream (0) Array We have a copy of our production environment for testing and everything works great until we start load-testing. I think the biggest object stored is about 170KB, but it will probably be about 500KB when all is said and done (well below the 1MB limit). Just FYI: Memcache gets hit about 10-20 times per page load. Here's the memcached settings: PORT="11211" USER="memcached" MAXCONN="1024" CACHESIZE="64" OPTIONS="" I'm running Memcache 1.4.5 with version 2.2.6 of the PHP-memcache module. PHP is version 5.2.6. memcache details from php -i: memcache memcache support = enabled Active persistent connections = 0 Version = 2.2.6 Revision = $Revision: 303962 $ Directive = Local Value = Master Value memcache.allow_failover = 1 = 1 memcache.chunk_size = 8192 = 8192 memcache.default_port = 11211 = 11211 memcache.default_timeout_ms = 1000 = 1000 memcache.hash_function = crc32 = crc32 memcache.hash_strategy = standard = standard memcache.max_failover_attempts = 20 = 20 Thanks everyone

  Read the article

• How do actually castings work at the CLR level?

  - by devoured elysium

  When doing an upcast or downcast, what does really happen behind the scenes? I had the idea that when doing something as: string myString = "abc"; object myObject = myString; string myStringBack = (string)myObject; the cast in the last line would have as only purpose tell the compiler we are safe we are not doing anything wrong. So, I had the idea that actually no casting code would be embedded in the code itself. It seems I was wrong: .maxstack 1 .locals init ( [0] string myString, [1] object myObject, [2] string myStringBack) L_0000: nop L_0001: ldstr "abc" L_0006: stloc.0 L_0007: ldloc.0 L_0008: stloc.1 L_0009: ldloc.1 L_000a: castclass string L_000f: stloc.2 L_0010: ret Why does the CLR need something like castclass string? There are two possible implementations for a downcast: You require a castclass something. When you get to the line of code that does an castclass, the CLR tries to make the cast. But then, what would happen had I ommited the castclass string line and tried to run the code? You don't require a castclass. As all reference types have a similar internal structure, if you try to use a string on an Form instance, it will throw an exception of wrong usage (because it detects a Form is not a string or any of its subtypes). Also, is the following statamente from C# 4.0 in a Nutshell correct? Upcasting and downcasting between compatible reference types performs reference conversions: a new reference is created that points to the same object. Does it really create a new reference? I thought it'd be the same reference, only stored in a different type of variable. Thanks

  Read the article

• php and mysql site design question

  - by Jacksta

  I am trying to build a website with mysql and php. This is the first site I have attempted so I want to write a little plan and get some feedback. The site allows users to add some text in a text field as a “comment”. Once the comment has been entered into the site it is added to the database where it can be voted for by other users. When a new comment has been added to the database it needs to create a new page, e.g. www.xxxxx.com/commentname or www.xxxxxx.com/?id=99981. There will be a list of "Comments" in the database along with the number of votes for each comment. The home page will have two functions. 1) Allow users to add a "comment" 2) Display two tables, each with 20 rows containing most "popular comments" and "recent comments" Each comment will generate its one page where the comment will be displayed. Here users can read the comment and Vote for the comment if they wish. Please help me out by explaining how to do the following. -Generate a new page whenever a comment is added to the database -Add a vote to the vote count in the comment database. -Display the top 20 most popular comments as per number of votes.

  Read the article

• Why can't I extract a C++ type from a Python type using boost::python::extractor?

  - by Robin

  I've wrapped a C++ class using Py++ and everything is working great in Python. I can instantiate the c++ class, call methods, etc. I'm now trying to embed some Python into a C++ application. This is also working fine for the most-part. I can call functions on a Python module, get return values, etc. The python code I'm calling returns one of the classes that I wrapped: import _myextension as myext def run_script(arg): my_cpp_class = myext.MyClass() return my_cpp_class I'm calling this function from C++ like this: // ... excluding error checking, ref counting, etc. for brevity ... PyObject *pModule, *pFunc, *pArgs, *pReturnValue; Py_Initialize(); pModule = PyImport_Import(PyString_FromString("cpp_interface")); pFunc = PyObject_GetAttrString(pModule, "run_script"); pArgs = PyTuple_New(1); PyTuple_SetItem(pArgs, 0, PyString_FromString("an arg")); pReturnValue = PyObject_CallObject(pFunc, pArgs); bp::extract< MyClass& > extractor(pReturnValue); // PROBLEM IS HERE if (extractor.check()) { // This check is always false MyClass& cls = extractor(); } The problem is the extractor never actually extracts/converts the PyObject* to MyClass (i.e. extractor.check() is always false). According to the docs this is the correct way to extract a wrapped C++ class. I've tried returning basic data types (ints/floats/dicts) from the Python function and all of them are extracted properly. Is there something I'm missing? Is there another way to get the data and cast to MyClass?

  Read the article

• What does it mean for an OS to "execute within user processes"? Do any modern OS's use that approach

  - by Chris Cooper

  I have recently become interested in operating system, and a friend of mine lent me a book called Operating Systems: Internals and Design Principles (I have the third edition), published in 1998. It's been a very interesting book so far, but I have come to the part dealing with process control, and it's using UNIX System V as one of its examples of an operating system that executes within user processes. This concept has struck me as a little strange. First of all, does this mean that OS instructions and data are stored in each user of the processes? Probably not, because that would be an absurdly redundant scheme. But if not, then what does it mean to "execute within" a user process? Do any modern operating systems use this approach? It seems much more logical to have the operating system execute as its own process, or even independently of all processes, if you're short on memory. All the inter-accessiblilty of process data required for this layout seems to greatly complicate things. (But maybe that's just because I don't quite get the concept ;D) Here is what the book says: "Execution within User Processes: An alternative that is common with operation systems on smaller machines is to execute virtually all operating system software in the context of a user process. ... "

  Read the article

< Previous Page | 581 582 583 584 585 586 587 588 589 590 591 592  | Next Page >