Search Results

Search found 7418 results on 297 pages for 'argument passing'.

Page 257/297 | < Previous Page | 253 254 255 256 257 258 259 260 261 262 263 264  | Next Page >

  • Python and the self parameter

    - by Svend
    I'm having some issues with the self parameter, and some seemingly inconsistent behavior in Python is annoying me, so I figure I better ask some people in the know. I have a class, Foo. This class will have a bunch of methods, m1, through mN. For some of these, I will use a standard definition, like in the case of m1 below. But for others, it's more convinient to just assign the method name directly, like I've done with m2 and m3. import os def myfun(x, y): return x + y class Foo(): def m1(self, y, z): return y + z + 42 m2 = os.access m3 = myfun f = Foo() print f.m1(1, 2) print f.m2("/", os.R_OK) print f.m3(3, 4) Now, I know that os.access does not take a self parameter (seemingly). And it still has no issues with this type of assignment. However, I cannot do the same for my own modules (imagine myfun defined off in mymodule.myfun). Running the above code yields the following output: 3 True Traceback (most recent call last): File "foo.py", line 16, in <module> print f.m3(3, 4) TypeError: myfun() takes exactly 2 arguments (3 given) The problem is that, due to the framework I work in, I cannot avoid having a class Foo at least. But I'd like to avoid having my mymodule stuff in a dummy class. In order to do this, I need to do something ala def m3(self,a1, a2): return mymodule.myfun(a1,a2) Which is hugely redundant when you have like 20 of them. So, the question is, either how do I do this in a totally different and obviously much smarter way, or how can I make my own modules behave like the built-in ones, so it does not complain about receiving 1 argument too many.

    Read the article

  • Which source control paradigm and solution to embed in a custom editor application?

    - by Greg Harman
    I am building an application that manages a number of custom objects, which may be edited concurrently by multiple users (using different instances of the application). These objects have an underlying serialized representation, and my plan is to persist them (through my application UI) in an external source control system. Of course this implies that my application can check the current version of an object for updates, a merging interface for each object, etc. My question is what source control paradigm(s) and specific solution(s) to support and why. The way I (perhaps naively) see the source control world is three general paradigms: Single-repository, locked access (MS SourceSafe) Single-repository, concurrent access (CVS/SVN) Distributed (Mercurial, Git) I haven't heard of anyone using #1 for quite a number of years, so I am planning to disregard this case altogether (unless I get a compelling argument otherwise). However, I'm at a loss as to whether to support #2 or #3, and which specific implementations. I'm concerned that the use paradigms are subtly different enough that I can't adequately capture basic operations in a single UI. The last bit of information I should convey is that this application is intended to be deployed in a commercial setting, where a source control system may already be in use. I would prefer not to support more than one solution unless it's really a deal-breaker, so wide adoption in a corporate setting is a plus.

    Read the article

  • PHP Facebook Cronjob with offline access

    - by Mohamed Salem
    1:the code to greet the user, ask for his permission and store his session data so that we can use a cronjob with his session data afterwards. <?php $db_server = "localhost"; $db_username = "username"; $db_password = "password"; $db_name = "databasename"; #go to line 85, the script actually starts there mysql_connect($db_server,$db_username,$db_password); mysql_select_db($db_name); #you have to create a database to store session values. #if you do not know what columns there should be look at line 76 to see column names. #make them all varchars # Now lets load the FB GRAPH API require './facebook.php'; // Create our Application instance. global $facebook; $facebook = new Facebook(array( 'appId' => '121036530138', 'secret' => '9bbec378147064', 'cookie' => false,)); # Lets set up the permissions we need and set the login url in case we need it. $par['req_perms'] = "friends_about_me,friends_education_history,friends_likes, friends_interests,friends_location,friends_religion_politics, friends_work_history,publish_stream,friends_activities, friends_events, friends_hometown,friends_location ,user_interests,user_likes,user_events, user_about_me,user_status,user_work_history,read_requests, read_stream,offline_access,user_religion_politics,email,user_groups"; $loginUrl = $facebook->getLoginUrl($par); function save_session($session){ global $facebook; # OK lets go to the database and see if we have a session stored $sid=mysql_query("Select access_token from facebook_user WHERE uid =".$session['uid']); $session_id=mysql_fetch_row($sid); if (is_array($session_id)) { # We have a stored session, but is it valid? echo " We have a session, but is it valid?"; try { $attachment = array('access_token' => $session_id[0]); $ret_code=$facebook->api('/me', 'GET', $attachment); } catch (Exception $e) { # We don't have a good session so echo " our old session is not valid, let's delete saved invalid session data "; $res = mysql_query("delete from facebook_user WHERE uid =".$session['uid']); #save new good session #to see what is our session data: print_r($session); if (is_array($session)) { $sql="insert into facebook_user (session_key,uid,expires,secret,access_token,sig) VALUES ('".$session['session_key']."','".$session['uid']."','". $session['expires']."','". $session['secret'] ."','" . $session['access_token']."','". $session['sig']."');"; $res = mysql_query($sql); return $session['access_token']; } # this should never ever happen echo " Something is terribly wrong: Our old session was bad, and now we cannot get the new session"; return; } echo " Our old stored session is valid "; return $session_id[0]; } else { echo " no stored session, this means the user never subscribed to our application before. "; # let's store the session $session = $facebook->getSession(); if (is_array($session)) { # Yes we have a session! so lets store it! $sql="insert into facebook_user (session_key,uid,expires,secret,access_token,sig) VALUES ('".$session['session_key']."','".$session['uid']."','". $session['expires']."','". $session['secret'] ."','". $session['access_token']."','". $session['sig']."');"; $res = mysql_query($sql); return $session['access_token']; } } } #this is the first meaningful line of this script. $session = $facebook->getSession(); # Is the user already subscribed to our application? if ( is_null($session) ) { # no he is not #send him to permissions page header( "Location: $loginUrl" ); } else { #yes, he is already subscribed, or subscribed just now #in case he just subscribed now, save his session information $access_token=save_session($session); echo " everything is ok"; # write your code here to do something afterwards } ?> error Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/content/28/9687528/html/ss/src/indexx.php:1) in /home/content/28/9687528/html/ss/src/facebook.php on line 49 Fatal error: Call to undefined method Facebook::getSession() in /home/content/28/9687528/html/ss/src/indexx.php on line 86 2:A cronjob template that reads the stored session of a user from database, uses his session data to work on his behalf, like reading status posts or publishing posts etc. <?php $db_server = "localhost"; $db_username = "username"; $db_password = "pass"; $db_name = "database"; # Lets connect to the Database and set up the table $link = mysql_connect($db_server,$db_username,$db_password); mysql_select_db($db_name); # Now lets load the FB GRAPH API require './facebook.php'; // Create our Application instance. global $facebook; $facebook = new Facebook(array( 'appId' => 'appid', 'secret' => 'secret', 'cookie' => false, )); function get_check_session($uidCheck){ global $facebook; # This function basically checks for a stored session and if we have one it returns it # OK lets go to the database and see if we have a session stored $sid=mysql_query("Select access_token from facebook_user WHERE uid =".$uidCheck); $session_id=mysql_fetch_row($sid); if (is_array($session_id)) { # We have a session # but, is it valid? try { $attachment = array('access_token' => $session_id[0],); $ret_code=$facebook->api('/me', 'GET', $attachment); } catch (Exception $e) { # We don't have a good session so echo " User ".$uidCheck." removed the application, or there is some other access problem. "; # let's delete stored data $res = mysql_query("delete from facebook_user where WHERE uid =".$uidCheck); return; } return $session_id[0]; } else { # "no stored session"; echo " error:newsFeedcrontab.php No stored sessions. This should not have happened "; } } # get all users that have given us offline access $users = getUsers(); foreach($users as $user){ # now for each user, check if they are still subscribed to our application echo " Checking user".$user; $access_token=get_check_session($user); # If we've not got an access_token we actually need to login. # but in the crontab, we just log the error, there is no way we can find the user to give us permission here. if ( is_null($access_token) ) { echo " error: newsFeedcrontab.php There is no access token for the user ".$user." "; } else { #we are going to read the newsfeed of user. There are user's friends' posts in this newsfeed try{ $attachment = array('access_token' => $access_token); $result=$facebook->api('/me/home', 'GET', $attachment); }catch(Exception $e){ echo " error: newsfeedcrontab.php, cannot get feed of ".$user.$e; } #do something with the result here #but what does the result look like? #go to http://developers.facebook.com/docs/reference/api/user/ and click on the "home" link under connections #we can also read the home of user. Home is the wall of the user who has given us offline access. try{ $attachment = array('access_token' => $access_token); $result=$facebook->api('/me/feed', 'GET', $attachment); }catch(Exception $e){ echo " error: newsfeedcrontab.php, cannot get wall of ".$user.$e; } #do something with the result here # #but what does the result look like? #go to http://developers.facebook.com/docs/reference/api/user/ and click on the "feed" link under connections } } function getUsers(){ $sql = "SELECT distinct(uid) from facebook_user Where 1"; $result = mysql_query($sql); while($row = mysql_fetch_array($result)){ $rows [] = $row['uid']; } print_r($rows); return $rows; } mysql_close($link); ?> error Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/content/28/9687528/html/ss/src/cron.php:1) in /home/content/28/9687528/html/ss/src/facebook.php on line 49 Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/content/28/9687528/html/ss/src/cron.php on line 110 Warning: Invalid argument supplied for foreach() in /home/content/28/9687528/html/ss/src/cron.php on line 64

    Read the article

  • Android depth buffer issue: Advice for anyone experiencing problem

    - by Andrew Smith
    I've wasted around 30 hours this week writing and re-writing code, believing that I had misunderstood how the OpenGL depth buffer works. Everything I tried, failed. I have now resolved my problem by finding what may be an error in the Android implementation of OpenGL. See this API entry: http://www.opengl.org/sdk/docs/man/xhtml/glClearDepth.xml void glClearDepth(GLclampd depth); Specifies the depth value used when the depth buffer is cleared. The initial value is 1. Android's implementation has two versions of this command: glClearDepthx which takes an integer value, clamped 0-1 glClearDepthf which takes a floating point value, clamped 0-1 If you use glClearDepthf(1) then you get the results you would expect. If you use glClearDepthx(1), as I was doing then you get different results. (Note that 1 is the default value, but calling the command with the argument 1 produces different results than not calling it at all.) Quite what is happening I do not know, but the depth buffer was being cleared to a value different from what I had specified.

    Read the article

  • MVC View Model Intellesense / Compile error

    - by Marty Trenouth
    I have one Library with my ORM and am working with a MVC Application. I have a problem where the pages won't compile because the Views can't see the Model's properties (which are inherited from lower level base classes). They system throws a compile error saying that 'object' does not contain a definition for 'ID' and no extension method 'ID' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?) implying that the View is not seeing the model. In the Controller I have full access to the Model and have check the Inherits from portion of the view to validate the correct type is being passed. Controller: return View(new TeraViral_Blog()); View: <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<com.models.TeraViral_Blog>" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Index2 </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2>Index2</h2> <fieldset> <legend>Fields</legend> <p> ID: <%= Html.Encode(Model.ID) %> </p> </fieldset> </asp:Content>

    Read the article

  • getting CS1502 compiler error on dev environment but not production.

    - by nw
    When I try to run my ASP.NET app from my development environment I get the following error message: Compiler Error Message: CS1502: The best overloaded method match for 'mmars.Printing.printFunctions.SetPrintSummaryProperties(mmars.contextInfo, ref mmars.Printing.printObjSummary)' has some invalid arguments. When I publish and run on our production server I don't get this error. It seems to compile fine when I build from the build menu (in fact if I change the second argument of the bolded function call below, i get a compiler error in visual studio), but now i've suddenly started getting this error message at runtime. So another question I have in addition to getting rid of the error is why is the .NET development server even trying to do JIT compilation on my project if it is already compiled into a DLL? Printing.printObjSummary myPrintObj = new Printing.printObjSummary(); Printing.printFunctions.SetPrintSummaryProperties(ci, ref myPrintObj); printObjects.Add(myPrintObj); This seems to have just suddenly appeared from nowhere today and it's extremely frustrating. Also, though there are no warnings at compile-time, when I get redirected to the page with that first compilation error there are many warnings like the following: Warning: CS0436: The type 'mmars.MMARSSummaryDataItem' in 'c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\3dad423c\40569048\App_Code.b0rgpkzr.4.cs' conflicts with the imported type 'mmars.MMARSSummaryDataItem' in 'c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\3dad423c\40569048\assembly\dl3\7179c19a\345f948c_ece7ca01\mmars.DLL'. Using the type defined in 'c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\3dad423c\40569048\App_Code.b0rgpkzr.4.cs'. What's the deal with that? Is the webserver complaining about name conflicts in the source file and dll resulting from the source file?

    Read the article

  • Popen is no able to process a command that runs in shell

    - by IceMan85
    Hello everybody, I have already read the previous questions posted on the same argument but I really haven't figured it out yet. I am trying to run a command that works without issues from the command line : xyz@klm:~/python-remoteWorkspace/PyLogParser/src:18:43ush -o PPP -p PRD -n log 'pwd' 6:43PM PPP:prd:lgsprdppp:/ama/log/PRD/ppp but when I do the same in python I always get errors : stringa = Popen(["ush -o PPP -p PRD -n log 'pwd'"], stdout=PIPE, stdin=PIPE).communicate()[0] Here the error. Traceback (most recent call last): File "getStatData.py", line 134, in retrieveListOfFiles(infoToRetList) File "getStatData.py", line 120, in retrieveListOfFiles stringa = Popen(["ush -o PPP -p PRD -n log 'pwd'"], stdout=PIPE, stdin=PIPE).communicate()[0] File "/opt/python-2.6-64/lib/python2.6/subprocess.py", line 595, in init errread, errwrite) File "/opt/python-2.6-64/lib/python2.6/subprocess.py", line 1092, in _execute_child raise child_exception OSError: [Errno 2] No such file or directory I've tried also different solutions like stringa = Popen(["ush", "-o", "PPP", "-p" "PRD", "-n", "log", '"pwd"'], stdout=PIPE, stdin=PIPE).communicate()[0] but nothing seems to work. I have also tried to put the absolute path to ush but nothing... Can somebody please explain me what am I doing wrong ? Thanks in advance, AM.

    Read the article

  • How to use R's ellipsis feature when writing your own function?

    - by Ryan Thompson
    The R language has a nifty feature for defining functions that can take a variable number of arguments. For example, the function data.frame takes any number of arguments, and each argument becomes the data for a column in the resulting data table. Example usage: > data.frame(letters=c("a", "b", "c"), numbers=c(1,2,3), notes=c("do", "re", "mi")) letters numbers notes 1 a 1 do 2 b 2 re 3 c 3 mi The function's signature includes an ellipsis, like this: function (..., row.names = NULL, check.rows = FALSE, check.names = TRUE, stringsAsFactors = default.stringsAsFactors()) { [FUNCTION DEFINITION HERE] } I would like to write a function that does something similar, taking multiple values and consolidating them into a single return value (as well as doing some other processing). In order to do this, I need to figure out how to "unpack" the ... from the function's arguments within the function. I don't know how to do this. The relevant line in the function definition of data.frame is object <- as.list(substitute(list(...)))[-1L], which I can't make any sense of. So how can I convert the ellipsis from the function's signature into, for example, a list? To be more specific, how can I write get_list_from_ellipsis in the code below? my_ellipsis_function(...) { input_list <- get.list.from.ellipsis(...) output_list <- lapply(X=input_list, FUN=do_something_interesting) return(output_list) } my_ellipsis_function(a=1:10,b=11:20,c=21:30)

    Read the article

  • va_arg with pointers

    - by Yktula
    I want to initialize a linked list with pointer arguments like so: /* * Initialize a linked list using variadic arguments * Returns the number of structures initialized */ int init_structures(struct structure *first, ...) { struct structure *s; unsigned int count = 0; va_list va; va_start(va, first); for (s = first; s != NULL; s = va_arg(va, (struct structure *))) { if ((s = malloc(sizeof(struct structure))) == NULL) { perror("malloc"); exit(EXIT_FAILURE); } count++; } va_end(va); return count; } The problem is that clang errors type name requires a specifier or qualifier at va_arg(va, (struct structure *)), and says that the type specifier defaults to int. It also notes instantiated form at (struct structure *) and struct structure *. This, what seems to be getting assigned to s is int (struct structure *). It compiles fine when parentheses are removed from (struct structure *), but the structures that are supposed to be initialized are inaccessible. Why is int assumed when parentheses are around the type argument passed to va_arg? How can I fix this?

    Read the article

  • JDBC transaction dead-lock solution required?

    - by user49767
    It's a scenario described my friend and challenged to find solution. He is using Oracle database and JDBC connection with read committed as transaction isolation level. In one of the transaction, he updates a record and executes selects statement and commits the transaction. when everything happening within single thread, things are fine. But when multiple requests are handled, dead-lock happens. Thread-A updates a record. Thread B updates another record. Thread-A issues select statement and waits for Thread-B's transaction to complete the commit operation. Thread-B issues select statement and waits for Thread-A's transaction to complete the commit operation. Now above causes dead-lock. Since they use command pattern, the base framework allows to issue commit only once (at the end of all the db operation), so they are unable to issue commit immediately after select statement. My argument was Thread-A supposed to select all the records which are committed and hence should not be issue. But he said that Thread-A will surely wait till Thread-B commits the record. is that true? What are all the ways, to avoid the above issue? is it possible to change isolation-level? (without changing underlying java framework) Little information about base framework, it is something similar to Struts action, their each and every request handled by one action, transaction begins before execution and commits after execution.

    Read the article

  • PHP Exceptions in Classes

    - by mike condiff
    I'm writing a web application (PHP) for my friend and have decided to use my limited OOP training from Java. My question is what is the best way to note in my class/application that specific critical things failed without actually breaking my page. Currently my problem is I have an Object "SummerCamper" which takes a camper_id as it's argument to load all of the necessary data into the object from the database. Say someone specifies a camper_id in the querystring that does not exist, I pass it to my objects constructor and the load fails. Currently I don't see a way for me to just return false from the constructor. I have read I could possibly do this with Exceptions, throwing an exception if no records are found in the database or if some sort of validation fails on input of the camper_id from the application etc. However, I have not really found a great way to alert my program that the Object Load has failed. I tried returning false from within the CATCH but the Object still persists in my php page. I do understand I could put a variable $is_valid = false if the load fails and then check the Object using a get method but I think there may be better ways. What is the best way of achieving the essential termination of an object if a load fails? Should I load data into the object from outside the constructor? Is there some osrt of design pattern that I should look into? Any help would be appreciated.

    Read the article

  • How to implement generic callbacks in C++

    - by Kylotan
    Forgive my ignorance in asking this basic question but I've become so used to using Python where this sort of thing is trivial that I've completely forgotten how I would attempt this in C++. I want to be able to pass a callback to a function that performs a slow process in the background, and have it called later when the process is complete. This callback could be a free function, a static function, or a member function. I'd also like to be able to inject some arbitrary arguments in there for context. (ie. Implementing a very poor man's coroutine, in a way.) On top of that, this function will always take a std::string, which is the output of the process. I don't mind if the position of this argument in the final callback parameter list is fixed. I get the feeling that the answer will involve boost::bind and boost::function but I can't work out the precise invocations that would be necessary in order to create arbitrary callables (while currying them to just take a single string), store them in the background process, and invoke the callable correctly with the string parameter.

    Read the article

  • Intermittent Issue Writing to Google Appengine Datastore

    - by user242153
    Hi, I have a functioning app and recently have had intermittent problems writing to the datastore. I did not make any relevant code changes, however in the last few days my attempts to write to the datastore sometimes work and sometimes don't. I am trying to save an object that is in a many to one relationship with an existing persisted parent. So, the logic works like this: 1) Parent pulled from the datastore 2) Child created / instantiated using constructor 3) Parent.addSingleChild(child); // the "addSingleChild" method just adds the object argument to the collection of children 4) child.setParent(Parent); // sets the Parent object to the parent field I am using transactions as explained in the documentation ending with "finally {if (tx.isActive()) {tx.rollback(); } }" When the servlet is called, the parent is called from the datastore and the child object is created and added to the many to one mapping to the pre-existing parent. The child should automatically be persisted, since the parent is already persistent, and the child is added to the collection of children that map to the parent. And it worked this way in the past. However, to be sure, i did add a pm.makePersistent(child). Doesn't seem to help, still have the intermittent problem. Any suggestions would be appreciated, and if you need to see the actual code I can post. Thanks

    Read the article

  • reshaping a data frame into long format in R

    - by user1773115
    I'm struggling with a reshape in R. I have 2 types of error (err and rel_err) that have been calculated for 3 different models. This gives me a total of 6 error variables (i.e. err_1, err_2, err_3, rel_err_1, rel_err_2, and rel_err_3). For each of these types of error I have 3 different types of predivtive validity tests (ie random holdouts, backcast, forecast). I would like to make my data set long so I keep the 4 types of test long while also making the two error measurements long. So in the end I will have one variable called err and one called rel_err as well as an id variable for what model the error corresponds to (1,2,or 3) Here is my data right now: iter err_1 rel_err_1 err_2 rel_err_2 err_3 rel_err_3 test_type 1 -0.09385732 -0.2235443 -0.1216982 -0.2898543 -0.1058366 -0.2520759 random 1 0.16141630 0.8575728 0.1418732 0.7537442 0.1584816 0.8419816 back 1 0.16376930 0.8700738 0.1431505 0.7605302 0.1596502 0.8481901 front 1 0.14345986 0.6765194 0.1213689 0.5723444 0.1374676 0.6482615 random 1 0.15890059 0.7435382 0.1589823 0.7439204 0.1608709 0.7527580 back 1 0.14412360 0.6743928 0.1442039 0.6747684 0.1463520 0.6848202 front and here is what I would like it to look like: iter model err rel_err test_type 1 1 -0.09385732 (#'s) random 1 2 -0.1216982 (#'s) random 1 3 -0.1216982 (#'s) random and on... I've tried playing around with the syntax but can't quite figure out what to put for the time.varying argument Thanks very much for any help you can offer.

    Read the article

  • Install h5py in Mac OS X 10.6.3

    - by zyq524
    I'm trying to install h5py in Mac OS X 10.6.3. First I installed HDF5 1.8, which used the following commands: ./configure \ --prefix=/Library/Frameworks/Python.framework/Versions/Current \ --enable-shared \ --enable-production \ --enable-threadsafe \ CPPFLAGS=-I/Library/Frameworks/Python.framework/Versions/Current/include \ LDFLAGS=-L/Library/Frameworks/Python.framework/Versions/Current/lib make make check sudo make install Then install h5py: /Library/Frameworks/Python.framework/Versions/Current/bin/python \ setup.py \ build \ --api=18 \ --hdf5=/Library/Frameworks/Python.framework/Versions/Current Then I got the errors: Configure: Autodetecting HDF5 settings... Custom HDF5 dir: /Library/Frameworks/Python.framework/Versions/Current Custom API level: (1, 8) ld: warning: in detect/vers.o, file was built for unsupported file format which is not the architecture being linked (i386) ld: warning: in /Library/Frameworks/Python.framework/Versions/Current/lib/libhdf5.dylib, file was built for unsupported file format which is not the architecture being linked (i386) Undefined symbols: "_main", referenced from: start in crt1.10.5.o ld: symbol(s) not found collect2: ld returned 1 exit status Failed to compile HDF5 test program. Please check to make sure: * You have a C compiler installed * A development version of Python is installed (including header files) * A development version of HDF5 is installed (including header files) * If HDF5 is not in a default location, supply the argument --hdf5=<path> error: command 'cc' failed with exit status 1 I just updated my Xcode, I don't know whether this is because my gcc's default setting. If so, how can I get rid of this error? Thanks.

    Read the article

  • Checking multiple conditions in Ruby (within Rails, which may not matter)

    - by Ev
    Hello rubyists and railers, I have a method which checks over a params hash to make sure that it contains certain keys, and to make sure that certain values are set within a certain range. This is for an action that responds to a POST query by an iPhone app. Anyway, this method is checking for about 10 different conditions - any of which will result in an HTTP error being returned (I'm still considering this, but possibly a 400: bad request error). My current syntax is basically this (paraphrased): def invalid_submission_params?(params) [check one] or [check two] or [check three] or [check four] etc etc end Where each of the check statements returns true if that particular parameter check results in an invalid parameter set. I call it as a before filter with params[:submission] as the argument. This seems a little ugly (all the strung together or statements). Is there a better way? I have tried using case but can't see a way to make it more elegant. Or, perhaps, is there a rails method that lets me check the incoming params hash for certain conditions before handing control off to my action method?

    Read the article

  • Exception error in Erlang

    - by Jim
    So I've been using Erlang for the last eight hours, and I've spent two of those banging my head against the keyboard trying to figure out the exception error my console keeps returning. I'm writing a dice program to learn erlang. I want it to be able to call from the console through the erlang interpreter. The program accepts a number of dice, and is supposed to generate a list of values. Each value is supposed to be between one and six. I won't bore you with the dozens of individual micro-changes I made to try and fix the problem (random engineering) but I'll post my code and the error. The Source: -module(dice2). -export([d6/1]). d6(1) - random:uniform(6); d6(Numdice) - Result = [], d6(Numdice, [Result]). d6(0, [Finalresult]) - {ok, [Finalresult]}; d6(Numdice, [Result]) - d6(Numdice - 1, [random:uniform(6) | Result]). When I run the program from my console like so... dice2:d6(1). ...I get a random number between one and six like expected. However when I run the same function with any number higher than one as an argument I get the following exception... **exception error: no function clause matching dice2:d6(1, [4|3]) ... I know I I don't have a function with matching arguments but I don't know how to write a function with variable arguments, and a variable number of arguments. I tried modifying the function in question like so.... d6(Numdice, [Result]) - Newresult = [random:uniform(6) | Result], d6(Numdice - 1, Newresult). ... but I got essentially the same error. Anyone know what is going on here?

    Read the article

  • C++. How to define template parameter of type T for class A when class T needs a type A template parameter?

    - by jaybny
    Executor class has template of type P and it takes a P object in constructor. Algo class has a template E and also has a static variable of type E. Processor class has template T and a collection of Ts. Question how can I define Executor< Processor<Algo> > and Algo<Executor> ? Is this possible? I see no way to defining this, its kind of an "infinite recursive template argument" See code. template <class T> class Processor { map<string,T> ts; void Process(string str, int i) { ts[str].Do(i); } } template <class P> class Executor { Proc &p; Executor(P &p) : Proc(p) {} void Foo(string str, int i) { p.Process(str,i); } Execute(string str) { } } template <class E> class Algo { static E e; void Do(int i) {} void Foo() { e.Execute("xxx"); } } main () { typedef Processor<Algo> PALGO; // invalid typedef Executor<PALGO> EPALGO; typedef Algo<EPALGO> AEPALGO; Executor<PALGO> executor(PALGO()); AEPALGO::E = executor; }

    Read the article

  • When are predicates appropriate and what is the best pattern for usage

    - by Maxim Gershkovich
    When are predicates appropriate and what is the best pattern for usage? What are the advantages of predicates? It seems to me like most cases where a predicate can be employed a tight loop would accomplish the same functionality? I don’t see a reusability argument given you will probably only implement a predicate in one method right? They look and feel nice but besides that they seem like you would only employ them when you need a quick hack on the collection classes? UPDATE But why would you be rewriting the tight loop again and again? In my mind/code when it comes to collections I always end up with something like Class Person End Class Class PersonList Inherits List(Of Person) Function FindByName(Name) as Person tight loop.... End Function End Class @Ani By that same logic I could implement the method as such Class PersonList Inherits List(Of Person) Function FindByName(Name) as PersonList End Function Function FindByAge(Age) as PersonList End Function Function FindBySocialSecurityNumber(SocialSecurityNumber) as PersonList End Function End Class And call it as such Dim res as PersonList = MyList.FindByName("Max").FindByAge(25).FindBySocialSecurityNumber(1234) and the result along with the amount of code and its reusability is largely the same, no? I am not arguing just trying to understand.

    Read the article

  • How do I create an inheritable Semaphore in .NET?

    - by pauldoo
    I am trying to create a Win32 Semaphore object which is inheritable. This means that any child processes I launch may automatically have the right to act on the same Win32 object. My code currently looks as follows: Semaphore semaphore = new Semaphore(0, 10); Process process = Process.Start(pathToExecutable, arguments); But the semaphore object in this code cannot be used by the child process. The code I am writing is a port of come working C++. The old C++ code achieves this by the following: SECURITY_ATTRIBUTES security = {0}; security.nLength = sizeof(security); security.bInheritHandle = TRUE; HANDLE semaphore = CreateSemaphore(&security, 0, LONG_MAX, NULL); Then later when CreateProcess is called the bInheritHandles argument is set to TRUE. (In both the C# and C++ case I am using the same child process (which is C++). It takes the semaphore ID on command line, and uses the value directly in a call to ReleaseSemaphore.) I suspect I need to construct a special SemaphoreSecurity or ProcessStartInfo object, but I haven't figured it out yet.

    Read the article

  • Strategies for when to use properties and when to use internal variables on internal classes?

    - by Edward Tanguay
    In almost all of my classes, I have a mixture of properties and internal class variables. I have always chosen one or the other by the rule "property if you need it externally, class variable if not". But there are many other issues which make me rethink this often, e.g.: at some point I want to use an internal variable from outside the class, so I have to refactor it into a property which makes me wonder why I don't just make all my internal variables properties in case I have to access them externally anyway, since most classes are internal classes anyway it aren't exposed on an API so it doesn't really matter if the internal variables are accessible from outside the class or not but then since C# doesn't allow you to instantiate e.g. List<string> property in the definition, then these properties have to be initialized in every possible constructor, so these variables I would rather have internal variables just to keep things cleaner in that they are all initialized in one place C# code reads more cleanly if constructor/method parameters are camel case and you assign them to pascal case properties instead of the ambiguity of seeing "templateIdCode" and having to look around to see if it is a local variable, method parameter or internal class variable, e.g. it is easier when you see "TemplateIdCode = templateIdCode" that this is a parameter being assigned to a class property. This would be an argument for always using only properties on internal classes. e.g.: public class TextFile { private string templateIdCode; private string absoluteTemplatePathAndFileName; private string absoluteOutputDirectory; private List<string> listItems = new List<string>(); public string Content { get; set; } public List<string> ReportItems { get; set; } public TextFile(string templateIdCode) { this.templateIdCode = templateIdCode; ReportItems = new List<string>(); Initialize(); } ... When creating internal (non-API) classes, what are your strategies in deciding if you should create an internal class variable or a property?

    Read the article

  • Program to find the result of primitive recursive functions

    - by alphomega
    I'm writing a program to solve the result of primitive recursive functions: 1 --Basic functions------------------------------ 2 3 --Zero function 4 z :: Int -> Int 5 z = \_ -> 0 6 7 --Successor function 8 s :: Int -> Int 9 s = \x -> (x + 1) 10 11 --Identity/Projection function generator 12 idnm :: Int -> Int -> ([Int] -> Int) 13 idnm n m = \(x:xs) -> ((x:xs) !! (m-1)) 14 15 --Constructors-------------------------------- 16 17 --Composition constructor 18 cn :: ([Int] -> Int) -> [([Int] -> Int)] -> ([Int] -> Int) 19 cn f [] = \(x:xs) -> f 20 cn f (g:gs) = \(x:xs) -> (cn (f (g (x:xs))) gs) these functions and constructors are defined here: http://en.wikipedia.org/wiki/Primitive_recursive_function The issue is with my attempt to create the compositon constructor, cn. When it gets to the base case, f is no longer a partial application, but a result of the function. Yet the function expects a function as the first argument. How can I deal with this problem? Thanks.

    Read the article

  • mysql query using global variables

    - by Carlos
    I am trying run a query to active the users account. I am not sure if I am having problem with the query itself or if there's something else that I dont know about. here is the code: if($_SESSION['lastid']&&$_SESSION['random']) { $check= mysql_query('SELECT * FROM members WHERE id= "$_SESSION[lastid]" AND random = " $_SESSION[random]"'); $checknum = mysql_num_rows($check); //$checknum = mysql_query($check) or die("Error: ". mysql_error(). " with query ". $check); if($checknum != 0) // run query to activate the account { $acti= mysql_query('UPDATE members SET activation = "1" WHERE id= "$_SESSION[lastid]"'); die('Your account has been activated. You may now log in!'); }else{ echo('Invalid id or activation code.') . ' lastid: ' .$_SESSION['lastid'] . ' random: ' .$_SESSION['random'] ; // die ('Invalid id or activation code.'); } }else{ die('Could not either find id or random number!'); } this is the warning I am getting from mysql: Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /hermes/bosweb26b/b2501/servername/folder/file.php on line 30 but when I echo the variables out, I get the same values that are stored in the database.... Invalid id or activation code. lastid: 2 and random: 36308075 could someone please give me a hint? thank you.

    Read the article

  • Android ListView: how to select an item?

    - by mmo
    I am having trouble with a ListView I created: I want an item to get selected when I click on it. My code for this looks like: protected void onResume() { ... ListView lv = getListView(); lv.setOnItemSelectedListener(new OnItemSelectedListener() { public void onItemSelected(AdapterView<?> adapterView, View view, int pos, long id) { Log.v(TAG, "onItemSelected(..., " + pos + ",...) => selected: " + getSelectedItemPosition()); } public void onNothingSelected(AdapterView<?> adapterView) { Log.v(TAG, "onNothingSelected(...) => selected: " + getSelectedItemPosition()); } }); lv.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView<?> adapterView, View view, int pos, long id) { lv.setSelection(pos); Log.v(TAG, "onItemClick(..., " + pos + ",...) => selected: " + getSelectedItemPosition()); } }); ... } When I run this and click e.g. on the second item (i.e. pos=1) I get: 04-03 23:08:36.994: V/DisplayLists(663): onItemClick(..., 1,...) => selected: -1 i.e. even though the OnItemClickListener is called with the proper argument and calls a setSelection(1), there is no item selected (and hence also OnItemSelectedListener.onItemSelected(...) is never called) and getSelectedItemPosition() still yields -1 after the setSelection(1)-call. What am I missing? Michael PS.: My list does have =2 elements...

    Read the article

  • Ruby TypeErrors involving `expected Data`

    - by Kenny Peng
    I've ran into situations where I have gotten these expected Data errors before, but they have always pointed to ActiveRecord not playing well with other libraries in the past. This piece of code: def load(kv_block, debug=false) # Converts a string block to a Hash using split kv_map = StringUtils.kv_array_to_hash(kv_block) # Loop through each key, value kv_map.each do |mem,val| # Format the member from camel case to underscore member = mem.camel_to_underscore() # If the object includes a method to set the key (i.e. the key # is a member of self), invoke the method, setting the value of # the member) if self.methods.include?(member.to_set_method_name()) then # Exception thrown here self.send(member.to_set_method_name(), val) # Else, check for the same case, this time for an instance variable elsif self.instance_variable_defined?(member.to_instance_var_name()) self.instance_variable_set(member.to_instance_var_name(), val) # Else, complain that the object doesn't understand the key with # respect to its class definition. else raise ArgumentError, "I don't know what to do with #{member}. #{self.class} does not have a member or function called #{member}" end end end produces the error wrong argument type #<Class:0x11a02088> (expected Data) (TypeError) in the each loop on the first if test. I've inspected a post-mortem debugging instance using rdebug, and running that line manually, it works without a hitch. Has anyone seen this error before and what's been your solution to it? I used to think it was ActiveRecord and other gems stomping on each other's definitions, but I removed any references to ActiveRecord and this still occurs.

    Read the article

< Previous Page | 253 254 255 256 257 258 259 260 261 262 263 264  | Next Page >