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  • Rails: Can't set or update tag_list using a text field with acts_as_taggable_on

    - by Josh
    Hey everyone, I'm trying to add tagging to a rails photo gallery system I'm working on. It works from the back-end, but if I try to set or change it in the form view, it doesn't work. I added acts_as_taggable to the photo model and did the migrations. My gallery builder is programmed to add one tag automatically to each photo it creates. This works fine, just as if it were setting it for the console. However, I can't seem to set tags using a text_field in the photo form. Here's the code I added to my photo form: <p> <%= f.label :tag_list %><br /> <%= f.text_field :tag_list %> </p> Now, that's pretty trivial, and since :tag_list supports single-string comma-separated assignment (e.g. tag_list = "this, that, the other" #= ['this', 'that', 'the other']), I don't see why using a text field doesn't work. And to make even less sense, if a tag list has already been populated, the list will still show up in the text field when editing the photo. I just can't seem to commit any changes to the list. The documentation on their github page doesn't appear to give any information on how to set these values from the view. Any ideas? Oh, and I'm using the Rails 3 gem version.

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  • PHP: imagepng is creating inordinately large files

    - by Rafael
    I'm using a simple thumbnailing script I wrote and it's pretty standard: $imgbuffer = imagecreatetruecolor($thumbwidth, $thumbheight); switch($type) { case 1: $image = imagecreatefromgif($img); break; case 2: $image = imagecreatefromjpeg($img); break; case 3: $image = imagecreatefrompng($img); break; case 6: $image = imagecreatefrombmp($img); break; case 15: $image = imagecreatefromwbmp($img); break; default: return log_error("Tried to create thumbnail from $img: not a valid image"); } imagecopyresampled($imgbuffer, $image, 0, 0, 0, 0, $thumbwidth, $thumbheight, $width, $height); $output = imagepng($imgbuffer, "$album/thumbs/$imgname.png", 9); 9 is the lowest quality setting, yet from a 400 x 600 JPEG image (at 56kB) I'm getting a thumbnail 27 kB in size (140 x 140). Using imagejpeg (quality of 80) instead of imagepng it's about 4kB. How can this be, especially at the lowest quality setting for imagepng? I tried using imagecopy instead of imagecopyresampled, and imagecreate instead of the true color version. Unfortunately the images come out mangled somehow. Is there any way to get PNG thumbnails of a reasonably small file size (about 4 kB at 140 x 140)? Or do I have to use JPEG?

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  • My list item's child label elements disappear in IE on accordion menu opening

    - by Scott B
    I've got an app that's working pretty flawlessly in Chrome and FF, however, when I view it in IE, all is well until I click on a header element to activate it (jQuery accordion). What happens then is that I see a brief flash where the content is there, then suddenly the entire left column disappears. This column is generated by a floated label element with a class of ".left" as seen below... <ul class="menu collapsible"> <li class='expand sectionTitle'><a href='#'>General Settings</a> <ul class='acitem'> <li class="section"> <label class="left">This item if floated left with a defined width of 190px via css. This is the item that's disappearing after a brief display</label> <input class="input" value="input element here" /> <label class="description">This element has a margin-left:212px; set via css in order to be positioned to the right of the label element as if in an adjacent table cell. When I add a max-width property to this element, it disappears in IE too!</label> </li> </ul> </li> </ul> As you can see from the comments in the code above (for the two label elements) the description label disappears once I set a max-width on it (I don't have a max-width on the left label element, but it disappears nonetheless). The initial view of this UL menu is fine (note the expand class declaration which makes this part of the accordion open at startup. Its not until I click the "General Settings" to toggle it closed, then back open, that the left class elements disappear (and only in IE)

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  • How do I switch out Views in a Cocoa application?

    - by David Garcia
    So I'm beginning to learn how to use Cocoa. I think I've pretty much got it but I'm hung up on creating and switching views. I'm rewriting a game I made a little bit ago for practice. All I want is one window (preferably not resizable) and I want to be able to switch out views for different screens in the game. First, I have the main menu (Start Game, High Scores, Exit). Then I need a window for each screen (Gameplay screen, Highscore screen). What I'm getting confused with is how to design this. I looked up NSViewController thinking it manages views but it doesn't. It only manages one view by loading it really. I don't understand why I'd need to use NSViewController then. Couldn't I just have a window class that contains multiple subclasses of NSView and load them like that? I'm not sure I understand the purpose of the ViewController. Does my Window Class really need to subclass NSWindowController? I was trying to follow the example of Apple's ViewController example and it has a window controller class that's a subclass of NSWindowController. I don't see what the purpose was of subclassing that. All NSWindowController seems to add is - initWithPath:(NSString *)newPath but I fail to see the use in that either when I can just edit the plist file to open the window on start up. Apple's example also has an NSView variable and an NSViewController variable. Don't you only need one variable to store the current view? Thanks in advance guys, I'm really confused as to how this works.

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  • Are there good reasons not to use an ORM?

    - by hangy
    During my apprenticeship, I have used NHibernate for some smaller projects which I mostly coded and designed on my own. Now, before starting some bigger project, the discussion arose how to design data access and whether or not to use an ORM layer. As I am still in my apprenticeship and still consider myself a beginner in enterprise programming, I did not really try to push in my opinion, which is that using an object relational mapper to the database can ease development quite a lot. The other coders in the development team are much more experienced than me, so I think I will just do what they say. :-) However, I do not completely understand two of the main reasons for not using NHibernate or a similar project: One can just build one’s own data access objects with SQL queries and copy those queries out of Microsoft SQL Server Management Studio. Debugging an ORM can be hard. So, of course I could just build my data access layer with a lot of SELECTs etc, but here I miss the advantage of automatic joins, lazy-loading proxy classes and a lower maintenance effort if a table gets a new column or a column gets renamed. (Updating numerous SELECT, INSERT and UPDATE queries vs. updating the mapping config and possibly refactoring the business classes and DTOs.) Also, using NHibernate you can run into unforeseen problems if you do not know the framework very well. That could be, for example, trusting the Table.hbm.xml where you set a string’s length to be automatically validated. However, I can also imagine similar bugs in a “simple” SqlConnection query based data access layer. Finally, are those arguments mentioned above really a good reason not to utilise an ORM for a non-trivial database based enterprise application? Are there probably other arguments they/I might have missed? (I should probably add that I think this is like the first “big” .NET/C# based application which will require teamwork. Good practices, which are seen as pretty normal on Stack Overflow, such as unit testing or continuous integration, are non-existing here up to now.)

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  • Error 100 When Attempting to post from app to Facebook wall?

    - by IMAPC
    I'm playing around with the Facebook API, and have gotten far enough to get the access token into my app, but when I go to actually send a post to my Facebook wall I get the error message, {"error":{"message":"(#100) You can't post this because it has a blocked link.","type":"OAuthException","code":100}}1 I'm not attempting to send any kind of link, just "Hello, World!" so this seems pretty weird to me :\ Here's my code so far: $content = urlencode("Hello, World!"); $accesstoken = urlencode($row['fbid']); $result = getPageWithPOST("https://graph.facebook.com/me/feed", "access_token=" . $accesstoken . "&message=" . $content); echo $result; where getPageWithPOST is, function getPageWithPOST($url, $posts) { $c = curl_init(); curl_setopt($c, CURLOPT_URL, $url); curl_setopt($c, CURLOPT_POST, true); curl_setopt($c, CURLOPT_POSTFIELDS, $posts); $content = curl_exec ($c); curl_close ($c); return $content; } thanks!

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  • ASP.NET MVC (VB) error when publishing to test server

    - by Colin
    I have an ASP.NET MVC project that works fine on my local machine (no build errors, server errors or anything). However, when I publish the project to a test server, I get an "Object reference not set to an instance of an object" error on a For Each I have in my view. I have a function within a model that returns a DataRowCollection. I'm calling that function in my controller and passing the DataRowCollection to my View, which then iterates over the rows and displays the necessary information: In the Controller I have: Function Index() As ActionResult Dim MyModel As New Model ViewData("MyDataRowCollection") = MyModel.GetDataRowCollection() Return View() End Function And then in the View, which is throwing the error: <%@ Page Language="VB" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %> <asp:Content ID="indexTitle" ContentPlaceHolderID="TitleContent" runat="server"> My Page Title </asp:Content> <asp:Content ID="indexContent" ContentPlaceHolderID="MainContent" runat="server"> <% For Each MyDataRow In ViewData("MyDataRowCollection") ' do stuff with each MyDataRow Next %> I'm pretty new to ASP.NET MVC so I'm sure there might be a better way to do what I'm doing (I'd be happy to hear if there is), but my main concern is why this works fine on my local machine but throws an error on the For Each on the test server? Please let me know if I can clarify any of the above, and thanks in advance for any information.

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  • Using awk to return only certain chunks of data

    - by Koriar
    I'm not 100% certain how to phrase my question simply, so I apologize if this has been answered somewhere and I was just unable to find it. What I have are debug logs with authentication packets in them along with a bunch of other output. I need to search through about 2 million lines of logs to find every packet that contains a certain mac address. The packets look something like this (slightly censored): -----------------[ header ]----------------- Event: Authd-Response (1900) Sequence: -54 Timestamp: 1969-12-31 19:30:00 (0) ---------------[ attributes ]--------------- Auth-Result = Auth-Accept Service-Profile-SID = 53 Service-Profile-SID = 49 RADIUS-Access-Accept-Attr/WiMAX-Capability = 0x(numbers) Session-Timeout = 3600 Service-Profile-SID = 4 Service-Profile-SID = 29 Chargeable-User-Identity = "(Numbers)" User-Password = "(the MAC address I'm looking for)" -------------------------------------------- However there are about 10 different possible types with different possible lengths. They all start with the header line and end with the all-dashes line. I've had success using awk to get the code blocks themselves using this: awk '/-----------------\[ header \]-----------------/,/--------------------------------------------/' filename.txt But I was hoping to be able to use it to return only the packets which contain the MAC address that I need. I've been trying to figure this out for a few days now and I'm pretty stuck. I could try and write a bash script, but I could swear that I've used awk to do something like this before...

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  • Implementing a bitfield using java enums

    - by soappatrol
    Hello, I maintain a large document archive and I often use bit fields to record the status of my documents during processing or when validating them. My legacy code simply uses static int constants such as: static int DOCUMENT_STATUS_NO_STATE = 0 static int DOCUMENT_STATUS_OK = 1 static int DOCUMENT_STATUS_NO_TIF_FILE = 2 static int DOCUMENT_STATUS_NO_PDF_FILE = 4 This makes it pretty easy to indicate the state a document is in, by setting the appropriate flags. For example: status = DOCUMENT_STATUS_NO_TIF_FILE | DOCUMENT_STATUS_NO_PDF_FILE; Since the approach of using static constants is bad practice and because I would like to improve the code, I was looking to use Enums to achieve the same. There are a few requirements, one of them being the need to save the status into a database as a numeric type. So there is a need to transform the enumeration constants to a numeric value. Below is my first approach and I wonder if this is the correct way to go about this? class DocumentStatus{ public enum StatusFlag { DOCUMENT_STATUS_NOT_DEFINED(1<<0), DOCUMENT_STATUS_OK(1<<1), DOCUMENT_STATUS_MISSING_TID_DIR(1<<2), DOCUMENT_STATUS_MISSING_TIF_FILE(1<<3), DOCUMENT_STATUS_MISSING_PDF_FILE(1<<4), DOCUMENT_STATUS_MISSING_OCR_FILE(1<<5), DOCUMENT_STATUS_PAGE_COUNT_TIF(1<<6), DOCUMENT_STATUS_PAGE_COUNT_PDF(1<<7), DOCUMENT_STATUS_UNAVAILABLE(1<<8), private final long statusFlagValue; StatusFlag(long statusFlagValue) { this.statusFlagValue = statusFlagValue } public long getStatusFlagValue(){ return statusFlagValue } } /** * Translates a numeric status code into a Set of StatusFlag enums * @param numeric statusValue * @return EnumSet representing a documents status */ public EnumSet<StatusFlag> getStatusFlags(long statusValue) { EnumSet statusFlags = EnumSet.noneOf(StatusFlag.class) StatusFlag.each { statusFlag -> long flagValue = statusFlag.statusFlagValue if ( (flagValue&statusValue ) == flagValue ) { statusFlags.add(statusFlag) } } return statusFlags } /** * Translates a set of StatusFlag enums into a numeric status code * @param Set if statusFlags * @return numeric representation of the document status */ public long getStatusValue(Set<StatusFlag> flags) { long value=0 flags.each { statusFlag -> value|=statusFlag.getStatusFlagValue() } return value } public static void main(String[] args) { DocumentStatus ds = new DocumentStatus(); Set statusFlags = EnumSet.of( StatusFlag.DOCUMENT_STATUS_OK, StatusFlag.DOCUMENT_STATUS_UNAVAILABLE) assert ds.getStatusValue( statusFlags )==258 // 0000.0001|0000.0010 long numericStatusCode = 56 statusFlags = ds.getStatusFlags(numericStatusCode) assert !statusFlags.contains(StatusFlag.DOCUMENT_STATUS_OK) assert statusFlags.contains(StatusFlag.DOCUMENT_STATUS_MISSING_TIF_FILE) assert statusFlags.contains(StatusFlag.DOCUMENT_STATUS_MISSING_PDF_FILE) assert statusFlags.contains(StatusFlag.DOCUMENT_STATUS_MISSING_OCR_FILE) } }

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  • How do I make a HTTP POST request to an url from within a c++ dll?

    - by tjorriemorrie
    Hi, there's an open-source application I need to use. It allows you to use a custom dll. Unfortunately, I can't code c++; i don't like it; it don't want to learn it. I do know PHP very well however, thus you can see that I'll rather do my logic within a PHP application. Thus I'm thinking about posting the data from c++/dll to a url on my localhost. (i have my local server set up, that's not the problem). I need to post a large amount of variables (thus a POST and not GET request required). The return value will only be one (int)variable, either 0, 1 or 2. So I need a c++ function that: 1) will post variables to an url. 2) Wait for, and receive the answer. The data type can be in xml, soap, json, whatever, doesn't matter. Is there anyone that can write a little c++ http function for me? pretty please? ;)

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  • Problem: Movie Clip contains just one frame

    - by Doug
    I'm a newbie at Flash, so started playing with a pretty standard code sample: one layer contains a movie clip with a flying rectangle, another layer has a button to control it. All script code is in Main.as file. The rectangle was named square1 through the Property window. Here is the problem: the constructor for Main has a line: square1.stop(); to prevent clip from playing, but it doesn't help - it plays. I know the constructor fires, because it has trace("stuff") in it. The code does check that the stage has been created. What strange is that square1.currentFrame always returns 1, and square1.totalFrames returns 1 as well. The layer has 24 frames on the timeline. I tried a tween with just 2 keyframes, then converted whole tween into frames - same result. I mean, the thing is flying before my eyes, how can it be 1 frame??? I even added a listener: square1.addEventListener(Event.ENTER_FRAME, onFrameChange); The event fires all the time, i.e. the frames change, but currentFrame is still 1. Also, tried to name individual frames and use square1.gotoAndStop("begin") and stuff like that. Nothing helps. I am really stuck with this stupid problem.

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  • MouseListener fired without checking JCheckBox

    - by Morinar
    This one is pretty crazy: I've got an AppSight recording (for those not familiar, it's a recording of what they did including keyboard/mouse input + network traffic, etc) of a customer reproducing a bug. Basically, we've got a series of items listed on the screen with JCheckBox-es down the left side. We've got a MouseListener set for the JPanel that looks something like this: private MouseAdapter createMouseListener() { return new MouseAdapter(){ public void mousePressed( MouseEvent e ) { if( e.getComponent() instanceof JCheckBox ) { // Do stuff } } }; } Based on the recording, it appears very strongly that they click just above one of the checkboxes. After that, it's my belief that this listener fired and the "Do stuff" block happened. However, it did NOT check the box. The user then saw that the box was unchecked, so they clicked on it. This caused the "Do stuff" block to fire again, thus undoing what it had done the first time. This time, the box was checked. Therefore, the user thinks that the box is checked, and it looks like it is, but our client thinks that the box is unchecked as it was clicked twice. Is this possible at all? For the life of me, I can't reproduce it or see how it could be possible, but based on the recording and the data the client sent to the server, I can't see any other logical explanation. Any help, thoughts, and or ideas would be much appreciated.

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  • Add a value to an element in a list of sets

    - by Kapelson
    Hello. I'm using python, and I have a list of sets, constructed like this: list = [set([])]*n ...where n is the number of sets I want in the list. I want to add a value to a specific set in the list. Say, the second set. I tried list[1].add(value) But this instead adds the value to each set in the list. This behaviour is pretty non-intuitive to me. Through further tests, I think I've found the problem: the list apparently contains 10 instances of the same set, or ten pointers to the same set, or something. Constructing the list through repeated calls of list.append(set([])) allowed me to use the syntax above to add elements to single sets. So my question is this: what exactly is going on in my first list-construction technique? It is clear I don't understand the syntax so well. Also, is there a better way to intialize an n-element list? I've been using this syntax for a while and this is my first problem with it.

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  • What runs faster? Wordpress or Drupal 6.x?

    - by electblake
    So... I run a pretty large Wordpress blog. Currently it gets around 20k+ pageviews a day, and its always a struggle to keep the bad boy running quickly - I currently run a vps.net with CentOS 5.3 I am also Drupal developer by trade so I love the CMS Framework for its versatility and the portability (I can take work from one site and implement on another with great ease) MY QUESTION IS: What is faster then? Wordpress 3.x & Drupal 6.x I'd love to migrate my site to Drupal to be able to roll out new features etc (which I find awkward to do in Wordpress) but I am scared that Drupal may not be able to handle the traffic. Any opinions? I know that some major players use Drupal - as Dries documents well on his blog but I'm not under any illusions that Drupal can be a real hog. Thanks for any/all help! Please try to avoid server optimization talk unless it pertains to Wordpress or Drupal 6.x specifically, I love to learn more about optimizations but I do want to sort out which platform is quicker :) p.s - I realize the fastest option is to use a lower-level framework (with less overhead) like CakePHP etc but assume that isn't an option ;)

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  • how do I best create a set of list classes to match my business objects

    - by ken-forslund
    I'm a bit fuzzy on the best way to solve the problem of needing a list for each of my business objects that implements some overridden functions. Here's the setup: I have a baseObject that sets up database, and has its proper Dispose() method All my other business objects inherit from it, and if necessary, override Dispose() Some of these classes also contain arrays (lists) of other objects. So I create a class that holds a List of these. I'm aware I could just use the generic List, but that doesn't let me add extra features like Dispose() so it will loop through and clean up. So if I had objects called User, Project and Schedule, I would create UserList, ProjectList, ScheduleList. In the past, I have simply had these inherit from List< with the appropriate class named and then written the pile of common functions I wanted it to have, like Dispose(). this meant I would verify by hand, that each of these List classes had the same set of methods. Some of these classes had pretty simple versions of these methods that could have been inherited from a base list class. I could write an interface, to force me to ensure that each of my List classes has the same functions, but interfaces don't let me write common base functions that SOME of the lists might override. I had tried to write a baseObjectList that inherited from List, and then make my other Lists inherit from that, but there are issues with that (which is really why I came here). One of which was trying to use the Find() method with a predicate. I've simplified the problem down to just a discussion of Dispose() method on the list that loops through and disposes its contents, but in reality, I have several other common functions that I want all my lists to have. What's the best practice to solve this organizational matter?

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  • force refresh of part of page in browser

    - by Jeremy
    I have the following html: <ul class="scr"> <li class="scr"> <input type="checkbox" class="chkscr"/> <h3>Item Name</h3> <div class="scr">Contents</div> </li> .... </ul> And the following jQuery: //Set initial state of each scr section $('.chkscr input, input.chkscr').each(function() { chkSCR_Click($(this)); }); //Setup click event $('.chkscr input, input.chkscr').click(function() { chkSCR_Click($(this)); }); //Toggle corresponding scr section for the checkbox function chkSCR_Click(ctl) { if (ctl.attr('checked')) { ctl.parents('li.scr').find('div.scr').stop().show(); } else { ctl.parents('li.scr').find('div.scr').stop().hide(); } } My issue is that when I toggle the last li element to display, the h3 element contents disapear, until I click somewhere else on the page, or scroll the page up and down to cause the browse to repaint that portion of the window. I don't get this behavior in Opera for example, and even in IE the behavior only happens on the last li element, so I'm pretty sure it's an IE quirk and not my code. Is there any workaround I can do through jquery/javascript to force it to repaint the h3 element?

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  • How to send data after form has been validated using jQuery?

    - by Keith Donegan
    I have a simple email address sign up form as follows: <form action="" id="newsletterform" method="get"> <input type="text" name="email" class="required email" id="textnewsletter" /> <input type="submit" id="signup" /> </form> Here's what I want to be able to do: Validate the form to look for an empty string or a incorrectly filled out email address one the user clicks submit or hits enter. If one of the above happens (empty string etc), I would like to generate an error to let the user know. Then once the user fills out a correctly formed email address and hits submit (or enter) I want the form to send the email address to wherever I specify in the jQuery code and then generate a little "Thank you for signing up notice", all without reloading the browser. I have looked at too many tutorials and my eyes are pretty much aching at this stage, so please don't point me to any urls (I most likely have been there). If someone could provide a barebone outline of what to do It would be so much appreciated.

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  • (RoR) How to: link multiple apps, multiple URLs, one database

    - by Samson
    Hello. I am currently developing a site using Ruby on Rails. I am still a beginner who just started around a month ago. I use InstantRails on Windows 7. Here's my question. Let's say app A is functional using MYSQL database A_development. The files such as views and controller are under folder 'A'. I now know how to, say for example, link www.app.com to this app by opening port 80 and changing some lines in the mySQL config. In this app, you can register your username, login, and post some messages. I now want to create some pretty identical apps say B and C. The only thing different will be the posts that shows, and the views. You can still log in with the same username, and everything is saved in the same database. I now want the URLs to look something like A.app.com leading to app A, B.app.com leading to app B, etc. Can that be achieved? How? I've been googling for a few days already and I'm still lost. As I'm new to this forum, I'm not quite sure what info do you guys need. Please list and I'll provide them asap. Any help will be appreciated! Thanks.

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  • Image swap with a javascript onclick dropdown menu

    - by AzzyDude
    So I've got this code that has an image and when you click it a dropdown menu appears. Pretty simple. The code works fine but I'm trying to incorporate an image swap on click and I'm having difficulty. Here's the HTML and the JS (there's some CSS too, but I'll leave that out): HTML: <div id="header"> <dl class="dropdown"> <dt><a href="#"><img src="images/cogwheel_btn.png"/></a></dt> <dd> <ul> <li><a href="#">Favorites</a></li> <li><a href="#">History</a></li> </ul> </dd> </dl> </div> JS: $(document).ready(function() { $(".dropdown img.flag").addClass("flagvisibility"); $(".dropdown dt a").click(function() { $(".dropdown dd ul").toggle(); }); $(".dropdown dd ul li a").click(function() { var text = $(this).html(); $(".dropdown dt a span").html(text); $(".dropdown dd ul").hide(); $("#result").html("Selected value is: " + getSelectedValue("sample")); }); function getSelectedValue(id) { return $("#" + id).find("dt a span.value").html(); } $(document).bind('click', function(e) { var $clicked = $(e.target); if (!$clicked.parents().hasClass("dropdown")) $(".dropdown dd ul").hide(); }); $("#flagSwitcher").click(function() { $(".dropdown img.flag").toggleClass("flagvisibility"); }); });? I've tried adding lines like ("dt").empty(); and then ("dt").html("new_image") but it causes the dropdown functionality to stop working. Anyone any ideas?

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  • Does it exist: smart pointer, owned by one object allowing access.

    - by Noah Roberts
    I'm wondering if anyone's run across anything that exists which would fill this need. Object A contains an object B. It wants to provide access to that B to clients through a pointer (maybe there's the option it could be 0, or maybe the clients need to be copiable and yet hold references...whatever). Clients, lets call them object C, would normally, if we're perfect developers, be written carefully so as to not violate the lifetime semantics of any pointer to B they might have...but we're not perfect, in fact we're pretty dumb half the time. So what we want is for object C to have a pointer to object B that is not "shared" ownership but that is smart enough to recognize a situation in which the pointer is no longer valid, such as when object A is destroyed or it destroys object B. Accessing this pointer when it's no longer valid would cause an assertion/exception/whatever. In other words, I wish to share access to data in a safe, clear way but retain the original ownership semantics. Currently, because I've not been able to find any shared pointer in which one of the objects owns it, I've been using shared_ptr in place of having such a thing. But I want clear owneship and shared/weak pointer doesn't really provide that. Would be nice further if this smart pointer could be attached to member variables and not just hold pointers to dynamically allocated memory regions. If it doesn't exist I'm going to make it, so I first want to know if someone's already released something out there that does it. And, BTW, I do realize that things like references and pointers do provide this sort of thing...I'm looking for something smarter.

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  • ActiveMq integration with Spring 2.5

    - by Tony
    I am using ActiveMq 5.32 with Spring 2.5.5. I use pretty generic configuration, as long as I include the jmsTransactionManager in DefaultMessageListenerContainer, Spring throw an error on start up: "Error creating bean with name 'org.springframework.jms.listener.DefaultMessageListenerContainer#0'" Without the transactionManager attribute , this works fine, but when I add 10 messages to the message queue, a transaction exception will occur. Part of my configurations : <bean class="org.springframework.jms.listener.DefaultMessageListenerContainer"> <property name="connectionFactory" ref="connectionFactory" /> <property name="destination" ref="emailDestination" /> <property name="messageListener" ref="emailServiceMDP" /> <property name="transactionManager" ref="jmsTransactionManager" /> </bean> <bean id="jmsTransactionManager" class="org.springframework.jms.connection.JmsTransactionManager"> <property name="connectionFactory" ref="connectionFactory" /> </bean> Does this version of Spring and Activemq has some know issues in integration ? Or do I need additional libs to get jmsTransactionManager to work ?

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  • Storing a jpa entity where only the timestamp changes results in updates rather than inserts (desire

    - by David Schlenk
    I have a JPA entity that stores a fk id, a boolean and a timestamp: @Entity public class ChannelInUse implements Serializable { @Id @GeneratedValue private Long id; @ManyToOne @JoinColumn(nullable = false) private Channel channel; private boolean inUse = false; @Temporal(TemporalType.TIMESTAMP) private Date inUseAt = new Date(); ... } I want every new instance of this entity to result in a new row in the table. For whatever reason no matter what I do it always results in the row getting updated with a new timestamp value rather than creating a new row. Even tried to just use a native query to run an insert but channel's ID wasn't populated yet so I gave up on that. I've tried using an embedded id class consisting of channel.getId and inUseAt. My equals and hashcode for are: public boolean equals(Object obj){ if(this == obj) return true; if(!(obj instanceof ChannelInUse)) return false; ChannelInUse ciu = (ChannelInUse) obj; return ( (this.inUseAt == null ? ciu.inUseAt == null : this.inUseAt.equals(ciu.inUseAt)) && (this.inUse == ciu.inUse) && (this.channel == null ? ciu.channel == null : this.channel.equals(ciu.channel)) ); } /** * hashcode generated from at, channel and inUse properties. */ public int hashCode(){ int hash = 1; hash = hash * 31 + (this.inUseAt == null ? 0 : this.inUseAt.hashCode()); hash = hash * 31 + (this.channel == null ? 0 : this.channel.hashCode()); if(inUse) hash = hash * 31 + 1; else hash = hash * 31 + 0; return hash; } } I've tried using hibernate's Entity annotation with mutable=false. I'm probably just not understanding what makes an entity unique or something. Hit the google pretty hard but can't figure this one out.

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  • Understanding C++ pointers (when they point to a pointer)

    - by Stephano
    I think I understand references and pointers pretty well. Here is what I (think I) know: int i = 5; //i is a primitive type, the value is 5, i do not know the address. int *ptr; //a pointer to an int. i have no way if knowing the value yet. ptr = &i; //now i have an address for the value of i (called ptr) *ptr = 10; //go get the value stored at ptr and change it to 10 Please feel free to comment or correct these statements. Now I'm trying to make the jump to arrays of pointers. Here is what I do not know: char **char_ptrs = new char *[50]; Node **node_ptrs = new Node *[50]; My understanding is that I have 2 arrays of pointers, one set of pointers to chars and one to nodes. So if I wanted to set the values, I would do something like this: char_ptrs[0] = new char[20]; node_ptrs[0] = new Node; Now I have a pointer, in the 0 position of my array, in each respective array. Again, feel free to comment here if I'm confused. So, what does the ** operator do? Likewise, what is putting a single * next to the instantiation doing (*[50])? (what is that called exactly, instantiation?)

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  • Python: why does this code take forever (infinite loop?)

    - by Rosarch
    I'm developing an app in Google App Engine. One of my methods is taking never completing, which makes me think it's caught in an infinite loop. I've stared at it, but can't figure it out. Disclaimer: I'm using http://code.google.com/p/gaeunitlink text to run my tests. Perhaps it's acting oddly? This is the problematic function: def _traverseForwards(course, c_levels): ''' Looks forwards in the dependency graph ''' result = {'nodes': [], 'arcs': []} if c_levels == 0: return result model_arc_tails_with_course = set(_getListArcTailsWithCourse(course)) q_arc_heads = DependencyArcHead.all() for model_arc_head in q_arc_heads: for model_arc_tail in model_arc_tails_with_course: if model_arc_tail.key() in model_arc_head.tails: result['nodes'].append(model_arc_head.sink) result['arcs'].append(_makeArc(course, model_arc_head.sink)) # rec_result = _traverseForwards(model_arc_head.sink, c_levels - 1) # _extendResult(result, rec_result) return result Originally, I thought it might be a recursion error, but I commented out the recursion and the problem persists. If this function is called with c_levels = 0, it runs fine. The models it references: class Course(db.Model): dept_code = db.StringProperty() number = db.IntegerProperty() title = db.StringProperty() raw_pre_reqs = db.StringProperty(multiline=True) original_description = db.StringProperty() def getPreReqs(self): return pickle.loads(str(self.raw_pre_reqs)) def __repr__(self): return "%s %s: %s" % (self.dept_code, self.number, self.title) class DependencyArcTail(db.Model): ''' A list of courses that is a pre-req for something else ''' courses = db.ListProperty(db.Key) def equals(self, arcTail): for this_course in self.courses: if not (this_course in arcTail.courses): return False for other_course in arcTail.courses: if not (other_course in self.courses): return False return True class DependencyArcHead(db.Model): ''' Maintains a course, and a list of tails with that course as their sink ''' sink = db.ReferenceProperty() tails = db.ListProperty(db.Key) Utility functions it references: def _makeArc(source, sink): return {'source': source, 'sink': sink} def _getListArcTailsWithCourse(course): ''' returns a LIST, not SET there may be duplicate entries ''' q_arc_heads = DependencyArcHead.all() result = [] for arc_head in q_arc_heads: for key_arc_tail in arc_head.tails: model_arc_tail = db.get(key_arc_tail) if course.key() in model_arc_tail.courses: result.append(model_arc_tail) return result Am I missing something pretty obvious here, or is GAEUnit acting up?

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  • OOP design issue: Polymorphism

    - by Graham Phillips
    I'm trying to solve a design issue using inheritance based polymorphism and dynamic binding. I have an abstract superclass and two subclasses. The superclass contains common behaviour. SubClassA and SubClassB define some different methods: SubClassA defines a method performTransform(), but SubClassB does not. So the following example 1 var v:SuperClass; 2 var b:SubClassB = new SubClassB(); 3 v = b; 4 v.performTransform(); would cause a compile error on line 4 as performTransform() is not defined in the superclass. We can get it to compile by casting... (v as SubClassA).performTransform(); however, this will cause a runtime exception to be thrown as v is actually an instance of SubClassB, which also does not define performTransform() So we can get around that by testing the type of an object before casting it: if( typeof v == SubClassA) { (cast v to SubClassA).performTransform(); } That will ensure that we only call performTransform() on v's that are instances of SubClassA. That's a pretty inelegant solution to my eyes, but at least its safe. I have used interface based polymorphism (interface meaning a type that can't be instantiated and defines the API of classes that implement it) in the past, but that also feels clunky. For the above case, if SubClassA and SubClassB implemented ISuperClass that defined performTransform, then they would both have to implement performTransform(). If SubClassB had no real need for a performTransform() you would have to implement an empty function. There must be a design pattern out there that addresses the issue.

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