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  • many to many and integrity when saving the null

    - by user369759
    I have two classes Software, Tag - they are related by ManyToMany. We CAN NOT create Software without putting the Tag to it. I want to write a test which check that: @Test public void createSoftwareWithNullTags() { List<Tag> tags = null; Software software = new Software("software1", "description1", tags); try { software.save(); fail("tags should not be null"); } catch (Exception ex) { // NEVER COME HERE !!! } } So, this test fails. I guess it is not good test for that case - because it even do not try to SAVE data to SOFTWARE_TAG table. Of course i could do validation manually but i want implement it with hibernate, using some annotation or something. Is it possible? Or how would you do this? My entities: @Entity public class Tag extends Model { public String title; public Tag(String title) { this.title = title; } @ManyToMany( cascade = {CascadeType.ALL}, mappedBy = "tags", targetEntity = Software.class ) public List<Software> softwares; } @Entity public class Software extends Model { public String title; public String description; @ManyToOne(optional = false) public Author author; @ManyToMany(cascade = CascadeType.ALL) @JoinTable( name = "SOFTWARE_TAG", joinColumns = @JoinColumn(name = "Software_id"), inverseJoinColumns = @JoinColumn(name = "Tag_id") ) public List<Tag> tags; public Software(String title, String description, Author author, List<Tag> tags) { this.title = title; this.description = description; this.author = author; this.tags = tags; } }

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  • Select ID in table ...

    - by Kris-I
    Hello, I have this code <% foreach (var item in Model.List) { %> <tr> <td><%: item.LastName %></td> <td><%: item.FirstName %></td> <td><%: item.IsEnable %></td> <td><a href="#" class="CustomerEdit">Edit</a></td> <td><a href="#" class="CustomerDetail">Detail</a></td> <td><a href="#" class="CustomerDelete">Delete</a></td> </tr> <% } %> <script language="javascript" type="text/javascript"> $(document).ready(function () { $(".CustomerEdit").click(function () { alert("blabla"); //need id here }); }); </script> It's not in the code but I have an "Item.Id", it's not place anywhere because I don't know where place it ;-). I'd like when I click on the "Edit" hyperlink get the id (item.Id) of the current line. Any idea ? Thanks,

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  • Vertically Aligning Divs

    - by Crays
    Hi, i'm trying to make a small username and password input box. I would like to ask how do you vertically align a div? What i have is a <div id="Login" class="BlackStrip floatright"> <div id="Username" class="floatleft">Username<br>Password</div> <div id="Form" class="floatleft"> <form action="" method="post"> <input type="text" border="0"><br> <input type="password" border="0"> </form> </div> </div> and how can i make the div with id Username and Form to vertically align itself to the center? I tried putting vertical-align: middle; in css for the div with id Login. But doesn't seem to work. Any help would be appreciated. Thanks.

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  • How to mimic polymorphism in classes with template methods (c++)?

    - by davide
    in the problem i am facing i need something which works more or less like a polymorphic class, but which would allow for virtual template methods. the point is, i would like to create an array of subproblems, each one being solved by a different technique implemented in a different class, but holding the same interface, then pass a set of parameters (which are functions/functors - this is where templates jump up) to all the subproblems and get back a solution. if the parameters would be, e.g., ints, this would be something like: struct subproblem { ... virtual void solve (double& solution, double parameter)=0; } struct subproblem0: public subproblem { ... virtual void solve (double& solution, double parameter){...}; } struct subproblem1: public subproblem { ... virtual void solve (double* solution, double parameter){...}; } int main{ subproblem problem[2]; subproblem[0] = new subproblem0(); subproblem[1] = new subproblem1(); double argument0(0), argument1(1), sol0[2], sol1[2]; for(unsigned int i(0);i<2;++i) { problem[i]->solve( &(sol0[i]) , argument0); problem[i]->solve( &(sol1[i]) , argument1); } return 0; } but the problem is, i need the arguments to be something like Arg<T1,T2> argument0(f1,f2) and thus the solve method to be something of the likes of template<T1,T2> solve (double* solution, Arg<T1,T2> parameter) which cant obviously be declared virtual ( so cant be called from a pointer to the base class)... now i'm pretty stuck and don't know how to procede...

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  • ROR accepts_nested_attributes_for one to many relationship with selection

    - by bilash.saha
    I have two models Doctors and Questions like the follwong: Doctor Model class Doctor < ActiveRecord::Base has_many :questions has_many :brands accepts_nested_attributes_for :questions end Question model class Question < ActiveRecord::Base belongs_to :discipline belongs_to :doctor belongs_to :brand end Now you can clearly see that Doctor has many questions and brands and question belongs to doctor and brand.I want to add previously saved question to a doctor from doctors edit page. I want to remove them as well.How can I proceed ? I tried like : <%= form.fields_for :questions, question,:child_index => (question.new_record? ? "index_to_replace_with_js" : nil) do |question_form| %> <table> <tr> <td> <div class="label">Select Question</div> <%= question_form.collection_select :id, Question.all, :id, :title ,{:include_blank => true } %> </td> </tr> </table> but this doesnot works for me.Can you give me a solution with proper example ?

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  • Validation on ManyToManyField before Save in Models.py

    - by Heyl1
    I have the following models: class Application(models.Model): users = models.ManyToManyField(User, through='Permission') folder = models.ForeignKey(Folder) class Folder(models.Model): company = models.ManyToManyField(Compnay) class UserProfile(models.Model): user = models.OneToOneField(User, related_name='profile') company = models.ManyToManyField(Company) What I would like to do is to check whether one of the users of the Application has the same company as the Application (via Folder). If this is the case the Application instance should not be saved. The problem is that the ManyToManyFields aren't updated until after the 'post-save' signal. The only option seems to be the new m2m_changed signal. But I'm not sure how I then roll back the save that has already happened. Another option would be to rewrite the save function (in models.py, because I'm talking about the admin here), but I'm not sure how I could access the manytomanyfield content. Finally I've read something about rewriting the save function in the admin of the model in admin.py, however I still wouldn't know how you would access the manytomanyfield content. I have been searching for this everywhere but nothing I come across seems to work for me. If anything is unclear, please tell me. Thanks for your help! Heleen

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  • How can I refactor this to work without breaking the pattern horribly?

    - by SnOrfus
    I've got a base class object that is used for filtering. It's a template method object that looks something like this. public class Filter { public void Process(User u, GeoRegion r, int countNeeded) { List<account> selected = this.Select(u, r, countNeeded); // 1 List<account> filtered = this.Filter(selected, u, r, countNeeded); // 2 if (filtered.Count > 0) { /* do businessy stuff */ } // 3 if (filtered.Count < countNeeded) this.SendToSuccessor(u, r, countNeeded - filtered) // 4 } } Select(...), Filter(...) are protected abstract methods and implemented by the derived classes. Select(...) finds objects in the based on x criteria, Filter(...) filters those selected further. If the remaining filtered collection has more than 1 object in it, we do some business stuff with it (unimportant to the problem here). SendToSuccessor(...) is called if there weren't enough objects found after filtering (it's a composite where the next class in succession will also be derived from Filter but have different filtering criteria) All has been ok, but now I'm building another set of filters, which I was going to subclass from this. The filters I'm building however would require different params and I don't want to just implement those methods and not use the params or just add to the param list the ones I need and have them not used in the existing filters. They still perform the same logical process though. I also don't want to complicated the consumer code for this (which looks like this) Filter f = new Filter1(); Filter f2 = new Filter2(); Filter f3 = new Filter3(); f.Sucessor = f2; f2.Sucessor = f3; /* and so on adding filters as successors to previous ones */ foreach (User u in users) { foreach (GeoRegion r in regions) { f.Process(u, r, ##); } } How should I go about it?

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  • IE7: container of hidden Div displays incorrectly

    - by dmr
    There is a search box div that contains a boxhead div and a boxbody div. Inside the boxbody div, there is a searchToggle div. When the user clicks a certain link on the page, the display style property of the searchToggle div is toggled between block and none. The 2 background-images for the body of the search box are set via the css of the searchBox div and the boxbody div. In IE7, when the searchToggle div is hidden, the background-image from the searchBox div extends on the left more than it should. It shows up correctly when the display of the searchToggle div is block. Everything show up correctly, in both cases in IE8 and FF. Any ideas why this is happening? The relevant HTML: <div class="searchBox"> <div class="boxhead"> <h2></h2> </div> <div class="boxbody"> <div id="searchToggle" name="searchToggle"> </div> </div> </div> The relevant CSS: .searchBox { margin: 0 auto; width: 700px; background: url(/images/myImageRight-r.gif) no-repeat bottom right; font-size: 100%; text-align: left; overflow: hidden; } .boxbody { margin: 0; padding: 5px 30px 31px; background-image: url(/images/myImageLeft.gif); background-repeat: no-repeat; background-position: left bottom; }

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  • Why does the entity framework need an ICollection for lazy loading?

    - by Akk
    I want to write a rich domain class such as public class Product { public IEnumerable<Photo> Photos {get; private set;} public void AddPhoto(){...} public void RemovePhoto(){...} } But the entity framework (V4 code first approach) requires an ICollection type for lazy loading! The above code no longer works as designed since clients can bypass the AddPhoto / RemovePhoto method and directly call the add method on ICollection. This is not good. public class Product { public ICollection<Photo> Photos {get; private set;} //Bad public void AddPhoto(){...} public void RemovePhoto(){...} } It's getting really frustrating trying to implement DDD with the EF4. Why did they choose the ICollection for lazy loading? How can i overcome this? Does NHibernate offer me a better DDD experience?

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  • varargs in lambda functions in Python

    - by brain_damage
    Is it possible a lambda function to have variable number of arguments? For example, I want to write a metaclass, which creates a method for every method of some other class and this newly created method returns the opposite value of the original method and has the same number of arguments. And I want to do this with lambda function. How to pass the arguments? Is it possible? class Negate(type): def __new__(mcs, name, bases, _dict): extended_dict = _dict.copy() for (k, v) in _dict.items(): if hasattr(v, '__call__'): extended_dict["not_" + k] = lambda s, *args, **kw: not v(s, *args, **kw) return type.__new__(mcs, name, bases, extended_dict) class P(metaclass=Negate): def __init__(self, a): self.a = a def yes(self): return True def maybe(self, you_can_chose): return you_can_chose But the result is totally wrong: >>>p = P(0) >>>p.yes() True >>>p.not_yes() # should be False Traceback (most recent call last): File "<pyshell#150>", line 1, in <module> p.not_yes() File "C:\Users\Nona\Desktop\p10.py", line 51, in <lambda> extended_dict["not_" + k] = lambda s, *args, **kw: not v(s, *args, **kw) TypeError: __init__() takes exactly 2 positional arguments (1 given) >>>p.maybe(True) True >>>p.not_maybe(True) #should be False True

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  • How to read a parameter passed to a facelet from a backing bean

    - by Antonio
    Hi, I've written a facelet, and a corresponding backing bean, that implements user management (addition, deletion and so on). I'd want to be able to perform some custom processing when, for instance, a new user is added. There is a "create" button in the facelet, whose click event is handled by its backing bean. At the end of the event handler, I'd want to be able to call a method of another backing bean, which is not known because ideally the facelet can be used in several pages, with different custom processing. I thought to implement this feature by providing to the facelet a backing bean name and a method name, like this: <myfacelet:subaccounts backingBean="myBackingBean" createListener="createListener" /> and at the end of the event handler call #{myBackingBean.createListener} someway. I'm using this method (along with some overloads) to obtain a MethodExpression: protected MethodExpression getMethodExpression(String beanName, String methodName, Class<?> expectedReturnType, Class<?>[] expectedParamTypes) { ExpressionFactory expressionFactory; MethodExpression method; ELContext elContext; String el; el = String.format("#{%s['%s']}", beanName, methodName); expressionFactory = getApplication().getExpressionFactory(); elContext = getFacesContext().getELContext(); method = expressionFactory.createMethodExpression(elContext, el, expectedReturnType, expectedParamTypes); return method; } and the click event handler should look like: public void saveSubaccountListener(ActionEvent event) { MethodExpression method; ... method = getMethodExpression( "backingBean", "createSubaccountListener", SubuserBean.class); if (method != null) method.invoke( getFacesContext().getELContext(), new Object[] { _editedSubuser }); } That works fine as long as I provide an existing bean name (myBackingBean), but if I use backingBean the invoke() doesn't work due to the following error: javax.el.PropertyNotFoundException: Target Unreachable, identifier 'backingBean' resolved to null Is there a way I can retrieve from the facelet backing bean the value of a parameter that has been passed to the facelet? In my case, the value of backingBean, which should be myBackingBean? I've searched for and tried different solutions, but with no luck yet.

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  • AJAX: Permission denied to access property in iframe

    - by Muhammad Sajid
    Hi I created an php website which uses for AJAX post and was live at http://sprook.com.au/ but my client change it's domain to http://www.sprookit.net/ from his service provider Godaddy and now the firebug says: Permission denied to access property 'stopAjax' here stopAjax is my method name. script is there: <div class="post_area"> <form action="post.php" method="post" id="addVideo" enctype="multipart/form-data" target="post" onsubmit="return startAjax(this);"> <iframe id="post" name="post" src="#" style="width:0;height:0;border:0px solid #fff;"></iframe> <table width="860" border="0" cellspacing="0" cellpadding="0"> <tr> <td width="435">POST YOUR AD FREE<br /> <em>Paste embed code from YouTube</em></td> <td width="322"><input type="text" id="videoLink" name="videoLink" class="input_textbox" /> </td> <td width="95"><input type="submit" name="set_video_link" id="set_video_link" value="" class="submt_post" /> </td> </tr> <tr> <td>&nbsp;</td> <td><div id="process"> Connecting please wait <img src="images/loading.gif" /><br/> </div></td> </tr> </table> </form> </div> And all content comes from old domain i removed index file and it stoped working, therefore it is cleared that scripts run from old domain.

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  • Firefox adding padding to first image in multiple images, although all images have same styling and size.

    - by Sam Gabriel
    Hey guys, I have this piece of code: while($uno=mysql_fetch_assoc($results)) { echo '<div class="wcapt"><a class="neutral" href="../images.php?id=' . $uno['id'] . '"><img class="pad" src="'. $uno['thumbs'].'" border="0" /></a><br/><center><p>'.$uno['name'].'</p></center></div>'; } And all the images I link to have exactly the same size. Here's the Mainstyles.css div.wcapt { border: 1px solid green; float: left; padding: 0; margin: 3px; font: 11px/1.4em Arial, sans-serif; color: gray; } img.pad { padding: 5px; } a.neutral { display: inline; font-weight: normal; text-transform: none; background-color: transparent; color: white; text-decoration: none; } The problem is that Firefox adds some extra padding to the first image, and only the first image. And this is really annoying. Here's a screenshot of the page:

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  • How are declared private ivars different from synthesized ivars?

    - by lemnar
    I know that the modern Objective-C runtime can synthesize ivars. I thought that synthesized ivars behaved exactly like declared ivars that are marked @private, but they don't. As a result, come code compiles only under the modern runtime that I expected would work on either. For example, a superclass: @interface A : NSObject { #if !__OBJC2__ @private NSString *_c; #endif } @property (nonatomic, copy) NSString *d; @end @implementation A @synthesize d=_c; - (void)dealloc { [_c release]; [super dealloc]; } @end and a subclass: @interface B : A { #if !__OBJC2__ @private NSString *_c; #endif } @property (nonatomic, copy) NSString *e; @end @implementation B @synthesize e=_c; - (void)dealloc { [_c release]; [super dealloc]; } @end A subclass can't have a declared ivar with the same name as one of its superclass's declared ivars, even if the superclass's ivar is private. This seems to me like a violation of the meaning of @private, since the subclass is affected by the superclass's choice of something private. What I'm more concerned about, however, is how should I think about synthesized ivars. I thought they acted like declared private ivars, but without the fragile base class problem. Maybe that's right, and I just don't understand the fragile base class problem. Why does the above code compile only in the modern runtime? Does the fragile base class problem exist when all superclass instance variables are private?

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  • pure/const functions in C++

    - by Albert
    Hi, I'm thinking of using pure/const functions more heavily in my C++ code. (pure/const attribute in GCC) However, I am curious how strict I should be about it and what could possibly break. The most obvious case are debug outputs (in whatever form, could be on cout, in some file or in some custom debug class). I probably will have a lot of functions, which don't have any side effects despite this sort of debug output. No matter if the debug output is made or not, this will absolutely have no effect on the rest of my application. Or another case I'm thinking of is the use of my own SmartPointer class. In debug mode, my SmartPointer class has some global register where it does some extra checks. If I use such an object in a pure/const function, it does have some slight side effects (in the sense that some memory probably will be different) which should not have any real side effects though (in the sense that the behaviour is in any way different). Similar also for mutexes and other stuff. I can think of many complex cases where it has some side effects (in the sense of that some memory will be different, maybe even some threads are created, some filesystem manipulation is made, etc) but has no computational difference (all those side effects could very well be left out and I would even prefer that). How does it work out in practice? If I mark such functions as pure/const, could it break anything (considering that the code is all correct)?

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  • PHP OOP singleton doesn't return object

    - by Misiur
    Weird trouble. I've used singleton multiple times but this particular case just doesn't want to work. Dump says that instance is null. define('ROOT', "/"); define('INC', 'includes/'); define('CLS', 'classes/'); require_once(CLS.'Core/Core.class.php'); $core = Core::getInstance(); var_dump($core->instance); $core->settings(INC.'config.php'); $core->go(); Core class class Core { static $instance; public $db; public $created = false; private function __construct() { $this->created = true; } static function getInstance() { if(!self::$instance) { self::$instance = new Core(); } else { return self::$instance; } } public function settings($path = null) { ... } public function go() { ... } } Error code Fatal error: Call to a member function settings() on a non-object in path It's possibly some stupid typo, but I don't have any errors in my editor. Thanks for the fast responses as always.

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  • C++ brain teaser

    - by mxp
    I recently refactored code like this (MyClass to MyClassR). class SomeMember { long m_value; public: SomeMember() : m_value(0) {} SomeMember(int a) : m_value(a) {} SomeMember(int a, int b) : m_value(a+b) {} }; class MyClass { SomeMember m_first, m_second, m_third; public: MyClass(const bool isUp, const int x, const int y) { if (isUp) { m_first = SomeMember(x); m_second = SomeMember(y); m_third = SomeMember(x, y); } else { m_first = SomeMember(y); m_second = SomeMember(x); m_third = SomeMember(y, x); } } }; class MyClassR { SomeMember m_first, m_second, m_third; public: MyClassR(const bool isUp, const int x, const int y) : m_first(isUp ? x : y) , m_second(isUp ? y : x) , m_third(isUp ? x, y : y, x) { } }; What is the error, why does it compile (at least VC6 with warning level 3 doesn't complain) and what is the right way of doing it? I (assume) I already have all these answers but I think it's and interesting problem to share.

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  • "no inclosing instance error " while getting top term frequencies for document from Lucene index

    - by Julia
    Hello ! I am trying to get the most occurring term frequencies for every particular document in Lucene index. I am trying to set the treshold of top occuring terms that I care about, maybe 20 However, I am getting the "no inclosing instance of type DisplayTermVectors is accessible" when calling Comparator... So to this function I pass vector of every document and max top terms i would like to know protected static Collection getTopTerms(TermFreqVector tfv, int maxTerms){ String[] terms = tfv.getTerms(); int[] tFreqs = tfv.getTermFrequencies(); List result = new ArrayList(terms.length); for (int i = 0; i < tFreqs.length; i++) { TermFrq tf = new TermFrq(terms[i], tFreqs[i]); result.add(tf); } Collections.sort(result, new FreqComparator()); if(maxTerms < result.size()){ result = result.subList(0, maxTerms); } return result; } /Class for objects to hold the term/freq pairs/ static class TermFrq{ private String term; private int freq; public TermFrq(String term,int freq){ this.term = term; this.freq = freq; } public String getTerm(){ return this.term; } public int getFreq(){ return this.freq; } } /*Comparator to compare the objects by the frequency*/ class FreqComparator implements Comparator{ public int compare(Object pair1, Object pair2){ int f1 = ((TermFrq)pair1).getFreq(); int f2 = ((TermFrq)pair2).getFreq(); if(f1 > f2) return 1; else if(f1 < f2) return -1; else return 0; } } Explanations and corrections i will very much appreciate, and also if someone else had experience with term frequency extraction and did it better way, I am opened to all suggestions! Please help!!!! Thanx!

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  • getSystemResourceAsStream() returns null

    - by Hitesh Solanki
    Hiii... I want to get the content of properties file into InputStream class object using getSystemResourceAsStream(). I have built the sample code. It works well using main() method,but when i deploy the project and run on the server, properties file path cannot obtained ... so inputstream object store null value. Sample code is here.. public class ReadPropertyFromFile { public static Logger logger = Logger.getLogger(ReadPropertyFromFile.class); public static String readProperty(String fileName, String propertyName) { String value = null; try { //fileName = "api.properties"; //propertyName = "api_loginid"; System.out.println("11111111...In the read proprty file....."); // ClassLoader loader = ClassLoader.getSystemClassLoader(); InputStream inStream = ClassLoader.getSystemResourceAsStream(fileName); System.out.println("In the read proprty file....."); System.out.println("File Name :" + fileName); System.out.println("instream = "+inStream); Properties prop = new Properties(); try { prop.load(inStream); value = prop.getProperty(propertyName); } catch (Exception e) { logger.warn("Error occured while reading property " + propertyName + " = ", e); return null; } } catch (Exception e) { System.out.println("Exception = " + e); } return value; } public static void main(String args[]) { System.out.println("prop value = " + ReadPropertyFromFile.readProperty("api.properties", "api_loginid")); } }

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  • Logback: Logging with two loggers

    - by gammay
    I would like to use slf4j+logback for two purposes in my application - log and audit. For logging, I log the normal way: static final Logger logger = LoggerFactory.getLogger(Main.class); logger.debug("-> main()"); For Audit, I create a special named logger and log to it: static final Logger logger = LoggerFactory.getLogger("AUDIT_LOGGER"); Object[] params = { new Integer(1) /* TenantID */, new Integer(10) /* UserID */, msg}; logger.info("{}|{}|{}", params); logback configuration: <logger name="AUDIT_LOGGER" level="info"> <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> <encoder> <pattern>%d{HH:mm:ss.SSS}|%msg%n </pattern> </encoder> </appender> </logger> <root level="all"> <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> <encoder> <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n </pattern> </encoder> </appender> </root> Problem: Messages logged through audit logger appear twice - once under the AUDIT_LOGGER and once under the root logger. 14:41:57.975 [main] DEBUG com.gammay.example.Main - - main() 14:41:57.978|1|10|welcome to main 14:41:57.978 [main] INFO AUDIT_LOGGER - 1|10|welcome to main How can I make sure audit messages appear only once under the audit logger?

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  • Sonata Media Bundle sortBy created_at

    - by tony908
    I use SonataMediaBundle and i would like sort Gallery by created_at field. In repository class i have (without orderBy working good!): $qb = $this->createQueryBuilder('m') ->orderBy('j.expires_at', 'DESC'); $query = $qb->getQuery(); return $query->getResult(); and this throw error: An exception has been thrown during the rendering of a template ("[Semantical Error] line 0, col 80 near 'created_at D': Error: Class Application\Sonata\MediaBundle\Entity\Gallery has no field or association named created_at") so i add this field to Gallery class: /** * @var \DateTime */ private $created_at; /** * Set created_at * * @param \DateTime $createdAt * @return Slider */ public function setCreatedAt($createdAt) { $this->created_at = $createdAt; return $this; } /** * Get created_at * * @return \DateTime */ public function getCreatedAt() { return $this->created_at; } but now i have error: FatalErrorException: Compile Error: Declaration of Application\Sonata\MediaBundle\Entity\Gallery::setCreatedAt() must be compatible with Sonata\MediaBundle\Model\GalleryInterface::setCreatedAt(DateTime $createdAt = NULL) in /home/tony/www/test/Application/Sonata/MediaBundle/Entity/Gallery.php line 32 GalleryInterface: https://github.com/sonata-project/SonataMediaBundle/blob/master/Model/GalleryInterface.php So... how can i use sortBy in my example?

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  • Why is TRest in Tuple<T1... TRest> not constrained?

    - by Anthony Pegram
    In a Tuple, if you have more than 7 items, you can provide an 8th item that is another tuple and define up to 7 items, and then another tuple as the 8th and on and on down the line. However, there is no constraint on the 8th item at compile time. For example, this is legal code for the compiler: var tuple = new Tuple<int, int, int, int, int, int, int, double> (1, 1, 1, 1, 1, 1, 1, 1d); Even though the intellisense documentation says that TRest must be a Tuple. You do not get any error when writing or building the code, it does not manifest until runtime in the form of an ArgumentException. You can roughly implement a Tuple in a few minutes, complete with a Tuple-constrained 8th item. I just wonder why it was left off the current implementation? Is it possibly a forward-compatibility issue where they could add more elements with a hypothetical C# 5? Short version of rough implementation interface IMyTuple { } class MyTuple<T1> : IMyTuple { public T1 Item1 { get; private set; } public MyTuple(T1 item1) { Item1 = item1; } } class MyTuple<T1, T2> : MyTuple<T1> { public T2 Item2 { get; private set; } public MyTuple(T1 item1, T2 item2) : base(item1) { Item2 = item2; } } class MyTuple<T1, T2, TRest> : MyTuple<T1, T2> where TRest : IMyTuple { public TRest Rest { get; private set; } public MyTuple(T1 item1, T2 item2, TRest rest) : base(item1, item2) { Rest = rest; } } ... var mytuple = new MyTuple<int, int, MyTuple<int>>(1, 1, new MyTuple<int>(1)); // legal var mytuple2 = new MyTuple<int, int, int>(1, 2, 3); // illegal

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  • Can I force the auto-generated Linq-to-SQL classes to use an OUTER JOIN?

    - by Gary McGill
    Let's say I have an Order table which has a FirstSalesPersonId field and a SecondSalesPersonId field. Both of these are foreign keys that reference the SalesPerson table. For any given order, either one or two salespersons may be credited with the order. In other words, FirstSalesPersonId can never be NULL, but SecondSalesPersonId can be NULL. When I drop my Order and SalesPerson tables onto the "Linq to SQL Classes" design surface, the class builder spots the two FK relationships from the Order table to the SalesPerson table, and so the generated Order class has a SalesPerson field and a SalesPerson1 field (which I can rename to SalesPerson1 and SalesPerson2 to avoid confusion). Because I always want to have the salesperson data available whenever I process an order, I am using DataLoadOptions.LoadWith to specify that the two salesperson fields are populated when the order instance is populated, as follows: dataLoadOptions.LoadWith<Order>(o => o.SalesPerson1); dataLoadOptions.LoadWith<Order>(o => o.SalesPerson2); The problem I'm having is that Linq to SQL is using something like the following SQL to load an order: SELECT ... FROM Order O INNER JOIN SalesPerson SP1 ON SP1.salesPersonId = O.firstSalesPersonId INNER JOIN SalesPerson SP2 ON SP2.salesPersonId = O.secondSalesPersonId This would make sense if there were always two salesperson records, but because there is sometimes no second salesperson (secondSalesPersonId is NULL), the INNER JOIN causes the query to return no records in that case. What I effectively want here is to change the second INNER JOIN into a LEFT OUTER JOIN. Is there a way to do that through the UI for the class generator? If not, how else can I achieve this? (Note that because I'm using the generated classes almost exclusively, I'd rather not have something tacked on the side for this one case if I can avoid it).

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  • Display: table-cell problems in chrome

    - by F21
    I have 3 divs that I would like to display as table cells: <div class="field"> <div class="row"> <label for="name">Subdomain</label> <input type="text" id="name" name="name"> <div class="subdomain-base ">test</div> </div> </div> This is the CSS that I am using: body{ font-size: 13px; } .field { width:450px; display: table; } .row { display: table-row; width: 100%; } .row > * { display: table-cell; border: 1px solid red; } label { width: 125px; height: 18px; } input { max-width: none; min-width: 0; overflow: auto; height: 18px; width: 100%; } .subdomain-base { height: 18px; width: 1px; } .subdomain-base { color: blue; font-size: 13px; } It works perfectly in Firefox 24: However, it has a height problem in Chrome 30 (latest): I have been trying all sorts of things to fix the problem with Chrome, but it seems like nothing works. Why is chrome getting that extra height? Jsfiddle: http://jsfiddle.net/ahLMH/

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  • Performance of C# method polymorphism with generics

    - by zildjohn01
    I noticed in C#, unlike C++, you can combine virtual and generic methods. For example: using System.Diagnostics; class Base { public virtual void Concrete() {Debug.WriteLine("base concrete");} public virtual void Generic<T>() {Debug.WriteLine("base generic");} } class Derived : Base { public override void Concrete() {Debug.WriteLine("derived concrete");} public override void Generic<T>() {Debug.WriteLine("derived generic");} } class App { static void Main() { Base x = new Derived(); x.Concrete(); x.Generic<PerformanceCounter>(); } } Given that any number of versions of Generic<T> could be instantiated, it doesn't look like the standard vtbl approach could be used to resolve method calls, and in fact it's not. Here's the generated code: x.Concrete(); mov ecx,dword ptr [ebp-8] mov eax,dword ptr [ecx] call dword ptr [eax+38h] x.Generic<PerformanceCounter>(); push 989A38h mov ecx,dword ptr [ebp-8] mov edx,989914h call 76A874F1 mov dword ptr [ebp-4],eax mov ecx,dword ptr [ebp-8] call dword ptr [ebp-4] The extra code appears to be looking up a dynamic vtbl according to the generic parameters, and then calling into it. Has anyone written about the specifics of this implementation? How well does it perform compared to the non-generic case?

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