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  • Get value of selected field from a dropdown list

    - by 47
    I have this class in my model: class ServiceCharge(models.Model): name = models.CharField(max_length=30) amount = models.PositiveIntegerField() extends_membership = models.BooleanField(default=False) def __unicode__(self): return str(self.name) What I want to have is in the form for charging users a service charge, when a charge is selected from the dropdown menu, the two values for amount and extends_membership are updated on the form depending on the selected charge. My forms.py: class vModelChoiceField(forms.ModelChoiceField): def label_from_instance(self, obj): return "%s" % obj.name class PayServiceChargeForm(PaymentsForm): service_charge = vModelChoiceField(queryset=ServiceCharge.objects.all(), empty_label=" ") class Meta(PaymentsForm.Meta): exclude = ('member', 'payment_type', 'transacted_by', 'description') Then the form template: <table border="0"> <tr> <td><strong>{% trans "Service Charge" %}</strong></td> <td>{{ form.service_charge }}</td> <td><strong>{% trans "Extends Membership" %}</strong></td> <td>{{ form.extends_membership }}</td> </tr> <tr> <td valign="top"><strong>{% trans "Expiry Date" %}</strong></td> <td valign="top">{{ form.expiry_date }}</td> <td valign="top"><strong>{% trans "Amount" %}</strong></td> <td>{{ form.amount }}</td> </tr> </table> I was trying out some jQuery but I got stuck after getting the currently selected charge: <script type="text/javascript"> $(document).ready(function(){ $("#id_service_charge").change(onSelectChange); }); function onSelectChange(){ var selected = $("#id_service_charge option:selected"); var output = ""; if(selected.val() != 0){ charge = selected.val(); .... (update values) .... } } </script>

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  • Why would one want to use the public constructors on Boolean and similar immutable classes?

    - by Robert J. Walker
    (For the purposes of this question, let us assume that one is intentionally not using auto(un)boxing, either because one is writing pre-Java 1.5 code, or because one feels that autounboxing makes it too easy to create NullPointerExceptions.) Take Boolean, for example. The documentation for the Boolean(boolean) constructor says: Note: It is rarely appropriate to use this constructor. Unless a new instance is required, the static factory valueOf(boolean) is generally a better choice. It is likely to yield significantly better space and time performance. My question is, why would you ever want to get a new instance in the first place? It seems like things would be simpler if constructors like that were private. For example, if they were, you could write this with no danger (even if myBoolean were null): if (myBoolean == Boolean.TRUE) It'd be safe because all true Booleans would be references to Boolean.TRUE and all false Booleans would be references to Boolean.FALSE. But because the constructors are public, someone may have used them, which means that you have to write this instead: if (Boolean.TRUE.equals(myBoolean)) But where it really gets bad is when you want to check two Booleans for equality. Something like this: if (myBooleanA == myBooleanB) ...becomes this: if ( (myBooleanA == null && myBooleanB == null) || (myBooleanA == null && myBooleanA.equals(myBooleanB)) ) I can't think of any reason to have separate instances of these objects which is more compelling than not having to do the nonsense above. What say you?

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  • Django ModelForm Imagefield Upload

    - by Wei Xu
    I am pretty new to Django and I met a problem in handling image upload using ModelForm. My model is as following: class Project(models.Model): name = models.CharField(max_length=100) description = models.CharField(max_length=2000) startDate = models.DateField(auto_now_add=True) photo = models.ImageField(upload_to="projectimg/", null=True, blank=True) And the modelform is as following: class AddProjectForm(ModelForm): class Meta: model = Project widgets = { 'description': Textarea(attrs={'cols': 80, 'rows': 50}), } fields = ['name', 'description', 'photo'] And the View function is: def addProject(request, template_name): if request.method == 'POST': addprojectform = AddProjectForm(request.POST,request.FILES) print addprojectform if addprojectform.is_valid(): newproject = addprojectform.save(commit=False) print newproject print request.FILES newproject.photo = request.FILES['photo'] newproject.save() print newproject.photo else: addprojectform = AddProjectForm() newProposalNum = projectProposal.objects.filter(solved=False).count() return render(request, template_name, {'addprojectform':addprojectform, 'newProposalNum':newProposalNum}) the template is: <form class="bs-example form-horizontal" method="post" action="">{% csrf_token %} <h2>Project Name</h2><br> {{ addprojectform.name }}<br> <h2>Project Description</h2> {{ addprojectform.description }}<br> <h2>Image Upload</h2><br> {{ addprojectform.photo }}<br> <input type="submit" class="btn btn-success" value="Add Project"> </form> Can anyone help me or could you give an example of image uploading? Thank you!

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  • Looping through NSArray while subtracting values from each object? [on hold]

    - by Julian
    I have NSNumber objects stored in an NSMutableArray. I am attempting to perform a calculation on each object in the array. What I want to do is: 1) Take a random higher number variable and keep subtracting a smaller number variable in increments until the value of the variable is equal to the value in the array. For example: NSMutableArray object is equal to 2.50. I have an outside variable of 25 that is not in the array. I want to subtract 0.25 multiple times from the variable until I reach less than or equal to 2.50. I also need a parameter so if the number does not divide evenly and goes below the array value, it resorts to the original array value of 2.50. Lastly, for each iteration, I want to print the values as they are counting down as a string. I was going to provide code, but I don't want to make this more confusing than it has to be. So my output would be: VALUE IS: 24.75 VALUE IS: 24.50 VALUE IS: 24.25 … VALUE IS: 2.50 END

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  • NVelocity (or Velocity) as a stand-alone formula evaluator

    - by dana
    I am using NVelocity in my application to generate html emails. My application has an event-driven model, where saving and/or updating of objects causes these emails to be sent out. Each event can trigger zero, one or multiple multiple emails. I want to be able to configure which emails get sent out at run-time without having to modify code. I was thinking I could leverage the NVelocity #if() directive to do this. Here is my idea... Step 1) Prior to email sending, the administrator must configure a formula for NVelocity to evaluate. For example: $User.FirstName == "Jack" Step 2) When an object is saved or created, build an NVelocity template in memory based on the input formula. For example: String formula = GetFormulaFromDB(); // $User.FirstName == "Jack" String templ = "#if( " + formula + ") 1 #else 0 #end"; Step 3) Execute the NVelocity engine in memory against the template. Check the results to see if we have to send the email: String result = VelocityMerge(templ); // utility function if( result.Trim() == "1" ) { SendEmail(); } I know this is not exactly what NVelocity was intended to do, but I think it just might work :) One of the benefits of doing things this way is that the same syntax can be used for the formula as is used inside the template. Does anybody have any words of caution or suggestions? Is there a way to execute the #if() directive without jumping through hoops like I have above? Is there a recommended way to validate the formula syntax ahead of time? Thanks.

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  • Can a PHP object respond to an undefined method?

    - by Nathan Long
    Rails relies on some of the neat aspects of Ruby. One of those is the ability to respond to an undefined method. Consider a relationship between Dog and Owner. Owner has_many :dogs and Dog belongs_to :owner. If you go into script/console, get a dog object with fido = Dog.find(1), and look at that object, you won't see a method or attribute called Owner. What you will see is an owner_id. And if you ask for fido.owner, the object will do something like this (at least, this is how it appears to me): I'm being asked for my .owner attribute. I don't have one of those! Before I throw a NoMethodError, do I have a rule about how to deal with this? Yes, I do: I should check and see if I have an owner_id. I do! OK, then I'll do a join and return that owner object. PHP's documentation is - ahem - a bit lacking sometimes, so I wonder if anyone here knows the answer to this: Can I define similar behavior for objects in PHP? If not, do you know of a workaround for flexible model joins like these?

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  • Do the 'up to date' guarantees provided by final field in Java's memory model extend to indirect ref

    - by mattbh
    The Java language spec defines semantics of final fields in section 17.5: The usage model for final fields is a simple one. Set the final fields for an object in that object's constructor. Do not write a reference to the object being constructed in a place where another thread can see it before the object's constructor is finished. If this is followed, then when the object is seen by another thread, that thread will always see the correctly constructed version of that object's final fields. It will also see versions of any object or array referenced by those final fields that are at least as up-to-date as the final fields are. My question is - does the 'up-to-date' guarantee extend to the contents of nested arrays, and nested objects? An example scenario: Thread A constructs a HashMap of ArrayLists, then assigns the HashMap to final field 'myFinal' in an instance of class 'MyClass' Thread B sees a (non-synchronized) reference to the MyClass instance and reads 'myFinal', and accesses and reads the contents of one of the ArrayLists In this scenario, are the members of the ArrayList as seen by Thread B guaranteed to be at least as up to date as they were when MyClass's constructor completed?

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  • What is the best way to get a reference to a spring bean in the backend layers?

    - by java_pill
    I have two spring config files and I'm specifying them in my web.xml as in below. web.xml snippet .. <context-param> <param-name>contextConfigLocation</param-name> <param-value>WEB-INF/classes/domain-context.xml WEB-INF/classes/client-ws.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> .. From my domain object I have to invoke a Web Service Client and in order to get a reference to the Web Service client I do this: ApplicationContext context = new ClassPathXmlApplicationContext("client-ws.xml"); //b'cos I don't want to use WebApplicationContextUtils ProductServiceClient client = (ProductServiceClient) context.getBean("productClient"); .. client.find(prodID); //calls a Web Service .. However, I have concerns that looking up the client-ws.xml file and getting a reference to the ProductServiceClient bean is not efficient. I thought of getting it using WebApplicationContextUtils. However, I don't want my domain objects to have a dependency on the ServletContext (a web/control layer object) because WebApplicationContextUtils depends on ServletContext. What is the best way to get a reference to a spring bean in the backend layers? Thanks!

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  • UIImage Object surprisingly returning null but not NSData

    - by riyaz
    i have created a sqlite db. and i have insert a few datas in my db.. UIImage * imagee=[UIImage imageNamed:@"image.png"]; NSData *mydata=[NSData dataWithData:UIImagePNGRepresentation(imagee)]; const char *dbpath = [databasePath UTF8String]; NSString *insertSQL=[NSString stringWithFormat:@"insert into CONTACTS values(\"%@\",\"%@\")",@"Mathan",mydata]; NSLog(@"mydata %@",mydata); sqlite3_stmt *addStatement; const char *insert_stmt=[insertSQL UTF8String]; if (sqlite3_open(dbpath,&contactDB)==SQLITE_OK) { sqlite3_prepare_v2(contactDB,insert_stmt,-1,&addStatement,NULL); if (sqlite3_step(addStatement)==SQLITE_DONE) { sqlite3_bind_blob(addStatement,1, [mydata bytes], [mydata length], SQLITE_TRANSIENT); NSLog(@"Data saved"); } else{ NSLog(@"Some Error occured"); } sqlite3_close(contactDB); } else{ NSLog(@"Failure"); } have written some codes to retrive the data sqlite3_stmt *statement; if (sqlite3_open([databasePath UTF8String], &contactDB) == SQLITE_OK) { NSString *sql = [NSString stringWithFormat:@"SELECT * FROM contacts"]; if (sqlite3_prepare_v2( contactDB, [sql UTF8String], -1, &statement, nil) == SQLITE_OK) { while (sqlite3_step(statement) == SQLITE_ROW) { char *field1 = (char *) sqlite3_column_text(statement, 0); NSString *field1Str = [[NSString alloc] initWithUTF8String: field1]; NSLog(@"UserName %@",field1Str); NSData *data = [[NSData alloc] initWithBytes:sqlite3_column_blob(statement, 1) length:sqlite3_column_bytes(statement, 1)]; UIImage *newImage = [[UIImage alloc]initWithData:data]; NSLog(@"Image OBJ %@",newImage); NSLog(@"Image Data %@",data); } sqlite3_close(contactDB); } } sqlite3_finalize(statement); the problem is in log, inserted NSData object and retrieved NSData Objects are different (printing in log gives different stream) moreover Image OBJ is printed null in log.. Have seen similar questions in stackoverflow. But nothing seems to help. Please give some suggestions to overcome this issue.

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  • Handling large (object) datasets with PHP

    - by Aron Rotteveel
    I am currently working on a project that extensively relies on the EAV model. Both entities as their attributes are individually represented by a model, sometimes extending other models (or at least, base models). This has worked quite well so far since most areas of the application only rely on filtered sets of entities, and not the entire dataset. Now, however, I need to parse the entire dataset (IE: all entities and all their attributes) in order to provide a sorting/filtering algorithm based on the attributes. The application currently consists of aproximately 2200 entities, each with aproximately 100 attributes. Every entity is represented by a single model (for example Client_Model_Entity) and has a protected property called $_attributes, which is an array of Attribute objects. Each entity object is about 500KB, which results in an incredible load on the server. With 2000 entities, this means a single task would take 1GB of RAM (and a lot of CPU time) in order to work, which is unacceptable. Are there any patterns or common approaches to iterating over such large datasets? Paging is not really an option, since everything has to be taken into account in order to provide the sorting algorithm.

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  • Java constructor using generic types

    - by user37903
    I'm having a hard time wrapping my head around Java generic types. Here's a simple piece of code that in my mind should work, but I'm obviously doing something wrong. Eclipse reports this error in BreweryList.java: The method initBreweryFromObject() is undefined for the type <T> The idea is to fill a Vector with instances of objects that are a subclass of the Brewery class, so the invocation would be something like: BreweryList breweryList = new BreweryList(BrewerySubClass.class, list); BreweryList.java package com.beerme.test; import java.util.Vector; public class BreweryList<T extends Brewery> extends Vector<T> { public BreweryList(Class<T> c, Object[] j) { super(); for (int i = 0; i < j.length; i++) { T item = c.newInstance(); // initBreweryFromObject() is an instance method // of Brewery, of which <T> is a subclass (right?) c.initBreweryFromObject(); // "The method initBreweryFromObject() is undefined // for the type <T>" } } } Brewery.java package com.beerme.test; public class Brewery { public Brewery() { super(); } protected void breweryMethod() { } } BrewerySubClass.java package com.beerme.test; public class BrewerySubClass extends Brewery { public BrewerySubClass() { super(); } public void androidMethod() { } } I'm sure this is a complete-generics-noob question, but I'm stuck. Thanks for any tips!

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  • Javascript code refactoring and assessment

    - by neitony
    I'm using javascript to toggle the display state of some objects based on the time of day. A sample of the code is given below. I was wondering if anyone could give a suggestion as to how I can refactor this code while at the same time improving the logic. switch(tcode) { case 'eur' : eur.setAttribute('style', 'display:block; opacity:0.5'); us.style.display = 'none'; asia.style.display = 'none'; us_inactive.style.display = 'block'; asia_inactive.style.display = 'block'; break; case 'us' : us.style.display = 'block'; eur.style.display = 'none'; asia.style.display = 'none'; eur_inactive.style.display = 'block'; asia_inactive.style.display = 'block'; break; case 'asia' : asia.setAttribute('style', 'display:block; opacity:0.5'); us.style.display = 'none'; eur.style.display = 'none'; eur_inactive.style.display = 'block'; us_inactive.style.display = 'block';

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  • NSMutableArray for Object which has NSString property causes memory leak

    - by user262325
    Hello everyone I hope to add objects to a NSMutableArray "myArray", The NSMutableArray is the array for FileObj which has a NSString property "fileName" #import <UIKit/UIKit.h> @interface FileObj : NSObject { NSString *fileName; } -(void) setfileName:(NSString *)s ; -(NSString *) getfileName ; @end // // File.m// #import "File.h" @implementation FileObj -(void) setfileName:(NSString *)s ; { fileName=s; } -(NSString *) getfileName ; { return fileName; } @end I initialize the myArray here: NSMutableArray *temarray; temarray=[[NSMutableArray alloc] init]; self.myArray=temarray; [temarray release]; the codes to add object to myArray FileObj *newobj=[[FileObj alloc]init ]; NSString *fieldValue2 = [[NSString alloc] initWithUTF8String:@"aaaa"]; [newobj setfileName:fieldValue2]; [myArray addObject:newobj]; [fieldValue2 release]; //**if I enabled the line, it will cause crash** //**if I disable the line, it will cause memory leak** [newobj release]; Welcome any comment Thanks interdev

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  • VSTO Outlook - Contact iteration is SO SLOW!

    - by DustinDavis
    I'm working on an outlook add-in and I have a dialog window that allows the user to select contacts. I havent been able to find a way to use the outlook contact window so I am looping through the ContactFolder.Items and doing my work that way. The problem is that I have to handle up to 70K contacts. I tried multi-threading and many other things but it is just so slow. It takes 15 seconds to load 30k contacts. I can load and bind 500k POCO objects in milliseconds but when I need to get the contact items from outlook it just takes forever. The problem seems to be when you actually need to get a property from the contactitem it has to fetch it from the database or something. Is there a contact cache I can pull from? I only need Display and Email, nothing else. An ID would be nice but I don't need it. Can someone please tell me a better way of getting contacts from outlook or at least tell me how to open the outlook contact selection window? I was able to find code to open it but it wont let me because I'm showing a modal dialog and it wont open if there is a modal open.

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  • Using map() on a _set in a template?

    - by Stuart Grimshaw
    I have two models like this: class KPI(models.Model): """KPI model to hold the basic info on a Key Performance Indicator""" title = models.CharField(blank=False, max_length=100) description = models.TextField(blank=True) target = models.FloatField(blank=False, null=False) group = models.ForeignKey(KpiGroup) subGroup = models.ForeignKey(KpiSubGroup, null=True) unit = models.TextField(blank=True) owner = models.ForeignKey(User) bt_measure = models.BooleanField(default=False) class KpiHistory(models.Model): """A historical log of previous KPI values.""" kpi = models.ForeignKey(KPI) measure = models.FloatField(blank=False, null=False) kpi_date = models.DateField() and I'm using RGraph to display the stats on internal wallboards, the handy thing is Python lists get output in a format that Javascript sees as an array, so by mapping all the values into a list like this: def f(x): return float(x.measure) stats = map(f, KpiHistory.objects.filter(kpi=1) then in the template I can simply use {{ stats }} and the RGraph code sees it as an array which is exactly what I want. [87.0, 87.5, 88.5, 90] So my question is this, is there any way I can achieve the same effect using Django's _set functionality to keep the amount of data I'm passing into the template, up until now I've been passing in a single KPI object to be graphed but now I want to pass in a whole bunch so is there anything I can do with _set {{ kpi.kpihistory_set }} dumps the whole model out, but I just want the measure field. I can't see any of the built in template methods that will let me pull out just the single field I want. How have other people handled this situation?

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  • Objective C Naming Convention for an object that owns itself

    - by Ed Marty
    With the latest releases of XCode that contain static analyzers, some of my objects are throwing getting analyzer issues reported. Specifically, I have an object that owns itself and is responsible for releasing itself, but should also be returned to the caller and possibly retained there manually. If I have a method like + (Foo) newFoo the analyzer sees the word New and reports an issue in the caller saying that newFoo is expected to return an object with retain +1, and it isn't being released anywhere. If I name it + (Foo) getFoo the analyzer reports an issue in that method, saying there's a potential leak because it's not deallocated before returning. My class basically looks like this: + (Foo *) newFoo { Foo *myFoo = [[[Foo new] retain] autorelease]; [myFoo performSelectorInBackground:@selector(bar) withObject:nil]; return myFoo; } - (void) bar { //Do something that might take awhile [self release]; } The object owns itself and when its done, will release itself, but there's nowhere that it's being stored, so the static analyzer sees it as a leak somewhere. Is there some naming or coding convention to help?

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  • Convert enumerated records to php object

    - by Matt H
    I have a table containing a bunch of records like this: +-----------+--------+----------+ | extension | fwd_to | type | +-----------+--------+----------+ | 800 | 11111 | noanswer | | 800 | 12345 | uncond | | 800 | 22222 | unavail | | 800 | 54321 | busy | | 801 | 123 | uncond | +-----------+--------+----------+ etc The query looks like this: select fwd_to, type from forwards where extension='800'; Now I get back an array containing objects which look like the following when printed with Kohana::debug: (object) stdClass Object ( [fwd_to] => 11111 [type] => noanswer ) (object) stdClass Object ( [fwd_to] => 12345 [type] => uncond ) (object) stdClass Object ( [fwd_to] => 22222 [type] => unavail ) (object) stdClass Object ( [fwd_to] => 54321 [type] => busy ) What I'd like to do is convert this to an object of this form: (object) stdClass Object ( [busy] => 54321 [uncond] => 12345 [unavail] => 22222 [noanswer] => 11111 ) The reason being I want to then call json_encode on it. This will allow me to use jquery populate to populate a form. Is there a suggested way I can do this nicely? I'm fairly new to PHP and I'm sure this is easy but it's eluding me at the moment.

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  • problem with "select new Object ... join ... where"

    - by jacob
    Hi, I'm having a problem with an HQL query Three classes ClassOne is my BusinessObject public class ClassOne { private int id; private int status; private Set<ClassTwo> classTwos; + other fields/getters/setters/constructor etc } ClassTwo is referenced in a set of ClassOne and is kind of the history of an object of ClassOne public class ClassTwo { private int id; private int oldStatus; private int newStatus; private String message; //+ getters/setters/constructor etc } ClassThree is my DTO/VO with just one classTwo (not the whole history) public class ClassThree { private int id; private int status; private ClassTwo classTwo; public ClassThree(int pId, int pStatus, ClassTwo pClassTwo) { id=pId; status=pStatus; classTwo=pClassTwo; } //+ getters/setters etc } Now I'd like to create an HQL query like this: I'd like to get all objects of ClassThree with a certain status and if it exists the newest ClassTwo with a certain newStatus. For example: I'd like to get all the DTOs (ClassThree) of ClassOne whose status is now 1, but earlier in their history it has been 2 and I'd like to have the latest ClassTwo object which has 2 as newStatus. SELECT new ClassThree(c1.id, c1.status, c2) FROM ClassOne c1 LEFT JOIN c1.classtwos c2 (...) and (...) is where I don't know what to do, I'm not even sure if it's a join / join fetch Looked around and tried quite a lot already, but no clue. Especially with the join fetch I get some Hibernate errors like org.hibernate.QueryException: query specified join fetching, but the owner of the fetched association was not present in the select list. Fetching the BusinessObject like that is no problem SELECT distinct(c1) FROM ClassOne c1 LEFT OUTER JOIN FETCH c1.classtwos c2 and I get the ClassTwos as my field. Thanks in advance, Jacob P.S.: One thing might be important, ClassTwo has no reference to ClassOne!!

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  • Wicket: Where to add components? Constructor? Or onBeforeRender?

    - by gmallett
    I'm a Wicket newb. This may just be my ignorance of the Wicket lifecycle so please enlighten me! My understanding is that Wicket WebPage objects are instantiated once and then serialized. This has led to a point of confusion for me, see below. Currently I have a template class which I intend to subclass. I followed the example in the Wicket docs demonstrating how to override the template's behavior in the subclass: protected void onBeforeRender() { add(new Label("title", getTitle())); super.onBeforeRender(); } protected String getTitle() { return "template"; } Subclass: protected String getTitle() { return "Home"; } This works very well. What's not clear to me are the "best practices" for this. It seems like onBeforeRender() is called on every request for the page, no? This seems like there would be substantially more processing done on a page if everything is in onBeforeRender(). I could easily follow the example of the other Wicket examples and add some components in the constructor that I do not want to override, but then I've divided by component logic into two places, something I'm hesitant to do. If I add a component that I intend to be in all subclasses, should I add it to the constructor or onBeforeRender()?

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  • Bind to a collection's view and just call ToString() in WPF

    - by womp
    I'm binding a GridView to a collection of objects that look like this: public class Transaction { public string PersonName { get; set; } public DateTime TransactionDate { get; set; } public MoneyCollection TransactedMoney { get; set;} } MoneyCollection simply inherits from ObservableCollection<T>, and is a collection of MyMoney type object. In my GridView, I just want to bind a column to the MoneyCollection's ToString() method. However, binding it directly to the TransactedMoney property makes every entry display the text "(Collection)", and the ToString() method is never called. Note that I do not want to bind to the items in MoneyCollection, I want to bind directly to the property itself and just call ToString() on it. I understand that it is binding to the collection's default view. So my question is - how can I make it bind to the collection in such a way that it calls the ToString() method on it? This is my first WPF project, so I know this might be a bit noobish, but pointers would be very welcome.

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  • Remove duplication's from my DropDownList

    - by user2976270
    In my controller i am returning list of my object with specific property: public ActionResult Index() { List<MyObject> list = db.MyObjects.Where(x => x.family == "Web").ToList(); ViewBag.Files = new SelectList(list, "Id", "protocol"); return View(); } This is my object: public class MyObject { public int id { get; set; } public string fileName { get; set; } public string browser { get; set; } public string protocol { get; set; } public string family { get; set; } } Index.cshtml: @Html.DropDownList("File", new SelectList(ViewBag.Files, "Id", "protocol_site"), "Select webmail site", new { style = "vertical-align:middle;" }) And i try to made 2 changes with no succeed: Remove all the duplication protocol from my DropDownListfor exapmle if i have 10 objects : 9 is doc protocol and 1 pdf i wand to see in my DropDownList only 2 items: DOC and PDF and not all the 10 items. Sort this DropDownList in alphabet order

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  • Laravel4: Checking many-to-many relationship attribute even when it does not exist

    - by Simo A.
    This is my first time with Laravel and also Stackoverflow... I am developing a simple course management system. The main objects are User and Course, with a many-to-many relationship between them. The pivot table has an additional attribute, participant_role, which defines whether the user is a student or an instructor within that particular course. class Course extends Eloquent { public function users() { return $this->belongsToMany('User')->withPivot('participant_role')->withTimestamps(); } } However, there is an additional role, system admin, which can be defined on the User object. And this brings me mucho headache. In my blade view I have the following: @if ($course->pivot->participant_role == 'instructor') { // do something here... } This works fine when the user has been assigned to that particular $course and there is an entry for this user-course combination in the pivot table. However, the problem is the system administrator, who also should be able to access course details. The if-clause above gives Trying to get property of non-object error, apparently because there is no entry in the pivot table for system administrator (as the role is defined within the User object). I could probably solve the problem by using some off-the-shelf bundle for handling role-based permissions. Or I could (but don't want to) do something like this with two internal if-clauses: if (!empty($course->pivot)) { if ($course->pivot->participant_role == 'instructor') { // do something... } } Other options (suggested in partially similar entries in Stackoverflow) would include 1) reading all the pivot table entries to an array, and use in_array to check if a role exists, or even 2) SQL left join to do this on database level. However, ultimately I am looking for a compact one-line solution? Can I do anything similar to this, which unfortunately does not seem to work? if (! empty ($course->pivot->participant_role == 'instructor') ) { // do something... } The shorter the answer, the better :-). Thanks a lot!

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  • Java Inheritance doubt in parameterised collection

    - by Gala101
    It's obvious that a parent class's object can hold a reference to a child, but does this not hold true in case of parameterised collection ?? eg: Car class is parent of Sedan So public void doSomething(Car c){ ... } public void caller(){ Sedan s = new Sedan(); doSomething(s); } is obviously valid But public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection<Sedan> s = new ArrayList<Sedan>(); doSomething(s); } Fails to compile Can someone please point out why? and also, how to implement such a scenario where a function needs to iterate through a Collection of parent objects, modifying only the fields present in parent class, using parent class methods, but the calling methods (say 3 different methods) pass the collection of three different subtypes.. Ofcourse it compiles fine if I do as below: public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection s = new ArrayList<Sedan>(); doSomething(s); }

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  • Same random numbers from instantiated class

    - by user1797202
    I'm learning C# and created a class within my program that holds a random number generator: class RandomNumberGenerator { Random RNG = new Random(); // A bunch of methods that use random numbers are in here } Inside this class are a few methods that use the RNG. Data gets sent here from other parts of the program, gets processed, then gets returned. One of the methods does the following: // Method works something like this int Value1 = RNG.Next(x, y); int Value2 = RNG.Next(x, y); int Value3 = RNG.Next(x, y); The x, y values are to be sent here from another class. So, I have to create an instance of the RandomNumberGenerator within that class so I can call its methods and pass the x and y values to it. class DoStuff { RandomNumberGenerator Randomizer = new RandomNumberGenerator // Here I call a bunch of Randomizer methods that give me values I need } The problem in the above method is that I get the same numbers every time for all three values. I'm not sure if it's because they're so close together and Randomizer's seed value hasn't had time to change or if I'm doing something wrong when I create a new instance of the RandomNumberGenerator class. I've gone through a bunch of answers on here already and typically problems like this are due to people creating many new Random objects when they run methods (thus setting the seed for all of them to the same value), but the only new Random object I create is within the RandomNumberGenerator class. I then instantiate that once within the other class so I can pass it data and use its methods. Why is this happening and how would I fix this?

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  • find nearest match to array of doubles

    - by Scott
    Given the code below, how do I compare a List of objects's values with a test value? I'm building a geolocation application. I'll be passing in longitude and latitude and would like to have the service answer back with the location closest to those values. I started down the path of converting to a string, and formatting the values down to two decimal places, but that seemed a bit too ghetto, and I'm looking for a more elegant solution. public class Location : IEnumerable { public string label { get; set; } public double lat { get; set; } public double lon { get; set; } //Implement IEnumerable public IEnumerator GetEnumerator() { return (IEnumerator)this; } } [HandleError] public class HomeController : Controller { private List<Location> myList = new List<Location> { new Location { label="Atlanta Midtown", lon=33.657674, lat=-84.423130}, new Location { label="Atlanta Airport", lon=33.794151, lat=-84.387228}, new Location { label="Stamford, CT", lon=41.053758, lat=-73.530979}, ... } public static int Main(String[] args) { string inLat = "-80.987654"; double dblInLat = double.Parse(inLat); // here's where I would like to find the closest location to the inLat // once I figure out this, I'll implement the Longitude, and I'll be set }

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