Search Results

Search found 47200 results on 1888 pages for 'null object pattern'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 83/1888 | < Previous Page | 79 80 81 82 83 84 85 86 87 88 89 90  | Next Page >

  • How can a JSON object refer to values in itself?

    - by Erin Drummond
    Hi, Lets say I have the following javascript: var obj = { key1 : "it ", key2 : key1 + " works!" }; alert(obj.key2); This errors with "key1 is not defined". I have tried this.key1 this[key1] obj.key1 obj[key1] this["key1"] obj["key1"] and they never seem to be defined. How can I get key2 to refer to key1's value?

    Read the article

  • Session is null when inherit from System.Web.UI.Page

    - by Andreas K.
    I want to extend the System.Web.UI.Page-class with some extra stuff. In the ctor I need the value of a session-variable. The problem is that the Session-object is null... public class ExtendedPage : System.Web.UI.Page { protected foo; public ExtendedPage() { this.foo = (int)HttpContext.Current.Session["foo"]; // NullReferenceException } } If I move the part with the session-object into the Load-Event everything works fine... public class ExtendedPage : System.Web.UI.Page { protected foo; public ExtendedPage() { this.Load += new EventHandler(ExtendedPage_Load); } void ExtendedPage_Load(object sender, EventArgs e) { this.foo = (int)HttpContext.Current.Session["foo"]; } } Why is the Session-object null in the first case??

    Read the article

  • Arrays of Objects: For each element in array 1, does an object value exist as a value in any of the objects in array 2

    - by DevOtts
    I have two arrays which contain objects in each element of the array. var array1 = [{firstName: "John", lastName: "McDonald"}, {firstName: "Sandy", lastName: "Johnson"},....,] var array2 = [{userName: "Donald"}, {userName: "John"},....,] In psuedo-code, I want to do the following: for each element in array1, is array1[i].firstName == to any of the userName's in array2. In plain english I want to look at each firstname in array1 and see if it exists at all in array2 as the value associated with the userName property.

    Read the article

  • Method Overloading for NULL parameter

    - by Phani
    I have added three methods with parameters: public static void doSomething(Object obj) { System.out.println("Object called"); } public static void doSomething(char[] obj) { System.out.println("Array called"); } public static void doSomething(Integer obj) { System.out.println("Array called"); } When I am calling doSomething(null) , then compiler throws error as ambiguous methods. So Is the issue because Integer and char[] methods or Integer and Object methods?

    Read the article

  • How to signal object instantiation in a Collaboration/Communication Diagram?

    - by devoured elysium
    I'd like to know how to translate the following line of code to a Collaboration Diagram: Food food = new Food("abc", 123); I know that I can call an Food's method using the following notation: MyStaticMethod() ----------------------> -------- | | | Food | | | -------- being that equivalent to Taste taste = Food.MyStaticMethod(); and MyInstanceMethod() ----------------------> --------------- | | | food : Food | | | --------------- is equivalent to food.MyInstanceMethod(); but how do I signal that I want to call a given constructor on Food? Thanks

    Read the article

  • Nhibernate:null index column for collection Error

    - by Quintin Par
    I am working a subsonic to NH migration(I can’t change the schema) and while creating the mapping I came across this error null index column for collection: Company.Core.CompanyUser.Addresses My mapping from the User side is mapping.HasMany(x => x.Addresses).AsList().KeyColumn("user_id").Cascade.All().Inverse(); xml <list cascade="all" inverse="true" name="Addresses"> <key> <column name="user_id" /> </key> <index /> <one-to-many class="Company.Core.CompanyAddress, Company.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" /> </list> On the Address side it is mapping.CompositeId().KeyReference(x => x.User, "user_id").KeyProperty(x => x.Type); xml <composite-id mapped="false" unsaved-value="undefined"> <key-property name="Type" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"> <column name="Type" /> </key-property> <key-many-to-one name="User" class="Company.Core.CompanyUser, Company.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"> <column name="user_id" /> </key-many-to-one> </composite-id> When I try to load this collection as user.Addresses I get the index null exception. How do I fix this error?

    Read the article

  • Checkboxes in ADF are initially null, where I want them to be 0

    - by Mark Tielemans
    I am using ADF in JDeveloper and don´t have any experience with either of the two. Now I´ve run into quite some trouble yet, but for this particular thing I decided to consult the wisom of stackoverflow. The thing is, I have an edit form for an object that contains 3 checkboxes. The checked values are set to 1, unchecked to 0. In my database, the values are NOT NULL, and I want to keep it that way. The thing is, in the edit form, if the user submits the form leaving any boxes unchecked, it will result in an error, because the unchecked box values apparently remain null. Only after checking and then unchecking the boxes again, their values will be '0' rather than null. I've tried some things, including making the attributes mandatory in the domain BCD, but that just gives a bit more neat error message.. Any help would be greatly appreciated!! EDIT I made a little progress thanks to the guide provided by Joe, but still run into problems. I changed the values that should be checkboxes in my model, making them BOOLEANs where the table columns are NUMBERs (All are also mandatory and have a default value of 0). This automatically changed the corresponding View Object too. In the Application module, this now works great. It shows checkboxes, a checked one will return 1, an untouched one will return 0. However, I deleted the old form, and inserted a new one using the corresponding Data Control. I gave these values the checkbox type. I still had to edit the bindings (which I think reflects the problem, as this is not the case with, say, a model-level defined LOV) and gave them 1 for checked and 0 for unchecked. However, now apart from the original problem still occurring, also the checkboxes cannot be unchecked after checking, and return 0 when checked (and null when left untouched). Even though this has created new problems, it works correctly in my AM. Does someone know what I'm doing wrong in my Swing form?

    Read the article

  • In java can i have more than one class/object in a file?

    - by David
    So the way i've been told to do things is you have your file and the file name is Classname.java and then the code is something like this: class ClassName { SOME METHODS main {} } and then thats all. I'd like to have two objects defined and used within the same .java file. (i don't want to have to put the other class in a difernt file just because i'd like to send this to someone and i want to avoid hasstle of atatching multiple files to an email [the lazy do make good programers though if you think about it]) is it possible to do this? do i have to do anything special and if so what? what are some mistakes i'm likely to make or that you have made in the past when doing this?

    Read the article

  • Property changing null whilst updating a value.

    - by dinesh
    retreiveing the Data object through a class which is partial class in linq to sql. i am using the same object model to update the changes. but proprertychanging is always null for this object. An anonoymoustype has been converted into strong object type. This strong type is updated again. any one can expalin reason for this? Sample Code: var questions = from Question in _db.CheckListInstanceQuestionDataSource join Question in _db.QuestionDataSource on CheckListInstanceQuestion.UI_QuestionID equals Question.UI_QuestionID where CheckListInstanceQuestion.UI_CheckListInstanceID == instanceID && CheckListInstanceForm.UI_TemplateCheckListFormID == selectedFormID orderby CheckListInstanceQuestion.IN_Order, CheckListInstanceQuestion.VC_Code select new { Question .UI_QuestionID, Question.VC_Description, }; ICollection checkListQuestions = new List(); foreach (var question in questions) { checkListQuestions.Add(new CheckListInstanceQuestion { UI_QuestionID = question.UI_QuestionID, VC_Description = question.VC_Description, });

    Read the article

  • hibernate empty collection in component

    - by Jurgen H
    I have a component mapped using Hibernate. If all fields in the component in the database are null, the component itself is set to null by hibernate. This is the expected behavior and also what I need. The problem I have, is that when I add a bag to that component, the bag is initialized to an empty list. This means the component has a non null value... resulting in the component being created. Any idea how to fix this? <class name="foo.bar.Entity" table="Entity"> <id name="id" column="id"> <generator class="native" /> </id> <property name="departure" column="departure_time" /> <property name="arrival" column="arrival_time" /> <component name="statistics"> <bag name="linkStatistics" lazy="false" cascade="all" > <key column="entity_id" not-null="true" /> <one-to-many class="foo.bar.LinkStatistics" /> </bag> <property name="loggedTime" column="logged_time" /> ... </component> A criteria with Restirctions.isNull("statistics") does return the expected values.

    Read the article

  • Why Is the sender type null when dealing with events

    - by ChloeRadshaw
    From C# Via CLR: Note A lot of people wonder why the event pattern requires the sender parameter to always be of type Object After all, since the MailManager will be the only type raising an event with a NewMail EventArgs object, it makes more sense for the callback method to be prototyped like this: void MethodName(Mai l Manager sender, NewMail EventArgs e); The pattern requires the sender parameter to be of type Object mostly because of inheritance What if Mai lManager were used as a base class for SmtpMailManager? In this case, the callback method should have the sender parameter prototyped as SmtpMailManager instead of Mail Manager, but this can’t happen because SmtpMai lManager just inherited the NewMai l event So the code that was expecting SmtpMail Manager to raise the event must still have to cast the sender argument to SmtpMailManager In other words, the cast is still required, so the sender parameter might as well be typed as Obj ect The next reason for typing the sender parameter as Obj ect is just fexibility It allows the delegate to be used by multiple types that offer an event that passes a NewMail EventArgs object For example, a PopMai lManager class could use the delegate even if this class were not derived from Mail Manager I just simply cannot understand why the sender is an object - Why can it not be generified? so most of the time we do not need to do generic casts

    Read the article

  • How do I insert data into a object relational table with multiple ref in the schema.

    - by Yiling
    I have a table with a schema of Table(number, ref, ref, varchar2, varchar2,...). How would I insert a row of data into this table? When I do: "insert into table values (1, select ref(p), ref(d), '239 F.3d 1343', '35 USC § 283', ... from plaintiff p, defendant d where p.name='name1' and d.name='name2');" I get a "missing expression" error. If I do: "insert into table 1, select ref(p), ref(d), ... from plaintiff p, defendant where p.name=...;" I get a "missing keyword VALUES" error.

    Read the article

  • How does one refer to the game1 class's variables in XNA

    - by user1149068
    I try to refer to an array in the Game1 class by creating an object of the Game1 class with its definition Game1 gameObject; , its declaration gameObject = new Game1(); in the constructor, and its usage gameObject.tileArray[xInt, yInt].treed = true;. The game1 class itself remains unchanged in its class code other than some methods and variables. When I try to use this code in the TreeRegion class it gives me "Object reference not set to an instance of an object," leading me to believe that the game1 class is null somehow. How might one change the class or object in order to refer to game1's variables? Mind you I am self-taught and still rather new to C#. The class that refers to game1: http://pastebin.com/0chEcKfq Game1 itself http://pastebin.com/zLDVzCca

    Read the article

  • LINQ2SQL: How to let a column accept null values as zero (0) in Self-Relation table

    - by Remon
    As described in the img, I got a parent-Children relation and since the ParentID not accepting null values (and I can't change to nullabel due to some restriction in the UI I have), how can I remove an existence relation between ReportDataSources in order to change the parent for them (here i want to set the parentId for one of them = 0) how could i do that since i cant change the ParentID directly and setting Parent = null is not valid public void SetReportDataSourceAsMaster(ReportDataSource reportDataSource) { //Some logic - not necessarily for this scenario //Reset Master this.ReportDataSources.ToList().ForEach(rds => rds.IsMaster = false); //Set Master reportDataSource.IsMaster = true; //Set Parent ID for the rest of the Reports data sources this.ReportDataSources.Where(rds => rds.ID != reportDataSource.ID).ToList().ForEach(rds => { //Change Parent ID rds.Parent = reportDataSource; //Remove filttering data rds.FilteringDataMembers.Clear(); //Remove Grouping Data rds.GroupingDataMembers.Clear(); }); //Delete parent HERE THE EXCEPTION THROWN AFTER CALLING SUBMITCHANGES() reportDataSource.Parent = null; //Other logic } Exception thrown after calling submitChanges An attempt was made to remove a relationship between a ReportDataSource and a ReportDataSource. However, one of the relationship's foreign keys (ReportDataSource.ParentID) cannot be set to null.

    Read the article

  • How do I loop through a SimpleXML object in PHP

    - by Aditya
    I have a simpleXml object and want to read the data from the object , I am new to PHP and dont quite know how to do this. The object details are as follows. I need to read [description] and [hours]. Thankyou. SimpleXMLElement Object ( [@attributes] = Array ( [type] = array ) [time-entry] = Array ( [0] = SimpleXMLElement Object ( [date] = 2010-01-26 [description] = TCDM1 data management: sort & upload NFP SubProducers list [hours] = 1.0 [id] = 21753865 [person-id] = 350501 [project-id] = 4287373 [todo-item-id] = SimpleXMLElement Object ( [@attributes] = Array ( [type] = integer [nil] = true ) ) ) [1] = SimpleXMLElement Object ( [date] = 2010-01-27 [description] = PDCH1: HTML [hours] = 0.25 [id] = 21782012 [person-id] = 1828493 [project-id] = 4249185 [todo-item-id] = SimpleXMLElement Object ( [@attributes] = Array ( [type] = integer [nil] = true ) ) ). Please help me. I tries a lot of stuff , but not getting the syntax right.

    Read the article

  • Looping through a SimpleXML object

    - by Aditya
    I have a simpleXml object and want to read the data from the object , I am new to PHP and dont quite know how to do this. The object details are as follows. I need to read [description] and [hours]. Thankyou. SimpleXMLElement Object ( [@attributes] = Array ( [type] = array ) [time-entry] = Array ( [0] = SimpleXMLElement Object ( [date] = 2010-01-26 [description] = TCDM1 data management: sort & upload NFP SubProducers list [hours] = 1.0 [id] = 21753865 [person-id] = 350501 [project-id] = 4287373 [todo-item-id] = SimpleXMLElement Object ( [@attributes] = Array ( [type] = integer [nil] = true ) ) ) [1] = SimpleXMLElement Object ( [date] = 2010-01-27 [description] = PDCH1: HTML [hours] = 0.25 [id] = 21782012 [person-id] = 1828493 [project-id] = 4249185 [todo-item-id] = SimpleXMLElement Object ( [@attributes] = Array ( [type] = integer [nil] = true ) ) ). Please help me. I tries a lot of stuff , but not getting the syntax right.

    Read the article

  • How to serialize a Linq to Sql object graph without hiding the child's "Parent" member

    - by Richard B
    Without hiding the Child object's reference to the Parent object, has anyone been able to use an XmlSerializer() object to move a Linq to SQL object to an XML document, or is the only appropriate way of handling this to create a custom serialization/deserialization class to handle moving the data to/from the xml document? I don't like the idea of hiding the child object's reference to the parent object is why I'm asking. Thx.

    Read the article

  • overload == (and != , of course) operator, can I bypass == to determine whether the object is null

    - by LLS
    Hello, when I try to overload operator == and != in C#, and override Equal as recommended, I found I have no way to distinguish a normal object and null. For example, I defined a class Complex. public static bool operator ==(Complex lhs, Complex rhs) { return lhs.Equals(rhs); } public static bool operator !=(Complex lhs, Complex rhs) { return !lhs.Equals(rhs); } public override bool Equals(object obj) { if (obj is Complex) { return (((Complex)obj).Real == this.Real && ((Complex)obj).Imaginary == this.Imaginary); } else { return false; } } But when I want to use if (temp == null) When temp is really null, some exception happens. And I can't use == to determine whether the lhs is null, which will cause infinite loop. What should I do in this situation. One way I can think of is to us some thing like Class.Equal(object, object) (if it exists) to bypass the == when I do the check. What is the normal way to solve the problem?

    Read the article

  • [PHP] How to unset object's inherited properties ?

    - by vbklv
    I have an Object ( [id] => 1 [parent_id] => 0 [result:Database:private] => [db:Database:private] => mysqli Object ( [affected_rows] => 0 ... ) ) Obviously, the Object has inherited the 'db' and 'result' properties of the parent Database class. unset($object-result) nor unset($object-result:Database) nor unset($object-result:Database:private) work. How could I unset those properties when they are no longer needed (i.e. when the object properties are about to be output)? Is it a generally a good idea to have a database object as an inherited property of other classes (extend one Database class with all other classes that use database connections)?

    Read the article

  • How do I make an object a property of a model in Ruby on Rails?

    - by iTake
    I have this in my schema: create_table "robots_matches", :force => true do |t| t.integer "robot_id" t.integer "match_id" and I think I want to be able to load a robot and match from within my robots_match model so I can do something like this: robots_match.find(:id).get_robot().Name My attempt in the robots_matches model was this: def get_robot Robot.find(this.id) end I am super new to rails, so feel free to correct my architectural decision here.

    Read the article

  • Copy not null and not empty fields from one object to another object of the same type(Objects are same type) in java

    - by Chinni
    I am using hibernate, struts, extjs in my project. I have a Customer object with these fields: custId, custName, address, phone and in my project from UI side I get an object customer with custName. So I need to update the above object(custName is unique). I have only one object with the same customer name. So I will get that object using customer name (object from DB). Now I have to save the object with the updated customer name. If I save as follows I have Customer Object from UI, is cust Customer cust1 = getCustomerByName(cust.getCustName()); cust.setCustId(cust1.getCustId()); save(cust); If I do this I lose the customer address and phone number. So, how can I copy one object not null or not empty field values to another object of same type. Can any one please help. I just stuck here. It's stopping me to save. Thanks in advance!

    Read the article

  • OOP beginner: classB extends classA. classA already object. method in classB needed.. etc.

    - by Yvo
    Hey guys, I'm learning myself to go from function based PHP coding to OOP. And this is the situation: ClassA holds many basic tool methods (functions). it's __construct makes a DB connection. ClassB holds specific methods based on a certain activity (extract widgets). ClassB extends ClassA because it uses some of the basic tools in there e.g. a database call. In a php file I create a $a_class = new ClassA object (thus a new DB connection). Now I need a method in ClassB. I do $b_class = new ClassB; and call a method, which uses a method from it's parent:: ClassA. In this example, i'm having ClassA 'used' twice. Onces as object, and onces via a parent:: call, so ClassA creates another DB connection (or not?). So what is the best setup for this basic classes parent, child (extend) situation? I only want to make one connection of course? I don't like to forward the object to ClassB like this $b_class = new ClassB($a_object); or is that the best way? Thanks for thinking with me, and helping :d

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 79 80 81 82 83 84 85 86 87 88 89 90  | Next Page >