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  • LINQ query code for complex merging of data.

    - by Stacey
    I've posted this before, but I worded it poorly. I'm trying again with a more well thought out structure. Re-writing this a bit to make it more clear. I have the following code and I am trying to figure out the shorter linq expression to do it 'inline'. Please examine the "Run()" method near the bottom. I am attempting to understand how to join two dictionaries together based on a matching identifier in one of the objects - so that I can use the query in this sort of syntax. var selected = from a in items.List() // etc. etc. select a; This is my class structure. The Run() method is what I am trying to simplify. I basically need to do this conversion inline in a couple of places, and I wanted to simplify it a great deal so that I can define it more 'cleanly'. class TModel { public Guid Id { get; set; } } class TModels : List<TModel> { } class TValue { } class TStorage { public Dictionary<Guid, TValue> Items { get; set; } } class TArranged { public Dictionary<TModel, TValue> Items { get; set; } } static class Repository { static public TItem Single<TItem, TCollection>(Predicate<TItem> expression) { return default(TItem); // access logic. } } class Sample { public void Run() { TStorage tStorage = new TStorage(); // access tStorage logic here. Dictionary<TModel, TValue> d = new Dictionary<TModel, TValue>(); foreach (KeyValuePair<Guid, TValue> kv in tStorage.Items) { d.Add(Repository.Single<TModel, TModels>(m => m.Id == kv.Key),kv.Value); } } }

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  • Python access an object byref / Need tagging

    - by Aaron C. de Bruyn
    I need to suck data from stdin and create a object. The incoming data is between 5 and 10 lines long. Each line has a process number and either an IP address or a hash. For example: pid=123 ip=192.168.0.1 - some data pid=123 hash=ABCDEF0123 - more data hash=ABCDEF123 - More data ip=192.168.0.1 - even more data I need to put this data into a class like: class MyData(): pid = None hash = None ip = None lines = [] I need to be able to look up the object by IP, HASH, or PID. The tough part is that there are multiple streams of data intermixed coming from stdin. (There could be hundreds or thousands of processes writing data at the same time.) I have regular expressions pulling out the PID, IP, and HASH that I need, but how can I access the object by any of those values? My thought was to do something like this: myarray = {} for each line in sys.stdin.readlines(): if pid and ip: #If we can get a PID out of the line myarray[pid] = MyData().pid = pid #Create a new MyData object, assign the PID, and stick it in myarray accessible by PID. myarray[pid].ip = ip #Add the IP address to the new object myarray[pid].lines.append(data) #Append the data myarray[ip] = myarray[pid] #Take the object by PID and create a key from the IP. <snip>do something similar for pid and hash, hash and ip, etc...</snip> This gives my an array with two keys (a PID and an IP) and they both point to the same object. But on the next iteration of the loop, if I find (for example) an IP and HASH and do: myarray[hash] = myarray[ip] The following is False: myarray[hash] == myarray[ip] Hopefully that was clear. I hate to admit that waaay back in the VB days, I remember being able handle objects byref instead of byval. Is there something similar in Python? Or am I just approaching this wrong?

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  • LINQ Join on Dictionary<K,T> where only K is changed.

    - by Stacey
    Assuming type TModel, TKey, and TValue. In a dictionary where KeyValuePair is declared, I need to merge TKey into a separate model of KeyValuePair where TKey in the original dictionary refers to an identifier in a list of TModel that will replace the item in the Dictionary. public TModel { public Guid Id { get; set; } // ... } public Dictionary<Guid, TValue> contains the elements. TValue relates to the TModel. The serialized/stored object is like this.. public SerializedModel { public Dictionary<Guid,TValue> Items { get; set; } } So I need to construct a new model... KeyValueModel { public Dictionary<TModel, TValue> { get; set; } } KeyValueModel kvm = = (from tModels in controller.ModelRepository.List<Models.Models>() join matchingModels in storedInformation.Items on tModels.Id equals matchingModels select tModels).ToDictionary( c => c.Id, storedInformation.Items.Values ) This linq query isn't doing what I'm wanting, but I think I'm at least headed in the right direction. Can anyone assist with the query? The original object is stored as a KeyValuePair. I need to merge the Guid Keys in the Dictionary to their actual related objects in another object (List) so that the final result is KeyValuePair. And as for what the query is not doing for me... it isn't compiling or running. It just says that "Join is not valid".

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  • Call method immediately after object construction in LINQ query

    - by Steffen
    I've got some objects which implement this interface: public interface IRow { void Fill(DataRow dr); } Usually when I select something out of db, I go: public IEnumerable<IRow> SelectSomeRows { DataTable table = GetTableFromDatabase(); foreach (DataRow dr in table.Rows) { IRow row = new MySQLRow(); // Disregard the MySQLRow type, it's not important row.Fill(dr); yield return row; } } Now with .Net 4, I'd like to use AsParallel, and thus LINQ. I've done some testing on it, and it speeds up things alot (IRow.Fill uses Reflection, so it's hard on the CPU) Anyway my problem is, how do I go about creating a LINQ query, which calls Fills as part of the query, so it's properly parallelized? For testing performance I created a constructor which took the DataRow as argument, however I'd really love to avoid this if somehow possible. With the constructor in place, it's obviously simple enough: public IEnumerable<IRow> SelectSomeRowsParallel { DataTable table = GetTableFromDatabase(); return from DataRow dr in table.Rows.AsParallel() select new MySQLRow(dr); } However like I said, I'd really love to be able to just stuff my Fill method into the LINQ query, and thus not need the constructor overload.

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  • Is there a way to use Linq projections with extension methods

    - by Acoustic
    I'm trying to use AutoMapper and a repository pattern along with a fluent interface, and running into difficulty with the Linq projection. For what it's worth, this code works fine when simply using in-memory objects. When using a database provider, however, it breaks when constructing the query graph. I've tried both SubSonic and Linq to SQL with the same result. Thanks for your ideas. Here's an extension method used in all scenarios - It's the source of the problem since everything works fine without using extension methods public static IQueryable<MyUser> ByName(this IQueryable<MyUser> users, string firstName) { return from u in users where u.FirstName == firstName select u; } Here's the in-memory code that works fine var userlist = new List<User> {new User{FirstName = "Test", LastName = "User"}}; Mapper.CreateMap<User, MyUser>(); var result = (from u in userlist select Mapper.Map<User, MyUser>(u)) .AsQueryable() .ByName("Test"); foreach (var x in result) { Console.WriteLine(x.FirstName); } Here's the same thing using a SubSonic (or Linq to SQL or whatever) that fails. This is what I'd like to make work somehow with extension methods... Mapper.CreateMap<User, MyUser>(); var result = from u in new DataClasses1DataContext().Users select Mapper.Map<User, MyUser>(u); var final = result.ByName("Test"); foreach(var x in final) // Fails here when the query graph built. { Console.WriteLine(x.FirstName); } The goal here is to avoid having to manually map the generated "User" object to the "MyUser" domain object- in other words, I'm trying to find a way to use AutoMapper so I don't have this kind of mapping code everywhere a database read operation is needed: var result = from u in new DataClasses1DataContext().Users select new MyUser // Can this be avoided with AutoMapper AND extension methods? { FirstName = v.FirstName, LastName = v.LastName };

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  • Setting synthesized arrays causing memory leaks using nested arrays

    - by webtoad
    Hello: Why is the following code causing a memory leak in an iPhone App? All of the initted objects below leak, including the arrays, the strings and the numbers. So, I'm thinking it has something to do with the the synthesized array property not releasing the object when I set the property again on the second and subsequent time this piece of code is called. Here is the code: "controller" (below) is my custom view controller class, which I have a reference to, and I am setting with this code snippet: sqlite3_stmt *statement; NSMutableArray *foo_IDs = [[NSMutableArray alloc] init]; NSMutableArray *foo_Names = [[NSMutableArray alloc] init]; NSMutableArray *foo_IDsBySection = [[NSMutableArray alloc] init]; NSMutableArray *foo_NamesBySection = [[NSMutableArray alloc] init]; // Get data: NSString *sql = @"select distinct p.foo_ID, p.foo_Name from foo as p "; if (sqlite3_prepare_v2(...) == SQLITE_OK) { while (sqlite3_step(statement) == SQLITE_ROW) { int p_id; NSString *foo_Name; p_id = sqlite3_column_int(statement, 0); char *str2 = (char *)sqlite3_column_text(statement, 1); foo_Name = [NSString stringWithCString:str2]; [foo_IDs addObject:[NSNumber numberWithInt:p_id]]; [foo_Names addObject:foo_Name]; } sqlite3_finalize(statement); } // Pass the array itself into another array: // (normally there is more than one array in each array) [foo_IDsBySection addObject: foo_IDs]; [foo_NamesBySection addObject: foo_Names]; [foo_IDs release]; [foo_Names release]; // Set some synthesized properties (of type NSArray, nonatomic, // retain) in controller: controller.foo_IDsBySection = foo_IDsBySection; controller.foo_NamesBySection = foo_NamesBySection; [foo_IDsBySection release]; [foo_NamesBySection release]; Thanks for any help!

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  • What is the difference between these two linq implementations?

    - by Mahesh Velaga
    I was going through Jon Skeet's Reimplemnting Linq to Objects series. In the implementation of where article, I found the following snippets, but I don't get what is the advantage that we are gettting by splitting the original method into two. Original Method: // Naive validation - broken! public static IEnumerable<TSource> Where<TSource>( this IEnumerable<TSource> source, Func<TSource, bool> predicate) { if (source == null) { throw new ArgumentNullException("source"); } if (predicate == null) { throw new ArgumentNullException("predicate"); } foreach (TSource item in source) { if (predicate(item)) { yield return item; } } } Refactored Method: public static IEnumerable<TSource> Where<TSource>( this IEnumerable<TSource> source, Func<TSource, bool> predicate) { if (source == null) { throw new ArgumentNullException("source"); } if (predicate == null) { throw new ArgumentNullException("predicate"); } return WhereImpl(source, predicate); } private static IEnumerable<TSource> WhereImpl<TSource>( this IEnumerable<TSource> source, Func<TSource, bool> predicate) { foreach (TSource item in source) { if (predicate(item)) { yield return item; } } } Jon says - Its for eager validation and then defferring for the rest of the part. But, I don't get it. Could some one please explain it in a little more detail, whats the difference between these 2 functions and why will the validations be performed in one and not in the other eagerly? Conclusion/Solution: I got confused due to my lack of understanding on which functions are determined to be iterator-generators. I assumed that, it is based on signature of a method like IEnumerable<T>. But, based on the answers, now I get it, a method is an iterator-generator if it uses yield statements.

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  • PHP Object Creation and Memory Usage

    - by JohnO
    A basic dummy class: class foo { var $bar = 0; function foo() {} function boo() {} } echo memory_get_usage(); echo "\n"; $foo = new foo(); echo memory_get_usage(); echo "\n"; unset($foo); echo memory_get_usage(); echo "\n"; $foo = null; echo memory_get_usage(); echo "\n"; Outputs: $ php test.php 353672 353792 353792 353792 Now, I know that PHP docs say that memory won't be freed until it is needed (hitting the ceiling). However, I wrote this up as a small test, because I've got a much longer task, using a much bigger object, with many instances of that object. And the memory just climbs, eventually running out and stopping execution. Even though these large objects do take up memory, since I destroy them after I'm done with each one (serially), it should not run out of memory (unless a single object exhausts the entire space for memory, which is not the case). Thoughts?

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  • nil object in view when building objects on two different associations

    - by Shako
    Hello all. I'm relatively new to Ruby on Rails so please don't mind my newbie level! I have following models: class Paintingdescription < ActiveRecord::Base belongs_to :paintings belongs_to :languages end class Paintingtitle < ActiveRecord::Base belongs_to :paintings belongs_to :languages end class Painting < ActiveRecord::Base has_many :paintingtitles, :dependent => :destroy has_many :paintingdescriptions, :dependent => :destroy has_many :languages, :through => :paintingdescriptions has_many :languages, :through => :paintingtitles end class Language < ActiveRecord::Base has_many :paintingtitles, :dependent => :nullify has_many :paintingdescriptions, :dependent => :nullify has_many :paintings, :through => :paintingtitles has_many :paintings, :through => :paintingdescriptions end In my painting new/edit view, I would like to show the painting details, together with its title and description in each of the languages, so I can store the translation of those field. In order to build the languagetitle and languagedescription records for my painting and each of the languages, I wrote following code in the new method of my Paintings_controller.rb: @temp_languages = @languages @languages.size.times{@painting.paintingtitles.build} @painting.paintingtitles.each do |paintingtitle| paintingtitle.language_id = @temp_languages[0].id @temp_languages.slice!(0) end @temp_languages = @languages @languages.size.times{@painting.paintingdescriptions.build} @painting.paintingdescriptions.each do |paintingdescription| paintingdescription.language_id = @temp_languages[0].id @temp_languages.slice!(0) end In form partial which I call in the new/edit view, I have <% form_for @painting, :html => { :multipart => true} do |f| %> ... <% languages.each do |language| %> <p> <%= label language, language.name %> <% paintingtitle = @painting.paintingtitles[counter] %> <% new_or_existing = paintingtitle.new_record? ? 'new' : 'new' %> <% prefix = "painting[#{new_or_existing}_title_attributes][]" %> <% fields_for prefix, paintingtitle do |paintingtitle_form| %> <%= paintingtitle_form.hidden_field :language_id%> <%= f.label :title %><br /> <%= paintingtitle_form.text_field :title%> <% end %> <% paintingdescription = @painting.paintingdescriptions[counter] %> <% new_or_existing = paintingdescription.new_record? ? 'new' : 'new' %> <% prefix = "painting[#{new_or_existing}_title_attributes][]" %> <% fields_for prefix, paintingdescription do |paintingdescription_form| %> <%= paintingdescription_form.hidden_field :language_id%> <%= f.label :description %><br /> <%= paintingdescription_form.text_field :description %> <% end %> </p> <% counter += 1 %> <% end %> ... <% end %> But, when running the code, ruby encounters a nil object when evaluating paintingdescription.new_record?: You have a nil object when you didn't expect it! You might have expected an instance of ActiveRecord::Base. The error occurred while evaluating nil.new_record? However, if I change the order in which I a) build the paintingtitles and painting descriptions in the paintings_controller new method and b) show the paintingtitles and painting descriptions in the form partial then I get the nil on the paintingtitles.new_record? call. I always get the nil for the objects I build in second place. The ones I build first aren't nil in my view. Is it possible that I cannot build objects for 2 different associations at the same time? Or am I missing something else? Thanks in advance!

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  • Grouping by property value and writing group members

    - by Will S
    I need to group the following list by the department value but am having trouble with the LINQ syntax. Here's my list of objects: var people = new List<Person> { new Person { name = "John", department = new List<fields> {new fields { name = "department", value = "IT"}}}, new Person { name = "Sally", department = new List<fields> {new fields { name = "department", value = "IT"}}}, new Person { name = "Bob", department = new List<fields> {new fields { name = "department", value = "Finance"}}}, new Person { name = "Wanda", department = new List<fields> {new fields { name = "department", value = "Finance"}}}, }; I've toyed around with grouping. This is as far as I've got: var query = from p in people from field in p.department where field.name == "department" group p by field.value into departments select new { Department = departments.Key, Name = departments }; So can iterate over the groups, but not sure how to list the Person names - foreach (var department in query) { Console.WriteLine("Department: {0}", department.Department); foreach (var foo in department.Department) { // ?? } } Any ideas on what to do better or how to list the names of the relevant departments?

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  • Distinctly LINQ &ndash; Getting a Distinct List of Objects

    - by David Totzke
    Let’s say that you have a list of objects that contains duplicate items and you want to extract a subset of distinct items.  This is pretty straight forward in the trivial case where the duplicate objects are considered the same such as in the following example: List<int> ages = new List<int> { 21, 46, 46, 55, 17, 21, 55, 55 }; IEnumerable<int> distinctAges = ages.Distinct(); Console.WriteLine("Distinct ages:"); foreach (int age in distinctAges) { Console.WriteLine(age); } /* This code produces the following output: Distinct ages: 21 46 55 17 */ What if you are working with reference types instead?  Imagine a list of search results where items in the results, while unique in and of themselves, also point to a parent.  We’d like to be able to select a bunch of items in the list but then see only a distinct list of parents.  Distinct isn’t going to help us much on its own as all of the items are distinct already.  Perhaps we can create a class with just the information we are interested in like the Id and Name of the parents.  public class SelectedItem { public int ItemID { get; set; } public string DisplayName { get; set; } } We can then use LINQ to populate a list containing objects with just the information we are interested in and then get rid of the duplicates. IEnumerable<SelectedItem> list = (from item in ResultView.SelectedRows.OfType<Contract.ReceiptSelectResults>() select new SelectedItem { ItemID = item.ParentId, DisplayName = item.ParentName }) .Distinct(); Most of you will have guessed that this didn’t work.  Even though some of our objects are now duplicates, because we are working with reference types, it doesn’t matter that their properties are the same, they’re still considered unique.  What we need is a way to define equality for the Distinct() extension method. IEqualityComparer<T> Looking at the Distinct method we see that there is an overload that accepts an IEqualityComparer<T>.  We can simply create a class that implements this interface and that allows us to define equality for our SelectedItem class. public class SelectedItemComparer : IEqualityComparer<SelectedItem> { public new bool Equals(SelectedItem abc, SelectedItem def) { return abc.ItemID == def.ItemID && abc.DisplayName == def.DisplayName; } public int GetHashCode(SelectedItem obj) { string code = obj.DisplayName + obj.ItemID.ToString(); return code.GetHashCode(); } } In the Equals method we simply do whatever comparisons are necessary to determine equality and then return true or false.  Take note of the implementation of the GetHashCode method.  GetHashCode must return the same value for two different objects if our Equals method says they are equal.  Get this wrong and your comparer won’t work .  Even though the Equals method returns true, mismatched hash codes will cause the comparison to fail.  For our example, we simply build a string from the properties of the object and then call GetHashCode() on that. Now all we have to do is pass an instance of our IEqualitlyComarer<T> to Distinct and all will be well: IEnumerable<SelectedItem> list =     (from item in ResultView.SelectedRows.OfType<Contract.ReceiptSelectResults>()         select new SelectedItem { ItemID = item.dahfkp, DisplayName = item.document_code })                         .Distinct(new SelectedItemComparer());   Enjoy. Dave Just because I can… Technorati Tags: LINQ,C#

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  • Importing AutoCAD/Solidworks drawings/objects into winforms?

    - by Dinoo
    Has anybody done anything like that? I need to import 3d objects, done in either AutoCAD or Solidworks, and draw them into a windows form. I only need the object to be viewed in 3D and moved around - no manipulation required. I am assuming I will need 2 libraries at least, one for a very simple 3D engine, and one to actually get what I need from the CAD/SW files. Autodesk has a SDK available for developing AutoCAD plugins using .NET, but I am not sure if you can use it the other way around - loading files into the .NET app. Any help, links, and ideas are appreciated.

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  • How to properly clean up Excel interop objects in C#

    - by HAdes
    I'm using the Excel interop in C# (ApplicationClass) and have placed the following code in my finally clause: while (System.Runtime.InteropServices.Marshal.ReleaseComObject(excelSheet) != 0) { } excelSheet = null; GC.Collect(); GC.WaitForPendingFinalizers(); Although, this kind of works the Excel.exe process is still in the background even after I close Excel. It is only released once my application is manually closed. Anyone realize what I am doing wrong, or has an alternative to ensure interop objects are properly disposed of. Thanks.

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  • What AMF Servers Support Remote Shared Objects?

    - by GrayB
    Greetings. I'm planning on building a Flex based multiplayer game, and I'm researching what will be required for the server end. I have PHP experience, so I started looking at ZendAMF. Now in this game, I'll need the concept of rooms, and real time updates to clients in those rooms, so it looks like I'll be using remote shared objects (correct, yes?). I'm not seeing where ZendAMF can support this. So I found this page: http://arunbluebrain.wordpress.com/2009/03/04/flex-frameworks-httpcorlanorg/ It seems to indicate that ZendAMF isn't going to do what I want. WebORB for PHP seems to be the only PHP based solution that does messaging, but on that page it doesn't mention "real-time" next to it like the Java based ones below it do. What should I be looking at for the server piece with my requirements? Do I need to make the jump to something like BlazeDS and try to pick up a bit of Java knowledge? Thanks.

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  • PropertyGrid: Merging multiple dynamic properties when editing multiple objects

    - by Andrei Stanescu
    Hi, Let's say I have a class A and a class B. I would like to edit using .NET PropertyGrid multiple instances of A and B simultaneously. The desired behavior would be to have the intersection of properties displayed. If A and B have static (written in the source code) properties everything works fine. Selecting A and B instances will only display the intersection of properties. However, if A and B also have dynamic properties (returned as a PropertyDescriptorCollection through the GetProperties() method) the behavior is wrong. When selecting multiple objects I will only see those static properties and none of the dynamic ones. When I select only one instance I can see all properties (static and dynamic). Anybody any ideas? I couldn't find anything on the internet.

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  • Fastest way to call a COM objects method without using a RCW

    - by Nathan W
    I'm trying to find the cleanest and fastest way for calling a COM objects methods. I was using a RCW for the object but every time a new version of the third party COM object comes out its GUID changes which then renders the RCW useless, so I had to change and start using Type mytype = Type.GetTypeFromProgID("MyCOMApp.Application"); so that every time a new version of the COM object comes out I don't have to recomplie and redeploy my app. At the moment I am using refelection like mytype.InvokeMemeber but I feel it is so slow compared to just calling the RCW. How does everyone else tackle the problem of changing 3rd party COM object versions, but still maintaining the speed of a RCW?

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  • Returning a tuple of multipe objects in Python C API

    - by celil
    I am writing a native function that will return multiple Python objects PyObject *V = PyList_New(0); PyObject *E = PyList_New(0); PyObject *F = PyList_New(0); return Py_BuildValue("ooo", V, E, F); This compiles fine, however, when I call it from a Python program, I get an error: SystemError: bad format char passed to Py_BuildValue How can this be done correctly? EDIT: The following works PyObject *rslt = PyTuple_New(3); PyTuple_SetItem(rslt, 0, V); PyTuple_SetItem(rslt, 1, E); PyTuple_SetItem(rslt, 2, F); return rslt; However, isn't there a shorter way to do this?

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  • List of objects to JSON to Html Table?

    - by DaveDev
    If I have a list of objects IEnumerable<MyType> myTypes; Is it possible for me to return this to the client as JSON return Json(myTypes); and if so, is it possible for me to convert this (now JSON format) list to a when it gets to the client? Is there any jQuery plugin to do this? The thing is, there's loads of other stuff I need to send as JSON also, so generating a table with a PartialView and embedding that into the JSON is a extra complexity that I'd like to avoid. Thanks.

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  • Building big, immutable objects without constructors having long parameter lists

    - by Malax
    Hi StackOverflow! I have some big (more than 3 fields) Objects which can and should be immutable. Every time I run into that case i tend to create constructor abominations with long parameter lists. It doesn't feel right, is hard to use and readability suffers. It is even worse if the fields are some sort of collection type like lists. A simple addSibling(S s) would ease the object creation so much but renders the object mutable. What do you guys use in such cases? I'm on Scala and Java, but i think the problem is language agnostic as long as the language is object oriented. Solutions I can think of: "Constructor abominations with long parameter lists" The Builder Pattern Thanks for your input!

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  • Building a clip area in a UIView from path objects in its subviews

    - by hkatz
    I'm trying to produce a clipping area in a UIView that's generated from path objects in its subviews. For example, I might have one subview containing a square and another containing a circle. I want to be able to produce a clip in the parent superview that's the union of both these shapes. Can someone explain how to do this? About all I've been able to figure out so far is that: 1 - the superview's drawRect: method is called before its subviews' drawRects are, and 2 - the ContextRef that's accessible in all three instances is the same. Other than that I'm stumped. Thanks, Howard

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  • Django aggregation query on related one-to-many objects

    - by parxier
    Here is my simplified model: class Item(models.Model): pass class TrackingPoint(models.Model): item = models.ForeignKey(Item) created = models.DateField() data = models.IntegerField() In many parts of my application I need to retrieve a set of Item's and annotate each item with data field from latest TrackingPoint from each item ordered by created field. For example, instance i1 of class Item has 3 TrackingPoint's: tp1 = TrackingPoint(item=i1, created=date(2010,5,15), data=23) tp2 = TrackingPoint(item=i1, created=date(2010,5,14), data=21) tp3 = TrackingPoint(item=i1, created=date(2010,5,12), data=120) I need a query to retrieve i1 instance annotated with tp1.data field value as tp1 is the latest tracking point ordered by created field. That query should also return Item's that don't have any TrackingPoint's at all. If possible I prefer not to use QuerySet's extra method to do this. That's what I tried so far... and failed :( Item.objects.annotate(max_created=Max('trackingpoint__created'), data=Avg('trackingpoint__data')).filter(trackingpoint__created=F('max_created')) Any ideas?

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  • iPhone autorotation for too many objects on screen

    - by Denis
    Hi! I have a BlahAppDelegate, BlahViewController and no nibs in my iPhone app project. Only some subclasses of UIView in addition. All this is situated in main.m. My app has 6 subclassed UIViews. Each of it contains 18 UIImageViews. I need to get autorotating work. Or custom rotating. Or something. For example it would be nice to fade the screen out when device is rotated, then move/resize views and then fade screen out. But I don't know how to automate it, without writing a resizing code for each of objects. Please help me if you can.

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  • How to keep my functions (objects/methods) 'lean and mean'

    - by Michel
    Hi, in all (Agile) articles i read about this: keep your code and functions small and easy to test. How should i do this with the 'controller' or 'coordinator' class? In my situation, i have to import data. In the end i have one object who coordinates this, and i was wondering if there is a way of keeping the coordinator lean(er) and mean(er). My coordinator now does the followling (pseudocode) //Write to the log that the import has started Log.StartImport() //Get the data in Excel sheet format result = new Downloader().GetExcelFile() //Log this step Log.LogStep(result ) //convert the data to intern objects result = new Converter().Convertdata(result); //Log this step Log.LogStep(result ) //write the data result = Repository.SaveData(result); //Log this step Log.LogStep(result ) Imho, this is one of those 'know all' classes or at least one being 'not lean and mean'? Or, am i taking this lean and mean thing to far and is it impossible to program an import without some kind of 'fat' importer/coordinator? Michel

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  • Sort ArrayList of custom Objects by property

    - by Samuel
    Hello World!! :D I had a question which is pretty easy if you know the answer I guess. I read about sorting ArrayLists using a Comparator but somehow in all of the examples people used compareTo which according to some research is a method working on Strings... I wanted to sort an ArrayList of custom objects by one of their properties: a Date object (getStartDay()). Normally I compare them by item1.getStartDate().before(item2.getStartDate()) so I was wondering whether I could write something like: public class customComparator { public boolean compare(Object object1, Object object2) { return object1.getStartDate().before(object2.getStartDate()); } } public class randomName { ... Collections.sort(Database.arrayList, new customComparator); ... } I just started with Java so please forgive my ignorance :) Thanks in advance!! -Samuel

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  • Building big, immutable objects without using constructors having long parameter lists

    - by Malax
    Hi StackOverflow! I have some big (more than 3 fields) Objects which can and should be immutable. Every time I run into that case i tend to create constructor abominations with long parameter lists. It doesn't feel right, is hard to use and readability suffers. It is even worse if the fields are some sort of collection type like lists. A simple addSibling(S s) would ease the object creation so much but renders the object mutable. What do you guys use in such cases? I'm on Scala and Java, but i think the problem is language agnostic as long as the language is object oriented. Solutions I can think of: "Constructor abominations with long parameter lists" The Builder Pattern Thanks for your input!

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