Search Results

Search found 25521 results on 1021 pages for 'static objects'.

Page 308/1021 | < Previous Page | 304 305 306 307 308 309 310 311 312 313 314 315  | Next Page >

  • C# Lists, Foreach, and Types

    - by user406470
    I was wondering if there is a version of foreach that checks only for a specific type and returns it. For example consider this class tree: org.clixel.ClxBasic - org.clixel.ClxObject - org.clixel.ClxSprite - WindowsGame1.test Then consider this code public List<ClxBasic> objects = new List<ClxBasic>(); foreach(GroupTester tester in objects) { tester.GroupTesterOnlyProperty = true; } tester.GroupTesterOnlyProperty is a property created in GroupTester. Is there some way to make something like this work, like an overload of foreach, or another snippet that might help me? I want to make it easy for a programmer to sort through the lists grabbing only what type they need.

    Read the article

  • Separation of interfaces and implementation

    - by bonefisher
    From assembly(or module) perspective, what do you think of separation of Interface (1.assembly) and its Implementation (2.assembly)? In this way we can use some IoC container to develop more decoupling desing.. Say we have an assembly 'A', which contains interfaces only. Then we have an assembly 'B' which references 'A' and implements those interfaces..It is dependent only on 'A'. In assembly 'C' then we can use the IoC container to create objects of 'A' using dependency injection of objects from 'B'. This way 'B' and 'C' are completely unaware (not dependent) of themselves..

    Read the article

  • proper Django ORM syntax to make this code work in MySQL

    - by gtujan
    I have the following django code working on an sqlite database but for some unknown reason I get a syntax error if I change the backend to MySQL...does django's ORM treat filtering differently in MySQL? def wsjson(request,imei): wstations = WS.objects.annotate(latest_wslog_date=Max('wslog__date'),latest_wslog_time=Max('wslog__time')) logs = WSLog.objects.filter(date__in=[b.latest_wslog_date for b in wstations],time__in=[b.latest_wslog_time for b in wstations],imei__exact=imei) data = serializers.serialize('json',logs) return HttpResponse(data,'application/javascript') The code basically gets the latest logs from WSlog corresponding to each record in WS and serializes it to json. Models are defined as: class WS(models.Model): name = models.CharField(max_length=20) imei = models.CharField(max_length=15) description = models.TextField() def __unicode__(self): return self.name class WSLog(models.Model): imei = models.CharField(max_length=15) date = models.DateField() time = models.TimeField() data1 = models.DecimalField(max_digits=8,decimal_places=3) data2 = models.DecimalField(max_digits=8,decimal_places=3) WS = models.ForeignKey(WS) def __unicode__(self): return self.imei

    Read the article

  • Should I use DTOs as my data models in MVVM?

    - by JonC
    I'm currently working on what will be my first real foray into using MVVM and have been reading various articles on how best to implement it. My current thoughts are to use my data models effectively as data transfer objects, make them serializable and have them exist on both the client and server sides. It seems like a logical step given that both object types are really just collections of property getters and setters and another layer in between seems like complete overkill. Obviously there would be issues with INotifyPropertyChanged not working correctly on the server side as there is no ViewModel to which to communicate, but as long as we are careful about constructing our proper domain model objects from data models in the service layer and not dealing the the data models on the server side I don't think it should be a big issue. I haven't found too much info about this approach in my reading, so I would like to know if this is a pretty standard thing, is this just assumed to be the de facto way of doing MVVM in a multi-tier environment? If I've got completely the wrong idea about things then thoughts on other approaches would be appreciated too.

    Read the article

  • what is a performance way to 'tree-walking' through my Entity Framework data

    - by Greg
    Hi, I have a Entity Framework design with a few tables that define a "graph". So there can be a large chain of relationships between objects in the few tables via concept of parent/child relationships. What is a performance way to 'tree-walking' through my Entity Framework data? That is I assume I wouldn't want to load the full set of all NODES and RELATIONSHIPS from the database for the purpose of walking the tree, where the end result may only be identifying leaf nodes? Or would this be OK with the way lazy loading may work at the column/parameter level? Else how could I load just the skeleton of the objects and then when needing to refer to any attributes have them lazy load then?

    Read the article

  • how to search values in a dictionary that is assigned to a key for a PFObject without downloading all PFObjects of that class (iOS/Parse)

    - by mkc842
    Suppose I have a set of PFObjects (essentially dictionaries) of class "myObject". Objects of this class contain for key "myDictionary" a dictionary. "myDictionary", in turn, has a key "myKey" that I want to access and search for matches against "mySearchTerm". I don't want to download all myObject objects and then iterate through them to check myKey in each, because that would be very inefficient. I want to use a findObjects message to return just the matches. Is such a query possible? In other words, how can I search the values in a dictionary that is assigned to a key for a PFObject without downloading all PFObjects of that class? Here's what it might look like if there were a simple method for it, but I made up the containsKey part to clarify what I am contemplating: PFQuery *objectQuery = [PFQuery queryWithClassName:@"myObject"]; [objectQuery whereKey:@"myDictionary" ~containsKey~:@"myKey" equalTo:"mySearchTerm"];

    Read the article

  • How does Hibernate detect dirty state of an entity object?

    - by ???'Lenik
    Is it using some kind of byte codes modification to the original classes? Or, maybe Hibernate get the dirty state by compare the given object with previously persisted version? I'm having a problem with hashCode() and equals() methods for complicated objects. I feel it would be very slow to compute hash code if the object has collection members, and cyclic references are also a problem. If Hibernate won't use hashCode()/equals() to check the dirty state, I guess I should not use equals()/hashCode() for the entity object (not value object), but I'm also afraid if the same operator (==) is not enough. So, the questions are: How does Hibernate know if a property of an object is changed? Do you suggest to override the hashCode()/equals() methods for complicated objects? What if they contains cyclic references? And, also, Would hashCode()/equals() with only the id field be enough?

    Read the article

  • How to keep historic details of modification in a database (Audit trail)?

    - by mada
    I'm a J2EE developer & we are using hibernate mapping with a PostgreSQL database. We have to keep track of any changes occurs in the database, in others words all previous & current values of any field should be saved. Each field can be any type (bytea, int, char...) With a simple table it is easy but we a graph of objects things are more difficult. So we have, speaking in a UML point of view, a graph of objects to store in the database with every changes & the user. Any idea or pattern how to do that?

    Read the article

  • java: "downcasting" to new object / opposite of slicing

    - by rhavin
    Sorry, i really dont know how to make a headline for that question; maybe there is a name for what im trying to do that i dont know, but i can explain it with some code: Guess you have a class that unfortunately neither has a copy-constructor nor a public static copy method. class A { private int i; // <- private, cant access String x; // <- even worse: cant access unless in same pkg! /* … other stuff, ctor, etc. … */ public A clone() { A a = new A(); a.i = i; a.x = x; return x; } } Guess further, there is some function that returns an object of that class: public static A someFn(x,y,z); Now the problem: I want to derive from that class to add some functionality. Unfortunately, i neither have a sizeof in java nor a cc or static copy method. So when i do a class B extends A { protected w; public B clone() { /* as usual */ } } then i can clone my B and get a new one, but how can i convert the returned A from someFn() into a B. Is there anyway to do the opposite of slicing in java? if i clone it, it's still an A, and i cant copy it field by field. This is all simple in c++, but how to do this in Java?

    Read the article

  • Javascript instanceof & typeof in GWT (JSNI)

    - by rybz
    Hi, I've encountered an curious problem while trying to use some objects through JSNI in GWT. Let's say we have javscript file with the function defined: test.js: function test(arg){ var type = typeof(arg); if (arg instanceof Array) alert('Array'); if (arg instanceof Object) alert('Object'); if (arg instanceof String) alert('String'); } And the we want to call this function user JSNI: public static native void testx()/ *-{ $wnd.test( new Array(1, 2, 3) ); $wnd.test( [ 1, 2, 3 ] ); $wnd.test( {val:1} ); $wnd.test( "Some text" ); }-*/; The questions are: why instanceof instructions will always return false? why typeof will always return "object" ? how to pass these objects so that they were recognized properly?

    Read the article

  • django m2m how can i get m2m table elements in a view

    - by dana
    i have a model using m2m feature: class Classroom(models.Model): user = models.ForeignKey(User, related_name = 'classroom_creator') classname = models.CharField(max_length=140, unique = True) date = models.DateTimeField(auto_now=True) open_class = models.BooleanField(default=True) members = models.ManyToManyField(User,related_name="list of invited members", through = 'Membership') and i want to take all members of one class in a view and display them using the template system. In the view, i'm trying to take all the members from a classroom like that: def inside_classroom(request,classname): try: theclass = Classroom.objects.get(classname = classname) members = Members.objects.all() etc but it doesn't work,(though the db_table is named Classroom_Members) i guess i have to use another query for getting all the members from the classroom classname. also, i want to verify if the request.user is a member using (if request.user in members) how can i het those members? Thanks in advance!

    Read the article

  • More strict query yields more results?

    - by Mark
    I've got a query that looks like this affiliates = User.objects.annotate(referral_count=Count('referrals')).filter(referral_count__gt=0) But when I restrict it more by adding referrals__user__date_joined__gt=start_date to the filter, I get even higher referral counts. I'm trying to count the number of people a user has referred within a time period. The relevant model looks like this: class Profile(models.Model): user = models.ForeignKey(User, unique=True, related_name='profile') referred_by = models.ForeignKey(User, null=True, blank=True, related_name='referrals') In contrast, when I try it like this: affiliates = User.objects \ .exclude(referrals__user__date_joined__lte=sd, referrals__user__date_joined__gt=ed) \ .annotate(referral_count=Count('referrals')) \ .filter(referral_count__gt=0) The exclude statement seems to do nothing... the counts don't change (should be 0 if no referred users have joined within that time period, but it isn't).

    Read the article

  • What is the best way to interoperably serialize a message?

    - by iwein
    I'm considering message serialization support for spring-integration. This would be useful for various wire level transports to implement guaranteed delivery, but also to allow interoperability with other messaging systems (e.g. through AMQP). The fundamental problem that arises is that a message containing Java object in it's payload and headers should be converted to a byte[] and/or written to a stream. Java's own serialization is clearly not going to cut it because that is not interoperable. My preference would be to create an interface that allows the user to implement the needed logic for all Objects that take part in serialization. Is this a sensible idea and what would the interface look like? Is there a standard interoperable way to serialize Objects that would make sense in this context?

    Read the article

  • How to expose an entity via alternate keys with spring data rest

    - by dan carter
    Spring-data-rest does a great job exposing entities via their primary key for GET, PUT and DELETE etc. operations. /myentityies/123 It also exposes search operations. /myentities/search/byMyOtherKey?myOtherKey=123 In my case the entities have a number of alternate keys. The systems calling us, will know the objects by these IDs, rather than our internal primary key. Is it possible to expose the objects via another URL and have the GET, PUT and DELETE handled by the built-in spring-data-rest controllers? /myentities/myotherkey/456 We'd like to avoid forcing the calling systems to have to make two requests for each update. I've tried playing with @RestResource path value, but there doesn't seem to be a way to add additional paths.

    Read the article

  • How to manually manage Core Data relationships when deleting

    - by Simon
    I have a Core Data entity, which contains a relationship to another entity. Under certain circumstances, I need to delete the managed objects in the relationship, and at other times no action needs to be taken. I have the Delete Rule on the entity is No Action because of this manual management. The problem I have is, where is the best place to enforce these rules? I cannot see any suitable messages to override on NSManagedObject (something that might notify the object it has been deleted and should clear up its relationships). I would rather not do it higher up in the application logic, because the entity objects can get deleted from array controllers and at different points in the applications, making it necessary to stuff relationship update code at all those levels.

    Read the article

  • how to wrap a function that only takes individual elements to make it take a list

    - by stevejb
    Hello, Say I have a function handed to me that I cannot change and must use as is. This function takes several objects in the form of oldFunction( object1, object2, object3, ...) where ... are other arguments. I want to write a wrapper to take a list of objects. My idea was this. sjb.ListWrapper <- function(myList,...) { lLen <- length(myList) myStr <- "" for( i in 1:lLen) { myStr <- paste(myStr, "myList[[", i , "]],",sep="") } myCode <- paste("oldFunction(", myStr, "...)") eval({myCode}) } However, the issue is that I want to use this from Sweave and I need the output of oldFunction to be printed. What is the right way to do this? Thanks.

    Read the article

  • How to analyse contents of binary serialization stream?

    - by Tao
    I'm using binary serialization (BinaryFormatter) as a temporary mechanism to store state information in a file for a relatively complex (game) object structure; the files are coming out much larger than I expect, and my data structure includes recursive references - so I'm wondering whether the BinaryFormatter is actually storing multiple copies of the same objects, or whether my basic "number of objects and values I should have" arithmentic is way off-base, or where else the excessive size is coming from. Searching on stack overflow I was able to find the specification for Microsoft's binary remoting format: http://msdn.microsoft.com/en-us/library/cc236844(PROT.10).aspx What I can't find is any existing viewer that enables you to "peek" into the contents of a binaryformatter output file - get object counts and total bytes for different object types in the file, etc; I feel like this must be my "google-fu" failing me (what little I have) - can anyone help? This must have been done before, right??

    Read the article

  • Python: Repeat elements in a list comprehension?

    - by User
    I have the following list comprehension which returns a list of coordinate objects for each location. coordinate_list = [Coordinates(location.latitude, location.longitude) for location in locations] This works. Now suppose the location object has a number_of_times member. I want a list comprehension to generate n Coordinate objects where n is the number_of_times for the particular location. So if a location has number_of_times = 5 then the coordinates for that location will be repeated 5 times in the list. (Maybe this is a case for a for-loop but I'm curious if it can be done via list comprehensions)

    Read the article

  • Ruby efficient way of building an array from an array of arrays

    - by randombits
    I have an array of ActiveRecord objects, each one which has its own respective errors array. I want to flatten it all out and get only the unique values into one array. So the top level array might look like: foo0 = Foo.new foo1 = Foo.new foo2 = Foo.new foo3 = Foo.new arr = [foo0, foo1, foo2, foo3] Each one of those objects could potentially have an array of errors, and I'd like to get just the unique message out of them and put them in another array, say called error_arr. How would you do it the "Ruby" way?

    Read the article

  • Sharepoint: How to obtain the current site/web/list properly

    - by driAn
    Hi all What is the best way to obtain the current site/web/list ? Option 1 - Reusing existing objects SPSite site = SPContext.Current.Site; SPweb web = SPContext.Current.Web; SPList list = SPContext.Current.List; Option 2 - Creating new objects SPSite site = new SPSite(SPContext.Current.Site.ID); // dispose me SPweb web = site.OpenWeb(SPContext.Current.Web.ID); // dispose me SPList list = web.Lists[SPContext.Current.List.ID]; I experienced problems when using option 1 in some situations. Since then I chose the 2nd option and it worked fine so far. What is your opinion on this? I is generally better to go with option 2? Other suggestions?

    Read the article

  • What explains the term orthogonal in a more non-nerd fashion?

    - by dontWatchMyProfile
    For example: Cardinality and optionality are orthogonal properties of a relationship. You can specify that a relationship is optional, even if you have specified upper and/or lower bounds. This means that there do not have to be any objects at the destination, but if there are then the number of objects must lie within the bounds specified. What exactly does "orthogonal" mean? I bet it's just a fancy soundig nerd-style word for something that could be expressed a lot easier to understand for average people ;) From wikipedia: In mathematics, two vectors are orthogonal if they are perpendicular, i.e., they form a right angle. The word comes from the Greek ????? (orthos), meaning "straight", and ????a (gonia), meaning "angle". Anyone?

    Read the article

  • FileInputStream for a generic file System

    - by Akhil
    I have a file that contains java serialized objects like "Vector". I have stored this file over Hadoop Distributed File System(HDFS). Now I intend to read this file (using method readObject) in one of the map task. I suppose FileInputStream in = new FileInputStream("hdfs/path/to/file"); wont' work as the file is stored over HDFS. So I thought of using org.apache.hadoop.fs.FileSystem class. But Unfortunately it does not have any method that returns FileInputStream. All it has is a method that returns FSDataInputStream but I want a inputstream that can read serialized java objects like vector from a file rather than just primitive data types that FSDataInputStream would do. Please help!

    Read the article

  • SForceAPI : unable to find classes listed on API? (Account, Contact, etc)

    - by Firefox
    Hi, API referred : http://www.salesforce.com/us/developer/docs/api/index.htm subsection: reference-standard objects Client side details : partner.wsdl, Axis2 1.5, generated stubs using unpacked option (-u). I was hoping to find some basic objects like Account, Contact, etc (which were listed on above url) so that I can do something like - SObject[] sObjArray = queryResult.getRecords(); for(SObject sObj : sObjArray){ Account acc = [Account] sObj; } [used above approach successfully in another webservice - 'Zuora'] However, I could not find Account class in the generated classes. I guess I am into wrong approach, but atleast I should be finding the classes listed in the reference API. Please help.

    Read the article

  • Best practices for extending third party databases?

    - by Eric Watkins
    I have a situation where our developers extended a Third party database (MS SQL) by adding tables, views, stored procedures, and functions. Recently when the vender issued updates to the database they dropped all of our custom objects. The question now is what are some best practices that will allow us to extend the third party database but keep our objects safe from future updates? My first thought is to create a separate database but then I’m stuck with fully qualifying all the references back to the original database which may cause issues promoting database changes from test to production.

    Read the article

< Previous Page | 304 305 306 307 308 309 310 311 312 313 314 315  | Next Page >