Search Results

Search found 31721 results on 1269 pages for 'adjacency list'.

Page 555/1269 | < Previous Page | 551 552 553 554 555 556 557 558 559 560 561 562  | Next Page >

  • Using an initializer_list on a map of vectors

    - by Hooked
    I've been trying to initialize a map of <ints, vector<ints> > using the new 0X standard, but I cannot seem to get the syntax correct. I'd like to make a map with a single entry with key:value = 1:<3,4 #include <initializer_list> #include <map> #include <vector> using namespace std; map<int, vector<int> > A = {1,{3,4}}; .... It dies with the following error using gcc 4.4.3: error: no matching function for call to std::map<int,std::vector<int,std::allocator<int> >,std::less<int>,std::allocator<std::pair<const int,std::vector<int,std::allocator<int> > > > >::map(<brace-enclosed initializer list>) Edit Following the suggestion by Cogwheel and adding the extra brace it now compiles with a warning that can be gotten rid of using the -fno-deduce-init-list flag. Is there any danger in doing so?

    Read the article

  • How to mock/stub a directory of files and their contents using RSpec?

    - by John Topley
    A while ago I asked "How to test obtaining a list of files within a directory using RSpec?" and although I got a couple of useful answers, I'm still stuck, hence a new question with some more detail about what I'm trying to do. I'm writing my first RubyGem. It has a module that contains a class method that returns an array containing a list of non-hidden files within a specified directory. Like this: files = Foo.bar :directory => './public' The array also contains an element that represents metadata about the files. This is actually a hash of hashes generated from the contents of the files, the idea being that changing even a single file changes the hash. I've written my pending RSpec examples, but I really have no idea how to implement them: it "should compute a hash of the files within the specified directory" it "shouldn't include hidden files or directories within the specified directory" it "should compute a different hash if the content of a file changes" I really don't want to have the tests dependent on real files acting as fixtures. How can I mock or stub the files and their contents? The gem implementation will use Find.find, but as one of the answers to my other question said, I don't need to test the library. I really have no idea how to write these specs, so any help much appreciated!

    Read the article

  • Serializing a class containing a custom class

    - by Netfangled
    I want to serialize an object as xml that contains other custom classes. From what I understand (I've been reading MSDN and SO mostly), the XmlSerializer doesn't take this into account. This is the line that's confusing me: XML serialization serializes only the public fields and property values of an object into an XML stream. XML serialization does not include type information. For example, if you have a Book object that exists in the Library namespace, there is no guarantee that it will be deserialized into an object of the same type. Taken from MSDN, here For example, I want to serialize an object of type Order, but it contains a list of Products, and each one contains an object of type Category: class Order { List<Product> products; } class Product { Category type; } class Category { string name; string description; } And I want my Order object to be serialized like so: <Order> <Product> <Category Name=""> <Description></Description> </Category> </Product> <Product> <Category Name=""> <Description></Description> </Category> </Product> <Order> Does the XmlSerializer already do this? If not, is there another class that does or do I have to define the serialization process myself?

    Read the article

  • Web Applications Development: Security practices for Application design

    - by Shyam
    Hi, As I am creating more web applications that are targeted for multiple users, I figured out that I have to start thinking about user management and security. At a glance and in my ideal world, all users belong to a group. Permissions and access is thus defined per group (and inherited by the users of that group). Logically, I have my group of administrators, which are identified with a level "7" (integer) clearance. A group of webusers have for example level "1". This in generally all works great for me, but I need some kind of list that I have to keep in mind how I secure my system, and some general practices. I am not looking for a specific environment; I want to learn the why's and how's. An example is privilege escalation. If someone would be able to "push" themselves inside a group with higher privileges, for example the Administration, how can I prevent this, or what measures should I take to have some sort of precaution? I don't like in that case to walk into a caveat. My question is basically: where can I find a good resource, list, policy, book that explains the security of web applications, the why's, the how's and readable if you don't have any experience in the realm of advanced security? I prefer a free resource, as I believe I couldn't be the first one who thought about this. Thank you for your answers, comments and feedback.

    Read the article

  • Nhibernate, can i improve my MAPPING or Query

    - by dbones
    take this simple example A staff class which references other instances of the staff class public class Staff { public Staff() { Team = new List<Staff>(); } public virtual int Id { get; set; } public virtual string Name { get; set; } public virtual IList<Staff> Team { get; set; } public virtual Staff Manager { get; set; } } The Fluent Mapping public class StaffMap : ClassMap<Staff> { public StaffMap() { Id(x => x.Id); Map(x => x.Name); References(x => x.Manager).Column("ManagerId"); HasMany(x => x.Team).KeyColumn("ManagerId").Inverse(); } } Now I want to run a query, which will load all the Staff and eager load the manager and Team members. This is what I came up with IList<Staff> resutls = session.CreateCriteria<Staff>() .SetFetchMode("Team", FetchMode.Eager) .SetResultTransformer(Transformers.DistinctRootEntity) .List<Staff>(); however the SQL (does what i want) has duplicate columns, 2 team2_.ManagerId and 2 team2_.Id SELECT this_.Id as Id0_1_, this_.Name as Name0_1_, this_.ManagerId as ManagerId0_1_, team2_.ManagerId as ManagerId3_, team2_.Id as Id3_, team2_.Id as Id0_0_, team2_.Name as Name0_0_, team2_.ManagerId as ManagerId0_0_ FROM [SelfRef].[dbo].[Staff] this_ left outer join [SelfRef].[dbo].[Staff] team2_ on this_.Id=team2_.ManagerId The question is, should this be happening? did i do something wrong in the query or map? or is it a feature of the HHib im using (which is Version 2.1.0.4000)? many thanks in advance

    Read the article

  • The right approach to loading dynamic content into a UITableView in iOS

    - by OS.
    ok, I've read tons of bits and pieces on the subject of loading dynamic content (from the web) into a UITableView and the problem with calculating cell height upfront. I've tried different simple implementations but the problem persists... Assuming I need to read a JSON file from the web, parse it into 'item' objects, each with variable size image and various text labels, here is what I believe would be the right approach to avoid long hang time of the app while everything is loading: on app load read JSON file and parse into items array provide only small part of the items array to the tableview (about 10 items) - since I need to load the images associated with each item to calculate cell height - I don't want the view to go through the whole items list and load all images - this hangs the app until every image is loaded display the tableview with the available cells (assuming I load a few 'spare' ones, user can even scroll to more items) in the background using Grand Central Dispatch download images for all/some of the remaining items and then reload the tableview with the new data (repeat step 4 if item list is very long) Step 2 above is necessary since I have no way to calculate the cell height without loading the images first, and since tableview first calculates height of all cells it may take a very long time to download all images for all items. Would you say this is the right approach? am I missing something?

    Read the article

  • Div appearing outside its parent, bizarre sizing problems...

    - by SLC
    I have a list, which is going to be a menu. I want to position it absolutely at the very top of the page. My code looks like this: <div id="sitenavmenu"> <div id="sitenavmenu-content"> <ul id="sitenavmenu-content-menu"> <li>Register</li> <li><%: Html.ActionLink("About", "About", "Home")%></li> <li>Contact Us</li> </ul> </div> </div> My CSS looks like this: #sitenavmenu { position:absolute; margin-left:300px; top:2px; width:500px; } #sitenavmenu-content-menu li { list-style-type:none; display:inline; padding-right:5px; font-size:small; } The problem I have is, if I don't position it absolutely, it looks fine. As soon as I position it absolutely (as it is shown above), the sitenavmenu div changes size, and although it shifts to the top, the sitenavmenu-content div appears below it. There is no other CSS as I have only just started, and I have checked padding etc. and everything is zero. I just can't figure out why it's not working, and I don't want to hack it. Edit: It's something to do with the height of #sitenavmenu. If I leave it, then the sitenav-content ends up horizontally centered in it, although #sitenavmenu is much taller. If I make them both the same size, so they should sit on top of each other, then the #sitenavmenu-content sits below.

    Read the article

  • WCF data services - Limiting related objects returned based on critera

    - by Mike Morley
    I have an object graph consisting of a base employee object, and a set of related message objects. I am able to return the employee objects based on search criteria on the employee properties (eg team) etc. However, if I expand on the messages, I get the full collection of messages back. I would like to be able to either take the top n messages (i.e. restrict to 10 most recent) or ideally use a date range on the message objects to limit how many are brought back. So far I have not been able to figure out a way of doing this: I get an error if I attempt to filter on properties on the message (&$filter=employee/message/StartDate gives an error "No property 'StartDate' exists in type 'System.Data.Objects.DataClasses.EntityCollection`1). Attempting to use Top on the message related object doesn't work either. I have also tried using a WebGet extension that takes a string list of employee IDs. That works until the list gets too long, and then fails due to the URL getting too long (it might be possible to setup a paging mechanism on this approach)... Unfortunately the UI control I am using requires the data to be in a fairly specific hierarchical shape, so I can't easily come at this from starting on the message side and working backwards. Outside of making multiple calls does anyone know of a method to accomplish this with wcf data services? Thanks! M.

    Read the article

  • EFv1 mapping 1 to many Relationship to POCOs

    - by Scott
    I'm trying to work through a problem where I'm mapping EF Entities to POCO which serve as DTO. I have two tables within my database, say Products and Categories. A Product belongs to one category and one category may contain many Products. My EF entities are named efProduct and efCategory. Within each entity there is the proper Navigation Property between efProduct and efCategory. My Poco objects are simple public class Product { public string Name { get; set; } public int ID { get; set; } public double Price { get; set; } public Category ProductType { get; set; } } public class Category { public int ID { get; set; } public string Name { get; set; } public List<Product> products { get; set; } } To get a list of products I am able to do something like public IQueryable<Product> GetProducts() { return from p in ctx.Products select new Product { ID = p.ID, Name = p.Name, Price = p.Price ProductType = p.Category }; } However there is a type mismatch error because p.Category is of type efCategory. How can I resolve this? That is, how can I convert p.Category to type Category? I know in .NET EF has added support for POCO, but I'm forced to use .NET 3.5 SP1.

    Read the article

  • Problem with Google Calendar API "getTimes()" method

    - by Raffo
    I'm trying to get several informations from google calendar's API in JAVA. While trying to access to informations about the time of an event I got a problem. I do the following: CalendarService myService = new CalendarService("project_name"); myService.setUserCredentials("user", "pwd"); URL feedUrl = new URL("http://www.google.com/calendar/feeds/default/private/full"); CalendarQuery q = new CalendarQuery(feedUrl); CalendarEventFeed resultFeed = myService.query(q, CalendarEventFeed.class); for (int i = 0; i < resultFeed.getEntries().size(); i++) { CalendarEventEntry g = resultFeed.getEntries().get(i); List<When> t = g.getTimes(); //other operations } The list t obtained with getTimes() on a CalendarEventEntry is always empty and I can't figure out why. This seems strange to me since for a calendar event it should always exist a description of when it should happen... what am I missing??

    Read the article

  • Pass view to viewmodel with datatemplate

    - by jpsstavares
    I have a ParameterView and ParameterViewModel, and I need the ParameterViewModel to have a reference to the Parameter view (more on that later). In the window I have a list of ParameterViewModels and in the ResourceDictionary I add the DataTemplate: <DataTemplate DataType="{x:Type my:ParameterViewModel}" > <my:ParameterView HorizontalAlignment="Left"/> </DataTemplate> I then bind an ItemsControl.ItemSource to the List of ParameterViewModels The problem is: How can I pass the ParameterView to the ParameterViewModel in this scenario? The reason I need the ParameterView in the ParameterViewModel is the following: I have a TextBox whose Text property is binded to the PropertyModelView.Name property. But I want to display a default string when the Name is empty or Null. I've tried to set the property value to the default string I want when that happens but the TextBox.Text is not set in this scenario. I do something like this: private string _name; public string Name { get { return _name; } set { if (value == null || value.Length == 0) Name = _defaultName; else _name = value; } } I've also tried to specifically set the TextBox.Text binding mode to TwoWay without success. I think this is a defense mechanism to prevent an infinite loop from happening but I don't know for sure. Any help on this front would also be highly appreciated. Thanks, José Tavares

    Read the article

  • Android debug mode not working waiting for device

    - by Blue42
    I'm trying to get my android phone working to run apps from inside an IDE. Got it working on windows no problem, currently working in fedora (18) a lot though so wanted to get it working with that. Got IntelliJ and android sdk installed, problem is when I try to run the default hello world app it wont work it just says waiting for device.. Ran adb devices got List of devices attached ???????????? no permissions Leads me to believe the driver isn't installed? Phone I'm using is a HTC Sensation. Does anyone know what I can do to try and resolve it? The HTC web page doesn't offer me drivers to install. Also noticed in /etc/udev/rules.d/..android.rules there is nothing about Sensation. Seems it recognises my nexus 7 though.. Edit: Tried my nexus.. got List of devices attached 901839238298923 offline So it doesn't even work with that.. confusing.. Any help would be appreciated. Thanks, B

    Read the article

  • ASP.net MVC3 howto edit sql database

    - by user1662380
    MovieStoreEntities MovieDb = new MovieStoreEntities(); public ActionResult Edit(int id) { //var EditMovie1 = MovieDb AddMovieModel EditMovie = (from M in MovieDb.Movies from C in MovieDb.Categories where M.CategoryId == C.Id where M.Id == id select new AddMovieModel { Name = M.Name, Director = M.Director, Country = M.Country, categorie = C.CategoryName, Category = M.CategoryId }).FirstOrDefault(); //AddMovieModel EditMovie1 = MovieDb.Movies.Where(m => m.Id == id).Select(m => new AddMovieModel {m.Id }).First(); List<CategoryModel> categories = MovieDb.Categories .Select(category => new CategoryModel { Category = category.CategoryName, id = category.Id }) .ToList(); ViewBag.Category = new SelectList(categories, "Id", "Category"); return View(EditMovie); } // // POST: /Default1/Edit/5 [HttpPost] public ActionResult Edit(AddMovieModel Model2) { List<CategoryModel> categories = MovieDb.Categories .Select(category => new CategoryModel { Category = category.CategoryName, id = category.Id }) .ToList(); ViewBag.Category = new SelectList(categories, "Id", "Category"); if (ModelState.IsValid) { //MovieStoreEntities model = new MovieStoreEntities(); MovieDb.SaveChanges(); return View("Thanks2", Model2); } else return View(); } This is the Code that I have wrote to edit Movie details and update database in the sql server. This dont have any compile errors, But It didnt update sql server database.

    Read the article

  • Creating Modules for VB Program (Similar to firefox add on)

    - by Assimilater
    Hi all. I have a contact manager program that I'd like to design for multiple network marketing companies. My desired structure would include a core program which covers basic contact management functions. After that one could purchase a module for their specific network marketing company. This module would contain a variety of controls that the original program would need to be able to manipulate. Here is an example of what it would have to have: A group box containing buttons that link to a genealogy view, and the option to import one's donwnline from the back office provided by a company. A panel which is displayed on the contact page allowing the user to input business information or which will be filled by importing a downline from the back office: ie business ID, qualification level, sponsor information etc. a panel displayed when one searches for contacts on the contact list page which allows the user to sort based on information such as when they joined, what their business id is and so forth. a panel which is displayed in a personal business overview page which presents to an individual how many people in their downline are at each qualification level and develop a mailing list for individuals of a certain qualification level. I have the code developed to perform all these functions, I just wanted to give you an example of what needed to be done. I'm thinking that what I'm trying to create is a library that one can download and the program will recognize, but I'm not really sure where to go. What I'm really trying to do is figure out what kind of file I can make that will contain all this code and the GUI information that the program will recognize. Any ideas? With thanks, John

    Read the article

  • IPhone - Memory Management problems.

    - by user321721
    i am going over my code and trying to get a handle on proper memory management. This code: imageView = [[[UIImageView alloc] initWithImage:myImage] autorelease]; causes my application to crash. I am using multiple view controllers within a nav bar controller. The app works fine, i cant select a person from the first view controller (tableview) and it puts me to a list of that persons photos, i can then select a photo from that view controller (tableview) and move to a final view with a scrollview for viewing the photo. Once i hit back on the navbar the previous view loads (list of photos in a tableview) however the app crashes right before the row is deselected using this code: (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; if(RowSelected != nil) { [MainTableView deselectRowAtIndexPath:RowSelected animated:YES]; } } Row selected is stored when a the user clicks a row. If i leave the code as : imageView = [[UIImageView alloc] initWithImage:myImage]; The app runs fine. Am i doing something wrong? do i not need to autorelease this? Thanks!

    Read the article

  • Comparison of Java and .NET technologies/frameworks

    - by Paul Sasik
    I work in a shop that is a mix of mostly Java and .NET technologists. When discussing new solutions and architectures we often encounter impedance in trying to compare the various technologies, frameworks, APIs etc. in use between the two camps. It seems that each camp knows little about the other and we end up comparing apples to oranges and forgetting about the bushels. While researching the topic I found this: Java -- .Net rough equivalents It's a nice list but it's not quite exhaustive and is missing the key .NET 3.0 technologies and a few other tidbits. To complete that list: what are the near/rough equivalents (or a combination of technologies) in Java to the following in .NET? WCF WPF Silverlight = JavaFx WF = jBMP (Java Business Process Management) Generics Lambda expressions = lambdaJ project or Closures Linq (not Linq-to-SQL) ...have i missed anything else? Note that I omitted technologies that are already covered in the linked article. I would also like to hear feedback on whether the linked article is accurate. Thanks. (Will CW if requested.)

    Read the article

  • overflow auto not working in IE

    - by Anthony Russo
    First off I have read a couple of q and a's on here about this issue but none of them seem to help. I have a couple other pages on the website that have no problems with resizing to height using overflow auto. The thing I have noticed is the pages work fine with one div. The page that is not working has two or more div and also I have tried it with a container but I still get the vertical and horizontal scroll bars. <div class="content"> <div class="container"> <div class="a"> <div class="left">List Items</div> <div class="right">List Items</div> </div> <div class="b"> This div is a FORM. </div> </div> </div> I could be making a simple error to you guys but I am new so bare with me!

    Read the article

  • GWT + JDO + ArrayList

    - by dvieira
    Hi, I'm getting a Null ArrayList in a program i'm developing. For testing purposes I created this really small example that still has the same problem. I already tried diferent Primary Keys, but the problem persists. Any ideas or suggestions? 1-Employee class @PersistenceCapable(identityType = IdentityType.APPLICATION) public class Employee { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true") private String key; @Persistent private ArrayList<String> nicks; public Employee(ArrayList<String> nicks) { this.setNicks(nicks); } public String getKey() { return key; } public void setNicks(ArrayList<String> nicks) { this.nicks = nicks; } public ArrayList<String> getNicks() { return nicks; } } 2-EmployeeService public class BookServiceImpl extends RemoteServiceServlet implements EmployeeService { public void addEmployee(){ ArrayList<String> nicks = new ArrayList<String>(); nicks.add("name1"); nicks.add("name2"); Employee employee = new Employee(nicks); PersistenceManager pm = PMF.get().getPersistenceManager(); try { pm.makePersistent(employee); } finally { pm.close(); } } /** * @return * @throws NotLoggedInException * @gwt.typeArgs <Employee> */ public Collection<Employee> getEmployees() { PersistenceManager pm = getPersistenceManager(); try { Query q = pm.newQuery("SELECT FROM " + Employee.class.getName()); Collection<Employee> list = pm.detachCopyAll((Collection<Employee>)q.execute()); return list; } finally { pm.close(); } } }

    Read the article

  • Get information from WebPage.

    - by william-hu
    I want to set up an app which can get the information from a particular web page. Then i display the value which got from that page to the iPhone user. Detail:In the webpage on server ,there is the schedule for bus time. If the user input origin and terminus then show the user the time information(list on webpage) in a label. That's all. What i have finished is : Open the iphone app, input two value(origin and terminus) to UITextField. Send the URL to server. Get the page, and show in UIWebView. What my problem next is how should i get the information form that page into another two labels to give the user about the bus time. I have store data in my Array receiveData: self.receivedData = data; I am not clear the data i received is XML or what? And how should i pick-up the value i want. (should i save the value to property list and the read the value?) Thank you so much!

    Read the article

  • mootools event listener disappears after element.innerHTML is changed

    - by baiano
    I putting together a page that will display a set of stored values. I am using mootools and AJAX calls to update the values without needing to refresh the page each time the user selects a new item from the drop down menus. the HTML each line looks something like: <div class="selections"> <input class="checkbox selector" type="checkbox" CHECKED /> <span class="b_name"> <select class="b_n selector"> <!-- options --> </select> </span> <span class="b_level"> <select class="b_l selector"> <!-- options --> </select> </span> <span class="values"> <!-- the values --> </span> In the head I have set up an event listener like: $$('.selector').addEvent('change', function(event){changeValues(this);}); My problem is that when the "b_name" select changes I have to update the list of options in the "b_level" select. I accomplish that by getting a list of the possible options from my database through a php script on another page and replacing "b_level"'s innerHTML. Once I do that, the event listener attached to "b_l selector" no longer works. I tried to resolve this issue by explicitly attaching an event listener to "b_l selector" each time "b_name" changes like so: row.getElement('.b_l').addEvent('change', function(event){changeValues(row.getElement('.b_l'));}); where 'row' is the html element 'div.selections'. It still isn't working and I have no idea what's going on. Can anyone offer a suggestion as to how I can get this resolved? or perhaps a better way to do what I'm doing. Thanks

    Read the article

  • App Engine - Query using a class member as parameter

    - by Zach
    I have a simple class, relevant details below: @PersistenceCapable(identityType = IdentityType.APPLICATION) public class SimpleCategory implements Serializable{ ... public static enum type{ Course, Category, Cuisine } @Persistent public type t; ... } I am attempting to query all SimpleCategory objects of the same type. public SimpleCategory[] getCategories(SimpleCategory.type type) { PersistenceManager pm = PMF.get().getPersistenceManager(); try{ Query q = pm.newQuery(SimpleCategory.class); q.setFilter("t == categoryType"); q.declareParameters("SimpleCategory.type categoryType"); List<SimpleCategory> cats = (List<SimpleCategory>) q.execute(type); ... } This results in a ClassNotResolvedException for SimpleCategory.type. The google hits I've found so far recommended to: Use query.declareImports to specify the class i.e. q.declareImports("com.test.zach.SimpleCategory.type"); Specify the fully qualified name of SimpleCategory in declareParameters Neither of these suggestions has worked. By removing .type and recompiling, I can verify that declareParameters can see SimpleCategory just fine, it simply cannot see the SimpleCategory.type, despite the fact that the remainder of the method has full visibility to it. What am I missing?

    Read the article

  • SEO - Does google+other search engines index links within <noscript> tags?

    - by Joe
    I have setup some dropdown menus allowing users to find pages on my website by selecting options across multiple dropdowns: eg. Color of Car, Year This would generate a link like: mysite.xyz/blue/2010/ The only problem is, because this link is dynamically assembled with Javascript, I've also had to assemble each possible combination from the dropdowns into a list like: <noscript> No javascript enabled? Here are all the links: <a href='mysite.xyz/blue/2009/'>mysite.xyz/blue/2009/</a> <a href='mysite.xyz/blue/2010/'>mysite.xyz/blue/2010/</a> <a href='mysite.xyz/red/2009/'>mysite.xyz/red/2009/</a> <a href='mysite.xyz/red/2010/'>mysite.xyz/red/2010/</a> </noscript> My question is, if I put these in a tag like this, will I be penalized or anything by search engines such as Google? I've already been doing so for some navigational stuff which required offsets etc. However, now I would be listing a whole list of links here too. I want to provide them here, moreso so that google can actually index my pages - but for those without javascript, they can still navigate too. Your thoughts? Also.. even though I have some links that appear to have been indexed, I AM NOT 100% SURE, which is why I'm asking :P

    Read the article

  • display flex xml with dash

    - by user217582
    In Flex, how do I display "midi-channel" to s:Label? I tried songTitle.text = mainXML.child("movement-title").text(); it worked but unsure how to display for midi-channel part. <score-partwise> <movement-title>zsdf</movement-title> <part-list> <score-part id="P1"> <part-name>Piano</part-name> <score-instrument id="P1-I1"> <instrument-name>Acoustic Grand Piano</instrument-name> </score-instrument> <midi-instrument id="P1-I1"> <midi-channel>1</midi-channel> <midi-program>1</midi-program> </midi-instrument> </score-part> </part-list>

    Read the article

  • Immutability and shared references - how to reconcile?

    - by davetron5000
    Consider this simplified application domain: Criminal Investigative database Person is anyone involved in an investigation Report is a bit of info that is part of an investigation A Report references a primary Person (the subject of an investigation) A Report has accomplices who are secondarily related (and could certainly be primary in other investigations or reports These classes have ids that are used to store them in a database, since their info can change over time (e.g. we might find new aliases for a person, or add persons of interest to a report) If these are stored in some sort of database and I wish to use immutable objects, there seems to be an issue regarding state and referencing. Supposing that I change some meta-data about a Person. Since my Person objects immutable, I might have some code like: class Person( val id:UUID, val aliases:List[String], val reports:List[Report]) { def addAlias(name:String) = new Person(id,name :: aliases,reports) } So that my Person with a new alias becomes a new object, also immutable. If a Report refers to that person, but the alias was changed elsewhere in the system, my Report now refers to the "old" person, i.e. the person without the new alias. Similarly, I might have: class Report(val id:UUID, val content:String) { /** Adding more info to our report */ def updateContent(newContent:String) = new Report(id,newContent) } Since these objects don't know who refers to them, it's not clear to me how to let all the "referrers" know that there is a new object available representing the most recent state. This could be done by having all objects "refresh" from a central data store and all operations that create new, updated, objects store to the central data store, but this feels like a cheesy reimplementation of the underlying language's referencing. i.e. it would be more clear to just make these "secondary storable objects" mutable. So, if I add an alias to a Person, all referrers see the new value without doing anything. How is this dealt with when we want to avoid mutability, or is this a case where immutability is not helpful?

    Read the article

  • What could trigger a change of http status to 500 on the client's end?

    - by VexedPanda
    We have a PHP web application that posts data to itself, and either displays an updated page based on that data, or redirects to another page. An example of this is a script with a paged list on it, where clicking on the Next link causes a post to the same page, which then returns an updated version of the page showing the new set of list items. One client is reporting that IE is displaying friendly error messages when the page updates itself instead of the correct behavior of displaying the updated page. Turning friendly error messages off "corrects" this problem, and displays the updated page normally, indicating no actual server error occurred. When testing from any location other than this client's our web app does not produce any http error statuses, and in this specific situation only produces 200 statuses. (According to Fiddler.) What could be interfering with the HTTP POST and changing the response's http status code to 500 (or another code that would trigger friendly errors in IE)? Are there certain proxies or other network tools that could be misconfigured or buggy in this manner? Is there any way we can alter our application (apart from avoiding posts to the same script, which is not feasible) to get around this misbehavior?

    Read the article

< Previous Page | 551 552 553 554 555 556 557 558 559 560 561 562  | Next Page >