Search Results

Search found 17041 results on 682 pages for 'architecture and design'.

Page 290/682 | < Previous Page | 286 287 288 289 290 291 292 293 294 295 296 297  | Next Page >

  • In Java how instance of and type cast(i.e (ClassName)) works on proxy object ?

    - by learner
    Java generates a proxy class for a given interface and provides the instance of the proxy class. But when we type cast the proxy object to our specific Object, how java handles this internally? Is this treated as special scenario? For example I have class 'OriginalClass' and it implements 'OriginalInterface', when I create proxy object by passing 'OriginalInterface' interface java created proxy class 'ProxyClass' using methods in the provided interface and provides object of this class(i.e ProxyClass). If my understanding is correct then can you please answer following queries 1) When I type cast object of ProxyClass to my class OriginalClass this works, but how java is allowing this? Same in case of instace of? 2) As my knowledge java creates a proxy class only with the methods, but what happen when I try to access attributes on this object? 3) Only interface methods are getting implemented in Proxy, but what happens when I try to access a method which not in interface and only mentioned in the class? Thanks, Student

    Read the article

  • Should we avoid to use Object as the input parameter/ output value of a method?

    - by developer.cyrus
    Take Java syntax as an example, though the question itself is language independent. If the following snippet takes an object MyAbstractEmailTemplate as input argument in the method setTemplate, the class MyGateway will then become tightly-coupled with the object MyAbstractEmailTemplate, which lessens the re-usability of the class MyGateway. A compromise is to use dependency-injection to ease the instantiation of MyAbstractEmailTemplate. This might solve the coupling problem to some extent, but the interface is still rigid, hardly providing enough ?exibility to other developers/ applications. So if we only use primitive data type (or even plain XML in web service) as the input/ output of a method, it seems the coupling problem no longer exists. So what do you think? public class MyGateway { protected MyAbstractEmailTemplate template; publoc void setTemplate(MyAbstractEmailTemplate template) { this.template = template; } }

    Read the article

  • Can I use the decorator pattern to wrap a method body?

    - by mgroves
    I have a bunch of methods with varying signatures. These methods interact with a fragile data connection, so we often use a helper class to perform retries/reconnects, etc. Like so: MyHelper.PerformCall( () => { doStuffWithData(parameters...) }); And this works fine, but it can make the code a little cluttery. What I would prefer to do is decorate the methods that interact with the data connection like so: [InteractsWithData] protected string doStuffWithData(parameters...) { // do stuff... } And then essentially, whenever doStuffWithData is called, the body of that method would be passed in as an Action to MyHelper.PerformCall(). How do I do this?

    Read the article

  • How value objects are saving and loading?

    - by yeraycaballero
    Since there isn't respositories for value objects. How can I load all value objects? Suppose we are modeling a blog application and we have this classes: Post (Entity) Comment (Value object) Tag (Value object) PostsRespository (Respository) I Know that when I save a new post, its tags are saving with it in the same table. But how could I load all tags of all posts. Has PostsRespository got a method to load all tags? I usually do it, but I want to know others opinions

    Read the article

  • How to use multiple identity numbers in one table?

    - by vincer
    I have an web application that creates printable forms, these forms have a unique number on them, the problem is I have 2 forms that separate numbers need to be created for them. ie) Form1- Numbered 2000000-2999999 Form2- Numbered 3000000-3999999 dbo.test2 - is my form information table Tsel - is my autoinc table for the 3000000 series numbers Tadv - is my autoinc table for the 2000000 series numbers What I have done is create 2 tables with just autoinc row (one for 2000000 series numbers and one for 3000000 series numbers), I then created a trigger to add a record to the coresponding table, read back the autoinc number and add it to my table that stores the form information including the just created autoinc number for the right series of forms. Although it does work, I'm concerned that the numbers will get messed up under load. I'm not sure the @@IDENTITY will always return the right value when many people are using the system. (I cannot have duplicates and I need to use the numbering form show above. See code below. ** TRIGGER ** CREATE TRIGGER MAKEANID2 ON dbo.test2 AFTER INSERT AS SET NOCOUNT ON declare @someid int declare @someid2 int declare @startfrom int declare @test1 varchar(10) select @someid=@@IDENTITY select @test1 = (Select name1 from test2 where sysid = @someid ) if @test1 = 'select' begin insert into Tsel Default values select @someid2 = @@IDENTITY end if @test1 = 'adv' begin insert into Tadv Default values select @someid2 = @@IDENTITY end update test2 set name2=(@someid2) where sysid = @someid SET NOCOUNT OFF

    Read the article

  • Bridge or Factory and How

    - by Chris
    I'm trying to learn patterns and I've got a job that is screaming for a pattern, I just know it but I can't figure it out. I know the filter type is something that can be abstracted and possibly bridged. I'M NOT LOOKING FOR A CODE REWRITE JUST SUGGESTIONS. I'm not looking for someone to do my job. I would like to know how patterns could be applied to this example. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; using System.IO; using System.Xml; using System.Text.RegularExpressions; namespace CopyTool { class CopyJob { public enum FilterType { TextFilter, RegExFilter, NoFilter } public FilterType JobFilterType { get; set; } private string _jobName; public string JobName { get { return _jobName; } set { _jobName = value; } } private int currentIndex; public int CurrentIndex { get { return currentIndex; } } private DataSet ds; public int MaxJobs { get { return ds.Tables["Job"].Rows.Count; } } private string _filter; public string Filter { get { return _filter; } set { _filter = value; } } private string _fromFolder; public string FromFolder { get { return _fromFolder; } set { if (Directory.Exists(value)) { _fromFolder = value; } else { throw new DirectoryNotFoundException(String.Format("Folder not found: {0}", value)); } } } private List<string> _toFolders; public List<string> ToFolders { get { return _toFolders; } } public CopyJob() { Initialize(); } private void Initialize() { if (ds == null) { ds = new DataSet(); } ds.ReadXml(Properties.Settings.Default.ConfigLocation); LoadValues(0); } public void Execute() { ExecuteJob(FromFolder, _toFolders, Filter, JobFilterType); } public void ExecuteAll() { string OrigPath; List<string> DestPaths; string FilterText; FilterType FilterWay; foreach (DataRow rw in ds.Tables["Job"].Rows) { OrigPath = rw["FromFolder"].ToString(); FilterText = rw["FilterText"].ToString(); switch (rw["FilterType"].ToString()) { case "TextFilter": FilterWay = FilterType.TextFilter; break; case "RegExFilter": FilterWay = FilterType.RegExFilter; break; default: FilterWay = FilterType.NoFilter; break; } DestPaths = new List<string>(); foreach (DataRow crw in rw.GetChildRows("Job_ToFolder")) { DestPaths.Add(crw["FolderPath"].ToString()); } ExecuteJob(OrigPath, DestPaths, FilterText, FilterWay); } } private void ExecuteJob(string OrigPath, List<string> DestPaths, string FilterText, FilterType FilterWay) { FileInfo[] files; switch (FilterWay) { case FilterType.RegExFilter: files = GetFilesByRegEx(new Regex(FilterText), OrigPath); break; case FilterType.TextFilter: files = GetFilesByFilter(FilterText, OrigPath); break; default: files = new DirectoryInfo(OrigPath).GetFiles(); break; } foreach (string fld in DestPaths) { CopyFiles(files, fld); } } public void MoveToJob(int RecordNumber) { Save(); LoadValues(RecordNumber - 1); } public void AddToFolder(string folderPath) { if (Directory.Exists(folderPath)) { _toFolders.Add(folderPath); } else { throw new DirectoryNotFoundException(String.Format("Folder not found: {0}", folderPath)); } } public void DeleteToFolder(int index) { _toFolders.RemoveAt(index); } public void Save() { DataRow rw = ds.Tables["Job"].Rows[currentIndex]; rw["JobName"] = _jobName; rw["FromFolder"] = _fromFolder; rw["FilterText"] = _filter; switch (JobFilterType) { case FilterType.RegExFilter: rw["FilterType"] = "RegExFilter"; break; case FilterType.TextFilter: rw["FilterType"] = "TextFilter"; break; default: rw["FilterType"] = "NoFilter"; break; } DataRow[] ToFolderRows = ds.Tables["Job"].Rows[currentIndex].GetChildRows("Job_ToFolder"); for (int i = 0; i <= ToFolderRows.GetUpperBound(0); i++) { ToFolderRows[i].Delete(); } foreach (string fld in _toFolders) { DataRow ToFolderRow = ds.Tables["ToFolder"].NewRow(); ToFolderRow["JobId"] = ds.Tables["Job"].Rows[currentIndex]["JobId"]; ToFolderRow["Job_Id"] = ds.Tables["Job"].Rows[currentIndex]["Job_Id"]; ToFolderRow["FolderPath"] = fld; ds.Tables["ToFolder"].Rows.Add(ToFolderRow); } } public void Delete() { ds.Tables["Job"].Rows.RemoveAt(currentIndex); LoadValues(currentIndex++); } public void MoveNext() { Save(); currentIndex++; LoadValues(currentIndex); } public void MovePrevious() { Save(); currentIndex--; LoadValues(currentIndex); } public void MoveFirst() { Save(); LoadValues(0); } public void MoveLast() { Save(); LoadValues(ds.Tables["Job"].Rows.Count - 1); } public void CreateNew() { Save(); int MaxJobId = 0; Int32.TryParse(ds.Tables["Job"].Compute("Max(JobId)", "").ToString(), out MaxJobId); DataRow rw = ds.Tables["Job"].NewRow(); rw["JobId"] = MaxJobId + 1; ds.Tables["Job"].Rows.Add(rw); LoadValues(ds.Tables["Job"].Rows.IndexOf(rw)); } public void Commit() { Save(); ds.WriteXml(Properties.Settings.Default.ConfigLocation); } private void LoadValues(int index) { if (index > ds.Tables["Job"].Rows.Count - 1) { currentIndex = ds.Tables["Job"].Rows.Count - 1; } else if (index < 0) { currentIndex = 0; } else { currentIndex = index; } DataRow rw = ds.Tables["Job"].Rows[currentIndex]; _jobName = rw["JobName"].ToString(); _fromFolder = rw["FromFolder"].ToString(); _filter = rw["FilterText"].ToString(); switch (rw["FilterType"].ToString()) { case "TextFilter": JobFilterType = FilterType.TextFilter; break; case "RegExFilter": JobFilterType = FilterType.RegExFilter; break; default: JobFilterType = FilterType.NoFilter; break; } if (_toFolders == null) _toFolders = new List<string>(); _toFolders.Clear(); foreach (DataRow crw in rw.GetChildRows("Job_ToFolder")) { AddToFolder(crw["FolderPath"].ToString()); } } private static FileInfo[] GetFilesByRegEx(Regex rgx, string locPath) { DirectoryInfo d = new DirectoryInfo(locPath); FileInfo[] fullFileList = d.GetFiles(); List<FileInfo> filteredList = new List<FileInfo>(); foreach (FileInfo fi in fullFileList) { if (rgx.IsMatch(fi.Name)) { filteredList.Add(fi); } } return filteredList.ToArray(); } private static FileInfo[] GetFilesByFilter(string filter, string locPath) { DirectoryInfo d = new DirectoryInfo(locPath); FileInfo[] fi = d.GetFiles(filter); return fi; } private void CopyFiles(FileInfo[] files, string destPath) { foreach (FileInfo fi in files) { bool success = false; int i = 0; string copyToName = fi.Name; string copyToExt = fi.Extension; string copyToNameWithoutExt = Path.GetFileNameWithoutExtension(fi.FullName); while (!success && i < 100) { i++; try { if (File.Exists(Path.Combine(destPath, copyToName))) throw new CopyFileExistsException(); File.Copy(fi.FullName, Path.Combine(destPath, copyToName)); success = true; } catch (CopyFileExistsException ex) { copyToName = String.Format("{0} ({1}){2}", copyToNameWithoutExt, i, copyToExt); } } } } } public class CopyFileExistsException : Exception { public string Message; } }

    Read the article

  • Drawbacks of using an integer as a bitfield?

    - by Mark
    I have a bunch of boolean options for things like "accepted payment types" which can include things like cash, credit card, cheque, paypal, etc. Rather than having a half dozen booleans in my DB, I can just use an integer and assign each payment method an integer, like so PAYMENT_METHODS = ( (1<<0, 'Cash'), (1<<1, 'Credit Card'), (1<<2, 'Cheque'), (1<<3, 'Other'), ) and then query the specific bit in python to retrieve the flag. I know this means the database can't index by specific flags, but are there any other drawbacks?

    Read the article

  • Using Multiple Databases

    - by sergiuoala
    A company is hired by another company for helping in a certain field. So I created the following tables: Companies: id, company name, company address Administrators: (in relation with companies) id, company_id, username, email, password, fullname Then, each company has some workers in it, I store data about workers. Hence, workers has a profession, Agreement Type signed and some other common things. Now, the parent tables and data in it for workers (Agreement Types, Professions, Other Common Things) are going to be the same for each company. Should I create 1 new database for each company? Or store All data into the same database? Thanks.

    Read the article

  • Which pattern to use for logging? Dependency Injection or Service Locator?

    - by andlju
    Consider this scenario. I have some business logic that now and then will be required to write to a log. interface ILogger { void Log(string stuff); } interface IDependency { string GetInfo(); } class MyBusinessObject { private IDependency _dependency; public MyBusinessObject(IDependency dependency) { _dependency = dependency; } public string DoSomething(string input) { // Process input var info = _dependency.GetInfo(); var intermediateResult = PerformInterestingStuff(input, info); if (intermediateResult== "SomethingWeNeedToLog") { // How do I get to the ILogger-interface? } var result = PerformSomethingElse(intermediateResult); return result; } } How would you get the ILogger interface? I see two main possibilities; Pass it using Dependency Injection on the constructor. Get it via a singleton Service Locator. Which method would you prefer, and why? Or is there an even better pattern? Update: Note that I don't need to log ALL method calls. I only want to log a few (rare) events that may or may not occur within my method.

    Read the article

  • What is the role of the Router Object in MVC based frameworks

    - by Saif Bechan
    In most MVC based framework I see a router object. If I look at it splits up the uri and decides what controller should be used, and which action should be fired. Even though this makes a lot of sense, I can not give this a place in the MVC patern. Is splitting up the uri not the job of the controller. And then the controller should just decide which class and function to run.

    Read the article

  • Rails 3 HABTM Strange Association: Project and Employee in a tree.

    - by Mauricio
    Hi guys I have to adapt an existing model to a new relation. I have this: A Project has many Employees. the Employees of a Project are organized in some kind of hierarchy (nothing fancy, I resolved this adding a parent_id for each employee to build the 'tree') class Employee < AR:Base belongs_to :project belongs_to :parent, :class_name => 'Employee' has_many :childs, :class_name => 'Employee', :foreign_column => 'parent_id' end class Project < AR:Base has_many :employees, end That worked like a charm, now the new requirement is: The Employees can belong to many Projects at the same time, and the hierarchy will be different according to the project. So I though I will need a new table to build the HABTM, and a new class to access the parent_id to build the tree. Something like class ProjectEmployee < AR:Base belongs_to :project belongs_to :employee belongs_to :parent, :class_name => 'Employee' # <--- ?????? end class Project < AR:Base has_many :project_employee has_many :employees, :through => :project_employee end class Employee < AR:Base has_many :project_employee has_many :projects, :through => :project_employee end How can I access the parent and the childs of an employee for a given project? I need to add and remove childs as wish from the employees of a project. Thank you!

    Read the article

  • Database schema to store AND, OR relation, association

    - by user455387
    Many thanks for your help on this. In order for an entreprise to get a call for tender it must meet certain requirements. For the first example the enterprise must have a minimal class 4, and have qualification 2 in sector 5. Minimal class is always one number. Qualification can be anything (single, or multiple using AND, OR logical operators) I have created tables in order to map each number to it's given name. Now I need to store requirements in the database. minimal class 4 Sector Qualification 5.2 minimal class 2 Sector Qualifications 3.9 and 3.10 minimal class 3 Sector Qualifications 6.1 or 6.3 minimal class 1 Sector Qualifications (3.1 and 3.2) or 5.6 class Domain < ActiveRecord::Base has_many :domain_classes has_many :domain_sectors has_many :sector_qualifications, :through => :domain_sectors end class DomainClass < ActiveRecord::Base belongs_to :domain end class DomainSector < ActiveRecord::Base belongs_to :domain has_many :sector_qualifications end class SectorQualification < ActiveRecord::Base belongs_to :domain_sector end create_table "domains", :force => true do |t| t.string "name" end create_table "domain_classes", :force => true do |t| t.integer "number" t.integer "domain_id" end create_table "domain_sectors", :force => true do |t| t.string "name" t.integer "number" t.integer "domain_id" end create_table "sector_qualifications", :force => true do |t| t.string "name" t.integer "number" t.integer "domain_sector_id" end

    Read the article

  • Best practice for near reuse of model components?

    - by Chris Knight
    I have a requirement to use a Fund model in my code. It will contain a fund name and fund code. In the interest of reuse I've poked around the package containing the other models used and found an existing Fund model. However the issue here is that, in addition to fund name and code, it also contains an amount. Amount isn't directly relevant in my context. So, do I: 1) Use the existing Fund model as is, ignoring the setters/getters for fund amount. 2) Put a FundDescription interface onto the existing Fund model for accessing only the information I'm interested in. 3) Make a FundDescription base class from which the existing Fund model could now extend 4) Create a whole new seperate model since the two are slightly contextually different

    Read the article

  • how to implement this observer pattern?

    - by lethal
    Hello. I have 4 classes, that describe state diagram. Node, Edge, ComponentOfNode, ComponentOfEdge. ComponentOfEdge compounds from ComponentsOfNode. Node can have 0..n outgoing edges. Edge can have only 2 nodes. Edge should be able to offer ComponentOfNode, but only from nodes that Edge has, in form ComponentOfEdge. The user can change ComponentsOfNode. I need this change spreads to all Edge. Hw to do it? I expect the observer should be used. Can you give me example in pseudocode please?

    Read the article

  • PHP Access property of a class from within a class instantiated in the original class.

    - by Iain
    I'm not certain how to explain this with the correct terms so maybe an example is the best method... $master = new MasterClass(); $master->doStuff(); class MasterClass { var $a; var $b; var $c; var $eventProccer; function MasterClass() { $this->a = 1; $this->eventProccer = new EventProcess(); } function printCurrent() { echo '<br>'.$this->a.'<br>'; } function doStuff() { $this->printCurrent(); $this->eventProccer->DoSomething(); $this->printCurrent(); } } class EventProcess { function EventProcess() {} function DoSomething() { // trying to access and change the parent class' a,b,c properties } } My problem is i'm not certain how to access the properties of the MasterClass from within the EventProcess-DoSomething() method? I would need to access, perform operations on and update the properties. The a,b,c properties will be quite large arrays and the DoSomething() method would be called many times during the execuction of the script. Any help or pointers would be much appreciated :)

    Read the article

  • Can I access elements/methods named "button1" "button2" "button3" etc. using "buttoni" inside a for-

    - by cksubs
    I have a bunch of buttons named: button1 button2 button3 etc. Is there a way to basically do this? pseudocode for(int i = 1, i < 15, i++) { button{i}.selected = YES; } This also goes for method calls, etc. I've often thought such a way of calling methods would be very convenient, but I don't think I've ever seen it done when using compiled languages. But I have done it using PHP. Is there any way to do this in Objective-C? (That's where my problem is now, but I'd also be interested in if you can do this in other languages.) Alternately, is there a reason why this is NOT a good way to go about accessing all the UI elements? Thanks!

    Read the article

  • What pattern to use in this scenario?

    - by jess
    Hi, We have got many forms(windows app C#) in our application.We have similar steps in most of them - user adds a new object(in a grid),fills values and save.On,save,we validate,and save if everything ok,else show message.Now,adding of object usually means we add a new row with some default values.

    Read the article

  • Why Are Ruby Programmers So Full of Themselves? [closed]

    - by Pierreten
    I've noticed this culture surrounding Ruby where developers truly believe that they are somehow more gifted than developers of other languages, regardless of experience and talent (even when that isn't the case, I've met some extremely junior Ruby developers come up with some pretty basic constructs, and pass them off as some sort of revolutionary idea). The derision of strongly typed languages seems to be a common theme as well; regardless of its merits. Is there something particular to the Ruby syntax in general that is to account for this? Is there a socialogical component to it?

    Read the article

  • How can I handle all my errors/messages in one place on an Asp.Net page?

    - by Atomiton
    Hi all, I'm looking for some guidance here. On my site I put things in Web user controls. For example, I will have a NewsItem Control, an Article Control, a ContactForm control. These will appear in various places on my site. What I'm looking for is a way for these controls to pass messages up to the Page that they exist on. I don't want to tightly couple them, so I think I will have to do this with Events/Delegates. I'm a little unclear as to how I would implement this, though. A couple of examples: 1 A contact form is submitted. After it's submitted, instead of replacing itself with a "Your mail has been sent" which limits the placement of that message, I'd like to just notify the page that the control is on with a Status message and perhaps a suggested behaviour. So, a message would include the text to render as well as an enum like DisplayAs.Popup or DisplayAs.Success 2 An Article Control queries the database for an Article object. Database returns an Exception. Custom Exception is passed to the page along with the DisplayAs.Error enum. The page handles this error and displays it wherever the errors go. I'm trying to accomplish something similar to the ValidationSummary Control, except that I want the page to be able to display the messages as the enum feels fit. Again, I don't want to tightly bind or rely a control existing on the Page. I want the controls to raise these events, but the page can ignore them if it wants. Am I going about this the right way? I'd love a code sample just to get me started. I know this is a more involved question, so I'll wait longer before voting/choosing the answers.

    Read the article

  • Naming of boolean column in database table

    - by Space Cracker
    I have 'Service' table and the following column description as below Is User Verification Required for service ? Is User's Email Activation Required for the service ? Is User's Mobile Activation required for the service ? I Hesitate in naming these columns as below IsVerificationRequired IsEmailActivationRequired IsMobileActivationRequired or RequireVerification RequireEmailActivation RequireMobileActivation I can't determined which way is the best .So, Is one of the above suggested name is the best or is there other better ones ?

    Read the article

  • How to Execute Base Class's ExtractPageData() Before Implementors's ExtractPageData()?

    - by DaveDev
    I have the following page public partial class GenericOfflineCommentary : OfflineFactsheetBase { } where OfflineFactsheetBase is defined as public class OfflineFactsheetBase : System.Web.UI.Page { public OfflineFactsheetBase() { this.Load += new EventHandler(this.Page_Load); this.PreInit += new EventHandler(this.Page_PreInit); } protected void Page_PreInit(object sender, EventArgs e) { if (Request.QueryString["data"] != null) { this.PageData = StringCompressor.DecompressString(Request.QueryString["data"]); this.ExtractPageData(); } } } OfflineFactsheetBase has the following virtual method: public virtual void ExtractPageData() { // get stuff relevant to all pages that impmement OfflineFactsheetBase } which is implemented in all pages that impmement OfflineFactsheetBase as follows: public partial class GenericOfflineCommentary : OfflineFactsheetBase { public override void ExtractPageData() { // get stuff relevant to an OfflineCommentary page. } } Currently, only GenericOfflineCommentary's ExtractPageData() is firing. How can I modify this to first run OfflineFactsheetBase's ExtractPageData() and then GenericOfflineCommentary's?

    Read the article

  • Using a user-defined type as a primary key

    - by Chris Kaminski
    Suppose I have a system where I have metadata such as: table: ====== key name address ... Then suppose I have a user-defined type described as so: datasource datasource-key A) are there systems where it's possible to have keys based on user-defined types? B) if so, how do you decompose the keys into a form suitable for querying? C) is this a case where I'm just better off with a composite primary key?

    Read the article

  • How do you manage web navigation info in your application?

    - by Dave
    I’m building an application where different users will have different menu items available to them depending on what they’ve paid for. There will also be multiple levels to the menu hierarchy. What’s the best approach to this problem? I’m assuming I need a database table that represents the menu hierarchy, including the parent-child relationships of the nodes in the navigation as well as the sorting of the items. Then another table which I use to manage whether a user is authorized to access a particular item in that table. When I render the view, I’d reference the menus, and the access rights of the user to output the menu, and I’d also need a function to check that same authorization from each controller in case a user manually types in a URL of a controller they’re not supposed to have access to. Is this the right approach? Any suggestions for caching this to prevent the constant look-ups of this type of info? I’m open to any suggestions on how you may have approached this type of requirement.

    Read the article

< Previous Page | 286 287 288 289 290 291 292 293 294 295 296 297  | Next Page >