Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>The Inversion of Control (IoC) and Dependency Injection (DI) patterns are all about removing dependencies from your code.</p> <p>For example, say your application has a text editor component and you want to provide spell checking. Your standard code would look something like this:</p> <pre><code>public class TextEditor { private SpellChecker checker; public TextEditor() { this.checker = new SpellChecker(); } } </code></pre> <p>What we've done here creates a dependency between the <code>TextEditor</code> and the <code>SpellChecker</code>. In an IoC scenario we would instead do something like this:</p> <pre><code>public class TextEditor { private IocSpellChecker checker; public TextEditor(IocSpellChecker checker) { this.checker = checker; } } </code></pre> <p>In the first code example we are instantiating <code>SpellChecker</code> (<code>this.checker = new SpellChecker();</code>), which means the <code>TextEditor</code> class directly depends on the <code>SpellChecker</code> class.</p> <p>In the second code example we are creating an abstraction by having the <code>SpellChecker</code> dependency class in <code>TextEditor</code> constructor signature (not initializing dependency in class). This allows us to call the dependency then pass it to the TextEditor class like so:</p> <pre><code>SpellChecker sc = new SpellChecker; // dependency TextEditor textEditor = new TextEditor(sc); </code></pre> <p>Now the client creating the <code>TextEditor</code> class has the control over which <code>SpellChecker</code> implementation to use because we're injecting the dependency to the <code>TextEditor</code> signature.</p> <p>This is just a simple example, there's <a href="http://dotnetslackers.com/articles/designpatterns/InversionOfControlAndDependencyInjectionWithCastleWindsorContainerPart1.aspx" rel="noreferrer">a good series of articles</a> by Simone Busoli that explains it in greater detail.</p>
    singulars
    1. This table or related slice is empty.
    1. POWhat is Inversion of Control?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USPatapoom
    1. USurini
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POWhat is Inversion of Control?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COGood clear example. However, suppose rather than requiring the ISpellChecker interface be passed to the object's constructor, we exposed it as a settable property (or SetSpellChecker method). Would this still constitute IoC?
      singulars
      1. PO
      1. USdevios1
    2. COchainguy1337 - yes it would. Using setters like that is called setter injection as opposed to constructor injection (both dependency injection techniques). IoC is a fairly generic pattern, but dependency injection acheives IoC
      singulars
      1. PO
      1. USSchneider
    3. CODespite the many up-votes, this answer is incorrect. Please see http://martinfowler.com/articles/injection.html#InversionOfControl. In particular, note the part saying "Inversion of Control is too generic a term, and thus people find it confusing. As a result with a lot of discussion with various IoC advocates we settled on the name Dependency Injection".
      singulars
      1. PO
      1. USRogério
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload