Databases
StackOverflow2013
Postsdbo
POGeneric extension method to convert from one collection to another
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POGeneric extension method to convert from one collection to another
    primarykey
    data
    text
    <p>I'm working in a code base which has a lot of first class collections.</p> <p>In order to ease using these collections with LINQ, there is an extension method per collection that looks like:</p> <pre><code>public static class CustomCollectionExtensions { public static CustomCollection ToCustomCollection(this IEnumerable&lt;CustomItem&gt; enumerable) { return new CustomCollection(enumerable); } } </code></pre> <p>With the accompanying constructors:</p> <pre><code>public class CustomCollection : List&lt;CustomItem&gt; { public CustomCollection(IEnumerable&lt;CustomItem&gt; enumerable) : base(enumerable) { } } </code></pre> <p>This winds up being a bunch of boilerplate so I attempted to write a generic <code>IEnumerable&lt;U&gt;.To&lt;T&gt;()</code> so that we wouldn't have to keep generating these specific ToXCollection() methods.</p> <p>I got as far as:</p> <pre><code>public static class GenericCollectionExtensions { public static T To&lt;T, U&gt;(this IEnumerable&lt;U&gt; enumerable) where T : ICollection&lt;U&gt;, new() { T collection = new T(); foreach (U u in enumerable) { collection.Add(u); } return collection; } } </code></pre> <p>Which has to be called like <code>customCollectionInstance.OrderBy(i =&gt; i.Property).To&lt;CustomCollection, CustomItem&gt;()</code></p> <p>Is there a way to avoid having to specify the <code>CustomItem</code> type so we can instead use <code>customCollectionInstance.OrderBy(i =&gt; i.Property).To&lt;CustomCollection&gt;()</code> or is this not something that can be done generically?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USJustin Edwards
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POGeneric extension method to convert from one collection to another
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POGeneric extension method to convert from one collection to another
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POGeneric extension method to convert from one collection to another
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI'm afraid there is not.
      singulars
      1. POGeneric extension method to convert from one collection to another
      1. USMarcinJuraszek
    2. COWhy exactly do you have so many different collections? That looks like code smell to me.
      singulars
      1. POGeneric extension method to convert from one collection to another
      1. USsvick
    3. CO@svick - there are a lot of collections because it's a large code base and first class collections were/are favored over generic object collections to have somewhere to encapsulate set based rules rather than defining them relative to generic IWhatever<DomainObject>. I'm not sure if that was a good or bad decision, but I do know that `var a = Member.Offers.ActiveOffers()` looks a bit cleaner than having to use a .Where() every time.
      singulars
      1. POGeneric extension method to convert from one collection to another
      1. USJustin Edwards
 

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