StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POJavaScript: Creating an object generically from its type and calling its constructor
primarykey
Id
15440175
data
AcceptedAnswerId
15477966
AnswerCount
5
ClosedDate
CommentCount
5
CommunityOwnedDate
CreationDate
2013-03-15T18:57:43.930
FavoriteCount
0
LastActivityDate
2014-05-14T15:00:37.473
LastEditDate
2013-03-17T13:59:48.007
LastEditorUserId
736006
OwnerUserId
736006
ParentId
0
PostTypeId
1
Score
1
ViewCount
1107
LastEditorDisplayName
text
Body
Say there's a JavaScript object with a childType property, which is an object constructor, and you want to write a generic addChild method. It needs to create an instance of this.childType, and invoke its constructor, passing whatever arguments were passed into addChild. To be clear, the point is for each collection to create child objects itself, using the inherited generic addChild method and its known childType, not to validate the type of passed-in child objects. I didn't think this would be hard to do, but I've tried various things and only failed so far. UPDATE: I've updated the <a href="http://plnkr.co/edit/XrsGkwGBXT3vyCpylI6i" rel="nofollow">demo plunk</a> with the best solution I know of so far, and included some comments about the issue in the code. The failed attempts discussed below are no longer there. This solution requires all potential chold objects to have a 'new Agnostic constructor', so it's still not ideal. Further thoughts are most welcome. <hr> I know this line is wrong, for two reasons: <pre><code>var child = new this.childItemType.call(args); </code></pre> First is that I think some sort of 'this' needs to be passed to the call function, and I don't see what it'd be there. Second is probably a result of the first, the error reported in the browser: <pre><code>Uncaught TypeError: function call() { [native code] } is not a constructor </code></pre> I think this should be doable, but the syntax for creating that child object from this.childType and passed arguments escapes me so far. Can someone point out the missing brain cell here?
Tags
<javascript><object><constructor>
Title
JavaScript: Creating an object generically from its type and calling its constructor
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. USenigment
UserOwnerUserId
1. USenigment
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
3. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 POJavaScript: Creating an object generically from its type and calling its constructor
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId

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.