A micro utility that converts a one-dimensional array with comments into a comments tree.
// We need the comments come from a database with such properties, at least.
interface DefaultCommentFromDb {
commentId: number | string;
parentId?: number | string;
}
// This utility will convert comments from the database to comments with this interface.
interface DefaultComment {
commentId: number | string;
children: this[];
parentId?: number | string;
parent?: this;
}This utility has one public method:
static getTree<T extends DefaultCommentFromDb>(
allCommentsFromDb: T[],
actionRoot: ActionArray = 'unshift',
actionChild: ActionArray = 'unshift'
)Please do not be afraid =). It's easy to use this method.
CommentsToTree.getTree() - converts a one-dimensional array of comments into a comments tree. The array must be sorted in reverse order - at its beginning there are the most recent comments.
allCommentsFromDb - one-dimensional array of comments from the database (the array sorted in reverse order).
actionRoot - the action you need to apply to insert a root comment to comments tree. By default unshift.
actionChild - the action you need to apply to insert a child comment to comments tree. By default unshift.
Copy main.ts from this repository. You need just implement DefaultCommentFromDb in your comment class:
import { DefaultCommentFromDb } from './main';
class MyCommentFromDb implements DefaultCommentFromDb {
commentId: number;
parentId?: number;
someOtherPropertyFromDb?: string;
}
const allCommentsFromDb: MyCommentFromDb[] = [
{ commentId: 5, parentId: 2, someOtherPropertyFromDb: 'comment5' },
{ commentId: 4, someOtherPropertyFromDb: 'root comment4' },
{ commentId: 3, parentId: 1, someOtherPropertyFromDb: 'comment3' },
{ commentId: 2, parentId: 1, someOtherPropertyFromDb: 'comment2' },
{ commentId: 1, someOtherPropertyFromDb: 'root comment1' },
];
const commentsTree = CommentsToTree.getTree<MyCommentFromDb>(allCommentsFromDb);