Ancestry - The tree structure implementations for Elixir Ecto

zven21 · June 20, 2019, 8:02am

The tree structure implementations for Elixir Ecto - Ancestry

Getting started

If available in Hex, the package can be installed
by adding ancestry to your list of dependencies in mix.exs:

def deps do
  [
    {:ancestry, "~> 0.1.2"}
  ]
end

Gen migration file to add string field in your model.

mix ecto.gen.migration add_ancestry_to_<model>

Add ancestry field and index to migration file.

def change do
  alter table(:my_models) do
    add :ancestry, :string
  end
  create index(:my_models, [:ancestry])
end

mix ecto.migration

Add use Ancestry, repo: MyApp.repo to you model.ex

defmodule MyModel do
  use Ecto.Schema
  use Ancestry, repo: MyApp.repo

  import Ecto.Changeset

  schema "my_models" do
    field :ancestry, :string
  end

  def changeset(struct, params) do
    struct
    |> cast(params, [:ancestry])
  end
end

Navigation

method	return value	usage example	finished?
`roots`	all root node	`MyModel.roots`	`true`
`parent`	parent of the record, nil for a root node	`MyModel.parent(record)`	`true`
`parent_id`	parent id of the record, nil for a root node	`MyModel.parent_id(record)`	`true`
`has_parent?`	true if the record has a parent, false otherwise	`MyModel.has_parent?(record)`	`true`
`root`	root of the record’s tree, self for a root node	`MyModel.root(record)`	`true`
`root_id`	root id of the record’s tree, self for a root node	`MyModel.root_id(record)`	`true`
`is_root?`	true if the record is a root node, false otherwise	`MyModel.is_root?(record)`	`true`
`ancestors`	ancestors of the record, starting with the root and ending with the parent	`MyModel.ancestors(record)`	`true`
`ancestor_ids`	ancestor ids of the record	`MyModel.ancestor_ids(record)`	`true`
`children`	direct children of the record	`MyModel.children(record)`	`true`
`child_ids`	direct children’s ids	`MyModel.child_ids(record)`	`true`
`has_children?`	true if the record has any children, false otherwise	`MyModel.has_children?(record)`	`true`
`is_childless?`	true is the record has no children, false otherwise	`MyModel.is_childless?(record)`	`true`
`siblings`	siblings of the record, the record itself is included*	`MyModel.siblings(record)`	`true`
`sibling_ids`	sibling ids	`MyModel.sibling_ids(record)`	`true`
`has_siblings?`	true if the record’s parent has more than one child	`MyModel.has_siblings?(record)`	`true`
`is_only_child?`	true if the record is the only child of its parent	`MyModel.is_only_child?(record)`	`true`
`descendants`	direct and indirect children of the record	`MyModel.descendants(record)`	`true`
`descendant_ids`	direct and indirect children’s ids of the record	`MyModel.descendant_ids(record)`	`true`
`subtree`	the model on descendants and itself	`MyModel.subtree(record)`	`true`
`subtree_ids`	a list of all ids in the record’s subtree	`MyModel.subtree_ids(record)`	`true`
`path`	path of the record, starting with the root and ending with self	`MyModel.path(record)`	`true`
`path_ids`	a list the path ids, starting with the root id and ending with the node’s own id	`MyModel.path_ids(record)`	`true`
`depth`	the depth of the node, root nodes are at depth 0	`MyModel.depth(record)`	`true`

More pls check it here:

Thank you for reading, have a good day.

dimitarvp · June 20, 2019, 10:14am

Looks pretty good. For the sake of comparison, there’s also arbor.

Good job.

mischov · June 20, 2019, 3:05pm

The github link is to the wrong library.

zven21 · June 20, 2019, 3:39pm

Sorry, but now can not edit, right library check here: https://github.com/zven21/ancestry