https://github.com/treble37/nested_filter
Providing Map#drop (by key or value) and Map#take functionality for nested maps
https://github.com/treble37/nested_filter
elixir elixir-library hacktoberfest nested-maps
Last synced: 5 months ago
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Providing Map#drop (by key or value) and Map#take functionality for nested maps
- Host: GitHub
- URL: https://github.com/treble37/nested_filter
- Owner: treble37
- License: mit
- Created: 2017-03-22T03:43:44.000Z (almost 9 years ago)
- Default Branch: main
- Last Pushed: 2024-01-05T13:37:43.000Z (about 2 years ago)
- Last Synced: 2024-11-17T17:49:29.787Z (about 1 year ago)
- Topics: elixir, elixir-library, hacktoberfest, nested-maps
- Language: Elixir
- Homepage:
- Size: 93.8 KB
- Stars: 35
- Watchers: 2
- Forks: 8
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# NestedFilter
[](https://codeclimate.com/github/treble37/nested_filter/maintainability)
[](https://codeclimate.com/github/treble37/nested_filter/test_coverage)
[](https://coveralls.io/github/treble37/nested_filter?branch=master)
[](https://hex.pm/packages/nested_filter)
[](https://hex.pm/packages/nested_filter)
[](https://github.com/treble37/nested_filter/stargazers)
[](https://raw.githubusercontent.com/treble37/nested_filter/master/LICENSE)
## The Problems
1. You have a nested map (or a struct that you converted to a nested map) and you want to remove ALL the keys with specific values such as nil.
2. You want to do a Map#take on a nested map
##### Example: Remove all the map keys with nil values
```elixir
nested_map = %{a: 1, b: %{c: nil, d: nil}, c: nil}
Map.drop(nested_map, [:c, :d])
# => %{a: 1, b: %{c: nil, d: nil}}
# But you actually wanted:
# => %{a: 1}
```
## The Solution: NestedFilter
NestedFilter drills down into a nested map and can do any of the following:
1. filters out keys according to user specified values.
2. filters out values according to user specified keys.
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `nested_filter` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[{:nested_filter, "~> 1.2.2"}]
end
```
Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
be found at .
## Usage
By default, when removing user specified values, empty values will be preserved
(see Case 1 below). You can add empty values to the user specified values list
if you wish those "empty values" (e.g., empty maps) to be removed.
### NestedFilter.drop_by_value
```elixir
# Case 1: Remove the nil values from a nested map, preserving empty map values
nested_map = %{a: 1, b: %{m: nil, n: 2}, c: %{p: %{q: nil, r: nil}, s: %{t: 2, u: 3}} }
NestedFilter.drop_by_value(nested_map, [nil])
# => %{a: 1, b: %{n: 2}, c: %{p: %{}, s: %{t: 2, u: 3}} }
# Case 2: Remove the nil values from a nested map, removing empty map values
nested_map = %{a: 1, b: %{m: nil, n: 2}, c: %{p: %{q: nil, r: nil}, s: %{t: 2, u: 3}} }
NestedFilter.drop_by_value(nested_map, [nil, %{}])
# => %{a: 1, b: %{n: 2}, c: %{s: %{t: 2, u: 3}} }
```
### NestedFilter.drop_by_key
```elixir
# Case 1: Remove values from a nested map by key
nested_map = %{a: 1, b: %{a: 2, b: 3}, c: %{a: %{a: 1, b: 2}, b: 2, c: %{d: 1, e: 2}}}
assert NestedFilter.drop_by_key(nested_map, [:a]) == %{b: %{b: 3},c: %{b: 2, c: %{d: 1, e: 2}}}
```
### NestedFilter.take_by_key
```elixir
# Case 1: Take values from a nested map by key
nested_map = %{a: %{b: 1}, c: 3, e: %{f: 4}}
assert NestedFilter.take_by_key(nested_map, [:b, :f]) == %{b: 1, f: 4 }
```
You can browse the tests for more usage examples.