# EctoJuno
A simple query sorting library
## Installation
Add `:ecto_juno` to the list of dependencies in `mix.exs`
```elixir
def deps do
[
{:ecto_juno, "~> 0.3.0"}
]
end
```
## Configuration
You can specify default sorting field and mode in your config.exs:
```elixir
config :ecto_juno, sort_by: :id, sort_direction: :desc
```
The default sorting is by `inserted_at` field with `asc` mode
## General sorting
Lets assume you have Accounts context with User schema and Repo module.
To sort users pass your query, schema module and params into `EctoJuno.Query.Sorting.sort_query/3`
```elixir
alias EctoJuno.Query.Sorting
def list_sorted_users(params) do
User
|> Sorting.sort_query(User, params)
|> Repo.all()
end
```
Where `params` structure is
```elixir
%{"sort_by" => "id", "sort_direction" => "desc"}
```
You can also pass sorting parameters keys as atoms:
```elixir
Sorting.sort_query(query, User, %{sort_by: "id", sort_direction: "desc"})
```
Moreover, instead of the `User` schema module, you can pass a list of which elements are atoms:
```elixir
Sorting.sort_query(query, [:id, :age, :name, :inserted_at], %{sort_by: "id", sort_direction: "desc"})
```
If you not specify any of sorting parameters, than the default ones will be used:
```elixir
# The default sort_direction will be used
Sorting.sort_query(query, User, %{sort_by: "id"})
# The default sort_by will be used
Sorting.sort_query(query, User, %{sort_direction: "desc"})
# The default sorting which configurable will be used
Sorting.sort_query(query, User)
```
If you'll pass invalid sorting parameters, than default sorting ones will be used for your query:
```elixir
Sorting.sort_query(query, User, %{sort_by: "invalid_field", sort_direction: "invalid_mode"})
```
by default will sort query by `inserted_at` field with `asc` mode
## Sorting by joint query
To apply sorting by joint query use `EctoJuno.Query.Sorting.sort_query/4` which accepts the same arguments as
`EctoJuno.Query.Sorting.sort_query/3` except new fourth argument - joint query binding name.
Let's assume that you also have a posts table that related to users table as many to one. And posts have `title` column. Than your sorting function will be something like:
```elixir
alias EctoJuno.Query.Sorting
def sort_users_by_posts do
params = %{"sort_by" => "title", "sort_direction" => "desc"}
User
|> join(:left, [u], p in assoc(u, :posts), as: :posts)
|> Sorting.sort_query(Post, params, :posts)
|> Repo.all()
end
```
If you provide binding that query doesn't have than sorting by base query in default mode will be applied
## Custom sorting
Define your custom sorting module
```elixir
defmodule Sample.UserSorting do
use EctoJuno.Query.SortingTemplate
def prepare_sorting_params("post_" <> field) do
{Post, field, :posts}
end
def prepare_sorting_params(nil) do
{User, "inserted_at"}
end
def prepare_sorting_params(field) do
{User, field}
end
end
```
Then you can use it like
```elixir
alias Sample.UserSorting
query = join(User, :left, [u], p in assoc(u, :posts), as: :posts)
# Sort users by posts title in desc mode
query
|> UserSorting.sort_query(%{sort_by: "post_title", sort_direction: "desc"})
|> Repo.all()
# Sort users by users age
query
|> UserSorting.sort_query(%{"sort_by" => "age", "sort_direction" => "desc"})
|> Repo.all()
```
Passing parameters may be done with a map either with string either atom keys. But not mixed.
## Be aware of
- Sorting with modes different from asc and desc is not supported
- If you pass sort_by and sort_direction values not as strings you'll get exception
## Testing
1. Clone repo: `git clone https://github.com/senconscious/ecto_juno`
2. Set `DATABASE_URL` environment variable before running tests locally
3. Run `mix check`