# Flop Phoenix

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Flop Phoenix provides Phoenix components for pagination, sortable tables, and
filter forms with [Flop]( and

## Installation

To start using flop_phoenix, add it to your list of dependencies in `mix.exs`
of your Phoenix application:

Add `flop_phoenix` to your list of dependencies in the `mix.exs` of your Phoenix

def deps do
    {:flop_phoenix, "~> 0.22.9"}

Next, set up your business logic according to the
[Flop documentation](

## Usage

First, define a function that utilizes `Flop.validate_and_run/3` to query your
desired list. For example:

defmodule MyApp.Pets do
  alias MyApp.Pet

  def list_pets(params) do
    Flop.validate_and_run(Pet, params, for: Pet)

### LiveView

In the LiveView, fetch the data and assign it alongside the meta data to the

defmodule MyAppWeb.PetLive.Index do
  use MyAppWeb, :live_view

  alias MyApp.Pets

  @impl Phoenix.LiveView
  def handle_params(params, _, socket) do
    case Pets.list_pets(params) do
      {:ok, {pets, meta}} ->
        {:noreply, assign(socket, %{pets: pets, meta: meta})}

      {:error, _meta} ->
        # This will reset invalid parameters. Alternatively, you can assign
        # only the meta and render the errors, or you can ignore the error
        # case entirely.
        {:noreply, push_navigate(socket, to: ~p"/pets")}

If you prefer the `Flop.Phoenix` components not to reflect pagination, sorting,
and filtering parameters in the URL, fetch and assign the data in the
`c:Phoenix.LiveView.handle_event/3` callback. You need to pass a
`Phoenix.LiveView.JS` command as an attribute to the components in that case.

### Controller

For non-LiveView ("dead") views, pass the data and Flop meta struct to your
template in the controller.

defmodule MyAppWeb.PetController do
  use MyAppWeb, :controller

  alias MyApp.Pets

  action_fallback MyAppWeb.FallbackController

  def index(conn, params) do
    with {:ok, {pets, meta}} <- Pets.list_pets(params) do
      render(conn, :index, meta: meta, pets: pets)

## Sortable tables and pagination

To add a sortable table and pagination links, you can add the following to your


<Flop.Phoenix.table items={@pets} meta={@meta} path={~p"/pets"}>
  <:col :let={pet} label="Name" field={:name}><%= %></:col>
  <:col :let={pet} label="Age" field={:age}><%= pet.age %></:col>

<Flop.Phoenix.pagination meta={@meta} path={~p"/pets"} />

In this context, path points to the current route, and Flop Phoenix appends
pagination, filtering, and sorting parameters to it. You can use verified
routes, route helpers, or custom path builder functions. You'll find
explanations for the different formats in the documentation for

Note that the field attribute in the `:col` slot is optional. If set and the
corresponding field in the schema is defined as sortable, the table header for
that column will be interactive, allowing users to sort by that column. However,
if the field isn't defined as sortable, or if the field attribute is omitted, or
set to `nil` or `false`, the table header will not be clickable.

By using the `for` option in your Flop query, Flop Phoenix can identify which
table columns are sortable. Additionally, it omits the `order` and `page_size`
parameters if they align with the default values specified via `Flop.Schema`.

You also have the option to pass a `Phoenix.LiveView.JS` command instead of or
in addition to a path. For more details, please refer to the component

If you wish to implement cursor-based pagination, see
`Flop.Phoenix.cursor_pagination/1` for setup instructions.

## Filter forms

Flop Phoenix implements the `Phoenix.HTML.FormData` for the `Flop.Meta` struct.
As such, you can easily pass the struct to Phoenix form functions. One
straightforward way to render a filter form is through the
`Flop.Phoenix.filter_fields/1` component, as shown below:

attr :fields, :list, required: true
attr :meta, Flop.Meta, required: true
attr :id, :string, default: nil
attr :on_change, :string, default: "update-filter"
attr :target, :string, default: nil

def filter_form(%{meta: meta} = assigns) do
  assigns = assign(assigns, form: Phoenix.Component.to_form(meta), meta: nil)

    <.filter_fields :let={i} form={@form} fields={@fields}>

    <button class="button" name="reset">reset</button>

Note that while the `filter_fields` component produces all necessary hidden
inputs, it doesn't automatically render inputs for filter values. Instead, it
passes the necessary details to the inner block, allowing you to customize the
filter inputs with your custom input component.

You can pass additional options for each field. Refer to the
`Flop.Phoenix.filter_fields/1` documentation for details.

Now, you can render a filter form like so:

  fields={[:name, :email]}

You will need to handle the `update-filter` event with the `handle_event/3`
callback function of your LiveView.

@impl true
def handle_event("update-filter", params, socket) do
  params = Map.delete(params, "_target")
  {:noreply, push_patch(socket, to: ~p"/pets?#{params}")}

## LiveView streams

To use LiveView streams, you can change your `handle_params/3` function as

def handle_params(params, _, socket) do
  case Pets.list_pets(params) do
    {:ok, {pets, meta}} ->
         |> assign(:meta, meta)
         |> stream(:pets, pets, reset: true)}

    # ...

When using LiveView streams, the data being passed to the table component
differs. Instead of passing `@pets`, you'll need to use `@streams.pets`.

The stream values are tuples, with the DOM ID as the first element and the items
(in this case, Pets) as the second element. You need to match on these tuples
within the `:let` attributes of the table component.

<Flop.Phoenix.table items={@streams.pets} meta={@meta} path={~p"/pets"}>
  <:col :let={{_, pet}} label="Name" field={:name}><%= %></:col>
  <:col :let={{_, pet}} label="Age" field={:age}><%= pet.age %></:col>