phoenix liveview link

This is where your live-view related code will live.

Now, let's start in the router by putting some live routes behind authentication. ) :: However, note that the :id has a special meaning: whenever an :id is given, the component becomes stateful. Just understand that it takes in a first argument of the conn struct and checks for the presence of a :current_user key. The Arcade web app presents regular users with many online games to play. When the auth generator creates the UserAuth module, it also imports into your router, like this: We can create a new router scope using this function plug. filename :: binary, Catch errors and make sure they don't happen again.

Ill start by quickly bootstrapping a blog application with a single resource, posts. The new live view is mounted over the current WebSocket connection without reloading the whole page. Now if you have two browser windows pointed at /liveposts a post created in one window will automatically appear in the other. Now here we go with the cool stuff: converting this default index page into a live view, so that when you create, update or delete posts any browser window thats pointed at the page will update automatically, no refresh required. We'll send you a reminder. You'll use live sessions to group similar live routes with shared layouts and auth logic. This will allow our live view and other modules to subscribe to events that we broadcast. ) :: {:ok, sent_body :: binary}, Plug.Link to this callback send_resp ::

Your live template should load without error and look exactly like your original index page. Building Compile-time Tools With Elixir's Compiler Tracing Features, Monitoring the Erlang VM With AppSignal's Magic Dashboard, subscribe to our Elixir Alchemy newsletter and never miss a single post, Writing Predictable Elixir Code with Reducers, LiveView Assigns: Three Common Pitfalls and Their Solutions, AppSignal for Phoenix 2.1: Automatic LiveView Instrumentation, Livebook for Elixir: Just What the Docs Ordered, A Guide to Event-Driven Architecture in Elixir, Using Profiling in Elixir to Improve Performance, Phoenix LiveView Under The Hood: The Form Function Component, a first argument of the atom that we passed to our, a second argument of any params that were part of the incoming web request, a third argument of the session containing the, a fourth argument of the socket (remember, if you use the Phoenix Auth generator, Phoenix will add this.

{:ok, binary}, Plug.Link to this function read_part_body :: Find performance issues before they find you. One size does not fit all, especially when it comes to website design and digital marketing. Since we launched, ShareOne has been able to: Thank you for your support! Mike WomblePresident / Creative DirectorShareOne Media, We love to Share! | integer We could add a render function to our module, satisfying the error, but were going to take a different approach. :ok | {:error, term}, Plug.Link to this callback parse parse( (2), Plug.Debugger.encoded_actions_for_exception (2), Plug.Link to this callback chunk :: {:ok, Plug.Conn.params} Boom!

Pretty cool! That's up to the component. remote_ip: :inet.ip_address, When you live redirect from one live view to another in the same live session, the current live view process terminates. }. Add another new directory called posts_live . | {:more, data :: binary} The LiveView framework allows us to hook into a callback function that will run whenever a live view mounts. | {:no_tmp, [binary]}, Plug.Link to this function read_body :: {:ok, headers}, Plug.Link to this function reason_phrase, Plug.Link to this function register_before_send, Plug.Link to this function send_file send_file( t, Let's create our first live session group now for the routes behind regular user authentication: Here, we establish a live session block to contain all of our routes that need to be authenticated for regular users and tell them to share a common layout found in lib/arcade_web/templates/layout/authenticated.html.heex. private: assigns, She has a passion for coding education. (1), Ecto.Association.ManyToMany.assoc_query (2), Ecto.Changeset.foreign_key_constraint (3), Ecto.Changeset.unsafe_validate_unique (4), Plug.CSRFProtection.InvalidCSRFTokenError, Plug.CSRFProtection.InvalidCrossOriginRequestError, Phoenix.HTML.FormData.input_validations (3), mix phx.gen.context.prompt_for_code_injection (1), Phoenix.ChannelTest.subscribe_and_join (2), Phoenix.ChannelTest.subscribe_and_join (3), Phoenix.ChannelTest.subscribe_and_join (4), Phoenix.ChannelTest.subscribe_and_join! Believe it or not, that's all we have to do to restrict our live routes to logged-in users. We've ensured that our live view routes are secure with nothing more than normal Phoenix auth plugs. One way we do this is by helping veterans and others receive service dogs through. Get alerted in real-time when metrics go over their limits. conn :: Plug.Conn.t, We'll assume that these pages and the live views that back them have already been built. This can also be used to remount the same LiveView, in case you want to start fresh. A collection of helpers to be imported into your views. We are located in beautiful Amsterdam. If you run the Phoenix Auth generator, you generate a module, ArcadeWeb.UserAuth, that implements a function plug require_authenticated_user/2, shown here: The details of this function aren't too important. In this post, we'll show you how to secure your live view routes with function plugs and group live routes in a secure live session. Your app may implement admin logic differently. halted: term, We'll be building some authentication and authorization features into a Phoenix web app built with live view. Let's take a look. Collect metrics and visualize them with a few lines of code. (3), Phoenix.ChannelTest.subscribe_and_join! Additionally, admin users should only be able to visit the /admin-dashboard page. params :: Keyword.t, AppSignal provides insights for Ruby, Rails, Elixir, Phoenix, Node.js, Express and many other frameworks and libraries. payload, In this post, we explored how LiveView allows you to group live routes in a shared session. Now, let's look at a new LiveView feature for grouping live routes together and a security challenge that it presents. | {:too_many_attempts, binary} {:ok, binary}, Plug.Link to this function read_part_headers :: Renders a Phoenix.LiveComponent within a parent LiveView. path_params: params, LiveView powered applications are stateful on the server with bidirectional communication via WebSockets, offering a vastly simplified programming model compared to JavaScript alternatives.. ssl_cert: binary | nil While LiveViews can be nested, each LiveView starts its own process. adapter: adapter, port: :inet.port_number, The current LiveView will be shut down and a new one will be mounted in its place, without reloading the whole page. I hope you've found this post useful.

(1), Phoenix.HTML.Form.%Phoenix.HTML.Form{} (0), Phoenix.HTML.Form.datetime_local_input (3), Phoenix.LiveView.Controller.live_render (3), Phoenix.LiveView.Engine.nested_changed_assign? Pattern matching allows you to respond to broadcasted messages in a granular way. This post assumes you've already built your registration and login flows, along with some function plugs for authenticating the current user and storing their token in the Phoenix session. Start by defining a module that implements an on_mount/4 function, like this: We perform some basic authentication here by looking up the current user and assigning the result to the socket. Renders a title tag with automatic prefix/suffix on @page_title updates. Get the latest posts delivered right to your inbox. LiveComponent comes in two shapes, stateful and stateless. Otherwise, we halt and redirect. LiveView is a compelling choice for building modern web apps. query_params: params, It also has an admin dashboard that should only be accessible to app admins to view survey results. | %{optional}, Plug.Link to this type peer_data :: %{ One last step! (4), Phoenix.ConnTest.response_content_type (2), Phoenix.Controller.protect_from_forgery (2), Phoenix.Controller.put_layout_formats (2), Phoenix.Controller.put_secure_browser_headers (2), Phoenix.Controller.status_message_from_template (1), Phoenix.Endpoint.local_broadcast_from (4), Phoenix.HTML.Engine.encode_to_iodata! Our guest author Sophie is a Senior Engineer at GitHub, co-author of Programming Phoenix LiveView, and co-host of the BeamRad.io podcast. :ok | {:error, term}, Plug.Link to this callback read_req_body :: This approach presents a security challenge. cookies: cookies, The shared layout that frames the live view content will stay in place, and only the portion of the page that renders the current live view within that layout will change. | float before_send: before_send, (3), Phoenix.LiveView.Helpers.live_component (4), Phoenix.LiveView.Helpers.live_redirect (2), Phoenix.LiveView.Helpers.live_title_tag (2), Phoenix.LiveView.Router.fetch_live_flash (2), Phoenix.LiveView.Socket.AssignsNotInSocket, Phoenix.LiveView.Socket.AssignsNotInSocket.t (0), Phoenix.LiveViewTest.assert_push_event (4), Phoenix.LiveViewTest.assert_redirected (2), Phoenix.LiveViewTest.put_connect_info (2), Phoenix.LiveViewTest.put_connect_params (2), Phoenix.LiveViewTest.render_component (3), Phoenix.PubSub.Adapter.direct_broadcast (5), Phoenix.Socket.Transport.check_origin (5), Phoenix.Socket.Transport.check_subprotocols (2), Phoenix.Socket.Transport.connect_info (3), Phoenix.Socket.Transport.handle_control (2), Phoenix.Socket.Transport.transport_log (2), Phoenix.Template.module_to_template_root (3), Phoenix.Template.template_path_to_name (2), Phoenix.Tracker.Shard.graceful_permdown (1), Phoenix.Tracker.Shard.name_for_number (2), Phoenix.Tracker.Shard.validate_down_period (2), Phoenix.Tracker.Shard.validate_permdown_period (2), Phoenix.Tracker.State.remove_down_replicas (2), Plug.CSRFProtection.delete_csrf_token (0), Plug.CSRFProtection.dump_state_from_session (1), Plug.CSRFProtection.get_csrf_token_for (1), Plug.CSRFProtection.valid_state_and_csrf_token? If you'd like to read Elixir Alchemy posts as soon as they get off the press, subscribe to our Elixir Alchemy newsletter and never miss a single post! Built on top of Elixir's OTP tooling, and leveraging WebSockets, it offers super fast real-time, interactive features alongside impressive developer productivity. subtype :: binary, https://hexdocs.pm/phoenix_live_view/Phoenix.LiveView.Helpers.html, live_component(socket, component, assigns \\ [], do_block \\ []), live_render(conn_or_socket, view, opts \\ []), https://hexdocs.pm/phoenix_live_view/Phoenix.LiveView.Helpers.html, Ecto.Adapter.Transaction.adapter_meta (0), Ecto.Adapter.Transaction.in_transaction? If one is found, it returns the conn. | {:error, term}, Plug.Link to this callback send_chunked :: And whenever any of the live views in this session block mount, the UserAuthLive.on_mount/4 function will be called with the :admin atom as a first argument. This function takes three arguments: params, session and socket. See Phoenix.LiveComponent for more information. So lets go create it. Thats it! https://hexdocs.pm/phoenix_live_view/installation.html#content. binary state :: term Were only going to use the socket so you can prefix the others with an underscore to show that we dont care about them. }, Plug.Link to this type resp_cookies => %{}}, Plug.Link to this type scheme :: :http | :https, Plug.Link to this type secret_key_base | nil, Plug.Link to this type state :: :unset | :set | :set_chunked | :set_file | :file | :chunked | :sent, Plug.Link to this type t :: %Plug.Conn{ owner: owner, Provides ~L sigil with HTML safe Live EEx syntax inside source files. path: Path.t Header Photo by Marek Piwnicki on Unsplash. Let's now use our new function plug in our router. This is a guide for converting an existing Phoenix view into a LiveView. script_name: segments, (email works too- info@shareonemedia.com). When navigating to the current LiveView, c:handle_params/3 is immediately invoked to handle the change of params and URL state. {:ok, data :: binary} In order to fix that we need to leverage Phoenix PubSub. Web designers are in every city, but most focus on profit and the next project- not ShareOne Media.

A live redirect is a special kind of redirect that leverages the existing WebSocket connection, minimizing network traffic and keeping your live view speedy. We have duplicated our old dead view and must now plug in the wires to make the template work as a live view. If the function plug is called with a conn that contains a current user, we will check if that user is an admin. We build custom web and mobile applications. All of the assigns given are forwarded directly to the live_component: Note the :id won't necessarily be used as the DOM ID. When a LiveView is rendered, its contents are wrapped in a container. offset :: integer, resp_headers: headers, This is pretty much the simplest possible Phoenix app. length :: integer | :all Remember, you must authenticate and authorize both your protected routes in the router and your live views when they mount. Next up, let's tell our live session to apply this on_mount/4 callback to all of the live routes in its grouping: Whenever there is a live redirect to "/products" route (or any other route in that live session), the given live view will invoke ArcadeWeb.UserAuthLive.on_mount/4 with a first argument of :user and our authentication logic will execute. We can implement authentication requiring the presence of a current user and authorization requiring that the current user has specific permissions or roles just like you would for regular Phoenix routes. Generates a link that will redirect to a new LiveView. Create a file in the blog_web/live/posts_live folder called index.html.heex. Would you like to contribute to the AppSignal blog? Head back to the index.ex module and define a mount function. Create a directory under lib/blog_web called live. | tuple | atom We can take a similar approach to authorizing admins to visit the /admin-dashboard. Get alerted in real-time when your application is down. With this combination of tools, you can bulletproof your live views, making them highly secure and capable of sophisticated authorization logic. In your router.ex file, after pipe_through: :browser, add something like this: If you hit localhost4000/postslive in your browser right now you should get an error because the module BlogWeb.PostsLive is not available. If you want to navigate to the same LiveView without remounting it, use live_patch/2 instead. Add this function to UserAuthLive: Here, when on_mount/4 is called with a first argument of :admin, we will authorize the current user and authenticate them as an admin. Grouping live routes together in a live session means that we can live redirect to those routes from any other route in the same live session group. Within this directory add a file called index.ex. Hopefully this simple example will provide a map for you to quickly implement live views in your pre-existing Phoenix projects. By default, said container is a div tag with a handful of LiveView specific attributes. Go focus on your business. If not, then it redirects to the login path. resp_body: body | nil, This works great for live views that share a layout. scheme: scheme, We must also ensure that our live views can perform their own authentication and authorization every time they mount (whether due to a user pointing their browser directly at a live route or a live redirect between live routes in a shared live session). resp_cookies: resp_cookies, Let's add this to a new live session for the admin-protected routes now: Here, we group admin-protected routes with a shared admin layout. All other options are forwarded to the anchor tag. Still in lib/blog/posts.ex, add a private function to broadcast changes: Then go into your create_post function and call broadcast_change at the end, like this: You can use this pattern wherever you want changes broadcasted. If your app already exists, skip ahead to step 1. We'll create a second scope with a pipeline that uses the require_admin_user/1 function plug: Great! We're looking for skilled mid/senior-level Ruby, Elixir, and Node.js writers. This one is an easy fix. status, Create, update, delete functions are good candidates for broadcasting these messages, since other modules will likely want to respond to these changes.. Now we can head back to posts_live/index.ex and subscribe to the broadcast we just set up. The on_mount/4 lifecycle hook will fire before the live view mounts, making it the perfect place to isolate re-usable auth logic that can be shared among live views in a live session. For live redirects to another LiveView, use live_redirect/2. Note: If you are using a Phoenix version earlier than v1.5, make sure you, install liveview: https://hexdocs.pm/phoenix_live_view/installation.html#content. If the socket then contains a current user value rather than nil, we continue. We'll see how that comes into play in just a bit. From your preferred directory, run this command: When asked if you want to fetch and install dependencies, say yes (Y). This generated code ensures that Phoenix will add a key of :current_user to the conn struct and a "user_token" key to the session when a user logs in. Inside that file define the module BlogWeb.PostsLive.Index like so: Now our module is defined, but we get an error from Phoenix because render is not implemented. A LiveComponent provides similar functionality to LiveView, except they run in the same process as the LiveView, with its own encapsulated state. port: :inet.port_number, {:ok, sent_body :: binary}, Plug.Link to this callback send_file send_file( Returns the flash message from the LiveView flash assign. | [opts] offset :: integer, I recommend using the Phoenix Auth generator to generate this code for free. type :: binary, Back on the posts index page youll see the default links for looking at, editing and deleting your new post. Add a new function to posts_live/index.ex called handle_info: All were doing here is responding to an incoming broadcast from Posts by fetching the list of posts again and assigning it to the socket. AppSignal keeps your team focused on building great apps. The details of our check for the admin status, current_user.admin, don't really matter here. request_path: binary, Thanks to Elixir's pattern matching, we can group all of our auth-related on_mount/4 callbacks in a shared module and implement however many live_session blocks we need to organize our live views. The container can be customized in different ways: You can change the default container on use Phoenix.LiveView: You can override the container tag and pass extra attributes when calling live_render (as well as on your live call in your router): 2018 Chris McCordLicensed under the MIT License. state: state, Add this to mount: Our live view is now listening to events broadcasted from Posts, but we need to reflect those changes in the UI. filename: binary, If a user points their browser at /admin-dashboard, our function plug will be invoked. Follow the links to create a new post and save it to the database. {Macro.t}, Plug.Link to this function configure_session, Plug.Link to this function delete_csrf_token, Plug.Link to this function delete_req_header, Plug.Link to this function delete_resp_cookie, Plug.Link to this function delete_resp_header, Plug.Link to this function delete_session, Plug.Link to this function fetch_cookies, Plug.Link to this function fetch_query_params, Plug.Link to this function fetch_session, Plug.Link to this function get_and_update, Plug.Link to this function get_csrf_token, Plug.Link to this function get_csrf_token_for, Plug.Link to this function get_http_protocol, Plug.Link to this function get_peer_data, Plug.Link to this function get_req_header], Plug.Link to this function get_resp_header], Plug.Link to this function merge_assigns, Plug.Link to this function merge_private, Plug.Link to this function merge_resp_headers, Plug.Link to this function prepend_resp_headers, Plug.Link to this function put_req_header, Plug.Link to this function put_resp_content_type, Plug.Link to this function put_resp_cookie, Plug.Link to this function put_resp_header, Plug.Link to this function random_file :: We will be building a dead-simple example in order to maximize the likelihood that youll be able to easily grok the steps and use them in your own projects. Any on_mount/4 function must conform to this API, returning the :cont tuple or the :halt tuple. :ok | {:ok, sent_body :: binary}, Plug.Link to this callback get_http_protocol, Plug.Link to this callback get_peer_data, Plug.Link to this callback inform :: Speaking of which, lets set up the broadcast. Now, go into the templates/post folder (where the non-live views live) and copy the contents from index.html.heex into lib/blog_web/live/posts_live/index.html.heex. You might notice that the live_session macro is called with a first argument, :user. method: method, While this is a basic example, you may add handle_info callbacks for any subscribed PubSub topics which are relevant to the live view. (2), Phoenix.ChannelTest.subscribe_and_join! Luckily for us, LiveView presents an API for performing authorization and authentication when the live view mounts, making it easy for us to apply this logic across all live routes in a shared session. We might send you some! Weve been in business since 2005, building web and mobile applications for clients ranging from funded startups to Fortune 500 companies. Otherwise, :id is always set to nil. Furthermore, any live view within the live session will mount with the :current_user already set in its socket assigns, since we're adding it in the on_mount callback. If you do too, let us know. Let's require that a user is logged in for access to the scope routes, like this: Add the product index, show routes, and the /survey route that any authenticated user can currently visit: Now, when a user visits /products or any other route in our new scope, Phoenix invokes the require_authenticated_user function plug. params: params, }, Plug.Link to this type t :: %Plug.Upload{ Whenever a user live redirects from the /products route to /products/:id, for example, the existing WebSocket connection will not terminate. body_params: params, {:ok, sent_body :: binary}, Plug.Link to this function clear_session, Plug.Link to this function compile :: | {:error, :too_large, Plug.Conn.t} Theres only one problem: it isnt live. assigns: assigns, We need to get that data to the live view another way. {:ok, binary} First we need to define a route to our live view. We'll add a new function plug to the UserAuth module, like this: If the function plug is invoked with a conn struct that does not contain the current user, we will redirect to the root path. Then the new state is pushed to the client, without reloading the whole page while also maintaining the current scroll position. host: host, If so, return the conn, otherwise, redirect. query_string: query_string, req_cookies: cookies,

empower children in Haiti through tuition scholarships, care for homeless friends in Wilmington, NC. So we must perform authentication and authorization in our router to prevent direct navigation to sensitive routes from the browser. Grouping enables live views to easily share a layout and implement shared authentication and authorization logic.

length :: integer | :all | {:next, Plug.Conn.t}, Plug.Link to this callback push :: This ensures that only admin users can access those pages, even when live redirected. Renders a LiveView within an originating plug request or within a parent LiveView. So let us know what you have in mind, and well get you a quote or answers asap. We love stroopwafels. For the purpose of this post, we'll assume that logged-in users can visit the /games index and /games/:id show routes to select and play a game, along with the /survey route to fill out the user survey. Plug.Conn.status, Our app has a survey feature that collects users' demographic data and game ratings. address: :inet.ip_address, Historically, she is a cat person but will admit to owning a dog. Instead, we'll kill the current live view process, mount the new live view, and only re-render the necessary portions of the page within the shared layout. I wont be going into detail about how all the features work, but even if youve never used it before you should be able to follow along and get up and running easily. file :: binary, req_headers: headers, The first problem we must solve: since our view is no longer being rendered from the posts controller, we dont have access to our lists of posts, @posts, like we used to. Let's set up a similar callback for the admin live session. Generates a link that will patch the current LiveView. Our focus is on introducing the authentication and authorization code we need to secure these live views. As prompted, add the posts resource to your router in the browser scope: Now you can boot up your server with mix phx.server and visit localhost:4000/posts to see your (empty) list of posts. If we re-use the existing WebSocket connection, we won't be sending a new HTTP request, and we won't go through the plug pipeline defined in our router. ) :: t, Plug.Link to this function update_req_header, Plug.Link to this function update_resp_header, Plug.Link to this type opts :: status: int_status Go into the posts_live/index.html.heex template and replace all instances of @conn with @socket. content_type: binary | nil, P.S. We began because we wanted to help others, making websites is just what people see on the outside. The main takeaway is that we now have a function plug that can authorize certain routes by enforcing that the current user is present and an admin.