#Read in json file elixir ecto how to
#Read in json file elixir ecto update

In this example, I locate the :user process and store its pid. For example, a file based backend may open a file and store the file handle. Normally, we would fetch configuration for the backend here and do any setup work which is required for that particular backend. We implement the callback init/1, which returns, just like a GenServer.

In this case, we are going to use fullscreen mode Exit fullscreen modeĪ backend is a gen_event, so we declare that we implement that behaviour. If we want to upload files to Amazon S3 we need to add some extra libraries from ExAws to what we already have: defp deps doĪfter that, it's time to set up some configurations. You can run your local server and go to try to add a new photo and check if everything works fine. Now let's check our changes and how what we've done works. The form_for/4 function accepts a keyword list of options where we can specify this: %> We also need to change our form into a multipart form. Let's go to our template in lib/file_uploader_web/templates/photo/ and change text input Okay, so now we can display our pictures, but we also need to make some changes when it comes to adding new images. We use the url/4 function which is injected into our FileImage module through use Waffle.Definition macro. This change will allow us to display the photos correctly. The same change we need to provide in our show template in lib/file_uploader_web/templates/photo/. We will start from lib/file_uploader_web/templates/photo/. Now we need to add some changes to the templates we generated earlier. We managed to configure everything on the backend side. Go to the lib/file_uploader_web/endpoint.ex and add a second static plug: plug Plug.Static, at: '/uploads', from: Path.expand( './uploads'), gzip: false So now we need to configure the endpoint.ex to indicate that we will be serving static resources from the /uploads directory. Next part is to add the uploader to the Photo module in lib/file_uploader/gallery/photo.ex: defmodule do use Ecto.Schemaįield :picture, Įnd false def changeset(photo, attrs) doīy default, our files are saved in /uploads folder. # Whitelist file extensions: def validate( png so let's add validation function to file_image.ex: defmodule FileUploader.FileImage do use Waffle.Definition Let's assume we want uploaded files to have the following extensions. We can also provide some file validation to our application. Add use at the top of the file which includes ecto support. Now let's provide some changes to lib/file_uploader_web/uploaders/file_image.ex. To store files locally in our project file system we will start with the setup of the storage provider in dev config: config :waffle, storage: For now, everything in this file is commented out but we will provide some changes there in next section. With above command we generated file in lib/_web/uploaders/file_image.ex. Next, we should generate a definition module with mix waffle.g : mix waffle.g file_image Setup WaffleĪdd the latest stable release of Waffle and Waffle.Ecto to your mix.exs file: defp deps do In the next chapter, we are going to add Waffle and Waffle.Ecto to our project. You can run mix phx.server to start an application and go to just to take a look at what we have created at the moment. Now provide your database credentials in your config and run mix ecto.create & mix ecto.migrate

#Read in json file elixir ecto update

We also need to provide an appropriate route for our new controller in router.ex so update the existing scope just like below: scope '/', FileUploaderWeb do We will have a table named 'photos' in the database with id, picture (for storing data about the file) and timestamps columns. The above command mix generates controller, views, and context for an HTML resource. Let's take a few shortcuts and create everything that we need with one command in the project folder: mix Gallery Photo photos picture:string It's time to create our app: mix phx.new file_uploader

#Read in json file elixir ecto how to

At the end, we will check how to upload files to S3 server. We will also use Waffle.Ecto library to integrate Waffle with Ecto and save file data in the database. To illustrate how to upload files we will start with a simple demo application, which let us upload pictures to local storage and viewing pictures on page. This library is forked from Arc and works much in the same way.

Waffle is a flexible file upload library for Elixir with straightforward integrations for Amazon S3 and ImageMagick.