File property in an drupal entity class? - php

Question

How can I store a file in a drupal entity? I have a plublic key to associate to an user so I have created an APIuser entity but I don't know what kind of field give to the public key property
function api_user_schema() {
$schema['api_user'] = array(
'description' => 'The base table for api_user.',
'fields' => array(
'id' => array(
'description' => 'The primary identifier for an artwork.',
'type' => 'serial',
'unsigned' => TRUE,
'not null' => TRUE,
),
'public_key' => array(
'description' => 'The primary identifier for the public key.',
'type' => ???,
'unsigned' => TRUE,
'not null' => TRUE,
)
'created' => array(
'description' =>
'The Unix timestamp when the api_user was created.',
'type' => 'int',
'not null' => TRUE,
'default' => 0,
),
'changed' => array(
'description' =>
'The Unix timestamp when the api_user was most recently saved.',
'type' => 'int',
'not null' => TRUE,
'default' => 0,
),
),
'unique keys' => array(
'id' => array('id')
),
'primary key' => array('id'),
);
return $schema;
}

Answer 1

What you've got there is the definition of a single database table; Drupal offers no layer on top of that for files, so if you want to store a file you'll have to do so manually.
The best example you can take is that of the core user entity. It defines the picture property, which is an ID referencing an entry in the file_managed table (incidentally this is how all permanent file storage is handled by Drupal core by default).
This is the schema definition for that db column (from user_schema()):
'picture' => array(
'type' => 'int',
'not null' => TRUE,
'default' => 0,
'description' => "Foreign key: {file_managed}.fid of user's picture.",
)
Which is very similar to what your definition will need to look like.
From there, have a look at the user_account_form() function (which defines the form element for the picture property), and the user_validate_picture() function, which will show you how to perform the file upload, save the file in the file_managed table, and change the submitted value for the picture field to the relevant file ID (so that it automatically gets saved against the entity).
You'll mostly be replicating the code from those two functions so it won't be that tricky.