Edge Storage API

The Edge Functions Storage API is an interface that allows access to the Edge Storage. Through this interface, it’s possible to read and write data in the storage and its buckets.

Class instantiation

To leverage this API, you need to import and instantiate the Storage class, passing the bucket’s name.

Syntax

Import:

import Storage from "azion:storage";

Instantiate:

const storage = new Storage(bucket);

Parameters

Parameter	Type	Description
`bucket`	string	Name of a bucket.

Return value

Storage object used to access Edge Storage.

Methods

async storage.put

The Storage.put method is used to insert a new object into the storage.

Syntax

async Storage.put(key, value, options)

Parameters

Parameter	Type	Description
`key`	string	Identifier that allows the search for an object in the storage
`value`	ArrayBuffer ou ReadableStream	Content of the object being stored. In case `value` implements a ReadableStream, the Stream APIs can be used, and the option `content-lenght` is required
`options`	object	The `options` attributes are described in the table below

options

To pass the options parameter, you must provide an object with the following attributes:

Attribute	Type	Description
`content-type`	string	The `content-type` of the object being created. It’s similar to the HTTP Header `content-type` and describes how the content of the bucket should be treated. `content-type` is optional. The default value is `application/octet-stream`
`content-length`	string	The size of the object to be created, in bytes. It’s mandatory when the value is `ReadableStream`
`metadata`	object	Any JavaScript object containing information about the object that will be stored in the Storage. All properties of the object must be strings

Return

Success	Error
No response	Throws a `StorageError`

Code sample

To persist the request body:

import Storage from "azion:storage";

async function handleRequest(event) {
    try{
        const bucket = “mybucket”
        const storage = new Storage(bucket);
        const key = "test";
        const inputStream = event.request.body;
        let contentLength = event.request.headers.get("content-length");
        await storage.put(key, inputStream, { "content-length": contentLength });
        return new Response("OK");
    }catch(error){
        return new Response(error, {status:500});
    }
}

addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

To persist a JSON object:

import Storage from "azion:storage";

async function handleRequest(event) {
    try{
        const bucket = "mybucket";
        const storage = new Storage(bucket);
        const key = "test";
        const data = JSON.stringify({
            name:"John",
            address:"Abbey Road"
        });
        const buffer = new TextEncoder().encode(data);
        await storage.put(key, buffer);
        return new Response("OK");
    }catch(error){
        return new Response(error, {status:500});
    }
}

addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

To save a JSON with metadata:

import Storage from "azion:storage";

async function handleRequest(event) {
    try{
        const bucket = "mybucket";
        const storage = new Storage(bucket);
        const key = "test2";
        const data = JSON.stringify({
            name:"Paul",
            address:"Abbey Road"
        });
        const buffer = new TextEncoder().encode(data);
        const options = { "content-type": "application/json",
                          "metadata": {
                            info:"test info",
                            counter: "1",
                          }}
        await storage.put(key, buffer, options);
        return new Response("OK");
    }catch(error){
        return new Response(error, {status:500});
    }
}

addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

async storage.get(key)

The storage.get(key) method is used to retrieve an object.

Syntax

async storage.get(key)

Parameters

Parameter	Type	Description
`key`	string	Identifier that allows the search for an object in the bucket

Return

Success	Error
Returns an object of the class `StorageObject`	Throws a `StorageError`

Code sample

To retrieve and return content from the storage:

import Storage from "azion:storage";

async function handleRequest(event) {
    try{
        const bucket = "mybucket";
        const storage = new Storage(bucket);
        const key = "test";
        const storageObject = await storage.get(key);
        return new Response(storageObject.content);
    }catch(error){
        return new Response(error, {status:500});
    }
}


addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

To get a JSON from the storage:

import Storage from "azion:storage";

async function handleRequest(event) {
    try{
        const bucket = "mybucket";
        const storage = new Storage(bucket);
        const key = "test";
        const storageObject = await storage.get(key);
        const data = new TextDecoder().decode(await storageObject.arrayBuffer());
        return new Response(data);
    }catch(error){
        return new Response(error, {status:500});
    }
}

addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

To read an object’s metadata:

import Storage from "azion:storage";

async function handleRequest(event) {
    try{
        const bucket = "mybucket";
        const storage = new Storage(bucket);
        const key = "test2"
        const storageObject = await storage.get(key);
        return new Response(storageObject.metadata.get("info"));
    }catch(error){
        return new Response(error, {status:500});
    }
}

addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

async storage.delete(key)

The Storage.delete(key) is used to remove an object from Edge Storage.

Syntax

async Storage.delete(key)

Parameters

Parameter	Type	Description
`key`	string	Identifier that allows the search for an object in the bucket

Return

Success	Error
No response	Throws a `StorageError`

Code sample

To remove an object stored in Edge Storage related to a specific bucket:

import Storage from "azion:storage";

async function handleRequest(event) {
    const bucket = "mybucket";
    const storage = new Storage(bucket);
    const key = "test";
    try{
        await storage.delete(key);
    }catch(error){
        return new Response(error, {status:500});
    }
    return new Response("Ok");
}

addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

async storage.list()

The Storage.list() method is used to list all objects belonging to the specific bucket.

Syntax

await storage.list()

Return

Success	Error
Returns an object of the class StorageObjectList	It throws a `StorageError`

Code sample

Listing objects from Azion Storage:

import Storage from "azion:storage";

async function handleRequest(event) {
    try{
        const bucket = "mybucket";
        const storage = new Storage(bucket);
        const objectsList = await storage.list();
        for (const entry of objectsList.entries) {
            console.log(`key: ${entry.key} length: ${entry.content_length}`);
        }
        return new Response("Ok");
    }catch(error){
        return new Response(error, {status:500});
    }
}

addEventListener("fetch", (event) => {
    event.respondWith(handleRequest(event));
});

StorageObject Class Methods

Method	Description
`StorageObject.content`	Read-only property containing a ReadableStream for the content stored in the storage
`async StorageObject.arrayBuffer()`	Asynchronous function that returns an ArrayBuffer with the content stored in the storage. This method consumes the ReadableStream from the content property
`StorageObject.metadata`	Read-only property containing a Map object with the metadata of the object stored in the storage
`StorageObject.contentType`	Read-only property containing the `content-type` of the content stored in the storage
`StorageObject.contentLength`	Read-only property containing the size in bytes of the content stored in the storage

Discover the power of the Edge Storage API interface for accessing and manipulating data in buckets. Watch the video below: