ESPSupabase

Simple library to connect ESP32/8266 to Supabase via REST API and WebSockets (for Realtime), including user authentication

Installation

This library is available at Arduino's Library Manager, as well as PlatformIO Library Manager

• Arduino Library Manager Guide

Examples

See all examples in examples folder

Supabase PostgREST API (#include <ESPSupabase.h>)

Directly Makes Connection to Database

Method	Description
login_email(String email_a, String password_a)	(OPTIONAL, ONLY IF USING RLS), Returns http response code int
login_phone(String phone_a, String password_a)	(OPTIONAL, ONLY IF USING RLS), Returns http response code int
begin(String url_a, String key_a);	url_a is a Supabase URL and key_a is supabase anon key. Returns void
insert(String table, String json, bool upsert)	Returns http response code int. If you want to do upsert, set thirt parameter to true
upload(String bucket, String filename, String mime_type, Stream *stream, uint32_t size)	bucket is the name of the Supabase Storage bucket without any /. filename is the name to upload the file with, should have extension but no /. Takes a Stream* pointer as an argument, this can be Arduino SD File* or SPIFFS File* types. Returns http response code int. mime_type is for eg. image/jpg. size is the total size in bytes of the file to upload. Returns http response code int.
upload(String bucket, String filename, String mime_type, uint8_t *buffer, uint32_t size)	Same function as the previous one but takes a uint8_t* buffer instead of a Stream*. Can be used for files stored in RAM.
.doSelect()	Called at the end of select query chain, see Examples. Returns http response payload (your data) from Supabase String
.doUpdate(String json)	Called at the end of update query chain, see Examples. Returns http response code from Supabase int

Building The Queries

When building the queries, you can chain the method like in this example.

Remember in .select() method, you have to put .limit(), so your microcontroller's memory don't get overflowed

String read = db.from("table").select("*").eq("column", "value").order("column", "asc", true).limit(1).doSelect();

Methods	Description
.from(String table);	Specify which table you want to query. It will append ?table_name in Request URL
.select(String colls);	Specify that you want to do select query. It will append &select=colls in Request URL
.update(String table);	Specify that you want to do update query. It will append &update in Request URL

Horizontal Filtering (comparison) Operator

Methods	Description
.eq(String colls, String value)	Equals
.gt(String colls, String value)	Greater than
.gte(String colls, String value)	Greater than or equal
.lt(String colls, String value)	Less than
.lte(String colls, String value)	Less than or equal
.neq(String colls, String value)	Not equal
.in(String colls, String value)	One of a list of values, e.g. 1,2,3 – also supports commas in quoted strings like "hi,there","yes,you"
.is(String colls, String value)	Checking for exact equality <null, true, false, unknown>
.cs(String colls, String value)	Contains e.g. example, new
.cd(String colls, String value)	Contained in e.g. 1, 2, 3
.ov(String colls, String value)	Overlap (have points in common), e.g. 2017-01-01, 2017-06-30
.sl(String colls, String value)	Strictly left of, e.g. 1,10
.sr(String colls, String value)	Strictly right of
.nxr(String colls, String value)	Does not extend to the right of, e.g. 1,10
.nxl(String colls, String value)	Does not extend to the left of
.adj(String colls, String value)	Is adjacent to, e.g. 1,10

Ordering, Limiting or Offseting the Result

Methods	Description
.order(String coll, String by, bool nulls);	This reorders the response rows. coll parameter is column name, by parameter is either asc or desc. The last parameter specifies the position of nulls, nullsfirst or nullslast
.limit(unsigned int by);	Limit the amount of response rows. THIS IS MANDATORY FOR SELECT METHOD!!!
.offset(int by);	Request response rows with offset is with its parameters.

Getting the Query URL (for debugging)

db.urlQuery_reset();

Reset the Query URL

This method calls in mandatory, must be called after one opetation (let's say doSelect(), or doUpdate()) before doing anything else.

db.urlQuery_reset();

Supabase Realtime API (#include <ESPSupabaseRealtime.h>)

To use Realtime (Postgres Changes), please see the examples/realtime-postgresChanges and examples/realtime-presence folder. The broadcast feature are not implemented yet.

Method	Description
login_email(String email_a, String password_a)	(OPTIONAL, ONLY IF USING RLS), Returns http response code int
login_phone(String phone_a, String password_a)	(OPTIONAL, ONLY IF USING RLS), Returns http response code int
begin(String hostname, String key, void (*func)(String))	Setup the Realtime connection with Supabase URL and Anon key, also put the handle function for the incoming message
sendPresence(String device_name)	Track the presence (online status) of your ESP device. Track presence on realtime channel "ESP"
addChangesListener(String table, String event, String schema, String filter)	Listen to Postgres Database changes, you can add multiple of this if you want to track changes form multiple tables
listen()	Start websocket connection
loop()	Put this in your loop() function, this will handle the websocket connection and send heartbeats to Supabase

To-do (sorted by priority)

• Implement Postgres Changes in Supabase Realtime
• Implement Presence in Supabase Realtime
• Implement Broadcast in Supabase Realtime

Project Using This Library

• Monitoring dan Data Logging Sensor dengan Platform Database Supabase dan Aplikasi Web React.js

References:

• Supabase Documentation
• Official Javascript Library
• PostgREST API Documentation