ESP32 Supabase

An Arduino Platform Library for connecting ESP32 to Supabase via REST API, including user authentication. For now, it only supports the architectures espressif32 in PlatformIO targets.

This library is build for microcontroller, so I think it is appropriate to not include as much user management features, filters or modifier as in Official Javascript Library.

For further information :

• Supabase Documentation
• PostgREST API Documentation

Table of Contents

• ESP32 Supabase
  • Project Using This Library
  • Table of Contents
  • Using This Library
  • Examples
  • Available Method
    • Directly Makes Connection to Database
    • Building The Queries
      • Horizontal Filtering (comparison) Operator
      • Ordering, Limiting or Offseting the Result
      • Getting the Query URL (for debugging)
      • Reset the Query URL
  • To-do (sorted by priority)

Using This Library

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

Available Method

Directly Makes Connection to Database

Method	Description
begin(String url_a, String key_a);	url_a is a Supabase URL and key_a is supabase anon key. Returns void
login_email(String email_a, String password_a)	Returns http response code int
login_phone(String phone_a, String password_a)	Returns http response code int
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, it is mandatory to put some low amount of .limit(), so you can avoid your microcontroller's memory 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();

To-do (sorted by priority)

• Make Select API (GET Request), full with row limits (one by default)
• Make filtering query builder method in Select and update
• Make order/sort query builder method to in Select
• Implement Update with PATCH HTTPS Request
• Port to ESP8266
• Implement calling RPC function with HTTPS Request
• Implement several methods to implement Supabase Realtime

Better documentation is always a welcoming change 😄️😄️