Calldata Coders & Helpers

calldata - Calldata.encode / Calldata.decode using utf8_to_hex and hex_to_utf8 helpers and more for inscriptions / inscribes for ethereum & co

What's Ethscription Calldata - Ethereum Inscription / Inscribe?!

See Introducing Ethscriptions - A new way of creating and sharing digital artifacts on the Ethereum blockchain using transaction calldata »

Usage

Calldata • DataUri

Calldata

Let's start with the Calldata encode/decode helpers. In an inscribe the data gets incode in the the calldata (hexdata notes) of a transaction. The calldata is a binary blob. Note: This gem uses hexstrings for binary blobs.

Option 1: Use the "low-level" global utf8_to_hex and hex_to_utf8 helper methods:

require 'calldata'

hex = utf8_to_hex( "data:image/png;base64,..." )
#=>  "646174613a696d6167652f706e673b6261736536342c2e2e2e"
utf8 = hex_to_utf8( "646174613a696d6167652f706e673b6261736536342c2e2e2e" )
#=>  "data:image/png;base64,..."

hex = utf8_to_hex( "Hello, World!" )
#=>  "48656c6c6f2c20576f726c6421"
utf8 = hex_to_utf8( "48656c6c6f2c20576f726c6421" )
#=>  "Hello, World!"

Option 2: Use the Calldata module helper methods encode/encode_utf8 and decode/decode_hex:

hex = Calldata.encode( "data:image/png;base64,..." )   
#=>  "646174613a696d6167652f706e673b6261736536342c2e2e2e"
utf8 = Calldata.decode( "0x646174613a696d6167652f706e673b6261736536342c2e2e2e" )    
#=>  "data:image/png;base64,..."

hex = Calldata.encode( "Hello, World!" )
#=>  "48656c6c6f2c20576f726c6421"
utf8 = Calldata.decode( "0x48656c6c6f2c20576f726c6421" )
#=>  "Hello, World!"

Note: The hex_to_utf8 helper (incl. Calldata.decode) works with or without leading 0x in hexstrings.

DataUri

Let's continue with the DataUri helpers. A valid inscribe must use a valid data uri in the calldata.

The "useless" (null) minimum is:


uri = "data:,"

DataUri.valid?( uri )  
#=> true
mediatype, data = DataUri.parse( uri )    ## returns mediatype (1) mimetype+parameters, 2) data)
#=> "", ""

Let's try the (genesis) inscribe no. 0:

uri = "data:,data:image/jpeg;base64,/9j/4AAQSkZJRgABAgAAZABkAAD/7AARRHV..."

DataUri.valid?( uri )  
#=> true
mediatype, data = DataUri.parse( uri )    ## returns mediatype (1) mimetype+parameters, 2) data)
#=> "image/jpeg", "<blob>"

## let's save the jpeg image (blob)
write_blob( "0.jpeg", data )

and voila!

Let's try the inscribe no. 15:

uri = "data:image/png;base64,/9j/4gxYSUNDX1BST0ZJTEUAAQEAAAxITGlubwIQAAB..."

DataUri.valid?( uri )  
#=> true
mediatype, data = DataUri.parse( uri )    ## returns mediatype (1) mimetype+parameters, 2) data)
#=> "image/png", "blob>"

## let's save the jpeg image (blob)
write_blob( "15.jpeg", data )

and voila!

That's it for now.

Bonus - More Blockchain (Crypto) Tools, Libraries & Scripts In Ruby

See /blockchain at the ruby code commons (rubycocos) org.

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