calldata

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

• home :: github.com/0xCompute/ethscribe
• bugs :: github.com/0xCompute/ethscribe/issues
• gem :: rubygems.org/gems/calldata
• rdoc :: rubydoc.info/gems/calldata

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

Let's start with the Calldata encode/decode helpers. In an inscribe the data gets encoded 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( "Hello, World!" )
#=>  "48656c6c6f2c20576f726c6421"
utf8 = hex_to_utf8( "48656c6c6f2c20576f726c6421" )
#=>  "Hello, World!"

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

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

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

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

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

Data URIs / URLs

Let's continue with the built-in data uri/url machinery. A valid inscribe must use a valid data uri/url in the calldata.

The "useless" (null) minimum is:

data_uri = "data:,"

Calldata.valid_data?( data_uri )  
#=> true
data = Calldata.parse_data( data_uri )    # returns a Calldata::Text object
data.type #=> "text/plain"
data.text #=> ""

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

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

Calldata.valid_data?( data_uri )  
#=> true
data = Calldata.parse_data( data_uri )   # returns a Calldata::Blob object 
data.type #=> "image/jpeg"
data.blob #=> <blob>
## let's save the jpeg image (blob)
data.write( "0.jpeg" )

and voila!

Let's try the inscribe no. 15:

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

Calldata.valid_data?( data_uri )  
#=> true
data = Calldata.parse_data( data_uri )    # returns a Calldata::Blob object 
data.type  #=> "image/png"
data.blob  #=> <blob>
## let's save the png image (blob)
data.write( "15.png" )

and voila!

Let's try a (structured) protocol message inscribe:

data_uri = %Q<data:,{"p":"erc-20","op":"mint","tick":"eths","id":"16888","amt":"1000"}>


Calldata.valid_data?( data_uri )  
#=> true
data = Calldata.parse_data( data_uri )    # returns a Calldata::Msg object 
data.type     #=> "application/json"  
data['p']     #=> "erc-20"
data['op']    #=> "mint"
data['tick']  #=> "eths"
data['id']    #=> "16888"
data['amt']   #=> "1000"

or use the convenience all-in-one parse_hex helper:

hex  = "0x646174613a2c7b2270223a226572632d3230222c226f70223a226d696e74222c227469636b223a2265746873222c226964223a223136383838222c22616d74223a2231303030227d"

data = Calldata.parse_hex( hex )    # returns a Calldata::Msg object 
data.type     #=> "application/json"  
data['p']     #=> "erc-20"
data['op']    #=> "mint"
data['tick']  #=> "eths"
data['id']    #=> "16888"
data['amt']   #=> "1000"

That's it for now.

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

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

Questions? Comments?

Join us in the 0xCompute discord (chat server) (or in the more general Ethscription discord). Yes you can. Your questions and commentary welcome.

Or post them over at the Help & Support page. Thanks.