Create SC for Decentralized lists

[damip]

A simple decentralized list tool

A simple decentralized tool to make lists.

Smart contract

Datastore layout

In the datastore we simply have one entry per entry of the list list_name:

["dlist"][len(list_name)][list_name][key] -> [value]  // note that len(list_name) is a constant-size integer that prevents key collisions when we have list names of various lengths

Smart contract interface:

read_item(list: Vec<u8>, key: Vec<u8>) -> Vec<u8>
    reads the value of an item, fails if does not exist

item_exists(list: Vec<u8>, key: Vec<u8>) -> bool
    checks if an item exists

remove_item(list: Vec<u8>, key: Vec<u8>)
    owner only
    removes an item, fails if does not exist

insert_item(list: Vec<u8>, key: Vec<u8>, value: Vec<u8>)
    owner only
    overwrites if exists

Web interface

A simple two-step interface:

• step 1: the list name is taken from a URL parameter https://zzzzzzzzz.zzzzz/yyy/?list=xxxxx and displayed in the frontend. The user is asked to enter a key
  • if key exists in the datastore at ["dlist"][len(list_name)][list_name][key] (do not use the item_exists function, directly read the datastore):
  • step 2:
    • Display that the key is in the list
    • Show the associated value in a multiline textarea and allow the user to update it
    • Display a Remove from list button to remove the item
  • if the key is not in the list
    • step 2:
    • Display the key.
    • Allow the user to enter a value in a multiline textarea. Max len = 10 megabytes when encoded to utf8
    • Have a "Insert to list" button to insert the new value in the list