Create SC for Decentralized lists

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

Start by locating the existing smart-contract and frontend entry points in the repository, then compare their conventions with the specified datastore layout and interface. Done means the decentralized list contract supports all four operations and the two-step web flow reads, inserts, updates, and removes values with the stated size limit.