TxComments

Blockchain operations

• comment

Columns

Name	Description
author	author of the post/comment (username)
permlink	a unique string identifier for the post, linked to the author of the post
parent_author	the author that comment is being submitted to, when posting a new blog this is an empty string
parent_permlink	specific post that comment is being submitted to, when posting a new blog this is an empty string
title	human-readable title of the post being submitted. This is left blank for comments
body	body of the post/comment being submitted, or diff-match-patch when updating
json_metadata	JSON object string containing post or comment metadata

Description

This operation is used to create or update posts and comments.

• permlink - Two authors may have the same permlink as it’s unique to the author only. For example, there could be two authors, Alice and Bob, and both could have a permlink of firstpost

• json_metadata - There is no blockchain-enforced validation on json_metadata, but the community has adopted a particular structure. It should contain a JSON object with the following keys:

  • tags - An array of up to 5 strings. Although the blockchain will accept more than 5, the tags plugin only looks at the first five

  • app - A user agent style application identifier. Typically app_name/version, e.g. hiveblog/0.1

  • format - The format of the body, e.g. markdown

  • In addition to the above keys, application developers are free to add any other keys they want to help manage the content they broadcast.

Create vs. Update

When a comment is first broadcasted, the permlink must be unique for the author. Otherwise, it is interpreted as an update operation. Updates either replace the entire body with the latest operation or patch the body if using diff-match-patch.

For example, if we have a paragraph that has already been broadcast:

“It’s been quite a lot of fun working with these wonderful folk on the Open Hive Network”

and it's changed to :

“It’s been quite a lot of fun working with these wonderful people on the Open Hive Network”

the comment operation will have the following body:

- "@@ -406,12 +406,14 @@"
- ful
- -folk
- +people
- at

In addition to body, the title and json_metadata fields are also replaced by the latest operation.