Function hdk::entry::get_details[−][src]

pub fn get_details<H: Into<AnyDhtHash>>(
    hash: H, 
    options: GetOptions
) -> ExternResult<Option<Details>>

Get an element from the hash AND the details for the entry or header hash passed in. Returns None if the entry/header does not exist. The details returned are a contextual mix of elements and header hashes, see below.

Note: The return details will be inferred by the hash type passed in, be careful to pass in the correct hash type for the details you want.

Note: If a header hash is passed in the element returned is the specified element. If an entry hash is passed in all the headers (so implicitly all the elements) are returned for the entry that matches that hash. See get for more information about what “oldest live” means.

The details returned include relevant creates, updates and deletes for the hash passed in.

Creates are initial header/entry combinations (elements) produced by commit_entry! and cannot reference other headers. Updates and deletes both reference a specific header+entry combination. Updates must reference another create or update header+entry. Deletes must reference a create or update header+entry (nothing can reference a delete).

Full elements are returned for direct references to the passed hash. Header hashes are returned for references to references to the passed hash.

Details for a header hash return:

  • the element for this header hash if it exists
  • all update and delete elements that reference that specified header

Details for an entry hash return:

  • all creates, updates and delete elements that reference that entry hash
  • all update and delete elements that reference the elements that reference the entry hash

Note: Entries are just values, so can be referenced by many CRUD headers by many authors. e.g. the number 1 or string “foo” can be referenced by anyone publishing CRUD headers at any time they need to represent 1 or “foo” for a create, update or delete. If you need to disambiguate entry values, provide uniqueness in the entry value such as a unique hash (e.g. current chain head), timestamp (careful about collisions!), or random bytes/uuid (see random_bytes() and the uuid rust crate that supports uuids from bytes).

Note: There are multiple header types that exist and operate entirely outside of CRUD elements so they cannot reference or be referenced by CRUD, so are immutable or have their own mutation logic (e.g. link create/delete) and will not be included in get_details results e.g. the DNA itself, links, migrations, etc. However the element will still be returned by get_details if a header hash is passed, these header-only elements will have None as the entry value.