Source Chain Retrieving

Related: Fundamentals • HDK • Architecture

Query

• Retrieve the source chain for the cell that’s calling “query()”
• Only way to retrieve private entries

use hdk::prelude::*;
 
#[hdk_extern]
fn query_my_full_chain(_: ()) -> ExternResult<Vec<Record>> { 
  let filter = ChainQueryFilter::new(); // We'll see more options
 
  let my_full_chain: Vec<Record> = query(filter)?; // No network calls
 
  Ok(my_full_chain)
}

use hdk::prelude::*;
 
#[hdk_entry_helper]
struct Comment {
  comment: String
}
 
#[hdk_entry_defs]
#[unit_enum(UnitEntryTypes)]
enum EntryTypes { 
  Comment(Comment),
}
 
#[hdk_extern]
fn query_my_comments(_: ()) -> ExternResult<Vec<Record>> { 
  let comment_entry_type: EntryType = UnitEntryTypes::Comment.try_into()?;
 
  let filter = ChainQueryFilter::new().entry_type(comment_entry_type); // Filter by the given entry type
 
  let all_my_comments = query(filter)?; // Only the records which create or update comments
 
  Ok(all_my_comments)
}
 
#[hdk_extern]
fn query_all_links_i_created(_: ()) -> ExternResult<Vec<Record>> { 
  let filter = ChainQueryFilter::new().action_type(ActionType::CreateLink);
 
  let all_links_i_created = query(filter)?; // Only the records whose action is of type "CreateLink"
 
  Ok(all_links_i_created)
}

Get_agent_activity()

• Retrieve the source chain actions for a given agent
  • All actions are public in the DHT
• Doesn’t return entries

use hdk::prelude::*;
 
#[hdk_extern]
fn get_comments_created_by(author: AgentPubKey) -> ExternResult<Vec<ActionHash>> { 
  let filter = ChainQueryFilter::new(); // Same options as "query"
 
  let agent_activity = get_agent_activity(
    author,
    filter,
    ActivityRequest::Full
  )?;
}