An asynchronous client for Bolt-compatible servers.

Example

The below example demonstrates how to connect to a Neo4j server and send it Bolt messages.

use std::collections::HashMap;
use std::convert::TryFrom;
use std::iter::FromIterator;

use failure::Error;
use tokio::prelude::*;

use bolt_client::*;
use bolt_client::message::*;
use bolt_client::value::*;

#[tokio::main]
async fn main() -> Result<(), Error> {
// Create a new connection to the server and perform a handshake to establish a
// protocol version.
let mut client = Client::new("127.0.0.1".parse().unwrap(), 7687).await?;

// Send an INIT message with authorization details to the server to initialize
// the session.
let response_msg: Message = client.init(
"my-client-name/1.0".to_string(),
HashMap::from_iter(vec![
("scheme".to_string(), Value::from("basic")),
("principal".to_string(), Value::from("neo4j")),
("credentials".to_string(), Value::from("test")),
])).await?;
assert!(Success::try_from(response_msg).is_ok());

// Run a query on the server and retrieve the results
let response_msg = client.run("RETURN 1 as num;".to_string(), None).await?;
// Successful RUN messages will return a SUCCESS message with related metadata
// Consuming these messages is optional and will be skipped for the rest of the example
assert!(Success::try_from(response_msg).is_ok());
// Use PULL_ALL to retrieve results of the query
let (response_msg, records): (Message, Vec<Record>) = client.pull_all().await?;
assert!(Success::try_from(response_msg).is_ok());
// Note that integers are automatically packed into the smallest possible byte
// representation.
assert_eq!(records[0].fields(), &[Value::from(1 as i8)]);

// Clear the database
client.run("MATCH (n) DETACH DELETE n;".to_string(), None).await?;
client.pull_all().await?;

// Run a more complex query with parameters
client.run("CREATE (:Client)-[:WRITTEN_IN]->(:Language {name: $name});".to_string(),
Some(HashMap::from_iter(
vec![("name".to_string(), Value::from("Rust"))]
))).await?;
client.pull_all().await?;
client.run("MATCH (rust:Language) RETURN rust;".to_string(), None).await?;
let (response_msg, records): (Message, Vec<Record>) = client.pull_all().await?;
assert!(Success::try_from(response_msg).is_ok());

// Access properties from returned values
let node = Node::try_from(records[0].fields()[0].clone())?;
assert_eq!(node.labels(), &["Language".to_string()]);
assert_eq!(node.properties(),
&HashMap::from_iter(vec![("name".to_string(), Value::from("Rust"))]));

Ok(())
}