Crate bolt_client

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::env;
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. In this example, all connection/authentication details are
    // stored in environment variables. A domain is optional - including it will
    // create a client that uses a TLS-secured connection.
    let mut client = Client::new(env::var("BOLT_TEST_ADDR")?,
                                 env::var("BOLT_TEST_DOMAIN").ok().as_deref()).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(), "basic".to_string()),
            ("principal".to_string(), env::var("BOLT_TEST_USERNAME")?),
            ("credentials".to_string(), env::var("BOLT_TEST_PASSWORD")?),
        ])).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());

    // 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(())
}

Modules

client
message
value

Structs

Client

Enums

Message
Value