Skip to contents

Prepare connection to neo4j database

Source: R/startGraph.R
startGraph.Rd

Prepare connection to neo4j database

Usage

startGraph(
  url,
  database = NA,
  username = NA,
  password = NA,
  importPath = NA,
  .opts = list(),
  check = TRUE,
  api = c("auto", "tx", "v2"),
  cypher_version = c("auto", "")
)

Arguments

url

the DB url

database

the name of the database. If NA (default) it will use "data" with versions 3.. of Neo4j and "neo4j" with versions 4..

username

the neo4j user name (default: NA; works only if authentication has been disabled in neo4j by setting NEO4J.AUTH=none)

password

the neo4j user password (default: NA; works only if authentication has been disabled in neo4j by setting NEO4J.AUTH=none)

importPath

path to the import directory (default: NA => no import directory). Import only works with local neo4j instance.

.opts

a named list identifying the curl options for the handle (see httr2::req_options() and curl option names for a complete list of available options; for example: .opts = list(ssl_verifypeer = 0)). Moreover, this parameter can be used to pass additional headers to the graph requests as "extendedHeaders": it is useful, for example, for OAuth access delegation (see details).

check

check the connection before returning it (default: TRUE). Set to false when connection to the "system" database

api

the HTTP API to use: "tx" for the legacy Transactional Cypher HTTP API (default for self-managed instances), "v2" for the Neo4j Query API v2 (required for Aura, available on self-managed Neo4j >= 5.19), or "auto" (default) to detect automatically — Aura URLs (*.databases.neo4j.io) select "v2", all others select "tx".

cypher_version

The version of the cypher language used by the database. Should be "" for neo4j version <= 5.

Value

A connection to the graph DB: a list with the url and necessary headers

Details

The "ssl.verifypeer" logical option available in the RCurl package used in former versions of neo2R (<= 2.2.0) is not recognized by httr2::req_options(). However, for backward compatibility, if it is used, it is translated into the "ssl_verifypeer" integer curl option with a warning message.

Headers in .opts$extendedHeaders are added to, or overwrite, the default Neo4j headers. If there is a .opts$extendedHeaders[["Authorization"]] value, the default Neo4j "Authorization" header (user credentials) is provided automaticaly as "X-Authorization". This mechanism is used for OAuth access delegation.