startGraph: Prepare connection to neo4j database

Description

Prepare connection to neo4j database

Usage

startGraph(
  url,
  database = NA,
  username = NA,
  password = NA,
  importPath = NA,
  .opts = list(),
  check = TRUE
)

Value

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

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 httr::config() and httr::httr_options() 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

Details

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