nodemgclient - Node.js Memgraph Client

nodemgclient a Node.js binding for
mgclient used to interact with
Memgraph.

Installation

As usual the package could be downloaded from npm by executing:

npm install @memgraph/client

At the moment only Linux shared library is shipped inside the package. For any
other operating system or incompatible library version, please proceed with
building from source as explained below.

Once the package is properly installed, you can run a simple example:

const memgraph = require('@memgraph/client');

(async () => {
  try {
    const connection = await memgraph.Connect({
      host: 'localhost',
      port: 7687,
    });
    await connection.ExecuteAndFetchAll("CREATE (:Graphs)-[:ARE]->(:Powerful);");
    console.log(await connection.ExecuteAndFetchAll(
      "MATCH (n)-[r]->(m) RETURN n, r, m;"));
  } catch (e) {
    console.log(e);
  }
})();

Build from Source

Below you can find instruction for Linux, MacOS and Windows. You'll know if the
package was successfully build when there will be a file called
nodemgclient/Release/nodemgclient.node, that's a shared library required to
use the client.
Once the library is in place you can pull it in your project just by running:

npm install <path-to-the-repo>

Build from Source on Linux

To install nodemgclient from source you will need:

• OpenSSL >= 1.0.2
• A CMake >= 3.10
• A Clang compiler supporting C11 and C++17 standard
• Node.js >= 12

First install the prerequisites:

• On Debian/Ubuntu:

sudo apt install -y npm nodejs cmake make gcc g++ clang libssl-dev

• On RedHat/CentOS:

sudo yum install -y npm nodejs cmake3 make gcc gcc-c++ clang openssl-devel

Once prerequisites are in place, you can build nodemgclient by running:

npm ci
npm run build:release

To test (Docker is required) run:

npm run test

Build from Source on Windows

Build on Windows using Visual Studio

Since cmake-js is used, compiling for Windows is very similar to compiling
for Linux:

npm ci
npm run build:release

If installing OpenSSL package from
https://slproweb.com/products/Win32OpenSSL.html, make sure to use the full one
because of the header files.

NOTE: Compilation does NOT work yet under MinGW.

Build from Source on MacOS

To build on MacOS it's required to install the openssl package, e.g.:

brew install openssl

Once the package is in place, please set the OPENSSL_ROOT_DIR environment variable:

export OPENSSL_ROOT_DIR="$(brew --prefix openssl)"

Once OpenSSL is in place, please run:

npm ci
npm run build:release

NOTE: For more adventurous folks, since cmake-js is used, it's also possible to set
the OpenSSL path via the following commend:

npx cmake-js compile --CDOPENSSL_ROOT_DIR="$(brew --prefix openssl)"

Implementation and Interface Notes

Temporal Types

Suitable JS type to store Memgrpah temporal types don't exist. In particular,
it's impossible to convert mg_duration and mg_local_time to the Date
type. Since the temporal
specification is not yet widely
supported, the decision was to expose plain JS objects (dict) with the exact
fields mgclient is providing (for more details, please take a look under
mgclient
header
and source
files). In addition, when possible (mg_date and mg_local_date_time), are
converted into objects which have date property,
which in fact, is the JS Date representation of these types. Keep in mind the
loss of precision because JS Date time fields can only store up to
milliseconds precision. However, Memgraph supports microsecond precision for
the local time and therefore any use of the date property (JS Date object)
can potentially cause loss of information.

Module exposes create functions, e.g. createMgDate, which simplify creation
of temporal object interpretable by Memgraph. For more details take a look
under the API docs under index.js file.