README.md

Neo4j for VS Code Preview

Getting started

After installing the extension from the VS Code Marketplace, open a file with a .cypher extension to start using it. To enable database aware features (such as completing labels, functions and procedures), set up a connection to a Neo4j instance using the database connection pane.

Feature Highlights

Our extension preview provides a rich set of features for working with Cypher, the query language for Neo4j databases, including:

• Syntax highlighting
• Linting - both simple and semantic errors (e.g. type errors, unknown labels, etc)
• Autocompletion for Cypher keywords, functions, labels, properties, database names and more
• Signature help for functions - shows the signature of the function while typing
• Formatting - format the document according to the Cypher styleguide
• Connection management.
• Query parameter management.
• Query execution.

It also provides syntax highlighting embedded in other languages, namely Markdown, Java, Python, Javascriopt, .NET and Go. This is possible having a multiline string that starts with //cypher or /*cypher*/ or a single line string starting with /*cypher*/. We also support a templated string /*cypher*/{{query here}}` in Javascript.

Inside those languages you can also select a Cypher snippet and either create a cypher file with language smarts (completions, linting, etc) from it or execute that snippet.

Examples for the syntax highligting:

Markdown

```cypher
MATCH (n) RETURN n
```

Java

String a = """//cypher
    MATCH (n)
    RETURN n
"""

String b = """/*cypher*/
    MATCH (n)
    RETURN n
"""

String c = "/*cypher*/ MATCH (n:Label) RETURN function(n.property)"

Javascript / Typescript

const a = /* cypher */ `
    MATCH (n)
    RETURN n
`;

const b = `//cypher
    MATCH (n)
    RETURN n
`;

const c = `/*cypher*/
    MATCH (n)
    RETURN n
`;

const d = '/*cypher*/ MATCH (n) RETURN n';

Managing connections

To add a new instance connection, you can launch the connection pane from the Neo4j icon in the Activity Bar (either on the Add new connection button when the pane is empty or on the + icon), or by using the Neo4j: Create New Connection command from the Command Palette.

Clicking on an instance will automatically connect to it. You can also manage a connection by right clicking on it, to connect, disconnect or edit it.

Once a connection is added, and a connection to your Neo4j instance is established, you will be able to use database aware features of the extension. You can change the database you want to run queries against by clicking or right clicking (Switch to database) on it.

You can store connections to different Neo4j instances.

Managing parameters

To add a new parameter, you can use the Neo4j: Add parameter command from the Command Palette or use the + on the Neo4j parameters pane:

You will be prompted for the name and value you want to use for that parameter. The type will be automatically recognized from the value. Some examples:

"something" // would set a string parameter
1234 // would set an Integer parameter
datetime() // would set a datetime parameter
[1,2,3] // would set a List parameter

Any expression that can appear in a RETURN expression can be set as value.

Parameters can be accessed from in a query prepending them with a dollar sign $.

Parameters can be edited / deleted hovering over them.

Executing a Cypher file

Once you've written your desired query (for example RETURN $a, $b) you can execute it by either of:

• Using the Neo4j: Run cypher statements command from the Command Palette.
• Right clicking inside the file you want to run and clicking on the Neo4j: Run cypher statements item.
• Using the shortcut Ctrl+Command+Space (where Command is either the ⌘ key or the alt key depending on your keyboard).

Upcoming features

We're working on adding more features to the extension, such as:

• Dynamically adjusting the language server depending on the neo4j version.
• Improved query results table.
• Graph visualization for the results.

Extension settings

The following settings are available in VS Code once the plugin is installed, which can be set either through the Settings menu on VS Code or by editing your .vscode/settings.json file.

Debug

• neo4j.trace.server: Traces the communication between VS Code and the language server for debugging purposes

Contributing

We welcome your suggestions, ideas, bug reports and contributions on our github.

To build the project locally, see the CONTRIBUTING.md file at the root of the git repository.