Integrating IntelliJ IDEA

This article describes how to run XPath/XQuery code from within the IntelliJ IDEA IDE. There are currently two XQuery plugins for IntelliJ IDEA on the market:

• The xquery-intellij-plugin by Reece H. Dunn.
• The XQuery Support plugin by Grzegorz Ligas.
• Both plugins offer support for XQuery 3.1 and can be run as a client or standalone instance. Please note that the two plugins are mutually exclusive and cannot be activated at the same time in IntelliJ.
• Note: BaseX itself is a highly compliant XQuery 3.1 processor. We strongly encourage you to use the XML editor integrated into the BaseX GUI to edit and query your XML data!

Preparations

The following steps apply to all operating systems and both plugins:

• Install either version of IntelliJ IDEA: the Community or Ultimate edition.
• Download your favorite BaseX distribution (JAR, ZIP, EXE).
• Start BaseX (see Startup).
• Create a BaseX database (see Databases).

xquery-intellij-plugin

This section focuses on Reece H. Dunn’s xquery-intellij-plugin.

Installation

After installing IntelliJ IDEA and BaseX, install the xquery-intellij-plugin by one of the following methods:

From the Start Screen

• Start IntelliJ IDEA and select Configure→Plugins.
• In the Plugins window, select the tab Marketplace.
• Type “XQuery” into the Search plugins in marketplace field.
• Click the Install button below xquery-intellij-plugin.
• You will be prompted to restart IDEA to load the new plugin.

From the IntelliJ IDEA Menu

• Select Settings (Windows)/Preferences (macOS) in the IntelliJ IDEA menu.
• In the Settings/Preferences window, select Plugins.
• In the Plugins window, select the tab Marketplace.
• Type “XQuery” into the Search plugins in marketplace field.
• Click the Install button below xquery-intellij-plugin plugin.
• You will be prompted to restart IDEA to load the new plugin.

Configuring The Processor

• Start IntelliJ IDEA and navigate to Settings (Windows)/Preferences (macOS) either using the Configure button from the start screen or the IntelliJ IDEA menu.
• In the Settings/Preferences window, expand the Languages & Frameworks item and select XQuery.
• Make the choices for your system from the dropdown boxes, e.g.:
  • Implementation = BaseX
  • Implementation version = BaseX 9.1
  • Default XQuery version = XQuery 3.1
  • Dialect for XQuery 3.0 = BaseX
  • Dialect for XQuery 3.1 = BaseX
• Click Apply to store your XQuery settings and then OK to exit the dialog.

Querying Your Data

Create a New Project

• To create a new project choose the Create new project option from the start screen or select New→Project... from the File menu.
• In the New Project dialog, select Empty Project from the left-hand column and click the Next button.
• Enter a name and location for your project and click on the Finish button.

Customize the XQuery Module

• Click the Add Configuration button below the IntelliJ IDEA menu bar.
  
• In the Run/Debug Configurations dialog, expand the Templates list and pick the XQuery entry.
• Click on the three dots ... next to the Query Processor dropdown box.
• In the Manage Query Processors dialog, click on the + button.
• In the New Query Processor Instance dialog, set the following preferences:
  • Description = BaseX (optional; if you leave this field blank, [Implementation] [Version] will be used as description)
  • Implementation = BaseX (should be preset!)
  • JAR File = BaseX.jar (name and location of the JAR file may differ depending on your BaseX distribution and version)
  • Hostname = localhost
  • Database port = 1984
  • Username = admin
  • Password = ...
  • If you tick the check box Create a standalone instance, the fields Hostname, Database port, Username, and Password remain empty.
    
• Click OK to exit the New Query Processor Instance dialog.
• In the Manage Query Processors dialog, now choose the “BaseX [Version] (BaseX)” entry and click OK.
• The Query Processor dropdown box in the Run/Debug Configurations dialog should now also display “BaseX [Version] (BaseX)”. If not, select it from the dropdown box.
• Click Apply and then OK to close the Run/Debug Configurations dialog.

Create a Query File

• In the project view, create a new XQuery file, either by right-clicking on the project name and choosing New→File or by selecting New→File from the File menu. Enter a file name and click OK.
• Type in your query, e.g. db:get("factbook"), and save your file.

Create a New Configuration

• Click on the Add Configuration button once again.
• In the Run/Debug Configurations dialog, click the + button to create a new configuration based on a template.
• Choose the “XQuery” template you configured earlier.
• Enter a name, e.g., “BaseX”, into the Name field.
• The query processor should be preset to “BaseX [Version] (BaseX)”.
• In the Run the query from area, either enter the path to your query file into the Local file field to limit the run configuration to that query or pick the Active editor file option to make the configuration run the script that is currently opened in the IntelliJ editor panel:

• Click Apply and then OK to close the Run/Debug Configurations dialog.
• Now, the configuration should be set, and the green Run button should be available below the IntelliJ IDEA menu bar:

Execute Your Query

• If the configuration does not run as a standalone instance, make sure that BaseX is up and running.
• Click the Run button to execute your query.

Conclusion

The plugin is very well maintained! It adds support for various XQuery Implementations to the IntelliJ IDEA (among them BaseX). It provides syntax highlighting for XQuery and XML, code completion and detects syntactical errors while you type, offering a description for each error. Queries are executed using Run Configurations for which you can configure various query processors, e.g., BaseX.

The BaseX admin log can be accessed and displayed using the Query Log button in the bottom left corner of the IntelliJ IDEA project window.

The plugin contains some minor flaws regarding the use of functions declared in user-defined modules. Such functions are not included in the code completion list and marked as unknown in the code. However, query execution in the BaseX backend works fine nonetheless.

XQuery Support Plugin

This section focuses on Grzegorz Ligas' XQuery Support plugin.

Installation

After installing IntelliJ IDEA and BaseX, install the XQuery Support plugin by one of the following methods:

From the Start Screen

• Start IntelliJ IDEA and select Configure→Plugins.
• In the Plugins window, select the tab Marketplace.
• Type “XQuery” into the Search plugins in marketplace field and press Enter.
• Click the Install button below the XQuery Support plugin or click on the XQuery Support link to get more information on the plugin before installing it.
• You will be prompted to restart IDEA to load the new plugin.

From the IntelliJ IDEA Menu

• Select Settings (Windows)/Preferences (macOS) from the IntelliJ IDEA menu.
• In the Settings/Preferences window, select Plugins.
• In the Plugins panel, select the tab Marketplace.
• Type “XQuery” into the Search plugins in marketplace field and press Enter.
• Click the Install button below the XQuery Support plugin, or click on the XQuery Support link to get more information on the plugin before installing it.
• You will be prompted to restart IDEA to load the new plugin.

Setting Up

File Extensions and XQuery Flavor

• Start IntelliJ IDEA and navigate to Settings (Windows)/Preferences (macOS) either using the Configure button on the start screen or the IntelliJ IDEA menu.
• In the Settings/Preferences window, expand the Languages & Frameworks item, select XQuery and choose which default file extensions and which XQuery flavor you would like to use.
• Click Apply to store your XQuery settings:

Configuring The Processor

You can set up the plugin as a standalone processor or client.

Standalone

• In the Settings (Windows)/Preferences (macOS) window, expand the Languages & Frameworks item and select XQuery Data Sources.
• Click on the + button in the middle column to add a new data source.
• Select BaseX (native embedded) from the dropdown box.
• In the right-hand column, check the User defined XQJ Driver check box.
• Use the + button below the checkbox to add the following jars from your BaseX distribution:
  • basex/BaseX.jar
  • basex/lib/basex-apj-9.1.2.jar
  • basex/lib/basex-xqj-9.0.jar
  • basex/lib/xqj2-0.2.0.jar
• Click Apply to store your settings.

Client

This assumes that you already have a BaseX database named factbook.

• In the Settings (Windows)/Preferences (macOS) window, expand the Languages & Frameworks item and select XQuery Data Sources.
• Click on the + button in the middle column to add a new data source.
• Select BaseX from the dropdown box.
• In the right-hand column, fill in the appropriate connection details, e.g., default values:
• Host = localhost
• Port = 1984
• Database name = factbook
• Username = admin
• Password = ...
• Select Apply, then OK and your BaseX factbook database is ready to query.

Querying Your Data

Create a New Project

• To create a new project, choose the Create new project option from the start screen or select New→Project… from the File menu.
• In the New Project dialog, select Empty Project from the left-hand column and click the Next button.
• Enter a name and location for your project and click on the Finish button.

Customize the XQuery Module

• Click the Add Configuration button below the IntelliJ IDEA menu bar:

• In the Run/Debug Configurations dialog, expand the Templates list and select the XQuery Main Module entry.
• Click on the Configure button next to the Data Source field and either pick the previously configured standalone version (BaseX (native embedded) item) or the client version (BaseX item) from the list.
• Click Apply and then OK to close the Run/Debug Configurations dialog.

Create a Query File

• In the project view, create a new XQuery file by right-clicking on the project name and choosing New→XQuery File. Enter a file name, select Main Module from the Kind dropdown and click OK.
• Type in your query and save your file:

Create a New Configuration

• Click on the Add Configuration button once again.
• In the Run/Debug Configurations dialog, click the + button to create a new configuration based on a template.
• Select the “XQuery Main Module” template you configured earlier.
• Enter a name, e.g., “BaseX”, into the Name field.
• The data source should be preset either to “BaseX (native embedded)” or BaseX depending on your processor configuration.
• In the Main file field, enter the path to your query file:

• Click Apply and then OK to close the Run/Debug Configurations dialog.
• Now, the configuration should be set, and the green Run button should be available below the IntelliJ IDEA menu bar:

Execute Your Query

• If the configuration does not run as a standalone instance, make sure that BaseX is up and running.
• Click the Run button to execute your query.

Conclusion

The plugin adds support for various XQuery Implementations to the IntelliJ IDEA (among them BaseX). It provides syntax highlighting for XQuery and XML and detects syntactical errors while you type, offering a description for each error. Queries are executed using Run Configurations for which you can configure various query processors, e.g., BaseX. The plugin offers code completion for XQuery functions, integrated library modules, such as FunctX or the BaseX [Functions], and user-defined modules. IntelliJ’s Find Usages and Go To options seem to work fine for variables and functions, even across modules. Users can set XQuery-specific code style preferences.

This plugin also has a few minor drawbacks. If no path is specified, syntax highlighting marks user-defined modules as unknown, even if they reside in the designated BaseX module repository. However, the BaseX query processor, resolves them correctly during query execution. Error messages in the editor seem to be kept rather general and should be more specific.

Parameter lists of code completion may be quite extensive and clog the screen.

Leading tab space can be increased in user-defined steps, but neither decreased in single, nor user-defined steps.