Providing Live Templates

This tutorial illustrates how to add default Custom Live Templates to an IntelliJ Platform plugin, and assign valid contexts for these templates based on the surrounding code and file type. In addition, the tutorial discusses how to export existing Live Templates, and bundle them within a plugin. Any Live Template that can be created and exported can be added to a plugin by following the Template Creation, Export, and Extension Point Registration processes.

This tutorial uses the SDK code sample live_templates.

Template Creation

Get started by creating a new Live Template within the IntelliJ Platform-based IDE:

Add a new Template Group, "Markdown" and create a new Live Template under this group.
Assign the template the abbreviation " { ".
Assign the description " SDK: New link reference ".
Paste the following snippet into the Template text field:

[$TEXT$]($LINK$)$END$

The variables $TEXT$ and $LINK$ may be further configured in the Edit variables dialogue to reorder their precedence and bind to the functions that invoke auto-completion at the appropriate time. In the Edit variables dialog, set the Expression for the LINK to complete() using the combo box.

There are many predefined functions that developers should become familiar with before implementing any unique functionality in a plugin.

Export the Live Template

Once the Live Template produces the expected result, export the Live Template. The export produces a file called Markdown.xml with the following contents:

<templateSet group="Markdown">
  <template
      name="{"
      value="[$TEXT$]($LINK$)$END$"
      description="SDK: New link reference"
      toReformat="false"
      toShortenFQNames="false">
    <variable
        name="TEXT"
        expression=""
        defaultValue=""
        alwaysStopAt="true"/>
    <variable
        name="LINK"
        expression="complete()"
        defaultValue=""
        alwaysStopAt="true"/>
  </template>
</templateSet>

The display description can also provide localized variants by specifying key and resource-bundle attributes instead (code insight is available in 2020.3 and later). A quick fix to extract the localized key is available since 2024.2.

Copy this file into the plugin's resources folder.

Implement `TemplateContextType`

A TemplateContextType tells the IntelliJ Platform where the Live Template is applicable: Markdown files. Every context must have a unique TemplateContextType defined for it, and the Platform defines many context types out of the box. The MarkdownContext class defines it for Markdown files. Ultimately, a file's extension determines the applicable Markdown context.

final class MarkdownContext extends TemplateContextType {

  MarkdownContext() {
    super("Markdown");
  }

  @Override
  public boolean isInContext(@NotNull TemplateActionContext templateActionContext) {
    return templateActionContext.getFile().getName().endsWith(".md");
  }

}

Within the <template>...</template> elements in the Markdown.xml Live Template definition file, add the following context elements:

<template>
  <variable ... />
  <context>
    <option name="MARKDOWN" value="true"/>
  </context>
</template>

It is not always necessary to define your own TemplateContextType, as there are many existing template contexts already defined in the IntelliJ Platform. Consider reusing one of the many existing template context types that inherit from TemplateContextType if you are augmenting language support to an existing area.

Completing the Live Template Implementation

Depending on the version of the IntelliJ Platform, different steps are used to complete the implementation of the feature.

Using the com.intellij.defaultLiveTemplates and com.intellij.liveTemplateContext extension points, register the implementations with the IntelliJ Platform. The file attribute in com.intellij.defaultLiveTemplates EP specifies path/filename under the src/main/resources folder.

Specify required contextId attribute in com.intellij.liveTemplateContext EP instead of TemplateContextType constructor (existing declarations will continue working).

<extensions defaultExtensionNs="com.intellij">
  <defaultLiveTemplates file="/liveTemplates/Markdown.xml"/>
  <liveTemplateContext
          contextId="MARKDOWN"
          implementation="org.intellij.sdk.liveTemplates.MarkdownContext"/>
</extensions>

Using the com.intellij.defaultLiveTemplates and com.intellij.liveTemplateContext extension points, register the implementations with the IntelliJ Platform. The file attribute in the com.intellij.defaultLiveTemplates EP specifies path/filename under the src/main/resources folder.

<extensions defaultExtensionNs="com.intellij">
  <defaultLiveTemplates file="/liveTemplates/Markdown.xml"/>
  <liveTemplateContext
      implementation="org.intellij.sdk.liveTemplates.MarkdownContext"/>
</extensions>

The MarkdownTemplateProvider implementing DefaultLiveTemplatesProvider tells the Platform where to find the Live Template settings file. Make sure to include the full path to the file, relative to the src/main/resources directory, excluding the file extension.

package org.intellij.sdk.liveTemplates;

import com.intellij.codeInsight.template.impl.DefaultLiveTemplatesProvider;
import org.jetbrains.annotations.Nullable;

final class MarkdownTemplateProvider implements DefaultLiveTemplatesProvider {
  @Override
  public String[] getDefaultLiveTemplateFiles() {
    return new String[]{"liveTemplates/Markdown"};
  }

  @Nullable
  @Override
  public String[] getHiddenLiveTemplateFiles() {
    return null;
  }
}

Using the com.intellij.defaultLiveTemplatesProvider and com.intellij.liveTemplateContext extension points, register the implementations with the IntelliJ Platform.

<extensions defaultExtensionNs="com.intellij">
  <defaultLiveTemplatesProvider
      implementation="org.intellij.sdk.liveTemplates.MarkdownTemplateProvider"/>
  <liveTemplateContext
      implementation="org.intellij.sdk.liveTemplates.MarkdownContext"/>
</extensions>

Check Plugin

Now verify the plugin is working correctly. Run the plugin in a Development Instance and verify there is a new entry under Settings | Live Templates | Markdown | { (SDK: New link reference).

Finally, create a new file test.md and confirm that the Live Template works by entering a { character and then pressing Tab.

Last modified: 14 May 2024