Theia - Variable Resolver Extension
The extension provides variable substitution mechanism inside of strings using ${variableName} syntax.
Variable Contribution Point
Extension provides a hook that allows any extensions to contribute its own variables. Here's the example of contributing two variables:
-
${file}- returns the name of the file opened in the current editor -
${lineNumber}- returns the current line number in the current file
@injectable()
export class EditorVariableContribution implements VariableContribution {
constructor(
@inject(EditorManager) protected readonly editorManager: EditorManager
) { }
registerVariables(variables: VariableRegistry): void {
variables.registerVariable({
name: 'file',
description: 'The name of the file opened in the current editor',
resolve: () => {
const currentEditor = this.getCurrentEditor();
if (currentEditor) {
return currentEditor.uri.displayName;
}
return undefined;
}
});
variables.registerVariable({
name: 'lineNumber',
description: 'The current line number in the current file',
resolve: () => {
const currentEditor = this.getCurrentEditor();
if (currentEditor) {
return `${currentEditor.cursor.line + 1}`;
}
return undefined;
}
});
}
protected getCurrentEditor(): TextEditor | undefined {
const currentEditor = this.editorManager.currentEditor;
if (currentEditor) {
return currentEditor.editor;
}
return undefined;
}
}Note that a Variable is resolved to MaybePromise<string | undefined> which means that it can be resolved synchronously or within a Promise.
Using the Variable Resolver Service
There's the example of how one can use Variable Resolver Service in its own plugin:
@injectable()
export class MyService {
constructor(
@inject(VariableResolverService) protected readonly variableResolver: VariableResolverService
) { }
async resolve(): Promise<void> {
const text = 'cursor is in file ${file} on line ${lineNumber}';
const resolved = await this.variableResolver.resolve(text);
console.log(resolved);
}
}If package.json file is currently opened and cursor is on line 5 then the following output will be logged to the console:
cursor is in file package.json on line 5