TMDL Extension for Visual Studio Code

Overview

A Visual Studio Code extension that adds language support for the Tabular Model Definition Language TMDL, enabling developers to work directly with the code behind semantic model

Note: This repository will eventually host the source code for the TMDL Language Extension.
For now, it serves only as a central location for tracking bugs and gathering feedback.

Getting Started

1. Install Visual Studio Code
   • VSCode
2. Install the TMDL View VSCode Extension extension
3. After setting up the extension, opening TMDL documents in Visual Studio Code will enable TMDL language features such as semantic highlighting and more.
   

🐞Feedback is welcome and appreciated! If you come across an issue/bug with the extension or have a feature request, please file an issue.

💡 VSCode Theme Support

TMDL syntax highlighting works best in the Default Light and Dark Modern themes in Visual Studio Code.

⚠️ In some themes like Visual Studio Dark and Visual Studio Light, the syntax highlighting may be less visible.
For the best experience, we recommend using one of the themes above.

Features

• Semantic Highlighting: Improves TMDL readability with context-aware coloring.
• Autocomplete: Offers intelligent auto completion suggestions.
• Error Diagnostics: Highlights TMDL language errors.
• Code Formatting: Automatically organizes TMDL code.
• Code Actions: Provides quick fixes and refactoring options for common TMDL issues such as duplicated lineage tag or misspelled property.
• Breadcrumbs: Allow easy navigation within a TMDL document.
• Hover Information: Provides contextual information on mouse hover.

Semantic Highlighting

Semantic highlighting enhances readability by providing consistent and context-aware styling—for enums, errors, integers and strings in property values, as well as strings and comments in Power Query (PQ) and many more! DAX expressions support highlighting of functions, reserved words, variables, strings and comments.

VS Code uses TextMate grammars for basic syntax highlighting via regex-based tokenization. Semantic tokenization adds context-aware highlights from language servers, enhancing the base highlighting improving the overall readability of TMDL documents.

The scope inspector tool allows you to explore what semantic tokens are present in a source file and what theme rules they match to.

Code Formatting

Automatically organizes TMDL code for enhanced readability and consistency along with enhanced formatting for embedded Power Query and DAX expressions within TMDL.

Note: DAX formatting can be enabled or disabled via extension settings.

Error Diagnostics

Identifies and highlights errors in TMDL code directly within the editor. Also detects syntax issues in embedded Power Query and DAX expressions. Error messages are shown in the user's language based on locale settings for TMDL and Power Query. Support for localized errors in DAX expressions will arrive soon.

Diagnostics now support workspace validation across multiple semantic models, providing project-level error detection and reporting.

Note: Users must update their locale setting separately for Power Query in the VS Code extension to enable localization. Workspace validation can be toggled via extension settings.

Autocomplete

Provides smart, context-aware suggestions while editing TMDL documents. Autocomplete support also includes embedded Power Query and DAX queries.

Hover Information

Displays helpful contextual information when hovering over elements in TMDL documents. Supports TMDL, embedded Power Query, and DAX expressions (limited to DAX functions only).

Code Actions

Offers quick fixes and refactoring suggestions for common TMDL issues. Examples include:

1. Resolving duplicated lineage tags
2. Correcting misspelled properties
3. Adding missing syntax elements like colons, quotes, equal signs, etc. And many more helpful fixes.

Breadcrumbs

Allows easy navigation within a TMDL document showing the hierarchical structure of TMDL code.

Limitations

• Currently, the extension on web supports only syntax highlighting. Additional features will be added in future releases.
• The Power Query Autocomplete feature may occasionally display 'No suggestion' in uncommon scenarios.
• The extension may become unresponsive when formatting TMDL scripts that include specific DAX expressions. If this occurs, users can disable DAX formatting in the extension settings. A restart of Visual Studio Code is required for the changes to take effect.
• Function calls to DAX user-defined functions (UDFs) triggers an error <functionName> is not a function when referenced within other DAX expressions.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.