Ensure No Code Execution or Display Without a Valid Language Parser

[Czompi]

Currently, if a language parser is not present or encounters an error, the raw script code still appears or executes, which may lead to unintended behavior or expose sensitive script logic to end users. This issue is critical to maintaining the integrity and user experience of XMDL-based documents.

Expected Behavior:

• If a parser for a specific language is not available or fails due to an error, the script block should be ignored, and no raw code should appear in the rendered output.
• An appropriate fallback or warning mechanism (e.g., a log message) should notify the developer about the missing parser or error without exposing the code.

Steps to Reproduce:

1. Write an XMDL script with a language parser that is not implemented or encounters an error.
   Examples:

   @lua{>
   -- Lua code
   <}

   @cs{>
   // C# code
   <}

   @java{>
   // Java code
   <}

2. Render the XMDL file.

3. Observe that the raw script code is displayed or executed, depending on the implementation.

Actual Behavior:

• The raw code appears in the rendered output if the parser is missing or fails, potentially exposing sensitive logic or breaking the UI.

Proposed Solution:

1. Implement a safeguard to ensure no raw script code is included in the output when:
   • The parser for the language is not implemented.
   • The parser encounters an error during execution.
2. Add a logging or debugging mechanism to indicate missing or faulty parsers without impacting the end-user experience.
3. Introduce a fallback mechanism, such as rendering a placeholder message or simply omitting the script content.

Impact:

• Exposes sensitive script content to end users.
• Reduces user confidence in the platform's reliability.
• Causes potential UI or functional disruptions.

Additional Notes:
This enhancement ensures that XMDL remains robust and user-friendly while preventing accidental exposure of raw code or execution errors. It applies to all supported scripting languages, including (but not limited to) Lua, C#, and Java.