[support] How to mark errors in a new language?

[krzychukula]

I'm working on on my own language support in monaco-editor and while adding tokenizer was pretty easy I'm not sure how can I show errors.

        const TokensProvider = {
            tokenize: (line) => {
                const tokens = tokenize(line)
                return {
                    tokens
                };
            }
        };

        monaco.languages.setTokensProvider('myLanguage', TokensProvider);

I was going throgh api and code and so far found info about Markers and Diagnostics.

For now I'm going to go with something like:

  const TokensProvider = {
            tokenize: (line) => {
                const tokens = tokenize(line)
                const markers = tokens.map(({startIndex, scopes, text}) => {
                    if (scopes === 'error') {
                        return {
                            severity: monaco.Severity.Error,
                            startLineNumber: 1,
                            startColumn: startIndex + 1,
                            endLineNumber: 1,
                            endColumn: startIndex + 1 + text.length,
                            message: 'Error \n'
                        };
                    }
                }).filter(exist => exist);

                monaco.editor.getModels()
                   .forEach(model => monaco.editor.setModelMarkers(model, '', markers));

                return {
                    tokens
                };
            }
        };

        monaco.languages.setTokensProvider('myLanguage', TokensProvider);

But I'm sure if it's the best place, on the other hand I would like to run tokenize only once.

Any suggestions?

[krzychukula]

1. I have realized that I don't have startLineNumber or endLineNumber in there so it's probably wrong place. Still I'm not sure how to reuse tokenization if I put it in some other place.

[krzychukula]

3. Last question. My context is a little different because I want to have editor for single line of code with folding. If I understand correctly Monaco editor has been build to be used as a editor window, but is it possible to react to how many folded lines there are and to expand the height of the editor?

Basically: have one one of text visible on the page but if it starts to fold - display two lines of text etc.

Thanks!

[alexdima]

The recommended way to set errors/warnings is via monaco.editor.setModelMarkers. These will then be rendered via squiggles. Here is for example how errors are set for TypeScript/JavaScript.

You can listen to editor.onDidScrollChange and check if e.scrollHeightChanged. Then, you could deduce that wrapping has occurred and then use editor.getLayoutInfo() to look at the lineHeight and then recompute a good height which can then be set via editor.layout({ width: w, height: h});.

[krzychukula]

Thanks