Method getYamlFrontmatter

src/rmarkdown/knit.ts:89–128

(docPath: string)

    }

    private getYamlFrontmatter(docPath: string): IYamlFrontmatter {
        const text = fs.readFileSync(docPath, 'utf8');
        const lines = text.split('\n');
        let startLine = -1;
        let endLine = -1;
        for (let i = 0; i < lines.length; i++) {
            if (/\S/.test(lines[i])) {
                if (startLine < 0) {
                    if (lines[i].startsWith('---')) {
                        startLine = i;
                    } else {
                        break;
                    }
                } else {
                    if (lines[i].startsWith('---')) {
                        endLine = i;
                        break;
                    }
                }
            }
        }

        let yamlText: string | undefined = undefined;
        if (startLine + 1 < endLine) {
            yamlText = lines.slice(startLine + 1, endLine).join('\n');
        }

        let paramObj: IYamlFrontmatter = {};
        if (yamlText) {
            try {
                paramObj = yaml.load(
                    yamlText
                ) as IYamlFrontmatter;
            } catch (e) {
                console.error(`Could not parse YAML frontmatter for "${docPath}". Error: ${String(e)}`);
            }
        }

        return paramObj;
    }

    private async getKnitCommand(yamlParams: IYamlFrontmatter, docPath: string, outputFormat?: string): Promise<string | undefined> {
        let knitCommand: string;