:sig
String markdown_to_html(String src)
String markdown_to_html(String src, DValue options)

:params
src : markdown source text
options : optional markdown options tree
return value : rendered HTML string

:see
markdown_to_ast
component
component_render
json_decode
String

:content
Renders Markdown source into HTML and returns the generated markup as a `String`.

`markdown_to_html()` does not write to the output stream directly. This keeps it aligned with the UCE naming convention where `render_*` names are reserved for direct-output helpers.

Because the return value is HTML markup, embed it with `<?: markdown_to_html(...) ?>`, `print(markdown_to_html(...))`, or pass it through a component.

By default the function aims at a practical GitHub-flavored Markdown target, including tables, task lists, fenced code blocks, autolinks, and strikethrough.

Example:

```uce
DValue options;
options["components"][":::warning"] = "components/markdown/warning";
options["components"]["node.code_block"] = "components/markdown/code_block";
String html = markdown_to_html(file_get_contents("guide.md"), options);
print(html);
```

Supported syntax:

- headings with `#` or setext underlines
- paragraphs
- ordered and unordered lists
- task lists
- blockquotes
- fenced code blocks
- horizontal rules
- tables
- inline emphasis, strong, strikethrough, and code spans
- links, images, and bare `http://` / `https://` URLs
- `:::name ... :::` directive blocks

Options:

- `options["gfm"]` defaults to `true` and turns on GitHub-style extras such as tables, task lists, autolinks, and strikethrough.
- `options["allow_html"]` defaults to `false`. When true, raw HTML blocks and inline tags may pass through as `raw_html` nodes instead of being escaped as plain text.
- `options["components"]` declares renderer extension points using normal UCE components.

Directive hook example:

```uce
options["components"][":::warning"] = "components/markdown/warning";
```

Generic node hook examples:

```uce
options["components"]["node.code_block"] = "components/markdown/code_block";
options["components"]["node.table"] = "components/markdown/table";
options["components"]["node.link"] = "components/markdown/link";
options["components"]["node.directive"] = "components/markdown/directive";
```

If both an exact directive hook and a generic `node.directive` hook exist, the exact directive hook wins.

When a markdown hook component is called, its props arrive in `context.props`.

Useful fields include:

- `context.props["hook"]` for the matched hook key such as `:::warning` or `node.code_block`
- `context.props["target"]` for the resolved component target name
- `context.props["default_html"]` for the renderer output without the hook
- `context.props["children_html"]` for already-rendered child HTML
- `context.props["node"]` for the full AST node
- `context.props["type"]` for the node type
- `context.props["name"]` for the directive name when applicable
- `context.props["argument"]` for directive remainder after the name
- `context.props["text"]` for source text used by nodes such as `code_block`
- `context.props["lang"]` for fenced code language
- `context.props["href"]`, `context.props["src"]`, and `context.props["title"]`
- `context.props["options"]` for the full markdown options tree

Directive blocks use this form:

```md
:::warning title="Heads up"
Body markdown here
:::
```

The parser stores:

```text
node["name"] = "warning"
node["argument"] = ...
node["attrs"] = ...
```

That makes directive components a good fit for alerts, callouts, cards, embeds, and richer page-level Markdown extensions.

Related:

- PHP: Parsedown, League CommonMark, or similar Markdown-to-HTML renderers
- JavaScript / Node.js: `marked`, `markdown-it`, `remark-html`, or other Markdown renderers