Provide another filter to handle the HTML(after all rendered)

[jiangtj]

Check List

Please check followings before submitting a new feature request.

• I have already read Docs page
• I have already searched existing issues

Feature Request

I tested adding the following filters to the initial example.

let index = 0;
hexo.extend.filter.register('after_render:html', (data) => {
  console.log('--------------------:' + (index++))
  console.log(data.substr(0,10))
});

This filter will be executed many times, such as md to html or ejs to html, etc.

I noticed that there are some built-in filters in hexo, but they are expected to be executed after the template engine to html rendering. If you can provide more accurate filters, you can reduce the number of regular matches and improve performance

hexo/lib/plugins/filter/after_render/index.js

Lines 6 to 7 in a9bbc42

	filter.register('after_render:html', require('./external_link'));
	filter.register('after_render:html', require('./meta_generator'));

Here are two ideas
- Provide after_render:${input}-${output}
- Provide after_render:generate

Others

[SukkaW]

Hexo use hexo.render.getOutput() to find the ext of rendered output. So after_render:html will execute after every rendering of post, partial, tag plugins.

hexo/lib/hexo/render.js

Lines 83 to 89 in 0bebf60

	}).then(result => {
	const output = this.getOutput(ext) || ext;
	return ctx.execFilter(`after_render:${output}`, result, {
	context: ctx,
	args: [data]
	});
	}).asCallback(callback);

hexo/lib/theme/view.js

Lines 116 to 126 in a9bbc42

	function buildFilterArguments(result) {
	const output = render.getOutput(ext) || ext;
	return [
	`after_render:${output}`,
	result,
	{
	context: ctx,
	args: [data]
	}
	];
	}

[jiangtj]

Hexo use hexo.render.getOutput() to find the ext of rendered output. So after_render:html will execute after every partial rendering.

Or provide another filter to handle the HTML(after all rendered), after_render:html isn't very accurate, due to md to html or partial will trigger this filter. But expect to filter the final rendered HTML

[SukkaW]

#4048 (comment)

So after_render:html will execute after every rendering of post, partial, tag plugins.

Firstly, hexo.render.render and hexo.render.renderSync will trigger hexo.extend.filter.execFilter and hexo.extend.filter.execFilterSync.

hexo/lib/hexo/render.js

Lines 83 to 89 in 0bebf60

	}).then(result => {
	const output = this.getOutput(ext) || ext;
	return ctx.execFilter(`after_render:${output}`, result, {
	context: ctx,
	args: [data]
	});
	}).asCallback(callback);

layout will trigger filter execution during precompile:

hexo/lib/theme/view.js

Lines 116 to 126 in a9bbc42

	function buildFilterArguments(result) {
	const output = render.getOutput(ext) || ext;
	return [
	`after_render:${output}`,
	result,
	{
	context: ctx,
	args: [data]
	}
	];
	}

Tag plugins will trigger filter execution because they are using hexo.render.renderSync:

hexo/lib/plugins/tag/blockquote.js

Line 64 in a9bbc42

result += ctx.render.renderSync({text: content, engine: 'markdown'});

hexo/lib/plugins/tag/pullquote.js

Line 14 in 087b3fa

const result = ctx.render.renderSync({text: content, engine: 'markdown'});

hexo/lib/plugins/helper/render.js

Lines 3 to 8 in 0b26940

	module.exports = ctx => function render(text, engine, options) {
	return ctx.render.renderSync({
	text,
	engine
	}, options);
	};

[SukkaW]

@jiangtj What about adding a new parameter noAfterRenderFilter? We could then disable after_render for tag plugins and helpers.

There is no way to determine if it is rendering the final HTML.

[jiangtj]

There is no way to determine if it is rendering the final HTML.

hexo/lib/hexo/index.js

Line 58 in f332669

log.debug(`Rendering HTML ${name}: ${magenta(path)}`);

This may be the starting point

[SukkaW]

This may be the starting point

@jiangtj

hexo/lib/hexo/index.js

Line 59 in f332669

return view.render(locals).tap(result => {

The related line. This view.render() should be the exact final html rendering.

However, how to make after_render:html is only called here is still unknown... Maybe a parameter enableAfterRenderHtml?

[jiangtj]

可能我表述的有误，我说的渲染完成指的是单个html渲染完成，当它完成后我们可以对它操作
Maybe I said something wrong, I said that the rendering completion refers to the completion of a single html rendering, when it is completed we can operate on it

Looking at the results below, I think adding a filter here may be a good choice.

The name of the filter may be after_theme_render after_view_render after_html_render or others

[jiangtj]

加过滤器好简单的，就是测试用例真不会, @SukkaW 大佬加油，我溜了

[SukkaW]

@jiangtj I still prefer to patch after_render:html for better plugin compatibility.

[jiangtj]

@jiangtj I still prefer to patch after_render:html for better plugin compatibility.

I didn't say to remove after_render: html, just add a new filter because it should be executed after a single hrml render is complete

BTW, since head is in partial in the default theme, </head> occurs twice in the match, so using after_render:html is more dangerous

https://github.com/hexojs/hexo-theme-landscape/blob/26f81d9c876182d789975b23f07a1520edf72a12/layout/layout.ejs#L3

hexo.extend.filter.register('after_render:html', (data) => {
  return data.replace('</head>','<meta value="取代内容"></head>')
});

[SukkaW]

#4048 (comment)

@jiangtj

The test case could be:

  it('_generate() - after_route_render filter', () => {
    const hook = sinon.spy();
    hexo.extend.filter.register('after_xxx_render', hook);

    hexo.theme.setView('test.swig', '0');

    hexo.extend.generator.register('test', () => ({
      path: 'test',
      layout: 'test'
    }));

    return hexo._generate().then(() => {
      hook.called.should.be.true;
    });
  });

[SukkaW]

Here are some plugins that should use after_route_render filter after #4051 is merged Hexo 4.3.0 is released:

• https://github.com/hexojs/hexo-filter-nofollow
• https://github.com/hexojs/hexo-html-minifier

[curbengh]

#4051 merged
Need to update doc.

[SukkaW]

@curbengh Will be updated when Hexo 4.3.0 is ready to release.