ssr.ts

import { set_current_component, current_component } from './lifecycle';
import { run_all, blank_object } from './utils';
import { boolean_attributes } from '../../shared/boolean_attributes';
export { is_void } from '../../shared/utils/names';

export const invalid_attribute_name_character = /[\s'">/=\u{FDD0}-\u{FDEF}\u{FFFE}\u{FFFF}\u{1FFFE}\u{1FFFF}\u{2FFFE}\u{2FFFF}\u{3FFFE}\u{3FFFF}\u{4FFFE}\u{4FFFF}\u{5FFFE}\u{5FFFF}\u{6FFFE}\u{6FFFF}\u{7FFFE}\u{7FFFF}\u{8FFFE}\u{8FFFF}\u{9FFFE}\u{9FFFF}\u{AFFFE}\u{AFFFF}\u{BFFFE}\u{BFFFF}\u{CFFFE}\u{CFFFF}\u{DFFFE}\u{DFFFF}\u{EFFFE}\u{EFFFF}\u{FFFFE}\u{FFFFF}\u{10FFFE}\u{10FFFF}]/u;
// https://html.spec.whatwg.org/multipage/syntax.html#attributes-2
// https://infra.spec.whatwg.org/#noncharacter

export function spread(args, attrs_to_add) {
	const attributes = Object.assign({}, ...args);
	if (attrs_to_add) {
		const classes_to_add = attrs_to_add.classes;
		const styles_to_add = attrs_to_add.styles;

		if (classes_to_add) {
			if (attributes.class == null) {
				attributes.class = classes_to_add;
			} else {
				attributes.class += ' ' + classes_to_add;
			}
		}

		if (styles_to_add) {
			if (attributes.style == null) {
				attributes.style = style_object_to_string(styles_to_add);
			} else {
				attributes.style = style_object_to_string(merge_ssr_styles(attributes.style, styles_to_add));
			}
		}
	}

	let str = '';

	Object.keys(attributes).forEach(name => {
		if (invalid_attribute_name_character.test(name)) return;

		const value = attributes[name];
		if (value === true) str += ' ' + name;
		else if (boolean_attributes.has(name.toLowerCase())) {
			if (value) str += ' ' + name;
		} else if (value != null) {
			str += ` ${name}="${value}"`;
		}
	});

	return str;
}

export function merge_ssr_styles(style_attribute, style_directive) {
	const style_object = {};
	for (const individual_style of style_attribute.split(';')) {
		const colon_index = individual_style.indexOf(':');
		const name = individual_style.slice(0, colon_index).trim();
		const value = individual_style.slice(colon_index + 1).trim();
		if (!name) continue;
		style_object[name] = value;
	}

	for (const name in style_directive) {
		const value = style_directive[name];
		if (value) {
			style_object[name] = value;
		} else {
			delete style_object[name];
		}
	}

	return style_object;
}

const ATTR_REGEX = /[&"]/g;
const CONTENT_REGEX = /[&<]/g;

/**
 * Note: this method is performance sensitive and has been optimized
 * https://github.com/sveltejs/svelte/pull/5701
 */
export function escape(html: string, is_attr = false) {
	if (typeof html !== 'string') return html;

	const pattern = is_attr ? ATTR_REGEX : CONTENT_REGEX;
	pattern.lastIndex = 0;

	let escaped = '';
	let last = 0;

  while (pattern.test(html)) {
    const i = pattern.lastIndex - 1;
    const ch = html[i];
    escaped += html.substring(last, i) + (ch === '&' ? '&amp;' : (ch === '"' ? '&quot;' : '&lt;'));
    last = i + 1;
  }

	return escaped + html.substring(last);
}

export function escape_attribute_value(value) {
	return typeof value === 'string' ? escape(value, true) : value;
}

export function escape_object(obj) {
	const result = {};
	for (const key in obj) {
		result[key] = escape_attribute_value(obj[key]);
	}
	return result;
}

export function each(items, fn) {
	let str = '';
	for (let i = 0; i < items.length; i += 1) {
		str += fn(items[i], i);
	}
	return str;
}

export const missing_component = {
	$$render: () => ''
};

export function validate_component(component, name) {
	if (!component || !component.$$render) {
		if (name === 'svelte:component') name += ' this={...}';
		throw new Error(`<${name}> is not a valid SSR component. You may need to review your build config to ensure that dependencies are compiled, rather than imported as pre-compiled modules`);
	}

	return component;
}

export function debug(file, line, column, values) {
	console.log(`{@debug} ${file ? file + ' ' : ''}(${line}:${column})`); // eslint-disable-line no-console
	console.log(values); // eslint-disable-line no-console
	return '';
}

let on_destroy;

export function create_ssr_component(fn) {
	function $$render(result, props, bindings, slots, context) {
		const parent_component = current_component;

		const $$ = {
			on_destroy,
			context: new Map(context || (parent_component ? parent_component.$$.context : [])),

			// these will be immediately discarded
			on_mount: [],
			before_update: [],
			after_update: [],
			callbacks: blank_object()
		};

		set_current_component({ $$ });

		const html = fn(result, props, bindings, slots);

		set_current_component(parent_component);
		return html;
	}

	return {
		render: (props = {}, { $$slots = {}, context = new Map() } = {}) => {
			on_destroy = [];

			const result: {
				title: string;
				head: string;
				css: Set<{
					map: null;
					code: string;
				}>;
			} = { title: '', head: '', css: new Set() };

			const html = $$render(result, props, {}, $$slots, context);

			run_all(on_destroy);

			return {
				html,
				css: {
					code: Array.from(result.css).map(css => css.code).join('\n'),
					map: null // TODO
				},
				head: result.title + result.head
			};
		},

		$$render
	};
}

export function add_attribute(name, value, boolean) {
	if (value == null || (boolean && !value)) return '';
	const assignment = (boolean && value === true) ? '' : `="${escape_attribute_value(value.toString())}"`;
	return ` ${name}${assignment}`;
}

export function add_classes(classes) {
	return classes ? ` class="${classes}"` : '';
}

function style_object_to_string(style_object) {
	return Object.keys(style_object)
		.filter(key => style_object[key])
		.map(key => `${key}: ${style_object[key]};`)
		.join(' ');
}

export function add_styles(style_object) {
  const styles = style_object_to_string(style_object);

  return styles ? ` style="${styles}"` : '';
}