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svelte

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Cybernetically enhanced web apps

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/** @import { AssignmentOperator, Expression, Identifier, Node, Statement, TemplateElement } from 'estree' */ /** @import { AST } from '#compiler' */ /** @import { ComponentContext, ServerTransformState } from '../../types.js' */ import { escape_html } from '../../../../../../escaping.js'; import { BLOCK_CLOSE, BLOCK_OPEN, EMPTY_COMMENT } from '../../../../../../internal/server/hydration.js'; import * as b from '../../../../../utils/builders.js'; import { sanitize_template_string } from '../../../../../utils/sanitize_template_string.js'; import { regex_whitespaces_strict } from '../../../../patterns.js'; /** Opens an if/each block, so that we can remove nodes in the case of a mismatch */ export const block_open = b.literal(BLOCK_OPEN); /** Closes an if/each block, so that we can remove nodes in the case of a mismatch. Also serves as an anchor for these blocks */ export const block_close = b.literal(BLOCK_CLOSE); /** Empty comment to keep text nodes separate, or provide an anchor node for blocks */ export const empty_comment = b.literal(EMPTY_COMMENT); /** * Processes an array of template nodes, joining sibling text/expression nodes and * recursing into child nodes. * @param {Array<AST.SvelteNode>} nodes * @param {ComponentContext} context */ export function process_children(nodes, { visit, state }) { /** @type {Array<AST.Text | AST.Comment | AST.ExpressionTag>} */ let sequence = []; function flush() { let quasi = b.quasi('', false); const quasis = [quasi]; /** @type {Expression[]} */ const expressions = []; for (let i = 0; i < sequence.length; i++) { const node = sequence[i]; if (node.type === 'Text' || node.type === 'Comment') { quasi.value.cooked += node.type === 'Comment' ? `<!--${node.data}-->` : escape_html(node.data); } else if (node.type === 'ExpressionTag' && node.expression.type === 'Literal') { if (node.expression.value != null) { quasi.value.cooked += escape_html(node.expression.value + ''); } } else { expressions.push(b.call('$.escape', /** @type {Expression} */ (visit(node.expression)))); quasi = b.quasi('', i + 1 === sequence.length); quasis.push(quasi); } } for (const quasi of quasis) { quasi.value.raw = sanitize_template_string(/** @type {string} */ (quasi.value.cooked)); } state.template.push(b.template(quasis, expressions)); } for (let i = 0; i < nodes.length; i += 1) { const node = nodes[i]; if (node.type === 'Text' || node.type === 'Comment' || node.type === 'ExpressionTag') { sequence.push(node); } else { if (sequence.length > 0) { flush(); sequence = []; } visit(node, { ...state }); } } if (sequence.length > 0) { flush(); } } /** * @param {Node} node * @returns {node is Statement} */ function is_statement(node) { return node.type.endsWith('Statement') || node.type.endsWith('Declaration'); } /** * @param {Array<Statement | Expression>} template * @param {Identifier} out * @param {AssignmentOperator} operator * @returns {Statement[]} */ export function build_template(template, out = b.id('$$payload.out'), operator = '+=') { /** @type {string[]} */ let strings = []; /** @type {Expression[]} */ let expressions = []; /** @type {Statement[]} */ const statements = []; const flush = () => { statements.push( b.stmt( b.assignment( operator, out, b.template( strings.map((cooked, i) => b.quasi(cooked, i === strings.length - 1)), expressions ) ) ) ); strings = []; expressions = []; }; for (let i = 0; i < template.length; i++) { const node = template[i]; if (is_statement(node)) { if (strings.length !== 0) { flush(); } statements.push(node); } else { if (strings.length === 0) { strings.push(''); } if (node.type === 'Literal') { strings[strings.length - 1] += node.value; } else if (node.type === 'TemplateLiteral') { strings[strings.length - 1] += node.quasis[0].value.cooked; strings.push(...node.quasis.slice(1).map((q) => /** @type {string} */ (q.value.cooked))); expressions.push(...node.expressions); } else { expressions.push(node); strings.push(''); } } } if (strings.length !== 0) { flush(); } return statements; } /** * * @param {AST.Attribute['value']} value * @param {ComponentContext} context * @param {boolean} trim_whitespace * @param {boolean} is_component * @returns {Expression} */ export function build_attribute_value( value, context, trim_whitespace = false, is_component = false ) { if (value === true) { return b.true; } if (!Array.isArray(value) || value.length === 1) { const chunk = Array.isArray(value) ? value[0] : value; if (chunk.type === 'Text') { const data = trim_whitespace ? chunk.data.replace(regex_whitespaces_strict, ' ').trim() : chunk.data; return b.literal(is_component ? data : escape_html(data, true)); } return /** @type {Expression} */ (context.visit(chunk.expression)); } let quasi = b.quasi('', false); const quasis = [quasi]; /** @type {Expression[]} */ const expressions = []; for (let i = 0; i < value.length; i++) { const node = value[i]; if (node.type === 'Text') { quasi.value.raw += trim_whitespace ? node.data.replace(regex_whitespaces_strict, ' ') : node.data; } else { expressions.push( b.call('$.stringify', /** @type {Expression} */ (context.visit(node.expression))) ); quasi = b.quasi('', i + 1 === value.length); quasis.push(quasi); } } return b.template(quasis, expressions); } /** * @param {Identifier} node * @param {ServerTransformState} state * @returns {Expression} */ export function build_getter(node, state) { const binding = state.scope.get(node.name); if (binding === null || node === binding.node) { // No associated binding or the declaration itself which shouldn't be transformed return node; } if (binding.kind === 'store_sub') { const store_id = b.id(node.name.slice(1)); return b.call( '$.store_get', b.assignment('??=', b.id('$$store_subs'), b.object([])), b.literal(node.name), build_getter(store_id, state) ); } return node; }