svelte/src/compile/render-dom/index.ts

376 lines
11 KiB

import deindent from '../../utils/deindent';
import { stringify, escape } from '../../utils/stringify';
import CodeBuilder from '../../utils/CodeBuilder';
import Component from '../Component';
import Renderer from './Renderer';
import { CompileOptions } from '../../interfaces';
import { walk } from 'estree-walker';
import stringifyProps from '../../utils/stringifyProps';
import addToSet from '../../utils/addToSet';
import getObject from '../../utils/getObject';
import { extractNames } from '../../utils/annotateWithScopes';
import { nodes_match } from '../../utils/nodes_match';
export default function dom(
component: Component,
options: CompileOptions
) {
const { name, code } = component;
const renderer = new Renderer(component, options);
const { block } = renderer;
block.hasOutroMethod = true;
// prevent fragment being created twice (#1063)
if (options.customElement) block.builders.create.addLine(`this.c = @noop;`);
const builder = new CodeBuilder();
if (component.options.dev) {
builder.addLine(`const ${renderer.fileVar} = ${JSON.stringify(component.file)};`);
}
const css = component.stylesheet.render(options.filename, !options.customElement);
const styles = component.stylesheet.hasStyles && stringify(options.dev ?
`${css.code}\n/*# sourceMappingURL=${css.map.toUrl()} */` :
css.code, { onlyEscapeAtSymbol: true });
if (styles && component.options.css !== false && !options.customElement) {
builder.addBlock(deindent`
function @add_css() {
var style = @createElement("style");
style.id = '${component.stylesheet.id}-style';
style.textContent = ${styles};
@append(document.head, style);
}
`);
}
// fix order
// TODO the deconflicted names of blocks are reversed... should set them here
const blocks = renderer.blocks.slice().reverse();
blocks.forEach(block => {
builder.addBlock(block.toString());
});
if (options.dev && !options.hydratable) {
block.builders.claim.addLine(
'throw new Error("options.hydrate only works if the component was compiled with the `hydratable: true` option");'
);
}
// TODO injecting CSS this way is kinda dirty. Maybe it should be an
// explicit opt-in, or something?
const should_add_css = (
!options.customElement &&
component.stylesheet.hasStyles &&
options.css !== false
);
const props = component.props.filter(x => component.writable_declarations.has(x.name));
const set = component.meta.props || props.length > 0
? deindent`
$$props => {
${component.meta.props && deindent`
if (!${component.meta.props}) ${component.meta.props} = {};
@assign(${component.meta.props}, $$props);
$$invalidate('${component.meta.props_object}', ${component.meta.props_object});
`}
${props.map(prop =>
`if ('${prop.as}' in $$props) $$invalidate('${prop.name}', ${prop.name} = $$props.${prop.as});`)}
}
`
: null;
const body = [];
const not_equal = component.meta.immutable ? `@not_equal` : `@safe_not_equal`;
let dev_props_check;
component.props.forEach(x => {
if (component.imported_declarations.has(x.name) || component.hoistable_names.has(x.name)) {
body.push(deindent`
get ${x.as}() {
return ${x.name};
}
`);
} else {
body.push(deindent`
get ${x.as}() {
return this.$$.ctx.${x.name};
}
`);
}
if (component.writable_declarations.has(x.as) && !renderer.readonly.has(x.as)) {
body.push(deindent`
set ${x.as}(${x.name}) {
this.$set({ ${x.name} });
@flush();
}
`);
} else if (component.options.dev) {
body.push(deindent`
set ${x.as}(value) {
throw new Error("<${component.tag}>: Cannot set read-only property '${x.as}'");
}
`);
}
});
if (component.options.dev) {
// TODO check no uunexpected props were passed, as well as
// checking that expected ones were passed
const expected = component.props
.map(x => x.name)
.filter(name => !component.initialised_declarations.has(name));
if (expected.length) {
dev_props_check = deindent`
const { ctx } = this.$$;
const props = ${options.customElement ? `this.attributes` : `options.props || {}`};
${expected.map(name => deindent`
if (ctx.${name} === undefined && !('${name}' in props)) {
console.warn("<${component.tag}> was created without expected prop '${name}'");
}`)}
`;
}
}
// instrument assignments
if (component.instance_script) {
let scope = component.instance_scope;
let map = component.instance_scope_map;
let pending_assignments = new Set();
walk(component.instance_script.content, {
enter: (node, parent) => {
if (map.has(node)) {
scope = map.get(node);
}
},
leave(node, parent) {
if (map.has(node)) {
scope = scope.parent;
}
if (node.type === 'AssignmentExpression') {
const names = node.left.type === 'MemberExpression'
? [getObject(node.left).name]
: extractNames(node.left);
if (node.operator === '=' && nodes_match(node.left, node.right)) {
const dirty = names.filter(name => {
return scope.findOwner(name) === component.instance_scope;
});
if (dirty.length) component.has_reactive_assignments = true;
code.overwrite(node.start, node.end, dirty.map(n => `$$invalidate('${n}', ${n})`).join('; '));
} else {
names.forEach(name => {
if (component.imported_declarations.has(name)) return;
if (scope.findOwner(name) !== component.instance_scope) return;
pending_assignments.add(name);
component.has_reactive_assignments = true;
});
}
}
else if (node.type === 'UpdateExpression') {
const { name } = getObject(node.argument);
if (component.imported_declarations.has(name)) return;
if (scope.findOwner(name) !== component.instance_scope) return;
pending_assignments.add(name);
component.has_reactive_assignments = true;
}
if (pending_assignments.size > 0) {
if (node.type === 'ArrowFunctionExpression') {
const insert = [...pending_assignments].map(name => `$$invalidate('${name}', ${name})`).join(';');
pending_assignments = new Set();
code.prependRight(node.body.start, `{ const $$result = `);
code.appendLeft(node.body.end, `; ${insert}; return $$result; }`);
pending_assignments = new Set();
}
else if (/Statement/.test(node.type)) {
const insert = [...pending_assignments].map(name => `$$invalidate('${name}', ${name})`).join('; ');
if (/^(Break|Continue|Return)Statement/.test(node.type)) {
if (node.argument) {
code.overwrite(node.start, node.argument.start, `var $$result = `);
code.appendLeft(node.argument.end, `; ${insert}; return $$result`);
} else {
code.prependRight(node.start, `${insert}; `);
}
} else if (parent && /(If|For(In|Of)?|While)Statement/.test(parent.type) && node.type !== 'BlockStatement') {
code.prependRight(node.start, '{ ');
code.appendLeft(node.end, `${code.original[node.end - 1] === ';' ? '' : ';'} ${insert}; }`);
} else {
code.appendLeft(node.end, `${code.original[node.end - 1] === ';' ? '' : ';'} ${insert};`);
}
pending_assignments = new Set();
}
}
}
});
if (pending_assignments.size > 0) {
throw new Error(`TODO this should not happen!`);
}
component.rewrite_props();
}
const args = ['$$self'];
if (component.props.length > 0 || component.has_reactive_assignments) args.push('$$props', '$$invalidate');
builder.addBlock(deindent`
function create_fragment($$, ctx) {
${block.getContents()}
}
${component.module_javascript}
${component.fully_hoisted.length > 0 && component.fully_hoisted.join('\n\n')}
`);
const filtered_declarations = component.declarations.filter(name => {
if (component.hoistable_names.has(name)) return false;
if (component.imported_declarations.has(name)) return false;
if (component.props.find(p => p.as === name)) return true;
return component.template_references.has(name);
});
const filtered_props = component.props.filter(prop => {
if (component.hoistable_names.has(prop.name)) return false;
if (component.imported_declarations.has(prop.name)) return false;
if (prop.name[0] === '$') return false;
return true;
});
const reactive_stores = Array.from(component.template_references).filter(n => n[0] === '$');
filtered_declarations.push(...reactive_stores);
const has_definition = (
component.javascript ||
filtered_props.length > 0 ||
component.partly_hoisted.length > 0 ||
filtered_declarations.length > 0 ||
reactive_stores.length > 0 ||
component.reactive_declarations.length > 0
);
const definition = has_definition
? component.alias('instance')
: 'null';
const all_reactive_dependencies = new Set();
component.reactive_declarations.forEach(d => {
addToSet(all_reactive_dependencies, d.dependencies);
});
const user_code = component.javascript || (
component.ast.js.length === 0 && filtered_props.length > 0
? `let { ${filtered_props.map(x => x.name).join(', ')} } = $$props;`
: null
);
const reactive_store_subscriptions = reactive_stores.length > 0 && reactive_stores
.map(name => deindent`
let ${name};
${component.options.dev && `@validate_store(${name.slice(1)}, '${name.slice(1)}');`}
$$self.$$.on_destroy.push(${name.slice(1)}.subscribe($$value => { ${name} = $$value; $$invalidate('${name}', ${name}); }));
`)
.join('\n\n');
if (has_definition) {
builder.addBlock(deindent`
function ${definition}(${args.join(', ')}) {
${user_code}
${component.partly_hoisted.length > 0 && component.partly_hoisted.join('\n\n')}
${reactive_store_subscriptions}
${set && `$$self.$set = ${set};`}
${component.reactive_declarations.length > 0 && deindent`
$$self.$$.update = ($$dirty = { ${Array.from(all_reactive_dependencies).map(n => `${n}: 1`).join(', ')} }) => {
${component.reactive_declarations.map(d => deindent`
if (${Array.from(d.dependencies).map(n => `$$dirty.${n}`).join(' || ')}) ${d.snippet}`)}
};
`}
return ${stringifyProps(filtered_declarations)};
}
`);
}
if (options.customElement) {
builder.addBlock(deindent`
class ${name} extends @SvelteElement {
constructor(options) {
super();
${css.code && `this.shadowRoot.innerHTML = \`<style>${escape(css.code, { onlyEscapeAtSymbol: true }).replace(/\\/g, '\\\\')}${options.dev ? `\n/*# sourceMappingURL=${css.map.toUrl()} */` : ''}</style>\`;`}
@init(this, { target: this.shadowRoot }, ${definition}, create_fragment, ${not_equal});
${dev_props_check}
if (options) {
if (options.target) {
@insert(options.target, this, options.anchor);
}
${(component.props.length > 0 || component.meta.props) && deindent`
if (options.props) {
this.$set(options.props);
@flush();
}`}
}
}
static get observedAttributes() {
return ${JSON.stringify(component.props.map(x => x.as))};
}
${body.length > 0 && body.join('\n\n')}
}
customElements.define("${component.tag}", ${name});
`);
} else {
const superclass = options.dev ? 'SvelteComponentDev' : 'SvelteComponent';
builder.addBlock(deindent`
class ${name} extends @${superclass} {
constructor(options) {
super(${options.dev && `options`});
${should_add_css && `if (!document.getElementById("${component.stylesheet.id}-style")) @add_css();`}
@init(this, options, ${definition}, create_fragment, ${not_equal});
${dev_props_check}
}
${body.length > 0 && body.join('\n\n')}
}
`);
}
return builder.toString();
}