svelte/src/compiler/compile/render_dom/index.ts

510 lines
16 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 { stringify_props } from '../utils/stringify_props';
import add_to_set from '../utils/add_to_set';
import get_object from '../utils/get_object';
import { extract_names } from '../utils/scope';
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.has_outro_method = true;
// prevent fragment being created twice (#1063)
if (options.customElement) block.builders.create.add_line(`this.c = @noop;`);
const builder = new CodeBuilder();
if (component.compile_options.dev) {
builder.add_line(`const ${renderer.file_var} = ${component.file && stringify(component.file, { only_escape_at_symbol: true })};`);
}
const css = component.stylesheet.render(options.filename, !options.customElement);
const styles = component.stylesheet.has_styles && stringify(options.dev ?
`${css.code}\n/*# sourceMappingURL=${css.map.toUrl()} */` :
css.code, { only_escape_at_symbol: true });
const add_css = component.get_unique_name('add_css');
if (styles && component.compile_options.css !== false && !options.customElement) {
builder.add_block(deindent`
function ${add_css}() {
var style = @element("style");
style.id = '${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.add_block(block.toString());
});
if (options.dev && !options.hydratable) {
block.builders.claim.add_line(
'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.has_styles &&
options.css !== false
);
const uses_props = component.var_lookup.has('$$props');
const $$props = uses_props ? `$$new_props` : `$$props`;
const props = component.vars.filter(variable => !variable.module && variable.export_name);
const writable_props = props.filter(variable => variable.writable);
/* eslint-disable @typescript-eslint/indent,indent */
const set = (uses_props || writable_props.length > 0 || component.slots.size > 0)
? deindent`
${$$props} => {
${uses_props && component.invalidate('$$props', `$$props = @assign(@assign({}, $$props), $$new_props)`)}
${writable_props.map(prop =>
`if ('${prop.export_name}' in ${$$props}) ${component.invalidate(prop.name, `${prop.name} = ${$$props}.${prop.export_name}`)};`
)}
${component.slots.size > 0 &&
`if ('$$scope' in ${$$props}) ${component.invalidate('$$scope', `$$scope = ${$$props}.$$scope`)};`}
}
`
: null;
/* eslint-enable @typescript-eslint/indent,indent */
const body = [];
const not_equal = component.component_options.immutable ? `@not_equal` : `@safe_not_equal`;
let dev_props_check;
props.forEach(x => {
const variable = component.var_lookup.get(x.name);
if (!variable.writable || component.component_options.accessors) {
body.push(deindent`
get ${x.export_name}() {
return ${x.hoistable ? x.name : 'this.$$.ctx.' + x.name};
}
`);
} else if (component.compile_options.dev) {
body.push(deindent`
get ${x.export_name}() {
throw new @_Error("<${component.tag}>: Props cannot be read directly from the component instance unless compiling with 'accessors: true' or '<svelte:options accessors/>'");
}
`);
}
if (component.component_options.accessors) {
if (variable.writable && !renderer.readonly.has(x.name)) {
body.push(deindent`
set ${x.export_name}(${x.name}) {
this.$set({ ${x.name === x.export_name ? x.name : `${x.export_name}: ${x.name}`} });
@flush();
}
`);
} else if (component.compile_options.dev) {
body.push(deindent`
set ${x.export_name}(value) {
throw new @_Error("<${component.tag}>: Cannot set read-only property '${x.export_name}'");
}
`);
}
} else if (component.compile_options.dev) {
body.push(deindent`
set ${x.export_name}(value) {
throw new @_Error("<${component.tag}>: Props cannot be set directly on the component instance unless compiling with 'accessors: true' or '<svelte:options accessors/>'");
}
`);
}
});
if (component.compile_options.dev) {
// checking that expected ones were passed
const expected = props.filter(prop => !prop.initialised);
if (expected.length) {
dev_props_check = deindent`
const { ctx } = this.$$;
const props = ${options.customElement ? `this.attributes` : `options.props || {}`};
${expected.map(prop => deindent`
if (ctx.${prop.name} === undefined && !('${prop.export_name}' in props)) {
@_console.warn("<${component.tag}> was created without expected prop '${prop.export_name}'");
}`)}
`;
}
}
// instrument assignments
if (component.ast.instance) {
let scope = component.instance_scope;
const map = component.instance_scope_map;
let pending_assignments = new Set();
walk(component.ast.instance.content, {
enter: (node) => {
if (map.has(node)) {
scope = map.get(node);
}
},
leave(node, parent) {
if (map.has(node)) {
scope = scope.parent;
}
if (node.type === 'AssignmentExpression' || node.type === 'UpdateExpression') {
const assignee = node.type === 'AssignmentExpression' ? node.left : node.argument;
let names = [];
if (assignee.type === 'MemberExpression') {
const left_object_name = get_object(assignee).name;
left_object_name && (names = [left_object_name]);
} else {
names = extract_names(assignee);
}
if (node.operator === '=' && nodes_match(node.left, node.right)) {
const dirty = names.filter(name => {
return name[0] === '$' || scope.find_owner(name) === component.instance_scope;
});
if (dirty.length) component.has_reactive_assignments = true;
code.overwrite(node.start, node.end, dirty.map(n => component.invalidate(n)).join('; '));
} else {
const single = (
node.type === 'AssignmentExpression' &&
assignee.type === 'Identifier' &&
parent.type === 'ExpressionStatement' &&
assignee.name[0] !== '$'
);
names.forEach(name => {
const owner = scope.find_owner(name);
if (owner && owner !== component.instance_scope) return;
const variable = component.var_lookup.get(name);
if (variable && (variable.hoistable || variable.global || variable.module)) return;
if (single && !(variable.subscribable && variable.reassigned)) {
if (variable.referenced || variable.is_reactive_dependency || variable.export_name) {
code.prependRight(node.start, `$$invalidate('${name}', `);
code.appendLeft(node.end, `)`);
}
} else {
pending_assignments.add(name);
}
component.has_reactive_assignments = true;
});
}
}
if (pending_assignments.size > 0) {
if (node.type === 'ArrowFunctionExpression') {
const insert = Array.from(pending_assignments).map(name => component.invalidate(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 = Array.from(pending_assignments).map(name => component.invalidate(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(({ name, reassigned }) => {
const value = `$${name}`;
const callback = `$value => { ${value} = $$value; $$invalidate('${value}', ${value}) }`;
if (reassigned) {
return `$$subscribe_${name}()`;
}
const subscribe = component.helper('subscribe');
let insert = `${subscribe}($$self, ${name}, $${callback})`;
if (component.compile_options.dev) {
const validate_store = component.helper('validate_store');
insert = `${validate_store}(${name}, '${name}'); ${insert}`;
}
return insert;
});
}
const args = ['$$self'];
if (props.length > 0 || component.has_reactive_assignments || component.slots.size > 0) {
args.push('$$props', '$$invalidate');
}
builder.add_block(deindent`
function create_fragment(ctx) {
${block.get_contents()}
}
${component.module_javascript}
${component.fully_hoisted.length > 0 && component.fully_hoisted.join('\n\n')}
`);
const filtered_declarations = component.vars
.filter(v => ((v.referenced || v.export_name) && !v.hoistable))
.map(v => v.name);
if (uses_props) filtered_declarations.push(`$$props: $$props = ${component.helper('exclude_internal_props')}($$props)`);
const filtered_props = props.filter(prop => {
const variable = component.var_lookup.get(prop.name);
if (variable.hoistable) return false;
if (prop.name[0] === '$') return false;
return true;
});
const reactive_stores = component.vars.filter(variable => variable.name[0] === '$' && variable.name[1] !== '$');
if (component.slots.size > 0) {
filtered_declarations.push('$$slots', '$$scope');
}
if (renderer.binding_groups.length > 0) {
filtered_declarations.push(`$$binding_groups`);
}
const has_definition = (
component.javascript ||
filtered_props.length > 0 ||
uses_props ||
component.partly_hoisted.length > 0 ||
filtered_declarations.length > 0 ||
component.reactive_declarations.length > 0
);
const definition = has_definition
? component.alias('instance')
: 'null';
const all_reactive_dependencies = new Set();
component.reactive_declarations.forEach(d => {
add_to_set(all_reactive_dependencies, d.dependencies);
});
const reactive_store_subscriptions = reactive_stores
.filter(store => {
const variable = component.var_lookup.get(store.name.slice(1));
return !variable || variable.hoistable;
})
.map(({ name }) => deindent`
${component.compile_options.dev && `@validate_store(${name.slice(1)}, '${name.slice(1)}');`}
@subscribe($$self, ${name.slice(1)}, $$value => { ${name} = $$value; $$invalidate('${name}', ${name}); });
`);
const resubscribable_reactive_store_unsubscribers = reactive_stores
.filter(store => {
const variable = component.var_lookup.get(store.name.slice(1));
return variable && variable.reassigned;
})
.map(({ name }) => `$$self.$$.on_destroy.push(() => $$unsubscribe_${name.slice(1)}());`);
if (has_definition) {
const reactive_declarations = [];
const fixed_reactive_declarations = []; // not really 'reactive' but whatever
component.reactive_declarations
.forEach(d => {
let uses_props;
const condition = Array.from(d.dependencies)
.filter(n => {
if (n === '$$props') {
uses_props = true;
return false;
}
const variable = component.var_lookup.get(n);
return variable && (variable.writable || variable.mutated);
})
.map(n => `$$dirty.${n}`).join(' || ');
let snippet = `[✂${d.node.body.start}-${d.node.end}✂]`;
if (condition) snippet = `if (${condition}) { ${snippet} }`;
if (condition || uses_props) {
reactive_declarations.push(snippet);
} else {
fixed_reactive_declarations.push(snippet);
}
});
const injected = Array.from(component.injected_reactive_declaration_vars).filter(name => {
const variable = component.var_lookup.get(name);
return variable.injected && variable.name[0] !== '$';
});
const reactive_store_declarations = reactive_stores.map(variable => {
const $name = variable.name;
const name = $name.slice(1);
const store = component.var_lookup.get(name);
if (store && store.reassigned) {
return `${$name}, $$unsubscribe_${name} = @noop, $$subscribe_${name} = () => { $$unsubscribe_${name}(); $$unsubscribe_${name} = ${name}.subscribe($$value => { ${$name} = $$value; $$invalidate('${$name}', ${$name}); }) }`;
}
return $name;
});
let unknown_props_check;
if (component.compile_options.dev && !component.var_lookup.has('$$props') && writable_props.length) {
unknown_props_check = deindent`
const writable_props = [${writable_props.map(prop => `'${prop.export_name}'`).join(', ')}];
@_Object.keys($$props).forEach(key => {
if (!writable_props.includes(key) && !key.startsWith('$$')) @_console.warn(\`<${component.tag}> was created with unknown prop '\${key}'\`);
});
`;
}
builder.add_block(deindent`
function ${definition}(${args.join(', ')}) {
${reactive_store_declarations.length > 0 && `let ${reactive_store_declarations.join(', ')};`}
${reactive_store_subscriptions}
${resubscribable_reactive_store_unsubscribers}
${component.javascript}
${unknown_props_check}
${component.slots.size && `let { $$slots = {}, $$scope } = $$props;`}
${renderer.binding_groups.length > 0 && `const $$binding_groups = [${renderer.binding_groups.map(_ => `[]`).join(', ')}];`}
${component.partly_hoisted.length > 0 && component.partly_hoisted.join('\n\n')}
${set && `$$self.$set = ${set};`}
${injected.length && `let ${injected.join(', ')};`}
${reactive_declarations.length > 0 && deindent`
$$self.$$.update = ($$dirty = { ${Array.from(all_reactive_dependencies).map(n => `${n}: 1`).join(', ')} }) => {
${reactive_declarations}
};
`}
${fixed_reactive_declarations}
return ${stringify_props(filtered_declarations)};
}
`);
}
const prop_names = `[${props.map(v => JSON.stringify(v.export_name)).join(', ')}]`;
if (options.customElement) {
builder.add_block(deindent`
class ${name} extends @SvelteElement {
constructor(options) {
super();
${css.code && `this.shadowRoot.innerHTML = \`<style>${escape(css.code, { only_escape_at_symbol: true }).replace(/\\/g, '\\\\')}${options.dev ? `\n/*# sourceMappingURL=${css.map.toUrl()} */` : ''}</style>\`;`}
@init(this, { target: this.shadowRoot }, ${definition}, create_fragment, ${not_equal}, ${prop_names});
${dev_props_check}
if (options) {
if (options.target) {
@insert(options.target, this, options.anchor);
}
${(props.length > 0 || uses_props) && deindent`
if (options.props) {
this.$set(options.props);
@flush();
}`}
}
}
${props.length > 0 && deindent`
static get observedAttributes() {
return ${JSON.stringify(props.map(x => x.export_name))};
}`}
${body.length > 0 && body.join('\n\n')}
}
`);
if (component.tag != null) {
builder.add_block(deindent`
@_customElements.define("${component.tag}", ${name});
`);
}
} else {
const superclass = options.dev ? 'SvelteComponentDev' : 'SvelteComponent';
builder.add_block(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}, ${prop_names});
${options.dev && `@dispatch_dev("SvelteRegisterComponent", { component: this, tagName: "${name}", id: create_fragment.name });`}
${dev_props_check}
}
${body.length > 0 && body.join('\n\n')}
}
`);
}
return builder.toString();
}