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svelte/src/compiler/compile/render_dom/wrappers/Element/Binding.ts

325 lines
8.6 KiB

import { b, x } from 'code-red';
import Binding from '../../../nodes/Binding';
import ElementWrapper from '../Element';
import get_object from '../../../utils/get_object';
import Block from '../../Block';
import Renderer from '../../Renderer';
import flatten_reference from '../../../utils/flatten_reference';
import EachBlock from '../../../nodes/EachBlock';
import { changed } from '../shared/changed';
import { Node, Identifier } from 'estree';
export default class BindingWrapper {
node: Binding;
parent: ElementWrapper;
object: string;
handler: {
uses_context: boolean;
mutation: (Node | Node[]);
contextual_dependencies: Set<string>;
snippet?: Node;
};
snippet: Node;
is_readonly: boolean;
needs_lock: boolean;
constructor(block: Block, node: Binding, parent: ElementWrapper) {
this.node = node;
this.parent = parent;
const { dependencies } = this.node.expression;
block.add_dependencies(dependencies);
// TODO does this also apply to e.g. `<input type='checkbox' bind:group='foo'>`?
if (parent.node.name === 'select') {
parent.select_binding_dependencies = dependencies;
dependencies.forEach((prop: string) => {
parent.renderer.component.indirect_dependencies.set(prop, new Set());
});
}
if (node.is_contextual) {
// we need to ensure that the each block creates a context including
// the list and the index, if they're not otherwise referenced
const { name } = get_object(this.node.expression.node);
const each_block = this.parent.node.scope.get_owner(name);
(each_block as EachBlock).has_binding = true;
}
this.object = get_object(this.node.expression.node).name;
// view to model
this.handler = get_event_handler(this, parent.renderer, block, this.object, this.node.raw_expression);
this.snippet = this.node.expression.manipulate(block);
this.is_readonly = this.node.is_readonly;
this.needs_lock = this.node.name === 'currentTime' || (parent.node.name === 'input' && parent.node.get_static_attribute_value('type') === 'number'); // TODO others?
}
get_dependencies() {
const dependencies = new Set(this.node.expression.dependencies);
this.node.expression.dependencies.forEach((prop: string) => {
const indirect_dependencies = this.parent.renderer.component.indirect_dependencies.get(prop);
if (indirect_dependencies) {
indirect_dependencies.forEach(indirect_dependency => {
dependencies.add(indirect_dependency);
});
}
});
return dependencies;
}
is_readonly_media_attribute() {
return this.node.is_readonly_media_attribute();
}
render(block: Block, lock: Identifier) {
if (this.is_readonly) return;
const { parent } = this;
const update_conditions: any[] = this.needs_lock ? [x`!${lock}`] : [];
const dependency_array = [...this.node.expression.dependencies];
if (dependency_array.length > 0) {
update_conditions.push(changed(dependency_array));
}
if (parent.node.name === 'input') {
const type = parent.node.get_static_attribute_value('type');
if (type === null || type === "" || type === "text" || type === "email" || type === "password") {
update_conditions.push(x`(${parent.var}.${this.node.name} !== ${this.snippet})`);
}
}
// model to view
let update_dom = get_dom_updater(parent, this);
// special cases
switch (this.node.name) {
case 'group':
{
const binding_group = get_binding_group(parent.renderer, this.node.expression.node);
block.chunks.hydrate.push(
b`#ctx.$$binding_groups[${binding_group}].push(${parent.var});`
);
block.chunks.destroy.push(
b`#ctx.$$binding_groups[${binding_group}].splice(#ctx.$$binding_groups[${binding_group}].indexOf(${parent.var}), 1);`
);
break;
}
case 'textContent':
update_conditions.push(x`${this.snippet} !== ${parent.var}.textContent`);
break;
case 'innerHTML':
update_conditions.push(x`${this.snippet} !== ${parent.var}.innerHTML`);
break;
case 'currentTime':
case 'playbackRate':
case 'volume':
update_conditions.push(x`!@_isNaN(${this.snippet})`);
break;
case 'paused':
{
// this is necessary to prevent audio restarting by itself
const last = block.get_unique_name(`${parent.var.name}_is_paused`);
block.add_variable(last, x`true`);
update_conditions.push(x`${last} !== (${last} = ${this.snippet})`);
update_dom = b`${parent.var}[${last} ? "pause" : "play"]();`;
break;
}
case 'value':
if (parent.node.get_static_attribute_value('type') === 'file') {
update_dom = null;
}
}
if (update_dom) {
if (update_conditions.length > 0) {
const condition = update_conditions.reduce((lhs, rhs) => x`${lhs} && ${rhs}`);
block.chunks.update.push(b`
if (${condition}) {
${update_dom}
}
`);
} else {
block.chunks.update.push(update_dom);
}
}
if (this.node.name === 'innerHTML' || this.node.name === 'textContent') {
block.chunks.mount.push(b`
if (${this.snippet} !== void 0) {
${update_dom}
}`);
} else if (!/(currentTime|paused)/.test(this.node.name)) {
block.chunks.mount.push(update_dom);
}
}
}
function get_dom_updater(
element: ElementWrapper,
binding: BindingWrapper
) {
const { node } = element;
if (binding.is_readonly_media_attribute()) {
return null;
}
if (binding.node.name === 'this') {
return null;
}
if (node.name === 'select') {
return node.get_static_attribute_value('multiple') === true ?
b`@select_options(${element.var}, ${binding.snippet})` :
b`@select_option(${element.var}, ${binding.snippet})`;
}
if (binding.node.name === 'group') {
const type = node.get_static_attribute_value('type');
const condition = type === 'checkbox'
? x`~${binding.snippet}.indexOf(${element.var}.__value)`
: x`${element.var}.__value === ${binding.snippet}`;
return b`${element.var}.checked = ${condition};`;
}
if (binding.node.name === 'value') {
return b`@set_input_value(${element.var}, ${binding.snippet});`;
}
return b`${element.var}.${binding.node.name} = ${binding.snippet};`;
}
function get_binding_group(renderer: Renderer, value: Node) {
const { parts } = flatten_reference(value); // TODO handle cases involving computed member expressions
const keypath = parts.join('.');
// TODO handle contextual bindings — `keypath` should include unique ID of
// each block that provides context
let index = renderer.binding_groups.indexOf(keypath);
if (index === -1) {
index = renderer.binding_groups.length;
renderer.binding_groups.push(keypath);
}
return index;
}
function get_event_handler(
binding: BindingWrapper,
renderer: Renderer,
block: Block,
name: string,
lhs: Node
): {
uses_context: boolean;
mutation: (Node | Node[]);
contextual_dependencies: Set<string>;
lhs?: Node;
} {
const value = get_value_from_dom(renderer, binding.parent, binding);
const contextual_dependencies = new Set(binding.node.expression.contextual_dependencies);
const context = block.bindings.get(name);
let set_store;
if (context) {
const { object, property, modifier, store } = context;
if (lhs.type === 'Identifier') {
lhs = modifier(x`${object}[${property}]`);
contextual_dependencies.add(object.name);
contextual_dependencies.add(property.name);
}
if (store) {
set_store = b`${store}.set(${`$${store}`});`;
}
} else {
const object = get_object(lhs);
if (object.name[0] === '$') {
const store = object.name.slice(1);
set_store = b`${store}.set(${object.name});`;
}
}
const mutation = b`
${lhs} = ${value};
${set_store}
`;
return {
uses_context: binding.node.is_contextual || binding.node.expression.uses_context, // TODO this is messy
mutation,
contextual_dependencies
};
}
function get_value_from_dom(
renderer: Renderer,
element: ElementWrapper,
binding: BindingWrapper
) {
const { node } = element;
const { name } = binding.node;
if (name === 'this') {
return x`$$node`;
}
// <select bind:value='selected>
if (node.name === 'select') {
return node.get_static_attribute_value('multiple') === true ?
x`@select_multiple_value(this)` :
x`@select_value(this)`;
}
const type = node.get_static_attribute_value('type');
// <input type='checkbox' bind:group='foo'>
if (name === 'group') {
const binding_group = get_binding_group(renderer, binding.node.expression.node);
if (type === 'checkbox') {
return x`@get_binding_group_value($$binding_groups[${binding_group}])`;
}
return x`this.__value`;
}
// <input type='range|number' bind:value>
if (type === 'range' || type === 'number') {
return x`@to_number(this.${name})`;
}
if ((name === 'buffered' || name === 'seekable' || name === 'played')) {
return x`@time_ranges_to_array(this.${name})`;
}
// everything else
return x`this.${name}`;
}