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

310 lines
8.6 KiB

import Block from './Block';
import { CompileOptions, Var } from '../../interfaces';
import Component from '../Component';
import FragmentWrapper from './wrappers/Fragment';
import { x } from 'code-red';
import { Node, Identifier, MemberExpression, Literal, Expression, BinaryExpression } from 'estree';
import flatten_reference from '../utils/flatten_reference';
import { reserved_keywords } from '../utils/reserved_keywords';
interface ContextMember {
name: string;
index: Literal;
is_contextual: boolean;
is_non_contextual: boolean;
variable: Var;
priority: number;
}
type BitMasks = Array<{
n: number;
names: string[];
}>;
export default class Renderer {
component: Component; // TODO Maybe Renderer shouldn't know about Component?
options: CompileOptions;
context: ContextMember[] = [];
initial_context: ContextMember[] = [];
context_lookup: Map<string, ContextMember> = new Map();
context_overflow: boolean;
blocks: Array<Block | Node | Node[]> = [];
readonly: Set<string> = new Set();
meta_bindings: Array<Node | Node[]> = []; // initial values for e.g. window.innerWidth, if there's a <svelte:window> meta tag
binding_groups: Map<string, { binding_group: (to_reference?: boolean) => Node; is_context: boolean; contexts: string[]; index: number }> = new Map();
block: Block;
fragment: FragmentWrapper;
file_var: Identifier;
locate: (c: number) => { line: number; column: number };
constructor(component: Component, options: CompileOptions) {
this.component = component;
this.options = options;
this.locate = component.locate; // TODO messy
this.file_var = options.dev && this.component.get_unique_name('file');
component.vars.filter(v => !v.hoistable || (v.export_name && !v.module)).forEach(v => this.add_to_context(v.name));
// ensure store values are included in context
component.vars.filter(v => v.subscribable).forEach(v => this.add_to_context(`$${v.name}`));
reserved_keywords.forEach(keyword => {
if (component.var_lookup.has(keyword)) {
this.add_to_context(keyword);
}
});
if (component.slots.size > 0) {
this.add_to_context('$$scope');
this.add_to_context('#slots');
}
if (this.binding_groups.size > 0) {
this.add_to_context('$$binding_groups');
}
// main block
this.block = new Block({
renderer: this,
name: null,
type: 'component',
key: null,
bindings: new Map(),
dependencies: new Set()
});
this.block.has_update_method = true;
this.fragment = new FragmentWrapper(
this,
this.block,
component.fragment.children,
null,
true,
null
);
// TODO messy
this.blocks.forEach(block => {
if (block instanceof Block) {
block.assign_variable_names();
}
});
this.block.assign_variable_names();
this.fragment.render(this.block, null, x`#nodes` as Identifier);
this.context_overflow = this.context.length > 31;
this.context.forEach(member => {
const { variable } = member;
if (variable) {
member.priority += 2;
if (variable.mutated || variable.reassigned) member.priority += 4;
// these determine whether variable is included in initial context
// array, so must have the highest priority
if (variable.is_reactive_dependency && (variable.mutated || variable.reassigned)) member.priority += 16;
if (variable.export_name) member.priority += 32;
if (variable.referenced) member.priority += 64;
} else if (member.is_non_contextual) {
// determine whether variable is included in initial context
// array, so must have the highest priority
member.priority += 8;
}
if (!member.is_contextual) {
member.priority += 1;
}
});
this.context.sort((a, b) => (b.priority - a.priority) || ((a.index.value as number) - (b.index.value as number)));
this.context.forEach((member, i) => member.index.value = i);
let i = this.context.length;
while (i--) {
const member = this.context[i];
if (member.variable) {
if (member.variable.referenced || member.variable.export_name || (member.variable.is_reactive_dependency && (member.variable.mutated || member.variable.reassigned))) break;
} else if (member.is_non_contextual) {
break;
}
}
this.initial_context = this.context.slice(0, i + 1);
}
add_to_context(name: string, contextual = false) {
if (!this.context_lookup.has(name)) {
const member: ContextMember = {
name,
index: { type: 'Literal', value: this.context.length }, // index is updated later, but set here to preserve order within groups
is_contextual: false,
is_non_contextual: false, // shadowed vars could be contextual and non-contextual
variable: null,
priority: 0
};
this.context_lookup.set(name, member);
this.context.push(member);
}
const member = this.context_lookup.get(name);
if (contextual) {
member.is_contextual = true;
} else {
member.is_non_contextual = true;
member.variable = this.component.var_lookup.get(name);
}
return member;
}
invalidate(name: string, value?, main_execution_context: boolean = false) {
const variable = this.component.var_lookup.get(name);
const member = this.context_lookup.get(name);
if (variable && (variable.subscribable && (variable.reassigned || variable.export_name))) {
return main_execution_context
? x`${`$$subscribe_${name}`}(${value || name})`
: x`${`$$subscribe_${name}`}($$invalidate(${member.index}, ${value || name}))`;
}
if (name[0] === '$' && name[1] !== '$') {
return x`${name.slice(1)}.set(${value || name})`;
}
if (
variable && (
variable.module || (
!variable.referenced &&
!variable.is_reactive_dependency &&
!variable.export_name &&
!name.startsWith('$$')
)
)
) {
return value || name;
}
if (value) {
return x`$$invalidate(${member.index}, ${value})`;
}
// if this is a reactive declaration, invalidate dependencies recursively
const deps = new Set([name]);
deps.forEach(name => {
const reactive_declarations = this.component.reactive_declarations.filter(x =>
x.assignees.has(name)
);
reactive_declarations.forEach(declaration => {
declaration.dependencies.forEach(name => {
deps.add(name);
});
});
});
// TODO ideally globals etc wouldn't be here in the first place
const filtered = Array.from(deps).filter(n => this.context_lookup.has(n));
if (!filtered.length) return null;
return filtered
.map(n => x`$$invalidate(${this.context_lookup.get(n).index}, ${n})`)
.reduce((lhs, rhs) => x`${lhs}, ${rhs}`);
}
dirty(names, is_reactive_declaration = false): Expression {
const renderer = this;
const dirty = (is_reactive_declaration
? x`$$self.$$.dirty`
: x`#dirty`) as Identifier | MemberExpression;
const get_bitmask = () => {
const bitmask: BitMasks = [];
names.forEach((name) => {
const member = renderer.context_lookup.get(name);
if (!member) return;
if (member.index.value === -1) {
throw new Error('unset index');
}
const value = member.index.value as number;
const i = (value / 31) | 0;
const n = 1 << (value % 31);
if (!bitmask[i]) bitmask[i] = { n: 0, names: [] };
bitmask[i].n |= n;
bitmask[i].names.push(name);
});
return bitmask;
};
// TODO: context-overflow make it less gross
return {
// Using a ParenthesizedExpression allows us to create
// the expression lazily. TODO would be better if
// context was determined before rendering, so that
// this indirection was unnecessary
type: 'ParenthesizedExpression',
get expression() {
const bitmask = get_bitmask();
if (!bitmask.length) {
return x`${dirty} & /*${names.join(', ')}*/ 0` as BinaryExpression;
}
if (renderer.context_overflow) {
return bitmask
.map((b, i) => ({ b, i }))
.filter(({ b }) => b)
.map(({ b, i }) => x`${dirty}[${i}] & /*${b.names.join(', ')}*/ ${b.n}`)
.reduce((lhs, rhs) => x`${lhs} | ${rhs}`);
}
return x`${dirty} & /*${names.join(', ')}*/ ${bitmask[0].n}` as BinaryExpression;
}
} as any;
}
reference(node: string | Identifier | MemberExpression) {
if (typeof node === 'string') {
node = { type: 'Identifier', name: node };
}
const { name, nodes } = flatten_reference(node);
const member = this.context_lookup.get(name);
// TODO is this correct?
if (this.component.var_lookup.get(name)) {
this.component.add_reference(name);
}
if (member !== undefined) {
const replacement = x`/*${member.name}*/ #ctx[${member.index}]` as MemberExpression;
if (nodes[0].loc) replacement.object.loc = nodes[0].loc;
nodes[0] = replacement;
return nodes.reduce((lhs, rhs) => x`${lhs}.${rhs}`);
}
return node;
}
remove_block(block: Block | Node | Node[]) {
this.blocks.splice(this.blocks.indexOf(block), 1);
}
}