Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 | 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 103x 404x 404x 404x 404x 404x 404x 89x 89x 404x 404x 404x 404x 404x 404x 404x 404x 404x 103x 103x 103x 103x 103x 103x 103x 103x 150x 150x 103x 103x 103x 404x 404x 404x 404x 404x 404x 404x 150x 150x 150x 150x 21x 21x 21x 21x 21x 21x 21x 129x 150x 23x 23x 23x 23x 23x 23x 23x 23x 23x 23x 129x 129x 245x 245x 245x 245x 3x 3x 3x 245x 129x 129x 129x 102x 100x 100x 100x 100x 102x 60x 60x 100x 100x 100x 100x 102x 60x 60x 129x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 150x 404x 404x 404x 404x 404x 404x 404x 404x 129x 129x 129x 129x 129x 404x 404x 404x 404x 404x 404x 404x 404x 404x 301x 301x 404x 404x 404x 404x 404x 404x 404x 404x 245x 245x 245x 245x 136x 136x 245x 245x 3x 3x 245x 245x 24x 24x 245x 245x 4x 4x 8x 4x 4x 4x 4x 4x 8x 4x 4x 4x 245x 245x 16x 16x 245x 245x 7x 7x 245x 245x 5x 5x 245x 245x 2x 2x 245x 245x 245x 245x 245x 245x 15x 15x 245x 245x 33x 33x 245x 245x 245x 245x 245x 245x 245x 245x 245x 245x 404x 404x 404x 404x 404x 404x 404x 404x 404x 11x 11x 21x 21x 21x 11x 404x 404x 404x 404x 404x 404x 404x 404x 404x 46x 46x 46x 46x 70x 67x 67x 70x 5x 5x 5x 5x 5x 5x 70x 70x 46x 46x 46x 46x 46x 46x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 404x 23x 23x 23x 17x 23x | /**
* @file TemplateInstance.js
* @description One mounted copy of a render program, and the effects that keep
* it in step with state.
*
* ## What replaces the update cycle
*
* The string renderer had a single reactive unit per component. Any dependency
* of any binding woke it, and waking it meant re-rendering, re-parsing and
* re-diffing the whole template. Change one cell in a table and the framework
* did work proportional to the table.
*
* Here each op is its own reactive unit. A binding's effect reads exactly the
* state its expression names, so a write wakes only the bindings that read it
* and each of those writes to exactly one node. Changing one cell costs one
* expression evaluation and one DOM write, whatever else the template contains.
*
* ## Why the effects are lazy with a queueing callback
*
* The obvious construction -- a plain effect that re-applies on every write --
* would update the DOM synchronously inside the assignment. That is faster to
* write and changes observable behaviour: `$nextTick` would resolve after the
* DOM had already been touched, and an action making three writes to one value
* would produce three DOM writes.
*
* So each binding uses the same shape the component's render watcher used: a
* lazy watcher whose callback queues a job. Writes still coalesce into one
* microtask flush, `$nextTick` still means "after the DOM has settled", and the
* only thing that changed is how much work the flush does.
*
* ## Errors and suspension
*
* A binding that throws does not take its siblings with it -- the rest of the
* template still updates, and the failure is reported once with the expression
* that caused it. A binding that throws a `Promise` is a resource read under
* Suspense, which is not an error: it is handed to the owner so the component
* can suspend as it did before.
* @module lib/core/renderer/program/TemplateInstance
*/
import { AvenxWatcher } from '../../reactive/watcher.js';
import { queueJob } from '../../reactive/scheduler.js';
import { OpKind, RANGE_OPS, programBlocks } from '../../../compiler/render/program.js';
import { getCompiledTemplate } from './CompiledTemplate.js';
import { DeferBinding, ForBinding, IfBinding, SlotBinding } from './blocks.js';
import {
applyAttribute,
applyAttributeParts,
applyBoolean,
applyClass,
applyHtml,
applyProp,
applyRaw,
applyShow,
applyStyle,
applyText,
attachEvent,
reportBindingError,
} from './bindings.js';
/**
* A mounted render program.
*/
export class TemplateInstance {
/**
* @param {object} program - The render program to instantiate.
* @param {object} host - The owner.
* @param {function(string): any} host.evaluate - Evaluates an expression.
* @param {function(Promise): void} [host.onSuspend] - Called when a binding
* throws a Promise, so the owner can suspend.
* @param {number} [host.jobId] - Orders this instance's jobs against other
* components in a flush, so a parent still updates before its children.
* @param {function(): void} [host.onRendered] - Called when a binding has
* re-applied, so the owner can fire its once-per-flush lifecycle hooks.
* @param {function(): void} [host.onChildProps] - Called when a prop for a
* child component changed value.
* @param {function(): void} [host.onBeforeRender] - Called before the first
* binding of a flush applies, so the owner can fire `onBeforeUpdate`.
* @param {object|null} [locals] - Names this instance binds that its
* component does not declare, such as a loop's item and index.
*/
constructor(program, host, locals = null) {
/** @type {object} */
this.program = program;
/** @type {object} */
this.host = host;
/**
* Names this instance binds that its component does not declare -- a loop's
* item and index. Null for a component's root instance.
*
* Held as one mutable object per instance so a reused list row can be given
* a new value in place, waking only the bindings that read it, instead of
* being rebuilt.
* @type {object|null}
*/
this.locals = locals;
/**
* Blocks this program's control flow can render.
*
* Read from the root program rather than from a block, because a block is
* `{html, ops, ...}` and has no table of its own: nesting is expressed by
* index into one table for the whole component.
* @type {object[]}
*/
this.blocks = programBlocks(host && host.program ? host.program : program);
/** @type {CompiledTemplate} */
this.compiled = getCompiledTemplate(program);
/** @type {Element[]} */
this.elements = [];
/** @type {Text[]} */
this.texts = [];
/**
* One entry per op, holding its watcher, its job and whatever state that
* op kind needs to remember between runs.
* @type {object[]}
*/
this.bindings = [];
/** @type {boolean} */
this.disposed = false;
/** @type {DocumentFragment|null} */
this.fragment = null;
}
/**
* Whether the program could be prepared for this host environment.
* @returns {boolean} True when this instance can be mounted.
*/
get usable() {
return !this.compiled.failed;
}
/**
* Clones the skeleton and runs every binding once.
*
* The bindings run while the tree is still detached, so the first paint sees
* finished markup rather than a skeleton that fills in.
* @returns {DocumentFragment|null} The populated fragment, ready to insert.
*/
create() {
const instance = this.compiled.instantiate();
if (!instance) {
return null;
}
this.fragment = instance.fragment;
this.elements = instance.elements;
this.texts = instance.texts;
for (const op of this.program.ops) {
this.#createBinding(op);
}
return this.fragment;
}
/**
* Creates one binding's state, effect and job.
* @param {object} op - The op to bind.
* @private
*/
#createBinding(op) {
const binding = { op, watcher: null, job: null, range: null };
this.bindings.push(binding);
if (op.k === OpKind.EVENT) {
// A handler is attached once and lives as long as the node. Giving it a
// reactive effect would make every write re-attach a listener, and would
// track whatever the handler's *source* happened to read while being
// looked up.
attachEvent(this.elements[op.e], op, (event) => this.host.runStatement(op.x, event, this.locals));
return;
}
if (RANGE_OPS.has(op.k)) {
binding.range = createRangeBinding(
op,
this.texts[op.t],
(block, locals) => new TemplateInstance(block, this.host, locals),
this.blocks,
this.locals,
this.host.onChildProps || null,
);
if (!binding.range) {
reportBindingError(op, new Error(`No anchor for range op "${op.k}"`));
return;
}
}
const run = () => {
if (this.disposed) return undefined;
try {
this.#apply(op, binding);
} catch (error) {
if (error instanceof Promise) {
// A resource read under Suspense. Not a failure: the owner decides
// what to show while it settles.
if (this.host.onSuspend) {
this.host.onSuspend(error);
}
return undefined;
}
reportBindingError(op, error);
}
return undefined;
};
const job = () => {
if (this.disposed) return;
// Announced before the first binding of the flush applies, not after:
// `onBeforeUpdate` means "the DOM is about to change", and a hook that
// fires once the first write has landed is telling the truth about the
// second write and lying about the first. The owner coalesces it.
if (this.host.onBeforeRender) {
this.host.onBeforeRender();
}
binding.watcher.evaluate();
// Tells the owner that *something* changed this flush. It coalesces the
// notification itself; from here every binding reports and the owner
// decides that means one update.
if (this.host.onRendered) {
this.host.onRendered();
}
};
job.id = this.host.jobId || 0;
// `name` is a read-only own property of a function expression, so the
// scheduler's diagnostic label has to be defined rather than assigned.
Object.defineProperty(job, 'name', { value: `binding:${op.k}`, configurable: true });
binding.job = job;
binding.watcher = new AvenxWatcher(run, () => queueJob(job), {
lazy: true,
// Trace names a woken binding by this, and "text:0" says nothing about
// what changed. A development build supplies the expression sources, so
// the name is the expression the binding evaluates; a production build
// supplies none, and the index is at least unambiguous.
name: this.#describe(op),
});
// The first run both paints the value and registers the dependencies that
// will wake it. Nothing is tracked until an expression has actually been
// evaluated, which is why this cannot be deferred to the first update.
binding.watcher.evaluate();
}
/**
* A readable name for one op, for diagnostics and Trace.
* @param {object} op - The op.
* @returns {string} The name.
* @private
*/
#describe(op) {
const describe = this.host.describeExpression;
const source = describe && typeof op.x === 'number' ? describe(op.x) : undefined;
const subject = source !== undefined ? source : op.a || (typeof op.x === 'number' ? `#${op.x}` : '');
return subject ? `${op.k} ${subject}` : op.k;
}
/**
* Evaluates an expression index against this instance's local bindings.
* @param {number} index - The expression index.
* @param {object|null} [locals] - Bindings to use instead of this instance's.
* @returns {any} The value.
* @private
*/
#evaluate(index, locals) {
return this.host.evaluate(index, locals === undefined ? this.locals : locals);
}
/**
* Evaluates one op and writes its result.
* @param {object} op - The op.
* @param {object} binding - Its per-binding state.
* @private
*/
#apply(op, binding) {
const evaluate = (index, locals) => this.#evaluate(index, locals);
switch (op.k) {
case OpKind.TEXT:
applyText(this.texts[op.t], evaluate(op.x), binding);
return;
case OpKind.RAW:
applyRaw(this.texts[op.t], evaluate(op.x), binding);
return;
case OpKind.ATTR:
applyAttribute(this.elements[op.e], op.a, evaluate(op.x));
return;
case OpKind.ATTR_PARTS: {
let value = '';
for (const part of op.p) {
if (typeof part === 'string') {
value += part;
} else {
const resolved = evaluate(part.x);
value += resolved === null || resolved === undefined ? '' : String(resolved);
}
}
applyAttributeParts(this.elements[op.e], op.a, value);
return;
}
case OpKind.BOOL:
applyBoolean(this.elements[op.e], op.a, evaluate(op.x));
return;
case OpKind.SHOW:
applyShow(this.elements[op.e], evaluate(op.x), binding);
return;
case OpKind.CLASS:
applyClass(this.elements[op.e], evaluate(op.x), binding);
return;
case OpKind.HTML:
applyHtml(this.elements[op.e], evaluate(op.x));
return;
case OpKind.PROP:
if (applyProp(this.elements[op.e], op.n, evaluate(op.x)) && this.host.onChildProps) {
// Only when the value actually changed. A prop re-evaluated to the
// same value must not schedule a child-mount pass, or a parent with
// several children would do that pass once per prop per flush.
this.host.onChildProps();
}
return;
case OpKind.STYLE:
applyStyle(this.elements[op.e], evaluate(op.x), binding);
return;
case OpKind.IF:
binding.range.update(op.arms, (index) => evaluate(index));
return;
case OpKind.FOR:
binding.range.update(op, evaluate);
return;
case OpKind.SLOT:
binding.range.update(op);
return;
case OpKind.DEFER:
binding.range.update(op, evaluate);
return;
case OpKind.EVENT:
// Attached once, at creation, and never re-evaluated: the handler's
// identity is the op, not the value of anything it reads. Reaching
// here would mean a dependency was tracked while attaching, which the
// binding deliberately does not do.
return;
default:
// The compiler and the runtime ship in the same bundle, so an unknown
// op means a program from a different build. Reporting beats guessing.
reportBindingError(op, new Error(`Unknown render op "${op.k}"`));
}
}
/**
* Re-runs every binding, whatever its dependencies say.
*
* Needed when something outside the reactive graph changes what an expression
* would return -- new props, a swapped bridge, a resource that settled. The
* fine-grained path handles state; this handles everything else.
*/
refresh() {
if (this.disposed) return;
for (const binding of this.bindings) {
binding.watcher.dirty = true;
binding.watcher.evaluate();
}
}
/**
* Releases every effect and forgets every node reference.
*
* Called on unmount. Without it each binding's watcher stays in the
* dependency sets of the state it read, which keeps the component, its DOM
* and its scope alive for as long as that state exists.
*/
dispose() {
if (this.disposed) return;
this.disposed = true;
for (const binding of this.bindings) {
if (binding.watcher) {
binding.watcher.teardown();
}
if (binding.range) {
// Releases the child instances this op mounted. Without it a list's
// rows keep their own effects, and every row stays in the dependency
// sets of the state it read for as long as that state exists.
binding.range.dispose();
binding.range = null;
}
binding.rawNodes = null;
}
this.bindings = [];
this.elements = [];
this.texts = [];
this.fragment = null;
}
}
/**
* Builds the controller for one range op.
* @param {object} op - The op.
* @param {Text} anchor - The anchor the compiler reserved.
* @param {function(object, (object|null)): object} createInstance - Builds a
* template instance for a block.
* @param {object[]} blocks - The program's block table.
* @param {object|null} locals - The enclosing block's local bindings.
* @param {function(): void|null} onBlockMounted - Announces a mounted block.
* @returns {object|null} The controller, or null when the anchor is missing.
*/
function createRangeBinding(op, anchor, createInstance, blocks, locals, onBlockMounted) {
if (!anchor) return null;
if (op.k === OpKind.IF) return new IfBinding(anchor, createInstance, blocks, locals, onBlockMounted);
if (op.k === OpKind.FOR) return new ForBinding(anchor, createInstance, blocks, locals, onBlockMounted);
if (op.k === OpKind.SLOT) return new SlotBinding(anchor, createInstance, blocks, locals, onBlockMounted);
if (op.k === OpKind.DEFER) return new DeferBinding(anchor, createInstance, blocks, locals, onBlockMounted);
return null;
}
|