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1. // plugins/web/compile.hl — THE FRAMEWORK COMPILES EACH COMPONENT.
2. //
3. // Mission 313 (the creator, 15 Sep 14:30: "clientside interpreter + table against
4. // component code per component, no tables needed"). The old hl:web ships ONE generic client
5. // that walks a tree the seed carries: it pairs elements with nodes, asks a table which
6. // members each element shows, asks `view.value` what each bound spot holds, and does it
7. // again on every paint. hl:web ships the ANSWERS instead — this file writes each
8. // component's own code, once, where the old hl:web would have walked.
9. //
10. // WHAT IS EMITTED, per component, beside the class `hlJs` compiled:
11. //
12. // v(c,m,o,host,i,rows,rk,fill,cr,opt) the component's View, unrolled: one
13. // statement per element, per handler, per
14. // bound spot. `cr` false CLAIMS the server's
15. // DOM (take host.children[i], step on), `cr`
16. // true CREATES it — the two walks the old hl:web
17. // spells out separately, which differ only in
18. // where an element comes from.
19. // b["<for site>"] one `for` body — the row factory the keyed
20. // region builds a row with.
21. // t/e["<if site>"] an `if`'s two branches.
22. // f["<reference site>"] the fragment this component writes into a
23. // child's `slot` — built in THIS frame, which
24. // is why it is this component's code.
25. // p["<element site>"] the paint statements: `p` writes what one
26. // member feeds (the old hl:web's paint(&m,s,name)),
27. // `r` rewrites a row's element where the DOM
28. // does not already hold it (rowPaint).
29. //
30. // The generated code calls a FIXED runtime (client.hl) for everything that is not this
31. // component: the mount records, the keyed region diff, the binding edges, the
32. // derivations, the socket, navigation. It never looks anything up in a table — the
33. // names, the sites and the write sets are written into the statements.
34. //
35. // It is TEXT the framework produces, served from memory beside the module (WebFramework
36. // `module`), never a JavaScript file under plugins/.
37. import { newline, tab } from './view.hl'
38. import HlwView from './view.hl'
40. // ---- the emitted half --------------------------------------------------------------
41. module(gen, key, nodes, fnTable) {
42. fns = [] // the sub-walks: row bodies, if branches, fills
43. done = {}
44. rowVars = []
45. tbl = tableOf(gen, key) // what the language says about this file, read once
46. regions = regionIndex(tbl) // a `for`'s list reads, an `if`'s condition reads
47. // A SHELL'S VIEW IS A `body` ELEMENT and the document already has one: the walk runs
48. // against document.body itself, so the root list is that element's children and the
49. // element only takes the marks a region rebuild on it would need.
50. let roots = nodes
51. let bodySite = null
52. if (nodes.length == 1 && nodes[0].k == 'el' && nodes[0].tag == 'body') {
53. roots = nodes[0].children
54. bodySite = nodes[0].site
55. }
56. let root = walkTop(key, roots)
57. if (bodySite != null) {
58. root = root.replace('let r=rows;', 'let r=rows;await c.markHost(m,host,' + str(bodySite) + ');')
59. }
60. let src = ';(function(){var g=(typeof globalThis!=="undefined"?globalThis:window);'
61. src = src + 'var C=(g.__hlC=g.__hlC||{});'
62. // the element a claim takes or a create makes — the one shape both walks share; a create
63. // inside an svg (or an svg itself) is made in the SVG namespace, as the parser makes it
64. // THE PRELUDE, one per module: the element a claim takes or a create makes, and the
65. // two reads. A read written out in full — `(r["title"]!=null?r["title"]:inst["title"])`
66. // — is 45 bytes and a component's View holds dozens of them; named, it is 16. The
67. // rule is the same rule (a `for` row variable in scope wins over a member of the
68. // same name, and a field path walks into it), spelled once.
69. // A claim also moves the host's CURSOR — the last node the walk took there — which is
70. // where a text leaf and a region's mark are looked for next (client.hl `leafNode`,
71. // `markAt`).
72. src = src + 'function A(cr,host,i,tag){if(cr){if(tag==="svg"||(host.namespaceURI==="http://www.w3.org/2000/svg"&&host.localName.toLowerCase()!=="foreignobject")){return document.createElementNS("http://www.w3.org/2000/svg",tag);}return document.createElement(tag);}var e=host.children[i];if(e!=null){host.__hlCur=e;}return e;}'
73. src = src + 'function S(v){return v==null?"":""+v;}'
74. src = src + 'function RV(r,q,n){return r[n]!=null?r[n]:q[n];}'
75. src = src + 'function RF(r,q,n,p){var v=RV(r,q,n);for(var k=0;k<p.length;k++){if(v==null)return null;v=v[p[k]];}return v;}'
76. src = src + 'var B={},T={},E={},F={},P={};'
77. // ONE FUNCTION PER LIST, however many sites reach it: a nested walk is written once
78. // and named — emitting it per site made the reference app's home page 215 KB of the
79. // same code over and over.
80. let wi = 0
81. for (f of fns) {
82. wi = wi + 1
83. let name = 'w' + wi
84. src = src + 'var ' + name + '=' + f.src + ';'
85. for (site of f.sites) { src = src + f.slot + '[' + str(site) + ']=' + name + ';' }
86. }
87. let paints = []
88. collectPaints(&paints, roots)
89. for (e of paints) { src = src + 'P[' + str(e.site) + ']={p:' + e.paint + ',r:' + e.row + '};' }
90. src = src + 'C[' + str(key) + ']={v:' + root + ',b:B,t:T,e:E,f:F,p:P'
91. // THE ANSWERS A LOOKUP STILL NEEDS, and only those. A local event's write set stands
92. // at its own listener and a region's names at its own region — written into the
93. // call. These three are asked for by NAME at run time and cannot be: an inbound
94. // frame names its event, a routine handed down names the member that holds it, and
95. // a write set names the derivations that follow it.
96. src = src + ',ev:' + eventMap() + ',mw:' + memberMap() + ',dv:' + derivList() + ',fn:' + fnMap(fnTable) + '};'
97. return src + '})();' + newline
98. }
100. tbl = null
101. regions = {}
103. // WHAT A FUNCTION VALUE WRITES, by the site it was made at (tickets #98, #99): the
104. // module announces a function's return with its site, and the browser repaints this
105. // set — the members it writes, closed over the methods it calls and the events it
106. // emits, the same closure a handler's set gets. A function that writes nothing has
107. // no entry.
108. fnMap(fns) {
109. let bySite = {}
110. if (fns != null) {
111. for (f of fns) {
112. let names = closeWrites(tbl, f.writes, f.reads)
113. if (names.length > 0) { bySite[f.site] = names }
114. }
115. }
116. return mapOf(bySite)
117. }
119. // what a DECLARED handler writes, by event: one entry per event name, unioned
120. eventMap() {
121. let byEvent = {}
122. for (h of tbl.handlers) {
123. if (!h.nested) {
124. let have = byEvent[h.event] == null ? [] : byEvent[h.event]
125. for (w of closeWrites(tbl, h.writes, h.reads)) { if (!have.includes(w)) { have.push(w) } }
126. byEvent[h.event] = have
127. }
128. }
129. return mapOf(byEvent)
130. }
132. // A MEMBER HOLDING A ROUTINE: what calling it writes is what its initializer writes
133. memberMap() {
134. let byName = {}
135. for (m of tbl.members) {
136. if (m.nodes != null) { byName[m.name] = memberNames(m.nodes.writes) }
137. }
138. return mapOf(byName)
139. }
141. // EVERY INITIALIZER, IN DECLARATION ORDER, with the members it reads — the whole of
142. // what a derivation needs; the class carries the computation itself as `__derive__`.
143. // `srv` (written only when true, same rule as `isStatic` on a read — every byte here
144. // ships to the browser) marks a SERVER REFERENCE SITE (COMPONENTS.md §9.1/§9.3): an
145. // initializer that calls an imported class (`import Store from './store.hl'`, then
146. // `Store.chatsOf(…)` — `hlDenotes`'s own `kind: 'class'`, not a second resolution).
147. // It is evaluated per request, on the SERVER, and its value ships into the page as
148. // state; `client.hl`'s `moved()` must never call it locally — routger's `conversations
149. // = … ? store.chatsOf(session.user.id) : []` reached `hl:time`, which ships no client
150. // half, the moment a session sync (0b17f65b) made `session` move in the browser and
151. // `moved()` re-ran every derivation that reads it. A fresh value for a server
152. // reference site ships in `sync` instead (WebFramework.hl `serverSyncNames`).
153. derivList() {
154. let src = '['
155. let first = true
156. for (d of tbl.derivations) {
157. if (!first) { src = src + ',' }
158. first = false
159. src = src + '{name:' + str(d.name) + ',site:' + str(d.site) + ',reads:' + list(memberNames(d.reads))
160. if (serverSite(d.reads)) { src = src + ',srv:true' }
161. src = src + '}'
162. }
163. return src + ']'
164. }
166. // does this read list (RAW — hlDenotes's own kind per name, before `memberNames`
167. // narrows it to members) reach an imported class or a braced static of one — the two
168. // forms COMPONENTS.md §9.1/§9.3 calls "a call on an imported class" (`import Store
169. // from './store.hl'`, `Store.noteRows()`, OR the form the maintained demos actually
170. // use, `import { postRow } from './store.hl'`, `postRow(id)`)? See `derivList` above.
171. serverSite(reads) {
172. if (reads == null) { return false }
173. for (r of reads) { if (r.kind == 'class' || r.kind == 'import') { return true } }
174. return false
175. }
177. mapOf(byName) {
178. let src = '{'
179. let first = true
180. for (k of byName.keys()) {
181. if (!first) { src = src + ',' }
182. first = false
183. src = src + str(k) + ':' + list(byName[k])
184. }
185. return src + '}'
186. }
188. // the write set and the read set of the handler at this site, closed over the methods
189. // it calls and the handlers it emits to — computed here, written into the listener
190. handlerSets(site) {
191. for (h of tbl.handlers) {
192. if (h.nested && h.site == site) {
193. return list(closeWrites(tbl, h.writes, h.reads)) + ',' + list(closeReads(tbl, h.reads))
194. }
195. }
196. return '[],[]'
197. }
199. regionNamesAt(site) {
200. let names = regions[site]
201. return list(names == null ? [] : names)
202. }
204. fns = []
206. // ---- the walk, unrolled ------------------------------------------------------------
207. // `top` marks the View's own root list: an element there is a COMPOSITION ROOT — a
208. // reference above may have overwritten some of its events and put classes on it, which
209. // is what `opt` carries (the old hl:web's rootOverwrites and withRootClasses).
210. walk(key, nodes) {
211. return plain(key, nodes)
212. }
214. // a list's walk
215. plain(key, nodes) {
216. let body = ''
217. for (n of nodes) { body = body + node(key, n, false, false) }
218. return 'async function(c,m,o,host,i,rows,rk,fill,cr,opt){let inst=m.instance;let r=rows;' + body + 'return i;}'
219. }
221. // the View's own root list, whose elements are composition roots
222. walkTop(key, nodes) {
223. let body = ''
224. for (n of nodes) { body = body + node(key, n, true, false) }
225. return 'async function(c,m,o,host,i,rows,rk,fill,cr,opt){let inst=m.instance;let r=rows;' + body + 'return i;}'
226. }
228. // a sub-walk, registered under its own site so the runtime can reach it by name
229. // A SUB-WALK IS WRITTEN ONCE, however often the compile reaches its list.
230. sub(key, nodes, slot, site) {
231. if (done[slot + ' ' + site] != null) { return null }
232. done[slot + ' ' + site] = true
233. fns.push({ slot = slot; sites = [site]; src = walk(key, nodes); })
234. return null
235. }
237. done = {}
239. node(key, n, top, filterOns) {
240. if (n.k == 'el') { return elNode(key, n, top) }
241. if (n.k == 'text') { return 'if(cr){host.appendChild(document.createTextNode(' + str(n.text) + '));}else{await c.leafAt(host,false,i,null,' + str(n.text) + ');}' }
242. if (n.k == 'on') {
243. // A REFERENCE ABOVE MAY HAVE OVERWRITTEN THIS EVENT on the composition root:
244. // the root's own handler for it is dropped and the reference's stands instead
245. // (the old hl:web's withoutOns, which applies to the root element's direct children).
246. let guard = filterOns ? 'if(!(opt&&opt.over&&opt.over.indexOf(' + str(n.event) + ')>=0)){' : '{'
247. return guard + 'await c.onAt(m,host,' + str(n.event) + ',' + str(n.site) + ',rows,' + handlerSets(n.site) + ');}'
248. }
249. if (n.k == 'member' && n.name == 'slot') {
250. // the SHELL's slot is where the route component hangs; a child's slot is the
251. // fragment its host wrote, and the host's frame builds it
252. return 'if(m.isShell){i=await c.slotShell(m,host,i,cr);}else if(fill!=null){i=await c.slotFill(m,o,host,i,fill,cr);}'
253. }
254. // A TEXT LEAF STANDING IN A LIST — an `if` branch, a `for` body — beside elements or
255. // alone: its own text node, and a site of the member it reads (or of the row it
256. // stands in), painted by rewriting that node.
257. if (n.k == 'member' || n.k == 'field') {
258. let names = (n.name == 'Style' || rowVars.includes(n.name)) ? [] : [n.name]
259. return 'await c.textAt(m,host,cr,function(inst,r){return ' + textRead(n) + ';},' + list(names) + ',rows,rk);'
260. }
261. if (n.k == 'for') {
262. // THE ROW VARIABLE IS IN SCOPE INSIDE THE BODY, and a read of it is the ROW's,
263. // not a member of the instance — the language resolves it that way and the site
264. // sets must say the same, or a member of the same name would paint the row.
265. rowVars.push(n.row)
266. sub(key, n.body, 'B', n.site)
267. rowVars.pop()
268. return 'i=await c.forAt(m,o,host,i,' + str(n.site) + ',' + str(n.row) + ',function(inst,r){return ' + rawRead(n.list) + ';},rows,rk,fill,cr,' + regionNamesAt(n.site) + ');'
269. }
270. if (n.k == 'if') {
271. sub(key, n.then, 'T', n.site)
272. sub(key, n.other, 'E', n.site)
273. return 'i=await c.ifAt(m,o,host,i,' + str(n.site) + ',function(inst,r){return ' + rawRead(n.cond) + ';},rows,rk,fill,cr,' + regionNamesAt(n.site) + ');'
274. }
275. if (n.k == 'component') {
276. if (n.fill != null && n.fill.length > 0) { sub(key, n.fill, 'F', n.site) }
277. return 'i=await c.kidAt(m,host,i,' + kidSpec(n) + ',rows,rk,fill,cr,opt);'
278. }
279. return ''
280. }
282. // ---- an element --------------------------------------------------------------------
283. elNode(key, n, top) {
284. let src = '{let el=A(cr,host,i,' + str(n.tag) + ');if(!cr){i=i+1;}'
285. src = src + 'if(el==null){await c.acqFail(' + str(n.tag) + ',host);}else{'
286. // the attributes, on the walk that BUILDS the element (a claim takes the server's)
287. src = src + 'if(cr){' + createAttrs(n) + (top ? 'await c.rootClasses(el,opt);' : '') + 'host.appendChild(el);}'
288. src = src + 'el.__hlRows=rows;el.__hlSite=' + str(n.site) + ';el.__hlKey=' + str(key) + ';'
289. // the element's own named entries, for the literal a handler on it fires
290. src = src + 'el.__hlLit=function(inst,r){return ' + litNamed(n) + ';};'
291. let names = siteNames(n)
292. let valueMember = 'null'
293. for (a of n.attrs) { if (a.member != null && a.name == 'value') { valueMember = str(a.member) } }
294. let sited = ''
295. if (names.length > 0 || valueMember != 'null') {
296. sited = 'await c.siteAt(m,el,' + list(names) + ',' + str(n.site) + ',' + valueMember + ',' + (n.tag == 'select' ? 'true' : 'false') + ',rows);'
297. }
298. let kids = ''
299. // AN ELEMENT THAT HOLDS ONLY TEXT is painted whole (`textContent`, see the paints):
300. // built, it gets that text as one node; claimed, the server's is taken as it stands
301. let whole = textOf(n)
302. if (whole != null) {
303. kids = 'if(cr){host.appendChild(document.createTextNode(' + whole + '));}'
304. for (c of n.children) { if (c.k == 'on') { kids = kids + node(key, c, false, top) } }
305. }
306. else if (mixed(n)) { kids = mixedKids(key, n, top) }
307. else { for (c of n.children) { kids = kids + node(key, c, false, top) } }
308. let inner = '{let host=el;let i=0;' + kids + '}'
309. // A SELECT IS SITED AFTER ITS OPTIONS: the member decides which option stands, and
310. // the read-back that `siteAt` does reports nothing before they exist.
311. if (n.tag == 'select') { src = src + inner + (selectValue(n) == 'null' ? '' : 'if(cr){await c.applySelectAt(m,el,' + selectValue(n) + ');}') + sited }
312. else { src = src + sited + inner }
313. return src + '}}'
314. }
316. // A TEXT LEAF BESIDE AN ELEMENT OR A REGION (ticket #86 follow-up): `td { d.n if (…) {…} }`
317. // cannot be painted through `textContent`, which would wipe the branch. Each RUN of
318. // adjacent leaves is one text node, held on the element (`__hlLeaves`, by the run's
319. // index) where the walk builds or claims it, and the paints rewrite that node alone.
320. mixed(n) {
321. if (textOf(n) != null) { return false }
322. for (c of n.children) { if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { return true } }
323. return false
324. }
326. isLeaf(c) { return c.k == 'text' || ((c.k == 'member' || c.k == 'field') && c.name != 'slot') }
328. // the runs of adjacent leaves, in order; an `on` renders nothing and splits none
329. runsOf(n) {
330. let out = []
331. let run = []
332. for (c of n.children) {
333. if (isLeaf(c)) { run.push(c) }
334. else if (c.k != 'on') {
335. if (run.length > 0) { out.push(run) }
336. run = []
337. }
338. }
339. if (run.length > 0) { out.push(run) }
340. return out
341. }
343. runText(run) {
344. let src = '""'
345. for (c of run) { src = src + '+(' + (c.k == 'text' ? str(c.text) : textRead(c)) + ')' }
346. return src
347. }
349. runFeeds(run) {
350. for (c of run) { if (c.k != 'text') { return true } }
351. return false
352. }
354. mixedKids(key, n, top) {
355. let kids = ''
356. let run = []
357. let k = 0
358. for (c of n.children) {
359. if (isLeaf(c)) { run.push(c) }
360. else {
361. if (c.k != 'on' && run.length > 0) { kids = kids + leafRun(run, k) k = k + 1 run = [] }
362. kids = kids + node(key, c, false, top)
363. }
364. }
365. if (run.length > 0) { kids = kids + leafRun(run, k) }
366. return kids
367. }
369. // EVERY CALL INTO THE CLIENT IS AWAITED: its methods are async in the browser, and one
370. // not awaited runs its DOM work after the walk has gone on — a built leaf then lands
371. // after the elements that follow it (ticket #104).
372. leafRun(run, k) {
373. if (!runFeeds(run)) { return 'if(cr){host.appendChild(document.createTextNode(' + runText(run) + '));}else{await c.leafAt(host,false,i,null,' + runText(run) + ');}' }
374. return 'await c.leafAt(host,cr,i,' + k + ',' + runText(run) + ');'
375. }
377. // the attributes an element is BUILT with — a bound one written in, a literal one as it
378. // stands. `value` is a property once the page is live and an attribute as the control's
379. // default; a textarea has no value attribute at all and a select's value is an option.
380. createAttrs(n) {
381. let src = ''
382. for (a of n.attrs) {
383. if (isBool(a)) {
384. src = src + '{' + boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) + '}'
385. } else {
386. let rd = a.member != null ? readOf({ k = 'member'; name = a.member; }) : (a.ref != null ? readOf(a.ref) : str(a.text))
387. src = src + '{let v=' + rd + ';'
388. if (a.extra != null) { src = src + 'v=v+" "+' + str(a.extra) + ';' }
389. if (n.tag == 'select' && a.name == 'value') { src = src + '}' }
390. else if (a.name == 'value') {
391. src = src + 'if(el.value!=null){el.value=v;' + (n.tag == 'textarea' ? '' : 'el.setAttribute("value",v);') + '}else{el.setAttribute("value",v);}}'
392. } else { src = src + 'el.setAttribute(' + str(a.name) + ',v);}' }
393. }
394. }
395. if (boundValue(n)) { src = src + 'el.setAttribute("autocomplete","off");' }
396. return src
397. }
399. // a BOUND boolean attribute — a literal one was decided at build (WebFramework `element`)
400. isBool(a) {
401. return (a.member != null || a.ref != null) && v.isBoolAttr(a.name)
402. }
404. // A BOUND BOOLEAN ATTRIBUTE, WRITTEN (ticket #33): set when the value is on, REMOVED when
405. // it is off — the markup's rule (view.boolAttrs) — and the DOM property with it, because
406. // once the page is live `checked` is the property and the attribute only its default.
407. boolWrite(a, raw) {
408. let prop = a.name == 'readonly' ? 'readOnly' : a.name
409. return 'let on=!!' + raw + ';if(on){el.setAttribute(' + str(a.name) + ',"");}else if(el.removeAttribute){el.removeAttribute(' + str(a.name) + ');}if(' + str(prop) + ' in el&&el[' + str(prop) + ']!==on){el[' + str(prop) + ']=on;}'
410. }
412. // view.hl's `boundValue`, to the letter: a FORM CONTROL whose `value` reads a member or
413. // a field, and not one the author gave an `autocomplete` of its own
414. boundValue(n) {
415. if (n.tag != 'input' && n.tag != 'textarea' && n.tag != 'select') { return false }
416. let bound = false
417. for (a of n.attrs) {
418. if (a.name == 'autocomplete') { return false }
419. if (a.name == 'value' && (a.member != null || a.ref != null)) { bound = true }
420. }
421. return bound
422. }
424. selectValue(n) {
425. for (a of n.attrs) {
426. if (a.name == 'value') {
427. if (a.member != null) { return readOf({ k = 'member'; name = a.member; }) }
428. if (a.ref != null) { return readOf(a.ref) }
429. return str(a.text)
430. }
431. }
432. return 'null'
433. }
435. // the element's own entries as the literal sees them — its attributes by name, then the
436. // `for` row variables in scope (the row rides on the value)
437. litNamed(n) {
438. let src = '{'
439. let first = true
440. for (a of n.attrs) {
441. if (!first) { src = src + ',' }
442. first = false
443. let v = a.member != null ? rawRead({ k = 'member'; name = a.member; }) : (a.ref != null ? rawRead(a.ref) : str(a.text))
444. src = src + str(a.name) + ':' + v
445. }
446. return src + '}'
447. }
449. // the reference's own description, written at its use site: what it binds, what it
450. // overwrites, the classes the host's `#Child` rule puts on it
451. kidSpec(n) {
452. let src = '{key:' + str(n.key) + ',kid:' + str(kidKeyOf(n)) + ',site:' + str(n.site) + ',fill:' + ((n.fill != null && n.fill.length > 0) ? 'true' : 'false')
453. src = src + ',bindings:['
454. let first = true
455. for (b of n.bindings) {
456. if (!first) { src = src + ',' }
457. first = false
458. src = src + '{name:' + str(b.name) + ',member:' + (b.member == null ? 'null' : str(b.member))
459. src = src + ',ref:' + (b.ref == null ? 'null' : 'function(inst,r){return ' + rawRead(b.ref) + ';}')
460. src = src + ',refName:' + (b.ref == null ? 'null' : str(b.ref.name))
461. src = src + ',text:' + (b.text == null ? 'null' : 'true') + ',value:' + (b.text == null ? 'null' : refLiteral(b)) + '}'
462. }
463. src = src + '],ons:['
464. first = true
465. for (o of n.ons) {
466. if (!first) { src = src + ',' }
467. first = false
468. src = src + '{event:' + str(o.event) + ',site:' + str(o.site) + ',sets:[' + handlerSets(o.site) + ']}'
469. }
470. src = src + '],classes:' + list(n.classes == null ? [] : n.classes) + '}'
471. return src
472. }
474. // view.hl's kidKey: the reference's path, joined — the key the server mounted it under
475. kidKeyOf(n) {
476. let out = ''
477. for (p of n.path) { out = out + '/' + p }
478. return out
479. }
481. // the value a literal binding carries — view.refValue, folded at compile time
482. refLiteral(b) {
483. if (b.kind == 'folded') { return jsValue(b.value) }
484. if (b.kind == 'number') { return '' + b.text }
485. if (b.kind == 'boolean') { return b.text == 'true' ? 'true' : 'false' }
486. if (b.kind == 'null_literal') { return 'null' }
487. return str(b.text)
488. }
490. jsValue(v) {
491. if (v == null) { return 'null' }
492. if (hlTypeName(v) == 'String') { return str(v) }
493. if (hlTypeName(v) == 'Boolean') { return v ? 'true' : 'false' }
494. if (hlTypeName(v) == 'Number') { return '' + v }
495. return JSON.stringify(v)
496. }
498. // ---- the site set: what this element SHOWS ------------------------------------------
499. // The old hl:web asked the module's table which members the element at this site reads. The
500. // answer is a fact about the View, so it is written in: the members its bound
501. // attributes and its text leaves name. `Style` is folded into a class name at build and
502. // the shell's `slot` is swapped by navigation — neither is ever painted, and neither is
503. // a member read that reaches here (a `for` row variable resolves to its row).
504. siteNames(n) {
505. let out = []
506. for (a of n.attrs) {
507. if (a.member != null && a.member != 'Style' && !rowVars.includes(a.member) && !out.includes(a.member)) { out.push(a.member) }
508. // A FIELD OF A MEMBER (`value = f.title`, ticket #93) is a read of the member:
509. // a write to `f.title`, or a new `f`, moves `f`, and this element repaints
510. if (a.ref != null && a.ref.name != 'Style' && !rowVars.includes(a.ref.name) && !out.includes(a.ref.name)) { out.push(a.ref.name) }
511. }
512. for (c of n.children) {
513. if ((c.k == 'member' || c.k == 'field') && c.name != 'slot' && c.name != 'Style' && !rowVars.includes(c.name)) {
514. if (!out.includes(c.name)) { out.push(c.name) }
515. }
516. }
517. return out
518. }
520. rowVars = []
522. // ---- the paints ---------------------------------------------------------------------
523. collectPaints(&out, nodes) {
524. for (n of nodes) {
525. if (n.k == 'el') {
526. let paint = paintFn(n)
527. let row = rowFn(n)
528. if (paint != null || row != 'null') {
529. out.push({ site = n.site; paint = paint == null ? 'null' : paint; row = row; })
530. }
531. collectPaints(&out, n.children)
532. } else if (n.k == 'for') { collectPaints(&out, n.body) }
533. else if (n.k == 'if') { collectPaints(&out, n.then) collectPaints(&out, n.other) }
534. else if (n.k == 'component') { if (n.fill != null) { collectPaints(&out, n.fill) } }
535. }
536. return null
537. }
539. // `paint(&m, s, name)`, compiled: the bound attributes under the member each reads, and
540. // the text where the member that moved stands among the leaves.
541. paintFn(n) {
542. let body = ''
543. for (a of n.attrs) {
544. if (a.member != null) {
545. body = body + 'if(n===' + str(a.member) + '){' + attrWrite(n, a, readOf({ k = 'member'; name = a.member; })) + '}'
546. } else if (a.ref != null) {
547. // a field of a member paints when the MEMBER moves (ticket #93)
548. body = body + 'if(n===' + str(a.ref.name) + '){' + attrWrite(n, a, readOf(a.ref)) + '}'
549. }
550. }
551. let text = textOf(n)
552. if (text != null) {
553. let guard = ''
554. for (c of n.children) {
555. if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') {
556. if (guard != '') { guard = guard + '||' }
557. guard = guard + 'n===' + str(c.name)
558. }
559. }
560. if (guard != '') { body = body + 'if(' + guard + '){el.textContent=' + text + ';}' }
561. } else if (mixed(n)) {
562. let k = 0
563. for (run of runsOf(n)) {
564. let guard = ''
565. for (c of run) {
566. if (c.k != 'text') {
567. if (guard != '') { guard = guard + '||' }
568. guard = guard + 'n===' + str(c.name)
569. }
570. }
571. if (guard != '') { body = body + 'if((' + guard + ')&&el.__hlLeaves&&el.__hlLeaves[' + k + ']){el.__hlLeaves[' + k + '].data=' + runText(run) + ';}' }
572. k = k + 1
573. }
574. }
575. if (body == '') { return null }
576. return 'function(el,inst,r,n){' + body + '}'
577. }
579. // `rowPaint(&m, el)`, compiled: every bound spot, written only where the DOM does not
580. // already hold it — which is why a push into 2000 rows costs the 1999 nothing.
581. rowFn(n) {
582. let body = ''
583. for (a of n.attrs) {
584. if (isBool(a)) {
585. body = body + '{' + boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) + '}'
586. } else if (a.member != null || a.ref != null) {
587. let one = 'let v=' + readOf(a.member != null ? { k = 'member'; name = a.member; } : a.ref) + ';'
588. if (a.extra != null) { one = one + 'v=v+" "+' + str(a.extra) + ';' }
589. if (n.tag == 'select' && a.name == 'value') { one = one + 'if(el.value!==v){el.value=v;}' }
590. else {
591. one = one + 'if(el.getAttribute(' + str(a.name) + ')!==v){el.setAttribute(' + str(a.name) + ',v);}'
592. if (a.name == 'value') { one = one + 'if(el.value!=null&&el.value!==v){el.value=v;}' }
593. }
594. body = body + '{' + one + '}'
595. }
596. }
597. let text = textOf(n)
598. let feeds = false
599. for (c of n.children) { if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { feeds = true } }
600. if (text != null && feeds) { body = body + '{let t=' + text + ';if(el.textContent!==t){el.textContent=t;}}' }
601. if (text == null && feeds) {
602. let k = 0
603. for (run of runsOf(n)) {
604. if (runFeeds(run)) { body = body + '{let x=el.__hlLeaves&&el.__hlLeaves[' + k + '];let t=' + runText(run) + ';if(x&&x.data!==t){x.data=t;}}' }
605. k = k + 1
606. }
607. }
608. if (body == '') { return 'null' }
609. return 'function(el,inst,r){' + body + '}'
610. }
612. attrWrite(n, a, v) {
613. if (isBool(a)) { return boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) }
614. let src = 'let v=' + v + ';'
615. if (a.extra != null) { src = src + 'v=v+" "+' + str(a.extra) + ';' }
616. if (n.tag == 'select' && a.name == 'value') { return src + 'el.value=v;' }
617. src = src + 'el.setAttribute(' + str(a.name) + ',v);'
618. if (a.name == 'value') { src = src + 'if(el.value!=null){el.value=v;}' }
619. return src
620. }
622. textOf(n) {
623. let parts = []
624. let content = 0
625. let feeds = false
626. for (c of n.children) {
627. if (c.k != 'on') {
628. content = content + 1
629. if (c.k == 'text') { parts.push(str(c.text)) }
630. else if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { parts.push(textRead(c)) feeds = true }
631. }
632. }
633. if (!feeds) { return null }
634. if (parts.length != content) { return null }
635. let src = '""'
636. for (p of parts) { src = src + '+(' + p + ')' }
637. return src
638. }
640. // ---- a read, written in ---------------------------------------------------------------
641. // `view.value`'s own rule as an expression: a `for` row variable in scope wins over a
642. // member of the same name, and a field path walks into it. `readOf` answers the STRING
643. // the DOM takes; `rawRead` the value itself (a binding, a list, a condition).
644. readOf(node) { return '(""+' + rawRead(node) + ')' }
646. // A READ SHOWN AS TEXT: null is no text, as the server writes it (view.hl `escape`)
647. textRead(node) { return 'S(' + rawRead(node) + ')' }
649. rawRead(node) {
650. if (node == null) { return 'null' }
651. if (node.k == 'text') { return node.kind == 'folded' && hlTypeName(node.value) == 'Hybrid' ? JSON.stringify(node.value) : str(node.text) }
652. if (node.k != 'field') { return 'RV(r,inst,' + str(node.name) + ')' }
653. return 'RF(r,inst,' + str(node.name) + ',' + list(node.path) + ')'
654. }
656. list(names) {
657. let src = '['
658. let first = true
659. for (n of names) {
660. if (!first) { src = src + ',' }
661. first = false
662. src = src + str(n)
663. }
664. return src + ']'
665. }
667. // a JavaScript string literal — JSON's escaping is a subset of JavaScript's, so a
668. // source text's quotes, newlines and backslashes survive into the statement unchanged
669. str(s) {
670. if (s == null) { return '""' }
671. return JSON.stringify('' + s)
672. }
674. // ---- WHAT THE LANGUAGE SAYS ABOUT THIS FILE, read HERE and written into the code ----
675. // The old hl:web shipped the language's answers to the browser as data: `hlJs` writes each file's
676. // members, handlers and methods — every node of every initializer, with the names it
677. // reads — into the module, and the client reduces that table on every boot. The answers
678. // are facts about the source, so this file asks for them once, at compile time, and
679. // writes the RESULT into the statements: a handler's write set stands at the listener
680. // that needs it, a region's names at the region, the derivations as a list of what to
681. // re-run. The module carries no table at all (WebFramework `module` drops the one the
682. // emitter writes).
683. //
684. // The reflection is the framework's own analysis generation — the same `gen` the View
685. // trees come from. Nothing starts a second one: a handle is only valid inside the
686. // generation that made it.
687. tableOf(gen, key) {
688. let members = []
689. let derivations = []
690. let handlers = []
691. let methods = []
692. for (m of hlMembers(gen, key)) {
693. let entry = { name = m.name; nodes = null; }
694. if (m.hasValue) {
695. let n = syntaxTree(gen, key, m.node)
696. entry.nodes = n
697. derivations.push({ name = m.name; site = n.site; reads = n.reads; serverSite = serverSite(n.reads); })
698. nestedHandlers(&handlers, n)
699. }
700. members.push(entry)
701. }
702. for (h of hlEvents(gen, key).handles) {
703. let n = syntaxTree(gen, key, h.node)
704. handlers.push({ event = h.event; site = n.site; reads = n.reads; writes = n.writes; nested = false; })
705. }
706. for (mm of hlMethods(gen, key)) {
707. if (!mm.inlineHandler) {
708. let n = syntaxTree(gen, key, mm.node)
709. methods.push({ name = mm.name; reads = n.reads; writes = n.writes; })
710. }
711. }
712. return { members = members; derivations = derivations; handlers = handlers; methods = methods; }
713. }
715. // A NESTED `on` IS A DOM HANDLER, filed under its own site — the id the View node
716. // carries. Its body is not the literal's syntax, so the node answers for it and the
717. // walk stops there.
718. nestedHandlers(&into, n) {
719. if (n == null) { return null }
720. if (n.tag == 'on_statement') {
721. into.push({ event = n.event; site = n.site; reads = n.reads; writes = n.writes; nested = true; })
722. return null
723. }
724. for (c of [n.value, n.list, n.body, n.condition, n.consequent, n.alternate, n.object, n.property, n.callee, n.left, n.right, n.operand]) {
725. if (c != null) { nestedHandlers(&into, c) }
726. }
727. for (l of [n.entries, n.args, n.elements]) {
728. if (l != null) { for (c of l) { nestedHandlers(&into, c) } }
729. }
730. return null
731. }
733. // the site with its file's base name: everything after the last '/'. The path part
734. // is not "up to the first ':'" — a package key has a colon of its own
735. // ('hl:markdown/Markdown.hl:24:3'), and that reading left a package component's
736. // sites unshortened, so its regions found no reads and never repainted (#111)
737. shortSite(site) {
738. if (site == null) { return null }
739. let cut = site.lastIndexOf('/')
740. if (cut < 0) { return site }
741. return site.slice(cut + 1)
742. }
744. // the syntax of one node, recursively — hl:core/AST's `tree`, read off the framework's
745. // own generation instead of starting one of its own
746. syntaxTree(gen, key, node) {
747. let n = hlSyntax(gen, key, node)
748. if (n == null) { return null }
749. // A SITE IS NAMED BY THE FILE'S BASE NAME. The reflection answers with the project
750. // key ('components/sort_list.hl:77:26'); the View tree, the emitter's own
751. // `__derive__` branches and every site this framework writes use the base name
752. // ('sort_list.hl:77:26'). One spelling, or a lookup by site finds nothing.
753. let out = { tag = n.tag; site = shortSite(n.site); reads = n.reads; writes = n.writes; }
754. if (n.tag == 'object_expression') {
755. let kids = []
756. for (h of n.entries) { kids.push(syntaxTree(gen, key, h)) }
757. out.entries = kids
758. } else if (n.tag == 'object_property') {
759. out.key = n.key
760. out.value = syntaxTree(gen, key, n.value)
761. } else if (n.tag == 'view_for') {
762. out.list = syntaxTree(gen, key, n.list)
763. out.body = syntaxTree(gen, key, n.body)
764. } else if (n.tag == 'view_if') {
765. out.condition = syntaxTree(gen, key, n.condition)
766. out.consequent = syntaxTree(gen, key, n.consequent)
767. out.alternate = syntaxTree(gen, key, n.alternate)
768. } else if (n.tag == 'on_statement') {
769. out.event = n.event
770. } else if (n.tag == 'member_expression') {
771. out.object = syntaxTree(gen, key, n.object)
772. out.property = syntaxTree(gen, key, n.property)
773. } else if (n.tag == 'call_expression') {
774. out.callee = syntaxTree(gen, key, n.callee)
775. let args = []
776. for (h of n.args) { args.push(syntaxTree(gen, key, h)) }
777. out.args = args
778. } else if (n.tag == 'binary_expression') {
779. out.left = syntaxTree(gen, key, n.left)
780. out.right = syntaxTree(gen, key, n.right)
781. } else if (n.tag == 'unary_expression') {
782. out.operand = syntaxTree(gen, key, n.operand)
783. } else if (n.tag == 'conditional_expression') {
784. out.condition = syntaxTree(gen, key, n.condition)
785. out.consequent = syntaxTree(gen, key, n.consequent)
786. out.alternate = syntaxTree(gen, key, n.alternate)
787. } else if (n.tag == 'array_expression') {
788. let els = []
789. for (h of n.elements) { els.push(syntaxTree(gen, key, h)) }
790. out.elements = els
791. }
792. return out
793. }
795. // ---- the reductions the browser used to make on every boot --------------------------
796. // A `for`'s names are what its list reads, an `if`'s what its condition reads — filed
797. // under the region's own site.
798. regionIndex(t) {
799. let idx = {}
800. for (m of t.members) { if (m.nodes != null) { indexRegions(&idx, m.nodes) } }
801. return idx
802. }
804. indexRegions(&idx, n) {
805. if (n == null) { return null }
806. if (n.tag == 'view_for') {
807. idx[n.site] = memberNames(nodeReads(n.list))
808. indexRegions(&idx, n.body)
809. return null
810. }
811. if (n.tag == 'view_if') {
812. idx[n.site] = memberNames(nodeReads(n.condition))
813. indexRegions(&idx, n.consequent)
814. indexRegions(&idx, n.alternate)
815. return null
816. }
817. if (n.tag == 'on_statement') { return null }
818. for (c of [n.value, n.list, n.body, n.condition, n.consequent, n.alternate, n.object, n.property, n.callee, n.left, n.right, n.operand]) {
819. if (c != null) { indexRegions(&idx, c) }
820. }
821. for (l of [n.entries, n.args, n.elements]) {
822. if (l != null) { for (c of l) { indexRegions(&idx, c) } }
823. }
824. return null
825. }
827. // the member reads of a read list — the language resolved every name, so this is a
828. // filter and not a second resolution
829. memberNames(reads) {
830. let out = []
831. if (reads == null) { return out }
832. for (r of reads) {
833. if (r.kind == 'member' && r.isStatic != true && !out.includes(r.name)) { out.push(r.name) }
834. }
835. return out
836. }
838. nodeReads(n) {
839. if (n == null) { return [] }
840. if (n.reads != null) { return n.reads }
841. let out = []
842. for (c of [n.value, n.list, n.body, n.condition, n.consequent, n.alternate, n.object, n.property, n.callee, n.left, n.right, n.operand]) {
843. if (c != null) { for (r of nodeReads(c)) { out.push(r) } }
844. }
845. for (l of [n.entries, n.args, n.elements]) {
846. if (l != null) { for (c of l) { for (r of nodeReads(c)) { out.push(r) } } }
847. }
848. return out
849. }
851. // A ROUTINE'S WRITES, PLUS THE WRITES OF EVERYTHING IT REACHES — the method it calls
852. // and the handler it emits to, transitively. Both are READS the language resolved, so
853. // this is a walk of its answer and never a guess.
854. closeWrites(t, writes, reads) {
855. let out = memberNames(writes)
856. let queue = []
857. reached(&queue, reads)
858. let seen = {}
859. while (queue.length > 0) {
860. let at = queue.shift()
861. if (seen[at] == null) {
862. seen[at] = true
863. let sp = at.indexOf(' ')
864. let kind = at.slice(0, sp)
865. let name = at.slice(sp + 1)
866. for (mm of t.methods) {
867. if (kind == 'method' && mm.name == name) {
868. for (w of memberNames(mm.writes)) { if (!out.includes(w)) { out.push(w) } }
869. reached(&queue, mm.reads)
870. }
871. }
872. for (h of t.handlers) {
873. if (kind == 'handler' && !h.nested && h.event == name) {
874. for (w of memberNames(h.writes)) { if (!out.includes(w)) { out.push(w) } }
875. reached(&queue, h.reads)
876. }
877. }
878. for (mb of t.members) {
879. if (kind == 'member' && mb.name == name && mb.nodes != null) {
880. for (w of memberNames(mb.nodes.writes)) { if (!out.includes(w)) { out.push(w) } }
881. reached(&queue, nodeReads(mb.nodes))
882. }
883. }
884. }
885. }
886. return out
887. }
889. // the mirror: a handler's reads plus the reads of everything it reaches — the
890. // candidates for a routine a host handed down, whose writes only the host's table names
891. closeReads(t, reads) {
892. let out = memberNames(reads)
893. let queue = []
894. reached(&queue, reads)
895. let seen = {}
896. while (queue.length > 0) {
897. let at = queue.shift()
898. if (seen[at] == null) {
899. seen[at] = true
900. let sp = at.indexOf(' ')
901. let kind = at.slice(0, sp)
902. let name = at.slice(sp + 1)
903. for (mm of t.methods) {
904. if (kind == 'method' && mm.name == name) {
905. for (r of memberNames(mm.reads)) { if (!out.includes(r)) { out.push(r) } }
906. reached(&queue, mm.reads)
907. }
908. }
909. for (h of t.handlers) {
910. if (kind == 'handler' && !h.nested && h.event == name) {
911. for (r of memberNames(h.reads)) { if (!out.includes(r)) { out.push(r) } }
912. reached(&queue, h.reads)
913. }
914. }
915. for (mb of t.members) {
916. if (kind == 'member' && mb.name == name && mb.nodes != null) {
917. for (r of memberNames(nodeReads(mb.nodes))) { if (!out.includes(r)) { out.push(r) } }
918. reached(&queue, nodeReads(mb.nodes))
919. }
920. }
921. }
922. }
923. return out
924. }
926. reached(&queue, reads) {
927. if (reads == null) { return null }
928. for (r of reads) {
929. if (r.kind == 'method' || r.kind == 'handler' || (r.kind == 'member' && r.isStatic != true)) { queue.push(r.kind + ' ' + r.name) }
930. }
931. return null
932. }
934. // ---- THE SERVER RENDER, COMPILED --------------------------------------------------
935. // The old hl:web rendered a page by WALKING the View tree per request: for every node it asks
936. // what kind it is, for every element it builds the attribute string, and it decides the
937. // indentation of every line again, on every request, for every one of the 121 mounts a
938. // page may hold. Every one of those decisions is a fact about the View.
939. //
940. // So a component's render is compiled ONCE into a list of STEPS — constant text, and a
941. // read with its own closure — and a request is a concatenation. The structure (tags,
942. // static attributes, the readable form's line breaks, which element is a block) is
943. // decided at compile time; only the values are asked for per request.
944. //
945. // KEYED BY THE INDENT IT IS RENDERED AT, because that is the only thing about a
946. // component's HTML that its caller decides: the shell renders at one tab, the page at
947. // the depth the slot stands, a fill compactly (null). An app has a handful of those.
948. serverSteps(key, nodes, indent, classes, slotted) {
949. let ck = key + '|' + (indent == null ? '~' : indent) + '|' + joinList(classes) + '|' + (slotted ? '1' : '0')
950. if (steps[ck] == null) {
951. steps[ck] = blockSteps(classes == null || classes.length == 0 ? nodes : v.withRootClasses(nodes, classes), indent, slotted)
952. }
953. return steps[ck]
954. }
956. // A `slot` THE HOST FILLED COUNTS AS CONTENT, and an empty one does not — the one
957. // thing about a component's shape its caller decides, so it is part of the key.
958. staticVoid = [ 'area' 'base' 'br' 'col' 'embed' 'hr' 'img' 'input' 'link' 'meta' 'source' 'track' 'wbr' ]
959. staticVerbatim = [ 'textarea' 'pre' 'script' 'style' ]
961. blocky(n, slotted) {
962. if (staticVerbatim.includes(n.tag)) { return false }
963. if (n.children.length == 0) { return false }
964. for (c of n.children) {
965. if (c.k == 'text' || c.k == 'field') { return false }
966. if (c.k == 'member' && !(c.name == 'slot' && slotted)) { return false }
967. }
968. return true
969. }
971. steps = {}
972. v = new HlwView
974. joinList(l) {
975. if (l == null) { return '' }
976. let out = ''
977. for (c of l) { out = out + ',' + c }
978. return out
979. }
981. // `render(nodes, …, indent)`: the readable form puts each element on its own line at
982. // `indent`, the compact one writes them end to end.
983. blockSteps(nodes, indent, slotted) {
984. let out = []
985. for (n of nodes) {
986. if (indent != null) {
987. if (n.k == 'el') { push(&out, { k = 's'; v = newline + indent; }) nodeSteps(&out, n, indent, slotted) }
988. else if (n.k == 'component') { nodeSteps(&out, n, indent, slotted) }
989. else if (n.k == 'for') { forSteps(&out, n, indent, slotted) }
990. else if (n.k == 'if') { ifSteps(&out, n, indent, slotted) }
991. else if (n.k == 'member' && n.name == 'slot') { push(&out, { k = 'slotline'; v = newline + indent; }) }
992. else if (n.k != 'on') { nodeSteps(&out, n, indent, slotted) }
993. } else {
994. nodeSteps(&out, n, null, slotted)
995. }
996. }
997. return out
998. }
1000. forSteps(&out, n, indent, slotted) {
1001. out.push({ k = 'for'; row = n.row; read = readFn(n.list); body = blockSteps(n.body, indent, slotted); })
1002. return null
1003. }
1005. ifSteps(&out, n, indent, slotted) {
1006. out.push({ k = 'if'; read = readFn(n.cond); then = blockSteps(n.then, indent, slotted); other = blockSteps(n.other, indent, slotted); })
1007. return null
1008. }
1010. // one node's steps — `html(node, …)`, decided once
1011. nodeSteps(&out, n, indent, slotted) {
1012. if (n.k == 'text') { push(&out, { k = 's'; v = v.escape(n.text); }) return null }
1013. if (n.k == 'on') { return null }
1014. if (n.k == 'member' && n.name == 'slot') { out.push({ k = 'slot'; }) return null }
1015. if (n.k == 'member' || n.k == 'field') { out.push({ k = 'r'; read = readFn(n); }) return null }
1016. if (n.k == 'for') { forSteps(&out, n, indent, slotted) return null }
1017. if (n.k == 'if') { ifSteps(&out, n, indent, slotted) return null }
1018. if (n.k == 'component') {
1019. out.push({ k = 'kid'; path = n.path; cls = n.cls; key = n.key; classes = n.classes; indent = indent;
1020. fill = (n.fill == null || n.fill.length == 0) ? null : blockSteps(n.fill, null, slotted); })
1021. return null
1022. }
1023. if (n.k == 'el') { elSteps(&out, n, indent, slotted) return null }
1024. push(&out, { k = 's'; v = '<!-- ' + n.tag + ' not rendered yet -->'; })
1025. return null
1026. }
1028. elSteps(&out, n, indent, slotted) {
1029. let attrs = []
1030. let valueRead = null // a textarea's value is its content
1031. let selRead = null // a select's value selects an option
1032. for (a of n.attrs) {
1033. if (n.tag == 'textarea' && a.name == 'value') { valueRead = attrRead(a) }
1034. else if (n.tag == 'select' && a.name == 'value') { selRead = attrRead(a) }
1035. // a bound BOOLEAN attribute is its presence (ticket #33): ` checked=""` or nothing
1036. else if ((a.member != null || a.ref != null) && v.isBoolAttr(a.name)) { attrs.push({ k = 'b'; name = a.name; read = attrRead(a); }) }
1037. else if (a.member != null || a.ref != null) {
1038. push(&attrs, { k = 's'; v = ' ' + a.name + '="'; })
1039. attrs.push({ k = 'r'; read = attrRead(a); })
1040. push(&attrs, { k = 's'; v = v.extraOf(a) + '"'; })
1041. } else {
1042. push(&attrs, { k = 's'; v = ' ' + a.name + '="' + v.escape(a.text) + '"'; })
1043. }
1044. }
1045. if (v.boundValue(n)) { push(&attrs, { k = 's'; v = ' autocomplete="off"'; }) }
1047. // the children, in the form this element takes: a block puts them one per line
1048. let kids = []
1049. if (indent != null && blocky(n, slotted)) {
1050. kids = blockSteps(n.children, indent + tab, slotted)
1051. push(&kids, { k = 's'; v = newline + indent; })
1052. } else {
1053. kids = blockSteps(n.children, null, slotted)
1054. }
1055. if (valueRead != null) { kids = [{ k = 'r'; read = valueRead; }] }
1057. // AN OPTION IS THE ONE ELEMENT WHOSE OWN TAG DEPENDS ON THE VALUE ABOVE IT: it
1058. // carries `selected` when its value is the select's. Everything else is settled.
1059. if (n.tag == 'option') {
1060. out.push({ k = 'opt'; attrs = attrs; body = kids; ov = optionRead(n); })
1061. return null
1062. }
1063. push(&out, { k = 's'; v = '<' + n.tag; })
1064. for (a of attrs) { push(&out, a) }
1065. if (staticVoid.includes(n.tag)) { push(&out, { k = 's'; v = '>'; }) return null }
1066. push(&out, { k = 's'; v = '>'; })
1067. // A SELECT HANDS ITS VALUE TO ITS OPTIONS, however deep they stand: its children
1068. // run under it, and it is the only element that changes anything for them.
1069. if (n.tag == 'select') { out.push({ k = 'sel'; read = selRead; body = kids; }) }
1070. else { for (kk of kids) { push(&out, kk) } }
1071. push(&out, { k = 's'; v = '</' + n.tag + '>'; })
1072. return null
1073. }
1075. // CONSTANT TEXT MERGES. Two literal steps in a row are one string decided at compile
1076. // time — which is what makes a request a concatenation of a handful of pieces instead
1077. // of one per node.
1078. push(&out, step) {
1079. if (step.k == 's' && out.length > 0 && out[out.length - 1].k == 's') {
1080. let last = out[out.length - 1]
1081. last.v = last.v + step.v
1082. out[out.length - 1] = last
1083. return null
1084. }
1085. out.push(step)
1086. return null
1087. }
1089. // ---- the reads, each with its own closure ------------------------------------------
1090. // `view.value`'s rule, split once: a `for` row variable in scope wins over a member of
1091. // the same name, and a field path walks into it. The closure holds the name — there is
1092. // no node to look at per request.
1093. readFn(node) {
1094. if (node == null) { return (inst, rows) => { return null } }
1095. if (node.k == 'text') { let t = v.refValue(node) return (inst, rows) => { return t } }
1096. let name = node.name
1097. if (node.k != 'field') {
1098. return (inst, rows) => { return rows[name] != null ? rows[name] : inst[name] }
1099. }
1100. let path = node.path
1101. return (inst, rows) => {
1102. let val = rows[name] != null ? rows[name] : inst[name]
1103. for (f of path) {
1104. if (val == null) { return null }
1105. val = val[f]
1106. }
1107. return val
1108. }
1109. }
1111. attrRead(a) {
1112. if (a.member != null) { return readFn({ k = 'member'; name = a.member; }) }
1113. if (a.ref != null) { return readFn(a.ref) }
1114. let t = a.text
1115. return (inst, rows) => { return t }
1116. }
1118. // an option's own value: its `value` attribute, or null when it has none (the browser
1119. // then reports its text, and the run compares against what it rendered)
1120. optionRead(n) {
1121. for (a of n.attrs) {
1122. if (a.name == 'value') { return attrRead(a) }
1123. }
1124. return null
1125. }
1127. // ---- the run: a concatenation ------------------------------------------------------
1128. // EVERY REGION IS WRITTEN BETWEEN TWO MARKS (tickets #103, #104): an `if` around the
1129. // branch that stands, a `for` around its rows and each row around its own nodes. The
1130. // client claims them as they are and builds the same ones, and a region's nodes are
1131. // exactly what stands between its two marks — nothing it holds has to be remembered
1132. // node by node, and text beside a region can never run into the region's text.
1133. markOpen = '<!--[-->'
1134. markClose = '<!--]-->'
1136. runSteps(list, &inst, &rows, &ctx) {
1137. let out = ''
1138. for (s of list) {
1139. if (s.k == 's') { out = out + s.v }
1140. else if (s.k == 'r') { let f = s.read out = out + v.escape(f(&inst, &rows)) }
1141. else if (s.k == 'b') { let f = s.read if (v.boolOn(f(&inst, &rows))) { out = out + ' ' + s.name + '=""' } }
1142. else if (s.k == 'slot') { if (ctx.slot != null) { out = out + ctx.slot } }
1143. else if (s.k == 'slotline') { if (ctx.slot != null) { out = out + s.v + ctx.slot } }
1144. else if (s.k == 'for') {
1145. let f = s.read
1146. let list2 = f(&inst, &rows)
1147. out = out + markOpen
1148. if (list2 != null) {
1149. let ri = 0
1150. for (entry of list2) {
1151. let inner = rows + {}
1152. inner[s.row] = entry
1153. let rc = v.rowCtx(&ctx, &entry, ri)
1154. out = out + markOpen + runSteps(s.body, &inst, &inner, &rc) + markClose
1155. ri = ri + 1
1156. }
1157. }
1158. out = out + markClose
1159. }
1160. else if (s.k == 'if') {
1161. let f = s.read
1162. if (f(&inst, &rows)) { out = out + markOpen + runSteps(s.then, &inst, &rows, &ctx) + markClose }
1163. else { out = out + markOpen + runSteps(s.other, &inst, &rows, &ctx) + markClose }
1164. }
1165. else if (s.k == 'opt') {
1166. let head = runSteps(s.attrs, &inst, &rows, &ctx)
1167. let body = runSteps(s.body, &inst, &rows, &ctx)
1168. let mark = ''
1169. if (ctx.sel != null) {
1170. let ov = body
1171. if (s.ov != null) { let f = s.ov ov = '' + f(&inst, &rows) }
1172. if (ov == ctx.sel) { mark = ' selected' }
1173. }
1174. out = out + '<option' + head + mark + '>' + body + '</option>'
1175. }
1176. else if (s.k == 'sel') {
1177. let f = s.read
1178. let inner = ctx + {}
1179. inner.sel = f == null ? null : '' + f(&inst, &rows)
1180. out = out + runSteps(s.body, &inst, &rows, &inner)
1181. }
1182. else if (s.k == 'kid') {
1183. let kid = ctx.kids[v.kidKeyIn(s.path, ctx)]
1184. if (kid == null) { out = out + '<!-- ' + s.cls + ' not mounted -->' }
1185. else {
1186. let fillText = s.fill == null ? null : runSteps(s.fill, &inst, &rows, &ctx)
1187. let kidCtx = { slot = fillText; kids = kid.kids; }
1188. let kidInst = kid.page
1189. let empty = {}
1190. out = out + runSteps(serverSteps(s.key, kid.view, s.indent, s.classes, fillText != null), &kidInst, &empty, &kidCtx)
1191. }
1192. }
1193. }
1194. return out
1195. }