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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 View from './view.hl'
40. // ---- the emitted half --------------------------------------------------------------
41. module(gen, key, nodes) {
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
63. // THE PRELUDE, one per module: the element a claim takes or a create makes, and the
64. // two reads. A read written out in full — `(r["title"]!=null?r["title"]:inst["title"])`
65. // — is 45 bytes and a component's View holds dozens of them; named, it is 16. The
66. // rule is the same rule (a `for` row variable in scope wins over a member of the
67. // same name, and a field path walks into it), spelled once.
68. // A claim also moves the host's CURSOR — the last node the walk took there — which is
69. // where a text leaf and a region's mark are looked for next (client.hl `leafNode`,
70. // `markAt`).
71. src = src + 'function A(cr,host,i,tag){if(cr){return document.createElement(tag);}var e=host.children[i];if(e!=null){host.__hlCur=e;}return e;}'
72. src = src + 'function S(v){return v==null?"":""+v;}'
73. src = src + 'function RV(r,q,n){return r[n]!=null?r[n]:q[n];}'
74. 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;}'
75. src = src + 'var B={},T={},E={},F={},P={};'
76. // ONE FUNCTION PER LIST, however many sites reach it: a nested walk is written once
77. // and named — emitting it per site made the reference app's home page 215 KB of the
78. // same code over and over.
79. let wi = 0
80. for (f of fns) {
81. wi = wi + 1
82. let name = 'w' + wi
83. src = src + 'var ' + name + '=' + f.src + ';'
84. for (site of f.sites) { src = src + f.slot + '[' + str(site) + ']=' + name + ';' }
85. }
86. let paints = []
87. collectPaints(&paints, roots)
88. for (e of paints) { src = src + 'P[' + str(e.site) + ']={p:' + e.paint + ',r:' + e.row + '};' }
89. src = src + 'C[' + str(key) + ']={v:' + root + ',b:B,t:T,e:E,f:F,p:P'
90. // THE ANSWERS A LOOKUP STILL NEEDS, and only those. A local event's write set stands
91. // at its own listener and a region's names at its own region — written into the
92. // call. These three are asked for by NAME at run time and cannot be: an inbound
93. // frame names its event, a routine handed down names the member that holds it, and
94. // a write set names the derivations that follow it.
95. src = src + ',ev:' + eventMap() + ',mw:' + memberMap() + ',dv:' + derivList() + '};'
96. return src + '})();' + newline
97. }
99. tbl = null
100. regions = {}
102. // what a DECLARED handler writes, by event: one entry per event name, unioned
103. eventMap() {
104. let byEvent = {}
105. for (h of tbl.handlers) {
106. if (!h.nested) {
107. let have = byEvent[h.event] == null ? [] : byEvent[h.event]
108. for (w of closeWrites(tbl, h.writes, h.reads)) { if (!have.includes(w)) { have.push(w) } }
109. byEvent[h.event] = have
110. }
111. }
112. return mapOf(byEvent)
113. }
115. // A MEMBER HOLDING A ROUTINE: what calling it writes is what its initializer writes
116. memberMap() {
117. let byName = {}
118. for (m of tbl.members) {
119. if (m.nodes != null) { byName[m.name] = memberNames(m.nodes.writes) }
120. }
121. return mapOf(byName)
122. }
124. // EVERY INITIALIZER, IN DECLARATION ORDER, with the members it reads — the whole of
125. // what a derivation needs; the class carries the computation itself as `__derive__`
126. derivList() {
127. let src = '['
128. let first = true
129. for (d of tbl.derivations) {
130. if (!first) { src = src + ',' }
131. first = false
132. src = src + '{name:' + str(d.name) + ',site:' + str(d.site) + ',reads:' + list(memberNames(d.reads)) + '}'
133. }
134. return src + ']'
135. }
137. mapOf(byName) {
138. let src = '{'
139. let first = true
140. for (k of byName.keys()) {
141. if (!first) { src = src + ',' }
142. first = false
143. src = src + str(k) + ':' + list(byName[k])
144. }
145. return src + '}'
146. }
148. // the write set and the read set of the handler at this site, closed over the methods
149. // it calls and the handlers it emits to — computed here, written into the listener
150. handlerSets(site) {
151. for (h of tbl.handlers) {
152. if (h.nested && h.site == site) {
153. return list(closeWrites(tbl, h.writes, h.reads)) + ',' + list(closeReads(tbl, h.reads))
154. }
155. }
156. return '[],[]'
157. }
159. regionNamesAt(site) {
160. let names = regions[site]
161. return list(names == null ? [] : names)
162. }
164. fns = []
166. // ---- the walk, unrolled ------------------------------------------------------------
167. // `top` marks the View's own root list: an element there is a COMPOSITION ROOT — a
168. // reference above may have overwritten some of its events and put classes on it, which
169. // is what `opt` carries (the old hl:web's rootOverwrites and withRootClasses).
170. walk(key, nodes) {
171. return plain(key, nodes)
172. }
174. // a list's walk
175. plain(key, nodes) {
176. let body = ''
177. for (n of nodes) { body = body + node(key, n, false, false) }
178. return 'async function(c,m,o,host,i,rows,rk,fill,cr,opt){let inst=m.instance;let r=rows;' + body + 'return i;}'
179. }
181. // the View's own root list, whose elements are composition roots
182. walkTop(key, nodes) {
183. let body = ''
184. for (n of nodes) { body = body + node(key, n, true, false) }
185. return 'async function(c,m,o,host,i,rows,rk,fill,cr,opt){let inst=m.instance;let r=rows;' + body + 'return i;}'
186. }
188. // a sub-walk, registered under its own site so the runtime can reach it by name
189. // A SUB-WALK IS WRITTEN ONCE, however often the compile reaches its list.
190. sub(key, nodes, slot, site) {
191. if (done[slot + ' ' + site] != null) { return null }
192. done[slot + ' ' + site] = true
193. fns.push({ slot = slot; sites = [site]; src = walk(key, nodes); })
194. return null
195. }
197. done = {}
199. node(key, n, top, filterOns) {
200. if (n.k == 'el') { return elNode(key, n, top) }
201. 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) + ');}' }
202. if (n.k == 'on') {
203. // A REFERENCE ABOVE MAY HAVE OVERWRITTEN THIS EVENT on the composition root:
204. // the root's own handler for it is dropped and the reference's stands instead
205. // (the old hl:web's withoutOns, which applies to the root element's direct children).
206. let guard = filterOns ? 'if(!(opt&&opt.over&&opt.over.indexOf(' + str(n.event) + ')>=0)){' : '{'
207. return guard + 'await c.onAt(m,host,' + str(n.event) + ',' + str(n.site) + ',rows,' + handlerSets(n.site) + ');}'
208. }
209. if (n.k == 'member' && n.name == 'slot') {
210. // the SHELL's slot is where the route component hangs; a child's slot is the
211. // fragment its host wrote, and the host's frame builds it
212. 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);}'
213. }
214. // A TEXT LEAF STANDING IN A LIST — an `if` branch, a `for` body — beside elements or
215. // alone: its own text node, and a site of the member it reads (or of the row it
216. // stands in), painted by rewriting that node.
217. if (n.k == 'member' || n.k == 'field') {
218. let names = (n.name == 'Style' || rowVars.includes(n.name)) ? [] : [n.name]
219. return 'await c.textAt(m,host,cr,function(inst,r){return ' + textRead(n) + ';},' + list(names) + ',rows,rk);'
220. }
221. if (n.k == 'for') {
222. // THE ROW VARIABLE IS IN SCOPE INSIDE THE BODY, and a read of it is the ROW's,
223. // not a member of the instance — the language resolves it that way and the site
224. // sets must say the same, or a member of the same name would paint the row.
225. rowVars.push(n.row)
226. sub(key, n.body, 'B', n.site)
227. rowVars.pop()
228. 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) + ');'
229. }
230. if (n.k == 'if') {
231. sub(key, n.then, 'T', n.site)
232. sub(key, n.other, 'E', n.site)
233. 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) + ');'
234. }
235. if (n.k == 'component') {
236. if (n.fill != null && n.fill.length > 0) { sub(key, n.fill, 'F', n.site) }
237. return 'i=await c.kidAt(m,host,i,' + kidSpec(n) + ',rows,rk,fill,cr,opt);'
238. }
239. return ''
240. }
242. // ---- an element --------------------------------------------------------------------
243. elNode(key, n, top) {
244. let src = '{let el=A(cr,host,i,' + str(n.tag) + ');if(!cr){i=i+1;}'
245. src = src + 'if(el==null){await c.acqFail(' + str(n.tag) + ',host);}else{'
246. // the attributes, on the walk that BUILDS the element (a claim takes the server's)
247. src = src + 'if(cr){' + createAttrs(n) + (top ? 'await c.rootClasses(el,opt);' : '') + 'host.appendChild(el);}'
248. src = src + 'el.__hlRows=rows;el.__hlSite=' + str(n.site) + ';el.__hlKey=' + str(key) + ';'
249. // the element's own named entries, for the literal a handler on it fires
250. src = src + 'el.__hlLit=function(inst,r){return ' + litNamed(n) + ';};'
251. let names = siteNames(n)
252. let valueMember = 'null'
253. for (a of n.attrs) { if (a.member != null && a.name == 'value') { valueMember = str(a.member) } }
254. let sited = ''
255. if (names.length > 0 || valueMember != 'null') {
256. sited = 'await c.siteAt(m,el,' + list(names) + ',' + str(n.site) + ',' + valueMember + ',' + (n.tag == 'select' ? 'true' : 'false') + ',rows);'
257. }
258. let kids = ''
259. // AN ELEMENT THAT HOLDS ONLY TEXT is painted whole (`textContent`, see the paints):
260. // built, it gets that text as one node; claimed, the server's is taken as it stands
261. let whole = textOf(n)
262. if (whole != null) {
263. kids = 'if(cr){host.appendChild(document.createTextNode(' + whole + '));}'
264. for (c of n.children) { if (c.k == 'on') { kids = kids + node(key, c, false, top) } }
265. }
266. else if (mixed(n)) { kids = mixedKids(key, n, top) }
267. else { for (c of n.children) { kids = kids + node(key, c, false, top) } }
268. let inner = '{let host=el;let i=0;' + kids + '}'
269. // A SELECT IS SITED AFTER ITS OPTIONS: the member decides which option stands, and
270. // the read-back that `siteAt` does reports nothing before they exist.
271. if (n.tag == 'select') { src = src + inner + 'if(cr){await c.applySelectAt(m,el,' + selectValue(n) + ');}' + sited }
272. else { src = src + sited + inner }
273. return src + '}}'
274. }
276. // A TEXT LEAF BESIDE AN ELEMENT OR A REGION (ticket #86 follow-up): `td { d.n if (…) {…} }`
277. // cannot be painted through `textContent`, which would wipe the branch. Each RUN of
278. // adjacent leaves is one text node, held on the element (`__hlLeaves`, by the run's
279. // index) where the walk builds or claims it, and the paints rewrite that node alone.
280. mixed(n) {
281. if (textOf(n) != null) { return false }
282. for (c of n.children) { if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { return true } }
283. return false
284. }
286. isLeaf(c) { return c.k == 'text' || ((c.k == 'member' || c.k == 'field') && c.name != 'slot') }
288. // the runs of adjacent leaves, in order; an `on` renders nothing and splits none
289. runsOf(n) {
290. let out = []
291. let run = []
292. for (c of n.children) {
293. if (isLeaf(c)) { run.push(c) }
294. else if (c.k != 'on') {
295. if (run.length > 0) { out.push(run) }
296. run = []
297. }
298. }
299. if (run.length > 0) { out.push(run) }
300. return out
301. }
303. runText(run) {
304. let src = '""'
305. for (c of run) { src = src + '+(' + (c.k == 'text' ? str(c.text) : textRead(c)) + ')' }
306. return src
307. }
309. runFeeds(run) {
310. for (c of run) { if (c.k != 'text') { return true } }
311. return false
312. }
314. mixedKids(key, n, top) {
315. let kids = ''
316. let run = []
317. let k = 0
318. for (c of n.children) {
319. if (isLeaf(c)) { run.push(c) }
320. else {
321. if (c.k != 'on' && run.length > 0) { kids = kids + leafRun(run, k) k = k + 1 run = [] }
322. kids = kids + node(key, c, false, top)
323. }
324. }
325. if (run.length > 0) { kids = kids + leafRun(run, k) }
326. return kids
327. }
329. // EVERY CALL INTO THE CLIENT IS AWAITED: its methods are async in the browser, and one
330. // not awaited runs its DOM work after the walk has gone on — a built leaf then lands
331. // after the elements that follow it (ticket #104).
332. leafRun(run, k) {
333. if (!runFeeds(run)) { return 'if(cr){host.appendChild(document.createTextNode(' + runText(run) + '));}else{await c.leafAt(host,false,i,null,' + runText(run) + ');}' }
334. return 'await c.leafAt(host,cr,i,' + k + ',' + runText(run) + ');'
335. }
337. // the attributes an element is BUILT with — a bound one written in, a literal one as it
338. // stands. `value` is a property once the page is live and an attribute as the control's
339. // default; a textarea has no value attribute at all and a select's value is an option.
340. createAttrs(n) {
341. let src = ''
342. for (a of n.attrs) {
343. if (isBool(a)) {
344. src = src + '{' + boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) + '}'
345. } else {
346. let rd = a.member != null ? readOf({ k = 'member'; name = a.member; }) : (a.ref != null ? readOf(a.ref) : str(a.text))
347. src = src + '{let v=' + rd + ';'
348. if (a.extra != null) { src = src + 'v=v+" "+' + str(a.extra) + ';' }
349. if (n.tag == 'select' && a.name == 'value') { src = src + '}' }
350. else if (a.name == 'value') {
351. src = src + 'if(el.value!=null){el.value=v;' + (n.tag == 'textarea' ? '' : 'el.setAttribute("value",v);') + '}else{el.setAttribute("value",v);}}'
352. } else { src = src + 'el.setAttribute(' + str(a.name) + ',v);}' }
353. }
354. }
355. if (boundValue(n)) { src = src + 'el.setAttribute("autocomplete","off");' }
356. return src
357. }
359. // a BOUND boolean attribute — a literal one was decided at build (WebFramework `element`)
360. isBool(a) {
361. return (a.member != null || a.ref != null) && v.isBoolAttr(a.name)
362. }
364. // A BOUND BOOLEAN ATTRIBUTE, WRITTEN (ticket #33): set when the value is on, REMOVED when
365. // it is off — the markup's rule (view.boolAttrs) — and the DOM property with it, because
366. // once the page is live `checked` is the property and the attribute only its default.
367. boolWrite(a, raw) {
368. let prop = a.name == 'readonly' ? 'readOnly' : a.name
369. 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;}'
370. }
372. // view.hl's `boundValue`, to the letter: a FORM CONTROL whose `value` reads a member or
373. // a field, and not one the author gave an `autocomplete` of its own
374. boundValue(n) {
375. if (n.tag != 'input' && n.tag != 'textarea' && n.tag != 'select') { return false }
376. let bound = false
377. for (a of n.attrs) {
378. if (a.name == 'autocomplete') { return false }
379. if (a.name == 'value' && (a.member != null || a.ref != null)) { bound = true }
380. }
381. return bound
382. }
384. selectValue(n) {
385. for (a of n.attrs) {
386. if (a.name == 'value') {
387. if (a.member != null) { return readOf({ k = 'member'; name = a.member; }) }
388. if (a.ref != null) { return readOf(a.ref) }
389. return str(a.text)
390. }
391. }
392. return 'null'
393. }
395. // the element's own entries as the literal sees them — its attributes by name, then the
396. // `for` row variables in scope (the row rides on the value)
397. litNamed(n) {
398. let src = '{'
399. let first = true
400. for (a of n.attrs) {
401. if (!first) { src = src + ',' }
402. first = false
403. let v = a.member != null ? rawRead({ k = 'member'; name = a.member; }) : (a.ref != null ? rawRead(a.ref) : str(a.text))
404. src = src + str(a.name) + ':' + v
405. }
406. return src + '}'
407. }
409. // the reference's own description, written at its use site: what it binds, what it
410. // overwrites, the classes the host's `#Child` rule puts on it
411. kidSpec(n) {
412. let src = '{key:' + str(n.key) + ',kid:' + str(kidKeyOf(n)) + ',site:' + str(n.site) + ',fill:' + ((n.fill != null && n.fill.length > 0) ? 'true' : 'false')
413. src = src + ',bindings:['
414. let first = true
415. for (b of n.bindings) {
416. if (!first) { src = src + ',' }
417. first = false
418. src = src + '{name:' + str(b.name) + ',member:' + (b.member == null ? 'null' : str(b.member))
419. src = src + ',ref:' + (b.ref == null ? 'null' : 'function(inst,r){return ' + rawRead(b.ref) + ';}')
420. src = src + ',refName:' + (b.ref == null ? 'null' : str(b.ref.name))
421. src = src + ',text:' + (b.text == null ? 'null' : 'true') + ',value:' + (b.text == null ? 'null' : refLiteral(b)) + '}'
422. }
423. src = src + '],ons:['
424. first = true
425. for (o of n.ons) {
426. if (!first) { src = src + ',' }
427. first = false
428. src = src + '{event:' + str(o.event) + ',site:' + str(o.site) + ',sets:[' + handlerSets(o.site) + ']}'
429. }
430. src = src + '],classes:' + list(n.classes == null ? [] : n.classes) + '}'
431. return src
432. }
434. // view.hl's kidKey: the reference's path, joined — the key the server mounted it under
435. kidKeyOf(n) {
436. let out = ''
437. for (p of n.path) { out = out + '/' + p }
438. return out
439. }
441. // the value a literal binding carries — view.refValue, folded at compile time
442. refLiteral(b) {
443. if (b.kind == 'folded') { return jsValue(b.value) }
444. if (b.kind == 'number') { return '' + b.text }
445. if (b.kind == 'boolean') { return b.text == 'true' ? 'true' : 'false' }
446. if (b.kind == 'null_literal') { return 'null' }
447. return str(b.text)
448. }
450. jsValue(v) {
451. if (v == null) { return 'null' }
452. if (hlTypeName(v) == 'String') { return str(v) }
453. if (hlTypeName(v) == 'Boolean') { return v ? 'true' : 'false' }
454. if (hlTypeName(v) == 'Number') { return '' + v }
455. return JSON.stringify(v)
456. }
458. // ---- the site set: what this element SHOWS ------------------------------------------
459. // The old hl:web asked the module's table which members the element at this site reads. The
460. // answer is a fact about the View, so it is written in: the members its bound
461. // attributes and its text leaves name. `Style` is folded into a class name at build and
462. // the shell's `slot` is swapped by navigation — neither is ever painted, and neither is
463. // a member read that reaches here (a `for` row variable resolves to its row).
464. siteNames(n) {
465. let out = []
466. for (a of n.attrs) {
467. if (a.member != null && a.member != 'Style' && !rowVars.includes(a.member) && !out.includes(a.member)) { out.push(a.member) }
468. }
469. for (c of n.children) {
470. if ((c.k == 'member' || c.k == 'field') && c.name != 'slot' && c.name != 'Style' && !rowVars.includes(c.name)) {
471. if (!out.includes(c.name)) { out.push(c.name) }
472. }
473. }
474. return out
475. }
477. rowVars = []
479. // ---- the paints ---------------------------------------------------------------------
480. collectPaints(&out, nodes) {
481. for (n of nodes) {
482. if (n.k == 'el') {
483. let paint = paintFn(n)
484. let row = rowFn(n)
485. if (paint != null || row != 'null') {
486. out.push({ site = n.site; paint = paint == null ? 'null' : paint; row = row; })
487. }
488. collectPaints(&out, n.children)
489. } else if (n.k == 'for') { collectPaints(&out, n.body) }
490. else if (n.k == 'if') { collectPaints(&out, n.then) collectPaints(&out, n.other) }
491. else if (n.k == 'component') { if (n.fill != null) { collectPaints(&out, n.fill) } }
492. }
493. return null
494. }
496. // `paint(&m, s, name)`, compiled: the bound attributes under the member each reads, and
497. // the text where the member that moved stands among the leaves.
498. paintFn(n) {
499. let body = ''
500. for (a of n.attrs) {
501. if (a.member != null) {
502. body = body + 'if(n===' + str(a.member) + '){' + attrWrite(n, a, readOf({ k = 'member'; name = a.member; })) + '}'
503. }
504. }
505. let text = textOf(n)
506. if (text != null) {
507. let guard = ''
508. for (c of n.children) {
509. if (c.k == 'member' && c.name != 'slot') {
510. if (guard != '') { guard = guard + '||' }
511. guard = guard + 'n===' + str(c.name)
512. }
513. }
514. if (guard != '') { body = body + 'if(' + guard + '){el.textContent=' + text + ';}' }
515. } else if (mixed(n)) {
516. let k = 0
517. for (run of runsOf(n)) {
518. let guard = ''
519. for (c of run) {
520. if (c.k != 'text') {
521. if (guard != '') { guard = guard + '||' }
522. guard = guard + 'n===' + str(c.name)
523. }
524. }
525. if (guard != '') { body = body + 'if((' + guard + ')&&el.__hlLeaves&&el.__hlLeaves[' + k + ']){el.__hlLeaves[' + k + '].data=' + runText(run) + ';}' }
526. k = k + 1
527. }
528. }
529. if (body == '') { return null }
530. return 'function(el,inst,r,n){' + body + '}'
531. }
533. // `rowPaint(&m, el)`, compiled: every bound spot, written only where the DOM does not
534. // already hold it — which is why a push into 2000 rows costs the 1999 nothing.
535. rowFn(n) {
536. let body = ''
537. for (a of n.attrs) {
538. if (isBool(a)) {
539. body = body + '{' + boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) + '}'
540. } else if (a.member != null || a.ref != null) {
541. let one = 'let v=' + readOf(a.member != null ? { k = 'member'; name = a.member; } : a.ref) + ';'
542. if (a.extra != null) { one = one + 'v=v+" "+' + str(a.extra) + ';' }
543. if (n.tag == 'select' && a.name == 'value') { one = one + 'if(el.value!==v){el.value=v;}' }
544. else {
545. one = one + 'if(el.getAttribute(' + str(a.name) + ')!==v){el.setAttribute(' + str(a.name) + ',v);}'
546. if (a.name == 'value') { one = one + 'if(el.value!=null&&el.value!==v){el.value=v;}' }
547. }
548. body = body + '{' + one + '}'
549. }
550. }
551. let text = textOf(n)
552. let feeds = false
553. for (c of n.children) { if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { feeds = true } }
554. if (text != null && feeds) { body = body + '{let t=' + text + ';if(el.textContent!==t){el.textContent=t;}}' }
555. if (text == null && feeds) {
556. let k = 0
557. for (run of runsOf(n)) {
558. if (runFeeds(run)) { body = body + '{let x=el.__hlLeaves&&el.__hlLeaves[' + k + '];let t=' + runText(run) + ';if(x&&x.data!==t){x.data=t;}}' }
559. k = k + 1
560. }
561. }
562. if (body == '') { return 'null' }
563. return 'function(el,inst,r){' + body + '}'
564. }
566. attrWrite(n, a, v) {
567. if (isBool(a)) { return boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) }
568. let src = 'let v=' + v + ';'
569. if (a.extra != null) { src = src + 'v=v+" "+' + str(a.extra) + ';' }
570. if (n.tag == 'select' && a.name == 'value') { return src + 'el.value=v;' }
571. src = src + 'el.setAttribute(' + str(a.name) + ',v);'
572. if (a.name == 'value') { src = src + 'if(el.value!=null){el.value=v;}' }
573. return src
574. }
576. textOf(n) {
577. let parts = []
578. let content = 0
579. let feeds = false
580. for (c of n.children) {
581. if (c.k != 'on') {
582. content = content + 1
583. if (c.k == 'text') { parts.push(str(c.text)) }
584. else if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { parts.push(textRead(c)) feeds = true }
585. }
586. }
587. if (!feeds) { return null }
588. if (parts.length != content) { return null }
589. let src = '""'
590. for (p of parts) { src = src + '+(' + p + ')' }
591. return src
592. }
594. // ---- a read, written in ---------------------------------------------------------------
595. // `view.value`'s own rule as an expression: a `for` row variable in scope wins over a
596. // member of the same name, and a field path walks into it. `readOf` answers the STRING
597. // the DOM takes; `rawRead` the value itself (a binding, a list, a condition).
598. readOf(node) { return '(""+' + rawRead(node) + ')' }
600. // A READ SHOWN AS TEXT: null is no text, as the server writes it (view.hl `escape`)
601. textRead(node) { return 'S(' + rawRead(node) + ')' }
603. rawRead(node) {
604. if (node == null) { return 'null' }
605. if (node.k == 'text') { return str(node.text) }
606. if (node.k != 'field') { return 'RV(r,inst,' + str(node.name) + ')' }
607. return 'RF(r,inst,' + str(node.name) + ',' + list(node.path) + ')'
608. }
610. list(names) {
611. let src = '['
612. let first = true
613. for (n of names) {
614. if (!first) { src = src + ',' }
615. first = false
616. src = src + str(n)
617. }
618. return src + ']'
619. }
621. // a JavaScript string literal — JSON's escaping is a subset of JavaScript's, so a
622. // source text's quotes, newlines and backslashes survive into the statement unchanged
623. str(s) {
624. if (s == null) { return '""' }
625. return JSON.stringify('' + s)
626. }
628. // ---- WHAT THE LANGUAGE SAYS ABOUT THIS FILE, read HERE and written into the code ----
629. // The old hl:web shipped the language's answers to the browser as data: `hlJs` writes each file's
630. // members, handlers and methods — every node of every initializer, with the names it
631. // reads — into the module, and the client reduces that table on every boot. The answers
632. // are facts about the source, so this file asks for them once, at compile time, and
633. // writes the RESULT into the statements: a handler's write set stands at the listener
634. // that needs it, a region's names at the region, the derivations as a list of what to
635. // re-run. The module carries no table at all (WebFramework `module` drops the one the
636. // emitter writes).
637. //
638. // The reflection is the framework's own analysis generation — the same `gen` the View
639. // trees come from. Nothing starts a second one: a handle is only valid inside the
640. // generation that made it.
641. tableOf(gen, key) {
642. let members = []
643. let derivations = []
644. let handlers = []
645. let methods = []
646. for (m of hlMembers(gen, key)) {
647. let entry = { name = m.name; nodes = null; }
648. if (m.hasValue) {
649. let n = syntaxTree(gen, key, m.node)
650. entry.nodes = n
651. derivations.push({ name = m.name; site = n.site; reads = n.reads; })
652. nestedHandlers(&handlers, n)
653. }
654. members.push(entry)
655. }
656. for (h of hlEvents(gen, key).handles) {
657. let n = syntaxTree(gen, key, h.node)
658. handlers.push({ event = h.event; site = n.site; reads = n.reads; writes = n.writes; nested = false; })
659. }
660. for (mm of hlMethods(gen, key)) {
661. if (!mm.inlineHandler) {
662. let n = syntaxTree(gen, key, mm.node)
663. methods.push({ name = mm.name; reads = n.reads; writes = n.writes; })
664. }
665. }
666. return { members = members; derivations = derivations; handlers = handlers; methods = methods; }
667. }
669. // A NESTED `on` IS A DOM HANDLER, filed under its own site — the id the View node
670. // carries. Its body is not the literal's syntax, so the node answers for it and the
671. // walk stops there.
672. nestedHandlers(&into, n) {
673. if (n == null) { return null }
674. if (n.tag == 'on_statement') {
675. into.push({ event = n.event; site = n.site; reads = n.reads; writes = n.writes; nested = true; })
676. return null
677. }
678. 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]) {
679. if (c != null) { nestedHandlers(&into, c) }
680. }
681. for (l of [n.entries, n.args, n.elements]) {
682. if (l != null) { for (c of l) { nestedHandlers(&into, c) } }
683. }
684. return null
685. }
687. shortSite(site) {
688. if (site == null) { return null }
689. let at = site.indexOf(':')
690. if (at < 0) { return site }
691. let path = site.slice(0, at)
692. let cut = path.lastIndexOf('/')
693. if (cut < 0) { return site }
694. return path.slice(cut + 1) + site.slice(at)
695. }
697. // the syntax of one node, recursively — hl:core/AST's `tree`, read off the framework's
698. // own generation instead of starting one of its own
699. syntaxTree(gen, key, node) {
700. let n = hlSyntax(gen, key, node)
701. if (n == null) { return null }
702. // A SITE IS NAMED BY THE FILE'S BASE NAME. The reflection answers with the project
703. // key ('components/sort_list.hl:77:26'); the View tree, the emitter's own
704. // `__derive__` branches and every site this framework writes use the base name
705. // ('sort_list.hl:77:26'). One spelling, or a lookup by site finds nothing.
706. let out = { tag = n.tag; site = shortSite(n.site); reads = n.reads; writes = n.writes; }
707. if (n.tag == 'object_expression') {
708. let kids = []
709. for (h of n.entries) { kids.push(syntaxTree(gen, key, h)) }
710. out.entries = kids
711. } else if (n.tag == 'object_property') {
712. out.key = n.key
713. out.value = syntaxTree(gen, key, n.value)
714. } else if (n.tag == 'view_for') {
715. out.list = syntaxTree(gen, key, n.list)
716. out.body = syntaxTree(gen, key, n.body)
717. } else if (n.tag == 'view_if') {
718. out.condition = syntaxTree(gen, key, n.condition)
719. out.consequent = syntaxTree(gen, key, n.consequent)
720. out.alternate = syntaxTree(gen, key, n.alternate)
721. } else if (n.tag == 'on_statement') {
722. out.event = n.event
723. } else if (n.tag == 'member_expression') {
724. out.object = syntaxTree(gen, key, n.object)
725. out.property = syntaxTree(gen, key, n.property)
726. } else if (n.tag == 'call_expression') {
727. out.callee = syntaxTree(gen, key, n.callee)
728. let args = []
729. for (h of n.args) { args.push(syntaxTree(gen, key, h)) }
730. out.args = args
731. } else if (n.tag == 'binary_expression') {
732. out.left = syntaxTree(gen, key, n.left)
733. out.right = syntaxTree(gen, key, n.right)
734. } else if (n.tag == 'unary_expression') {
735. out.operand = syntaxTree(gen, key, n.operand)
736. } else if (n.tag == 'conditional_expression') {
737. out.condition = syntaxTree(gen, key, n.condition)
738. out.consequent = syntaxTree(gen, key, n.consequent)
739. out.alternate = syntaxTree(gen, key, n.alternate)
740. } else if (n.tag == 'array_expression') {
741. let els = []
742. for (h of n.elements) { els.push(syntaxTree(gen, key, h)) }
743. out.elements = els
744. }
745. return out
746. }
748. // ---- the reductions the browser used to make on every boot --------------------------
749. // A `for`'s names are what its list reads, an `if`'s what its condition reads — filed
750. // under the region's own site.
751. regionIndex(t) {
752. let idx = {}
753. for (m of t.members) { if (m.nodes != null) { indexRegions(&idx, m.nodes) } }
754. return idx
755. }
757. indexRegions(&idx, n) {
758. if (n == null) { return null }
759. if (n.tag == 'view_for') {
760. idx[n.site] = memberNames(nodeReads(n.list))
761. indexRegions(&idx, n.body)
762. return null
763. }
764. if (n.tag == 'view_if') {
765. idx[n.site] = memberNames(nodeReads(n.condition))
766. indexRegions(&idx, n.consequent)
767. indexRegions(&idx, n.alternate)
768. return null
769. }
770. if (n.tag == 'on_statement') { return null }
771. 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]) {
772. if (c != null) { indexRegions(&idx, c) }
773. }
774. for (l of [n.entries, n.args, n.elements]) {
775. if (l != null) { for (c of l) { indexRegions(&idx, c) } }
776. }
777. return null
778. }
780. // the member reads of a read list — the language resolved every name, so this is a
781. // filter and not a second resolution
782. memberNames(reads) {
783. let out = []
784. if (reads == null) { return out }
785. for (r of reads) {
786. if (r.kind == 'member' && r.isStatic != true && !out.includes(r.name)) { out.push(r.name) }
787. }
788. return out
789. }
791. nodeReads(n) {
792. if (n == null) { return [] }
793. if (n.reads != null) { return n.reads }
794. let out = []
795. 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]) {
796. if (c != null) { for (r of nodeReads(c)) { out.push(r) } }
797. }
798. for (l of [n.entries, n.args, n.elements]) {
799. if (l != null) { for (c of l) { for (r of nodeReads(c)) { out.push(r) } } }
800. }
801. return out
802. }
804. // A ROUTINE'S WRITES, PLUS THE WRITES OF EVERYTHING IT REACHES — the method it calls
805. // and the handler it emits to, transitively. Both are READS the language resolved, so
806. // this is a walk of its answer and never a guess.
807. closeWrites(t, writes, reads) {
808. let out = memberNames(writes)
809. let queue = []
810. reached(&queue, reads)
811. let seen = {}
812. while (queue.length > 0) {
813. let at = queue.shift()
814. if (seen[at] == null) {
815. seen[at] = true
816. let sp = at.indexOf(' ')
817. let kind = at.slice(0, sp)
818. let name = at.slice(sp + 1)
819. for (mm of t.methods) {
820. if (kind == 'method' && mm.name == name) {
821. for (w of memberNames(mm.writes)) { if (!out.includes(w)) { out.push(w) } }
822. reached(&queue, mm.reads)
823. }
824. }
825. for (h of t.handlers) {
826. if (kind == 'handler' && !h.nested && h.event == name) {
827. for (w of memberNames(h.writes)) { if (!out.includes(w)) { out.push(w) } }
828. reached(&queue, h.reads)
829. }
830. }
831. for (mb of t.members) {
832. if (kind == 'member' && mb.name == name && mb.nodes != null) {
833. for (w of memberNames(mb.nodes.writes)) { if (!out.includes(w)) { out.push(w) } }
834. reached(&queue, nodeReads(mb.nodes))
835. }
836. }
837. }
838. }
839. return out
840. }
842. // the mirror: a handler's reads plus the reads of everything it reaches — the
843. // candidates for a routine a host handed down, whose writes only the host's table names
844. closeReads(t, reads) {
845. let out = memberNames(reads)
846. let queue = []
847. reached(&queue, reads)
848. let seen = {}
849. while (queue.length > 0) {
850. let at = queue.shift()
851. if (seen[at] == null) {
852. seen[at] = true
853. let sp = at.indexOf(' ')
854. let kind = at.slice(0, sp)
855. let name = at.slice(sp + 1)
856. for (mm of t.methods) {
857. if (kind == 'method' && mm.name == name) {
858. for (r of memberNames(mm.reads)) { if (!out.includes(r)) { out.push(r) } }
859. reached(&queue, mm.reads)
860. }
861. }
862. for (h of t.handlers) {
863. if (kind == 'handler' && !h.nested && h.event == name) {
864. for (r of memberNames(h.reads)) { if (!out.includes(r)) { out.push(r) } }
865. reached(&queue, h.reads)
866. }
867. }
868. for (mb of t.members) {
869. if (kind == 'member' && mb.name == name && mb.nodes != null) {
870. for (r of memberNames(nodeReads(mb.nodes))) { if (!out.includes(r)) { out.push(r) } }
871. reached(&queue, nodeReads(mb.nodes))
872. }
873. }
874. }
875. }
876. return out
877. }
879. reached(&queue, reads) {
880. if (reads == null) { return null }
881. for (r of reads) {
882. if (r.kind == 'method' || r.kind == 'handler' || (r.kind == 'member' && r.isStatic != true)) { queue.push(r.kind + ' ' + r.name) }
883. }
884. return null
885. }
887. // ---- THE SERVER RENDER, COMPILED --------------------------------------------------
888. // The old hl:web rendered a page by WALKING the View tree per request: for every node it asks
889. // what kind it is, for every element it builds the attribute string, and it decides the
890. // indentation of every line again, on every request, for every one of the 121 mounts a
891. // page may hold. Every one of those decisions is a fact about the View.
892. //
893. // So a component's render is compiled ONCE into a list of STEPS — constant text, and a
894. // read with its own closure — and a request is a concatenation. The structure (tags,
895. // static attributes, the readable form's line breaks, which element is a block) is
896. // decided at compile time; only the values are asked for per request.
897. //
898. // KEYED BY THE INDENT IT IS RENDERED AT, because that is the only thing about a
899. // component's HTML that its caller decides: the shell renders at one tab, the page at
900. // the depth the slot stands, a fill compactly (null). An app has a handful of those.
901. serverSteps(key, nodes, indent, classes, slotted) {
902. let ck = key + '|' + (indent == null ? '~' : indent) + '|' + joinList(classes) + '|' + (slotted ? '1' : '0')
903. if (steps[ck] == null) {
904. steps[ck] = blockSteps(classes == null || classes.length == 0 ? nodes : v.withRootClasses(nodes, classes), indent, slotted)
905. }
906. return steps[ck]
907. }
909. // A `slot` THE HOST FILLED COUNTS AS CONTENT, and an empty one does not — the one
910. // thing about a component's shape its caller decides, so it is part of the key.
911. staticVoid = [ 'area' 'base' 'br' 'col' 'embed' 'hr' 'img' 'input' 'link' 'meta' 'source' 'track' 'wbr' ]
912. staticVerbatim = [ 'textarea' 'pre' 'script' 'style' ]
914. blocky(n, slotted) {
915. if (staticVerbatim.includes(n.tag)) { return false }
916. if (n.children.length == 0) { return false }
917. for (c of n.children) {
918. if (c.k == 'text' || c.k == 'field') { return false }
919. if (c.k == 'member' && !(c.name == 'slot' && slotted)) { return false }
920. }
921. return true
922. }
924. steps = {}
925. v = new View
927. joinList(l) {
928. if (l == null) { return '' }
929. let out = ''
930. for (c of l) { out = out + ',' + c }
931. return out
932. }
934. // `render(nodes, …, indent)`: the readable form puts each element on its own line at
935. // `indent`, the compact one writes them end to end.
936. blockSteps(nodes, indent, slotted) {
937. let out = []
938. for (n of nodes) {
939. if (indent != null) {
940. if (n.k == 'el') { push(&out, { k = 's'; v = newline + indent; }) nodeSteps(&out, n, indent, slotted) }
941. else if (n.k == 'component') { nodeSteps(&out, n, indent, slotted) }
942. else if (n.k == 'for') { forSteps(&out, n, indent, slotted) }
943. else if (n.k == 'if') { ifSteps(&out, n, indent, slotted) }
944. else if (n.k == 'member' && n.name == 'slot') { push(&out, { k = 'slotline'; v = newline + indent; }) }
945. else if (n.k != 'on') { nodeSteps(&out, n, indent, slotted) }
946. } else {
947. nodeSteps(&out, n, null, slotted)
948. }
949. }
950. return out
951. }
953. forSteps(&out, n, indent, slotted) {
954. out.push({ k = 'for'; row = n.row; read = readFn(n.list); body = blockSteps(n.body, indent, slotted); })
955. return null
956. }
958. ifSteps(&out, n, indent, slotted) {
959. out.push({ k = 'if'; read = readFn(n.cond); then = blockSteps(n.then, indent, slotted); other = blockSteps(n.other, indent, slotted); })
960. return null
961. }
963. // one node's steps — `html(node, …)`, decided once
964. nodeSteps(&out, n, indent, slotted) {
965. if (n.k == 'text') { push(&out, { k = 's'; v = v.escape(n.text); }) return null }
966. if (n.k == 'on') { return null }
967. if (n.k == 'member' && n.name == 'slot') { out.push({ k = 'slot'; }) return null }
968. if (n.k == 'member' || n.k == 'field') { out.push({ k = 'r'; read = readFn(n); }) return null }
969. if (n.k == 'for') { forSteps(&out, n, indent, slotted) return null }
970. if (n.k == 'if') { ifSteps(&out, n, indent, slotted) return null }
971. if (n.k == 'component') {
972. out.push({ k = 'kid'; path = n.path; cls = n.cls; key = n.key; classes = n.classes; indent = indent;
973. fill = (n.fill == null || n.fill.length == 0) ? null : blockSteps(n.fill, null, slotted); })
974. return null
975. }
976. if (n.k == 'el') { elSteps(&out, n, indent, slotted) return null }
977. push(&out, { k = 's'; v = '<!-- ' + n.tag + ' not rendered yet -->'; })
978. return null
979. }
981. elSteps(&out, n, indent, slotted) {
982. let attrs = []
983. let valueRead = null // a textarea's value is its content
984. let selRead = null // a select's value selects an option
985. for (a of n.attrs) {
986. if (n.tag == 'textarea' && a.name == 'value') { valueRead = attrRead(a) }
987. else if (n.tag == 'select' && a.name == 'value') { selRead = attrRead(a) }
988. // a bound BOOLEAN attribute is its presence (ticket #33): ` checked=""` or nothing
989. else if ((a.member != null || a.ref != null) && v.isBoolAttr(a.name)) { attrs.push({ k = 'b'; name = a.name; read = attrRead(a); }) }
990. else if (a.member != null || a.ref != null) {
991. push(&attrs, { k = 's'; v = ' ' + a.name + '="'; })
992. attrs.push({ k = 'r'; read = attrRead(a); })
993. push(&attrs, { k = 's'; v = v.extraOf(a) + '"'; })
994. } else {
995. push(&attrs, { k = 's'; v = ' ' + a.name + '="' + v.escape(a.text) + '"'; })
996. }
997. }
998. if (v.boundValue(n)) { push(&attrs, { k = 's'; v = ' autocomplete="off"'; }) }
1000. // the children, in the form this element takes: a block puts them one per line
1001. let kids = []
1002. if (indent != null && blocky(n, slotted)) {
1003. kids = blockSteps(n.children, indent + tab, slotted)
1004. push(&kids, { k = 's'; v = newline + indent; })
1005. } else {
1006. kids = blockSteps(n.children, null, slotted)
1007. }
1008. if (valueRead != null) { kids = [{ k = 'r'; read = valueRead; }] }
1010. // AN OPTION IS THE ONE ELEMENT WHOSE OWN TAG DEPENDS ON THE VALUE ABOVE IT: it
1011. // carries `selected` when its value is the select's. Everything else is settled.
1012. if (n.tag == 'option') {
1013. out.push({ k = 'opt'; attrs = attrs; body = kids; ov = optionRead(n); })
1014. return null
1015. }
1016. push(&out, { k = 's'; v = '<' + n.tag; })
1017. for (a of attrs) { push(&out, a) }
1018. if (staticVoid.includes(n.tag)) { push(&out, { k = 's'; v = '>'; }) return null }
1019. push(&out, { k = 's'; v = '>'; })
1020. // A SELECT HANDS ITS VALUE TO ITS OPTIONS, however deep they stand: its children
1021. // run under it, and it is the only element that changes anything for them.
1022. if (n.tag == 'select') { out.push({ k = 'sel'; read = selRead; body = kids; }) }
1023. else { for (kk of kids) { push(&out, kk) } }
1024. push(&out, { k = 's'; v = '</' + n.tag + '>'; })
1025. return null
1026. }
1028. // CONSTANT TEXT MERGES. Two literal steps in a row are one string decided at compile
1029. // time — which is what makes a request a concatenation of a handful of pieces instead
1030. // of one per node.
1031. push(&out, step) {
1032. if (step.k == 's' && out.length > 0 && out[out.length - 1].k == 's') {
1033. let last = out[out.length - 1]
1034. last.v = last.v + step.v
1035. out[out.length - 1] = last
1036. return null
1037. }
1038. out.push(step)
1039. return null
1040. }
1042. // ---- the reads, each with its own closure ------------------------------------------
1043. // `view.value`'s rule, split once: a `for` row variable in scope wins over a member of
1044. // the same name, and a field path walks into it. The closure holds the name — there is
1045. // no node to look at per request.
1046. readFn(node) {
1047. if (node == null) { return (inst, rows) => { return null } }
1048. if (node.k == 'text') { let t = v.literalValue(node.kind, node.text) return (inst, rows) => { return t } }
1049. let name = node.name
1050. if (node.k != 'field') {
1051. return (inst, rows) => { return rows[name] != null ? rows[name] : inst[name] }
1052. }
1053. let path = node.path
1054. return (inst, rows) => {
1055. let val = rows[name] != null ? rows[name] : inst[name]
1056. for (f of path) {
1057. if (val == null) { return null }
1058. val = val[f]
1059. }
1060. return val
1061. }
1062. }
1064. attrRead(a) {
1065. if (a.member != null) { return readFn({ k = 'member'; name = a.member; }) }
1066. if (a.ref != null) { return readFn(a.ref) }
1067. let t = a.text
1068. return (inst, rows) => { return t }
1069. }
1071. // an option's own value: its `value` attribute, or null when it has none (the browser
1072. // then reports its text, and the run compares against what it rendered)
1073. optionRead(n) {
1074. for (a of n.attrs) {
1075. if (a.name == 'value') { return attrRead(a) }
1076. }
1077. return null
1078. }
1080. // ---- the run: a concatenation ------------------------------------------------------
1081. // EVERY REGION IS WRITTEN BETWEEN TWO MARKS (tickets #103, #104): an `if` around the
1082. // branch that stands, a `for` around its rows and each row around its own nodes. The
1083. // client claims them as they are and builds the same ones, and a region's nodes are
1084. // exactly what stands between its two marks — nothing it holds has to be remembered
1085. // node by node, and text beside a region can never run into the region's text.
1086. markOpen = '<!--[-->'
1087. markClose = '<!--]-->'
1089. runSteps(list, &inst, &rows, &ctx) {
1090. let out = ''
1091. for (s of list) {
1092. if (s.k == 's') { out = out + s.v }
1093. else if (s.k == 'r') { let f = s.read out = out + v.escape(f(&inst, &rows)) }
1094. else if (s.k == 'b') { let f = s.read if (v.boolOn(f(&inst, &rows))) { out = out + ' ' + s.name + '=""' } }
1095. else if (s.k == 'slot') { if (ctx.slot != null) { out = out + ctx.slot } }
1096. else if (s.k == 'slotline') { if (ctx.slot != null) { out = out + s.v + ctx.slot } }
1097. else if (s.k == 'for') {
1098. let f = s.read
1099. let list2 = f(&inst, &rows)
1100. out = out + markOpen
1101. if (list2 != null) {
1102. let ri = 0
1103. for (entry of list2) {
1104. let inner = rows + {}
1105. inner[s.row] = entry
1106. let rc = v.rowCtx(&ctx, &entry, ri)
1107. out = out + markOpen + runSteps(s.body, &inst, &inner, &rc) + markClose
1108. ri = ri + 1
1109. }
1110. }
1111. out = out + markClose
1112. }
1113. else if (s.k == 'if') {
1114. let f = s.read
1115. if (f(&inst, &rows)) { out = out + markOpen + runSteps(s.then, &inst, &rows, &ctx) + markClose }
1116. else { out = out + markOpen + runSteps(s.other, &inst, &rows, &ctx) + markClose }
1117. }
1118. else if (s.k == 'opt') {
1119. let head = runSteps(s.attrs, &inst, &rows, &ctx)
1120. let body = runSteps(s.body, &inst, &rows, &ctx)
1121. let mark = ''
1122. if (ctx.sel != null) {
1123. let ov = body
1124. if (s.ov != null) { let f = s.ov ov = '' + f(&inst, &rows) }
1125. if (ov == ctx.sel) { mark = ' selected' }
1126. }
1127. out = out + '<option' + head + mark + '>' + body + '</option>'
1128. }
1129. else if (s.k == 'sel') {
1130. let f = s.read
1131. let inner = ctx + {}
1132. inner.sel = f == null ? null : '' + f(&inst, &rows)
1133. out = out + runSteps(s.body, &inst, &rows, &inner)
1134. }
1135. else if (s.k == 'kid') {
1136. let kid = ctx.kids[v.kidKeyIn(s.path, ctx)]
1137. if (kid == null) { out = out + '<!-- ' + s.cls + ' not mounted -->' }
1138. else {
1139. let fillText = s.fill == null ? null : runSteps(s.fill, &inst, &rows, &ctx)
1140. let kidCtx = { slot = fillText; kids = kid.kids; }
1141. let kidInst = kid.page
1142. let empty = {}
1143. out = out + runSteps(serverSteps(s.key, kid.view, s.indent, s.classes, fillText != null), &kidInst, &empty, &kidCtx)
1144. }
1145. }
1146. }
1147. return out
1148. }