gitoria

46.6 KB

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, 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
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() + ',fn:' + fnMap(fnTable) + '};'
96. return src + '})();' + newline
97. }
99. tbl = null
100. regions = {}
102. // WHAT A FUNCTION VALUE WRITES, by the site it was made at (tickets #98, #99): the
103. // module announces a function's return with its site, and the browser repaints this
104. // set — the members it writes, closed over the methods it calls and the events it
105. // emits, the same closure a handler's set gets. A function that writes nothing has
106. // no entry.
107. fnMap(fns) {
108. let bySite = {}
109. if (fns != null) {
110. for (f of fns) {
111. let names = closeWrites(tbl, f.writes, f.reads)
112. if (names.length > 0) { bySite[f.site] = names }
113. }
114. }
115. return mapOf(bySite)
116. }
118. // what a DECLARED handler writes, by event: one entry per event name, unioned
119. eventMap() {
120. let byEvent = {}
121. for (h of tbl.handlers) {
122. if (!h.nested) {
123. let have = byEvent[h.event] == null ? [] : byEvent[h.event]
124. for (w of closeWrites(tbl, h.writes, h.reads)) { if (!have.includes(w)) { have.push(w) } }
125. byEvent[h.event] = have
126. }
127. }
128. return mapOf(byEvent)
129. }
131. // A MEMBER HOLDING A ROUTINE: what calling it writes is what its initializer writes
132. memberMap() {
133. let byName = {}
134. for (m of tbl.members) {
135. if (m.nodes != null) { byName[m.name] = memberNames(m.nodes.writes) }
136. }
137. return mapOf(byName)
138. }
140. // EVERY INITIALIZER, IN DECLARATION ORDER, with the members it reads — the whole of
141. // what a derivation needs; the class carries the computation itself as `__derive__`
142. derivList() {
143. let src = '['
144. let first = true
145. for (d of tbl.derivations) {
146. if (!first) { src = src + ',' }
147. first = false
148. src = src + '{name:' + str(d.name) + ',site:' + str(d.site) + ',reads:' + list(memberNames(d.reads)) + '}'
149. }
150. return src + ']'
151. }
153. mapOf(byName) {
154. let src = '{'
155. let first = true
156. for (k of byName.keys()) {
157. if (!first) { src = src + ',' }
158. first = false
159. src = src + str(k) + ':' + list(byName[k])
160. }
161. return src + '}'
162. }
164. // the write set and the read set of the handler at this site, closed over the methods
165. // it calls and the handlers it emits to — computed here, written into the listener
166. handlerSets(site) {
167. for (h of tbl.handlers) {
168. if (h.nested && h.site == site) {
169. return list(closeWrites(tbl, h.writes, h.reads)) + ',' + list(closeReads(tbl, h.reads))
170. }
171. }
172. return '[],[]'
173. }
175. regionNamesAt(site) {
176. let names = regions[site]
177. return list(names == null ? [] : names)
178. }
180. fns = []
182. // ---- the walk, unrolled ------------------------------------------------------------
183. // `top` marks the View's own root list: an element there is a COMPOSITION ROOT — a
184. // reference above may have overwritten some of its events and put classes on it, which
185. // is what `opt` carries (the old hl:web's rootOverwrites and withRootClasses).
186. walk(key, nodes) {
187. return plain(key, nodes)
188. }
190. // a list's walk
191. plain(key, nodes) {
192. let body = ''
193. for (n of nodes) { body = body + node(key, n, false, false) }
194. return 'async function(c,m,o,host,i,rows,rk,fill,cr,opt){let inst=m.instance;let r=rows;' + body + 'return i;}'
195. }
197. // the View's own root list, whose elements are composition roots
198. walkTop(key, nodes) {
199. let body = ''
200. for (n of nodes) { body = body + node(key, n, true, false) }
201. return 'async function(c,m,o,host,i,rows,rk,fill,cr,opt){let inst=m.instance;let r=rows;' + body + 'return i;}'
202. }
204. // a sub-walk, registered under its own site so the runtime can reach it by name
205. // A SUB-WALK IS WRITTEN ONCE, however often the compile reaches its list.
206. sub(key, nodes, slot, site) {
207. if (done[slot + ' ' + site] != null) { return null }
208. done[slot + ' ' + site] = true
209. fns.push({ slot = slot; sites = [site]; src = walk(key, nodes); })
210. return null
211. }
213. done = {}
215. node(key, n, top, filterOns) {
216. if (n.k == 'el') { return elNode(key, n, top) }
217. 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) + ');}' }
218. if (n.k == 'on') {
219. // A REFERENCE ABOVE MAY HAVE OVERWRITTEN THIS EVENT on the composition root:
220. // the root's own handler for it is dropped and the reference's stands instead
221. // (the old hl:web's withoutOns, which applies to the root element's direct children).
222. let guard = filterOns ? 'if(!(opt&&opt.over&&opt.over.indexOf(' + str(n.event) + ')>=0)){' : '{'
223. return guard + 'await c.onAt(m,host,' + str(n.event) + ',' + str(n.site) + ',rows,' + handlerSets(n.site) + ');}'
224. }
225. if (n.k == 'member' && n.name == 'slot') {
226. // the SHELL's slot is where the route component hangs; a child's slot is the
227. // fragment its host wrote, and the host's frame builds it
228. 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);}'
229. }
230. // A TEXT LEAF STANDING IN A LIST — an `if` branch, a `for` body — beside elements or
231. // alone: its own text node, and a site of the member it reads (or of the row it
232. // stands in), painted by rewriting that node.
233. if (n.k == 'member' || n.k == 'field') {
234. let names = (n.name == 'Style' || rowVars.includes(n.name)) ? [] : [n.name]
235. return 'await c.textAt(m,host,cr,function(inst,r){return ' + textRead(n) + ';},' + list(names) + ',rows,rk);'
236. }
237. if (n.k == 'for') {
238. // THE ROW VARIABLE IS IN SCOPE INSIDE THE BODY, and a read of it is the ROW's,
239. // not a member of the instance — the language resolves it that way and the site
240. // sets must say the same, or a member of the same name would paint the row.
241. rowVars.push(n.row)
242. sub(key, n.body, 'B', n.site)
243. rowVars.pop()
244. 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) + ');'
245. }
246. if (n.k == 'if') {
247. sub(key, n.then, 'T', n.site)
248. sub(key, n.other, 'E', n.site)
249. 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) + ');'
250. }
251. if (n.k == 'component') {
252. if (n.fill != null && n.fill.length > 0) { sub(key, n.fill, 'F', n.site) }
253. return 'i=await c.kidAt(m,host,i,' + kidSpec(n) + ',rows,rk,fill,cr,opt);'
254. }
255. return ''
256. }
258. // ---- an element --------------------------------------------------------------------
259. elNode(key, n, top) {
260. let src = '{let el=A(cr,host,i,' + str(n.tag) + ');if(!cr){i=i+1;}'
261. src = src + 'if(el==null){await c.acqFail(' + str(n.tag) + ',host);}else{'
262. // the attributes, on the walk that BUILDS the element (a claim takes the server's)
263. src = src + 'if(cr){' + createAttrs(n) + (top ? 'await c.rootClasses(el,opt);' : '') + 'host.appendChild(el);}'
264. src = src + 'el.__hlRows=rows;el.__hlSite=' + str(n.site) + ';el.__hlKey=' + str(key) + ';'
265. // the element's own named entries, for the literal a handler on it fires
266. src = src + 'el.__hlLit=function(inst,r){return ' + litNamed(n) + ';};'
267. let names = siteNames(n)
268. let valueMember = 'null'
269. for (a of n.attrs) { if (a.member != null && a.name == 'value') { valueMember = str(a.member) } }
270. let sited = ''
271. if (names.length > 0 || valueMember != 'null') {
272. sited = 'await c.siteAt(m,el,' + list(names) + ',' + str(n.site) + ',' + valueMember + ',' + (n.tag == 'select' ? 'true' : 'false') + ',rows);'
273. }
274. let kids = ''
275. // AN ELEMENT THAT HOLDS ONLY TEXT is painted whole (`textContent`, see the paints):
276. // built, it gets that text as one node; claimed, the server's is taken as it stands
277. let whole = textOf(n)
278. if (whole != null) {
279. kids = 'if(cr){host.appendChild(document.createTextNode(' + whole + '));}'
280. for (c of n.children) { if (c.k == 'on') { kids = kids + node(key, c, false, top) } }
281. }
282. else if (mixed(n)) { kids = mixedKids(key, n, top) }
283. else { for (c of n.children) { kids = kids + node(key, c, false, top) } }
284. let inner = '{let host=el;let i=0;' + kids + '}'
285. // A SELECT IS SITED AFTER ITS OPTIONS: the member decides which option stands, and
286. // the read-back that `siteAt` does reports nothing before they exist.
287. if (n.tag == 'select') { src = src + inner + 'if(cr){await c.applySelectAt(m,el,' + selectValue(n) + ');}' + sited }
288. else { src = src + sited + inner }
289. return src + '}}'
290. }
292. // A TEXT LEAF BESIDE AN ELEMENT OR A REGION (ticket #86 follow-up): `td { d.n if (…) {…} }`
293. // cannot be painted through `textContent`, which would wipe the branch. Each RUN of
294. // adjacent leaves is one text node, held on the element (`__hlLeaves`, by the run's
295. // index) where the walk builds or claims it, and the paints rewrite that node alone.
296. mixed(n) {
297. if (textOf(n) != null) { return false }
298. for (c of n.children) { if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { return true } }
299. return false
300. }
302. isLeaf(c) { return c.k == 'text' || ((c.k == 'member' || c.k == 'field') && c.name != 'slot') }
304. // the runs of adjacent leaves, in order; an `on` renders nothing and splits none
305. runsOf(n) {
306. let out = []
307. let run = []
308. for (c of n.children) {
309. if (isLeaf(c)) { run.push(c) }
310. else if (c.k != 'on') {
311. if (run.length > 0) { out.push(run) }
312. run = []
313. }
314. }
315. if (run.length > 0) { out.push(run) }
316. return out
317. }
319. runText(run) {
320. let src = '""'
321. for (c of run) { src = src + '+(' + (c.k == 'text' ? str(c.text) : textRead(c)) + ')' }
322. return src
323. }
325. runFeeds(run) {
326. for (c of run) { if (c.k != 'text') { return true } }
327. return false
328. }
330. mixedKids(key, n, top) {
331. let kids = ''
332. let run = []
333. let k = 0
334. for (c of n.children) {
335. if (isLeaf(c)) { run.push(c) }
336. else {
337. if (c.k != 'on' && run.length > 0) { kids = kids + leafRun(run, k) k = k + 1 run = [] }
338. kids = kids + node(key, c, false, top)
339. }
340. }
341. if (run.length > 0) { kids = kids + leafRun(run, k) }
342. return kids
343. }
345. // EVERY CALL INTO THE CLIENT IS AWAITED: its methods are async in the browser, and one
346. // not awaited runs its DOM work after the walk has gone on — a built leaf then lands
347. // after the elements that follow it (ticket #104).
348. leafRun(run, k) {
349. if (!runFeeds(run)) { return 'if(cr){host.appendChild(document.createTextNode(' + runText(run) + '));}else{await c.leafAt(host,false,i,null,' + runText(run) + ');}' }
350. return 'await c.leafAt(host,cr,i,' + k + ',' + runText(run) + ');'
351. }
353. // the attributes an element is BUILT with — a bound one written in, a literal one as it
354. // stands. `value` is a property once the page is live and an attribute as the control's
355. // default; a textarea has no value attribute at all and a select's value is an option.
356. createAttrs(n) {
357. let src = ''
358. for (a of n.attrs) {
359. if (isBool(a)) {
360. src = src + '{' + boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) + '}'
361. } else {
362. let rd = a.member != null ? readOf({ k = 'member'; name = a.member; }) : (a.ref != null ? readOf(a.ref) : str(a.text))
363. src = src + '{let v=' + rd + ';'
364. if (a.extra != null) { src = src + 'v=v+" "+' + str(a.extra) + ';' }
365. if (n.tag == 'select' && a.name == 'value') { src = src + '}' }
366. else if (a.name == 'value') {
367. src = src + 'if(el.value!=null){el.value=v;' + (n.tag == 'textarea' ? '' : 'el.setAttribute("value",v);') + '}else{el.setAttribute("value",v);}}'
368. } else { src = src + 'el.setAttribute(' + str(a.name) + ',v);}' }
369. }
370. }
371. if (boundValue(n)) { src = src + 'el.setAttribute("autocomplete","off");' }
372. return src
373. }
375. // a BOUND boolean attribute — a literal one was decided at build (WebFramework `element`)
376. isBool(a) {
377. return (a.member != null || a.ref != null) && v.isBoolAttr(a.name)
378. }
380. // A BOUND BOOLEAN ATTRIBUTE, WRITTEN (ticket #33): set when the value is on, REMOVED when
381. // it is off — the markup's rule (view.boolAttrs) — and the DOM property with it, because
382. // once the page is live `checked` is the property and the attribute only its default.
383. boolWrite(a, raw) {
384. let prop = a.name == 'readonly' ? 'readOnly' : a.name
385. 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;}'
386. }
388. // view.hl's `boundValue`, to the letter: a FORM CONTROL whose `value` reads a member or
389. // a field, and not one the author gave an `autocomplete` of its own
390. boundValue(n) {
391. if (n.tag != 'input' && n.tag != 'textarea' && n.tag != 'select') { return false }
392. let bound = false
393. for (a of n.attrs) {
394. if (a.name == 'autocomplete') { return false }
395. if (a.name == 'value' && (a.member != null || a.ref != null)) { bound = true }
396. }
397. return bound
398. }
400. selectValue(n) {
401. for (a of n.attrs) {
402. if (a.name == 'value') {
403. if (a.member != null) { return readOf({ k = 'member'; name = a.member; }) }
404. if (a.ref != null) { return readOf(a.ref) }
405. return str(a.text)
406. }
407. }
408. return 'null'
409. }
411. // the element's own entries as the literal sees them — its attributes by name, then the
412. // `for` row variables in scope (the row rides on the value)
413. litNamed(n) {
414. let src = '{'
415. let first = true
416. for (a of n.attrs) {
417. if (!first) { src = src + ',' }
418. first = false
419. let v = a.member != null ? rawRead({ k = 'member'; name = a.member; }) : (a.ref != null ? rawRead(a.ref) : str(a.text))
420. src = src + str(a.name) + ':' + v
421. }
422. return src + '}'
423. }
425. // the reference's own description, written at its use site: what it binds, what it
426. // overwrites, the classes the host's `#Child` rule puts on it
427. kidSpec(n) {
428. let src = '{key:' + str(n.key) + ',kid:' + str(kidKeyOf(n)) + ',site:' + str(n.site) + ',fill:' + ((n.fill != null && n.fill.length > 0) ? 'true' : 'false')
429. src = src + ',bindings:['
430. let first = true
431. for (b of n.bindings) {
432. if (!first) { src = src + ',' }
433. first = false
434. src = src + '{name:' + str(b.name) + ',member:' + (b.member == null ? 'null' : str(b.member))
435. src = src + ',ref:' + (b.ref == null ? 'null' : 'function(inst,r){return ' + rawRead(b.ref) + ';}')
436. src = src + ',refName:' + (b.ref == null ? 'null' : str(b.ref.name))
437. src = src + ',text:' + (b.text == null ? 'null' : 'true') + ',value:' + (b.text == null ? 'null' : refLiteral(b)) + '}'
438. }
439. src = src + '],ons:['
440. first = true
441. for (o of n.ons) {
442. if (!first) { src = src + ',' }
443. first = false
444. src = src + '{event:' + str(o.event) + ',site:' + str(o.site) + ',sets:[' + handlerSets(o.site) + ']}'
445. }
446. src = src + '],classes:' + list(n.classes == null ? [] : n.classes) + '}'
447. return src
448. }
450. // view.hl's kidKey: the reference's path, joined — the key the server mounted it under
451. kidKeyOf(n) {
452. let out = ''
453. for (p of n.path) { out = out + '/' + p }
454. return out
455. }
457. // the value a literal binding carries — view.refValue, folded at compile time
458. refLiteral(b) {
459. if (b.kind == 'folded') { return jsValue(b.value) }
460. if (b.kind == 'number') { return '' + b.text }
461. if (b.kind == 'boolean') { return b.text == 'true' ? 'true' : 'false' }
462. if (b.kind == 'null_literal') { return 'null' }
463. return str(b.text)
464. }
466. jsValue(v) {
467. if (v == null) { return 'null' }
468. if (hlTypeName(v) == 'String') { return str(v) }
469. if (hlTypeName(v) == 'Boolean') { return v ? 'true' : 'false' }
470. if (hlTypeName(v) == 'Number') { return '' + v }
471. return JSON.stringify(v)
472. }
474. // ---- the site set: what this element SHOWS ------------------------------------------
475. // The old hl:web asked the module's table which members the element at this site reads. The
476. // answer is a fact about the View, so it is written in: the members its bound
477. // attributes and its text leaves name. `Style` is folded into a class name at build and
478. // the shell's `slot` is swapped by navigation — neither is ever painted, and neither is
479. // a member read that reaches here (a `for` row variable resolves to its row).
480. siteNames(n) {
481. let out = []
482. for (a of n.attrs) {
483. if (a.member != null && a.member != 'Style' && !rowVars.includes(a.member) && !out.includes(a.member)) { out.push(a.member) }
484. // A FIELD OF A MEMBER (`value = f.title`, ticket #93) is a read of the member:
485. // a write to `f.title`, or a new `f`, moves `f`, and this element repaints
486. if (a.ref != null && a.ref.name != 'Style' && !rowVars.includes(a.ref.name) && !out.includes(a.ref.name)) { out.push(a.ref.name) }
487. }
488. for (c of n.children) {
489. if ((c.k == 'member' || c.k == 'field') && c.name != 'slot' && c.name != 'Style' && !rowVars.includes(c.name)) {
490. if (!out.includes(c.name)) { out.push(c.name) }
491. }
492. }
493. return out
494. }
496. rowVars = []
498. // ---- the paints ---------------------------------------------------------------------
499. collectPaints(&out, nodes) {
500. for (n of nodes) {
501. if (n.k == 'el') {
502. let paint = paintFn(n)
503. let row = rowFn(n)
504. if (paint != null || row != 'null') {
505. out.push({ site = n.site; paint = paint == null ? 'null' : paint; row = row; })
506. }
507. collectPaints(&out, n.children)
508. } else if (n.k == 'for') { collectPaints(&out, n.body) }
509. else if (n.k == 'if') { collectPaints(&out, n.then) collectPaints(&out, n.other) }
510. else if (n.k == 'component') { if (n.fill != null) { collectPaints(&out, n.fill) } }
511. }
512. return null
513. }
515. // `paint(&m, s, name)`, compiled: the bound attributes under the member each reads, and
516. // the text where the member that moved stands among the leaves.
517. paintFn(n) {
518. let body = ''
519. for (a of n.attrs) {
520. if (a.member != null) {
521. body = body + 'if(n===' + str(a.member) + '){' + attrWrite(n, a, readOf({ k = 'member'; name = a.member; })) + '}'
522. } else if (a.ref != null) {
523. // a field of a member paints when the MEMBER moves (ticket #93)
524. body = body + 'if(n===' + str(a.ref.name) + '){' + attrWrite(n, a, readOf(a.ref)) + '}'
525. }
526. }
527. let text = textOf(n)
528. if (text != null) {
529. let guard = ''
530. for (c of n.children) {
531. if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') {
532. if (guard != '') { guard = guard + '||' }
533. guard = guard + 'n===' + str(c.name)
534. }
535. }
536. if (guard != '') { body = body + 'if(' + guard + '){el.textContent=' + text + ';}' }
537. } else if (mixed(n)) {
538. let k = 0
539. for (run of runsOf(n)) {
540. let guard = ''
541. for (c of run) {
542. if (c.k != 'text') {
543. if (guard != '') { guard = guard + '||' }
544. guard = guard + 'n===' + str(c.name)
545. }
546. }
547. if (guard != '') { body = body + 'if((' + guard + ')&&el.__hlLeaves&&el.__hlLeaves[' + k + ']){el.__hlLeaves[' + k + '].data=' + runText(run) + ';}' }
548. k = k + 1
549. }
550. }
551. if (body == '') { return null }
552. return 'function(el,inst,r,n){' + body + '}'
553. }
555. // `rowPaint(&m, el)`, compiled: every bound spot, written only where the DOM does not
556. // already hold it — which is why a push into 2000 rows costs the 1999 nothing.
557. rowFn(n) {
558. let body = ''
559. for (a of n.attrs) {
560. if (isBool(a)) {
561. body = body + '{' + boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) + '}'
562. } else if (a.member != null || a.ref != null) {
563. let one = 'let v=' + readOf(a.member != null ? { k = 'member'; name = a.member; } : a.ref) + ';'
564. if (a.extra != null) { one = one + 'v=v+" "+' + str(a.extra) + ';' }
565. if (n.tag == 'select' && a.name == 'value') { one = one + 'if(el.value!==v){el.value=v;}' }
566. else {
567. one = one + 'if(el.getAttribute(' + str(a.name) + ')!==v){el.setAttribute(' + str(a.name) + ',v);}'
568. if (a.name == 'value') { one = one + 'if(el.value!=null&&el.value!==v){el.value=v;}' }
569. }
570. body = body + '{' + one + '}'
571. }
572. }
573. let text = textOf(n)
574. let feeds = false
575. for (c of n.children) { if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { feeds = true } }
576. if (text != null && feeds) { body = body + '{let t=' + text + ';if(el.textContent!==t){el.textContent=t;}}' }
577. if (text == null && feeds) {
578. let k = 0
579. for (run of runsOf(n)) {
580. if (runFeeds(run)) { body = body + '{let x=el.__hlLeaves&&el.__hlLeaves[' + k + '];let t=' + runText(run) + ';if(x&&x.data!==t){x.data=t;}}' }
581. k = k + 1
582. }
583. }
584. if (body == '') { return 'null' }
585. return 'function(el,inst,r){' + body + '}'
586. }
588. attrWrite(n, a, v) {
589. if (isBool(a)) { return boolWrite(a, rawRead(a.member != null ? { k = 'member'; name = a.member; } : a.ref)) }
590. let src = 'let v=' + v + ';'
591. if (a.extra != null) { src = src + 'v=v+" "+' + str(a.extra) + ';' }
592. if (n.tag == 'select' && a.name == 'value') { return src + 'el.value=v;' }
593. src = src + 'el.setAttribute(' + str(a.name) + ',v);'
594. if (a.name == 'value') { src = src + 'if(el.value!=null){el.value=v;}' }
595. return src
596. }
598. textOf(n) {
599. let parts = []
600. let content = 0
601. let feeds = false
602. for (c of n.children) {
603. if (c.k != 'on') {
604. content = content + 1
605. if (c.k == 'text') { parts.push(str(c.text)) }
606. else if ((c.k == 'member' || c.k == 'field') && c.name != 'slot') { parts.push(textRead(c)) feeds = true }
607. }
608. }
609. if (!feeds) { return null }
610. if (parts.length != content) { return null }
611. let src = '""'
612. for (p of parts) { src = src + '+(' + p + ')' }
613. return src
614. }
616. // ---- a read, written in ---------------------------------------------------------------
617. // `view.value`'s own rule as an expression: a `for` row variable in scope wins over a
618. // member of the same name, and a field path walks into it. `readOf` answers the STRING
619. // the DOM takes; `rawRead` the value itself (a binding, a list, a condition).
620. readOf(node) { return '(""+' + rawRead(node) + ')' }
622. // A READ SHOWN AS TEXT: null is no text, as the server writes it (view.hl `escape`)
623. textRead(node) { return 'S(' + rawRead(node) + ')' }
625. rawRead(node) {
626. if (node == null) { return 'null' }
627. if (node.k == 'text') { return str(node.text) }
628. if (node.k != 'field') { return 'RV(r,inst,' + str(node.name) + ')' }
629. return 'RF(r,inst,' + str(node.name) + ',' + list(node.path) + ')'
630. }
632. list(names) {
633. let src = '['
634. let first = true
635. for (n of names) {
636. if (!first) { src = src + ',' }
637. first = false
638. src = src + str(n)
639. }
640. return src + ']'
641. }
643. // a JavaScript string literal — JSON's escaping is a subset of JavaScript's, so a
644. // source text's quotes, newlines and backslashes survive into the statement unchanged
645. str(s) {
646. if (s == null) { return '""' }
647. return JSON.stringify('' + s)
648. }
650. // ---- WHAT THE LANGUAGE SAYS ABOUT THIS FILE, read HERE and written into the code ----
651. // The old hl:web shipped the language's answers to the browser as data: `hlJs` writes each file's
652. // members, handlers and methods — every node of every initializer, with the names it
653. // reads — into the module, and the client reduces that table on every boot. The answers
654. // are facts about the source, so this file asks for them once, at compile time, and
655. // writes the RESULT into the statements: a handler's write set stands at the listener
656. // that needs it, a region's names at the region, the derivations as a list of what to
657. // re-run. The module carries no table at all (WebFramework `module` drops the one the
658. // emitter writes).
659. //
660. // The reflection is the framework's own analysis generation — the same `gen` the View
661. // trees come from. Nothing starts a second one: a handle is only valid inside the
662. // generation that made it.
663. tableOf(gen, key) {
664. let members = []
665. let derivations = []
666. let handlers = []
667. let methods = []
668. for (m of hlMembers(gen, key)) {
669. let entry = { name = m.name; nodes = null; }
670. if (m.hasValue) {
671. let n = syntaxTree(gen, key, m.node)
672. entry.nodes = n
673. derivations.push({ name = m.name; site = n.site; reads = n.reads; })
674. nestedHandlers(&handlers, n)
675. }
676. members.push(entry)
677. }
678. for (h of hlEvents(gen, key).handles) {
679. let n = syntaxTree(gen, key, h.node)
680. handlers.push({ event = h.event; site = n.site; reads = n.reads; writes = n.writes; nested = false; })
681. }
682. for (mm of hlMethods(gen, key)) {
683. if (!mm.inlineHandler) {
684. let n = syntaxTree(gen, key, mm.node)
685. methods.push({ name = mm.name; reads = n.reads; writes = n.writes; })
686. }
687. }
688. return { members = members; derivations = derivations; handlers = handlers; methods = methods; }
689. }
691. // A NESTED `on` IS A DOM HANDLER, filed under its own site — the id the View node
692. // carries. Its body is not the literal's syntax, so the node answers for it and the
693. // walk stops there.
694. nestedHandlers(&into, n) {
695. if (n == null) { return null }
696. if (n.tag == 'on_statement') {
697. into.push({ event = n.event; site = n.site; reads = n.reads; writes = n.writes; nested = true; })
698. return null
699. }
700. 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]) {
701. if (c != null) { nestedHandlers(&into, c) }
702. }
703. for (l of [n.entries, n.args, n.elements]) {
704. if (l != null) { for (c of l) { nestedHandlers(&into, c) } }
705. }
706. return null
707. }
709. shortSite(site) {
710. if (site == null) { return null }
711. let at = site.indexOf(':')
712. if (at < 0) { return site }
713. let path = site.slice(0, at)
714. let cut = path.lastIndexOf('/')
715. if (cut < 0) { return site }
716. return path.slice(cut + 1) + site.slice(at)
717. }
719. // the syntax of one node, recursively — hl:core/AST's `tree`, read off the framework's
720. // own generation instead of starting one of its own
721. syntaxTree(gen, key, node) {
722. let n = hlSyntax(gen, key, node)
723. if (n == null) { return null }
724. // A SITE IS NAMED BY THE FILE'S BASE NAME. The reflection answers with the project
725. // key ('components/sort_list.hl:77:26'); the View tree, the emitter's own
726. // `__derive__` branches and every site this framework writes use the base name
727. // ('sort_list.hl:77:26'). One spelling, or a lookup by site finds nothing.
728. let out = { tag = n.tag; site = shortSite(n.site); reads = n.reads; writes = n.writes; }
729. if (n.tag == 'object_expression') {
730. let kids = []
731. for (h of n.entries) { kids.push(syntaxTree(gen, key, h)) }
732. out.entries = kids
733. } else if (n.tag == 'object_property') {
734. out.key = n.key
735. out.value = syntaxTree(gen, key, n.value)
736. } else if (n.tag == 'view_for') {
737. out.list = syntaxTree(gen, key, n.list)
738. out.body = syntaxTree(gen, key, n.body)
739. } else if (n.tag == 'view_if') {
740. out.condition = syntaxTree(gen, key, n.condition)
741. out.consequent = syntaxTree(gen, key, n.consequent)
742. out.alternate = syntaxTree(gen, key, n.alternate)
743. } else if (n.tag == 'on_statement') {
744. out.event = n.event
745. } else if (n.tag == 'member_expression') {
746. out.object = syntaxTree(gen, key, n.object)
747. out.property = syntaxTree(gen, key, n.property)
748. } else if (n.tag == 'call_expression') {
749. out.callee = syntaxTree(gen, key, n.callee)
750. let args = []
751. for (h of n.args) { args.push(syntaxTree(gen, key, h)) }
752. out.args = args
753. } else if (n.tag == 'binary_expression') {
754. out.left = syntaxTree(gen, key, n.left)
755. out.right = syntaxTree(gen, key, n.right)
756. } else if (n.tag == 'unary_expression') {
757. out.operand = syntaxTree(gen, key, n.operand)
758. } else if (n.tag == 'conditional_expression') {
759. out.condition = syntaxTree(gen, key, n.condition)
760. out.consequent = syntaxTree(gen, key, n.consequent)
761. out.alternate = syntaxTree(gen, key, n.alternate)
762. } else if (n.tag == 'array_expression') {
763. let els = []
764. for (h of n.elements) { els.push(syntaxTree(gen, key, h)) }
765. out.elements = els
766. }
767. return out
768. }
770. // ---- the reductions the browser used to make on every boot --------------------------
771. // A `for`'s names are what its list reads, an `if`'s what its condition reads — filed
772. // under the region's own site.
773. regionIndex(t) {
774. let idx = {}
775. for (m of t.members) { if (m.nodes != null) { indexRegions(&idx, m.nodes) } }
776. return idx
777. }
779. indexRegions(&idx, n) {
780. if (n == null) { return null }
781. if (n.tag == 'view_for') {
782. idx[n.site] = memberNames(nodeReads(n.list))
783. indexRegions(&idx, n.body)
784. return null
785. }
786. if (n.tag == 'view_if') {
787. idx[n.site] = memberNames(nodeReads(n.condition))
788. indexRegions(&idx, n.consequent)
789. indexRegions(&idx, n.alternate)
790. return null
791. }
792. if (n.tag == 'on_statement') { return null }
793. 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]) {
794. if (c != null) { indexRegions(&idx, c) }
795. }
796. for (l of [n.entries, n.args, n.elements]) {
797. if (l != null) { for (c of l) { indexRegions(&idx, c) } }
798. }
799. return null
800. }
802. // the member reads of a read list — the language resolved every name, so this is a
803. // filter and not a second resolution
804. memberNames(reads) {
805. let out = []
806. if (reads == null) { return out }
807. for (r of reads) {
808. if (r.kind == 'member' && r.isStatic != true && !out.includes(r.name)) { out.push(r.name) }
809. }
810. return out
811. }
813. nodeReads(n) {
814. if (n == null) { return [] }
815. if (n.reads != null) { return n.reads }
816. let out = []
817. 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]) {
818. if (c != null) { for (r of nodeReads(c)) { out.push(r) } }
819. }
820. for (l of [n.entries, n.args, n.elements]) {
821. if (l != null) { for (c of l) { for (r of nodeReads(c)) { out.push(r) } } }
822. }
823. return out
824. }
826. // A ROUTINE'S WRITES, PLUS THE WRITES OF EVERYTHING IT REACHES — the method it calls
827. // and the handler it emits to, transitively. Both are READS the language resolved, so
828. // this is a walk of its answer and never a guess.
829. closeWrites(t, writes, reads) {
830. let out = memberNames(writes)
831. let queue = []
832. reached(&queue, reads)
833. let seen = {}
834. while (queue.length > 0) {
835. let at = queue.shift()
836. if (seen[at] == null) {
837. seen[at] = true
838. let sp = at.indexOf(' ')
839. let kind = at.slice(0, sp)
840. let name = at.slice(sp + 1)
841. for (mm of t.methods) {
842. if (kind == 'method' && mm.name == name) {
843. for (w of memberNames(mm.writes)) { if (!out.includes(w)) { out.push(w) } }
844. reached(&queue, mm.reads)
845. }
846. }
847. for (h of t.handlers) {
848. if (kind == 'handler' && !h.nested && h.event == name) {
849. for (w of memberNames(h.writes)) { if (!out.includes(w)) { out.push(w) } }
850. reached(&queue, h.reads)
851. }
852. }
853. for (mb of t.members) {
854. if (kind == 'member' && mb.name == name && mb.nodes != null) {
855. for (w of memberNames(mb.nodes.writes)) { if (!out.includes(w)) { out.push(w) } }
856. reached(&queue, nodeReads(mb.nodes))
857. }
858. }
859. }
860. }
861. return out
862. }
864. // the mirror: a handler's reads plus the reads of everything it reaches — the
865. // candidates for a routine a host handed down, whose writes only the host's table names
866. closeReads(t, reads) {
867. let out = memberNames(reads)
868. let queue = []
869. reached(&queue, reads)
870. let seen = {}
871. while (queue.length > 0) {
872. let at = queue.shift()
873. if (seen[at] == null) {
874. seen[at] = true
875. let sp = at.indexOf(' ')
876. let kind = at.slice(0, sp)
877. let name = at.slice(sp + 1)
878. for (mm of t.methods) {
879. if (kind == 'method' && mm.name == name) {
880. for (r of memberNames(mm.reads)) { if (!out.includes(r)) { out.push(r) } }
881. reached(&queue, mm.reads)
882. }
883. }
884. for (h of t.handlers) {
885. if (kind == 'handler' && !h.nested && h.event == name) {
886. for (r of memberNames(h.reads)) { if (!out.includes(r)) { out.push(r) } }
887. reached(&queue, h.reads)
888. }
889. }
890. for (mb of t.members) {
891. if (kind == 'member' && mb.name == name && mb.nodes != null) {
892. for (r of memberNames(nodeReads(mb.nodes))) { if (!out.includes(r)) { out.push(r) } }
893. reached(&queue, nodeReads(mb.nodes))
894. }
895. }
896. }
897. }
898. return out
899. }
901. reached(&queue, reads) {
902. if (reads == null) { return null }
903. for (r of reads) {
904. if (r.kind == 'method' || r.kind == 'handler' || (r.kind == 'member' && r.isStatic != true)) { queue.push(r.kind + ' ' + r.name) }
905. }
906. return null
907. }
909. // ---- THE SERVER RENDER, COMPILED --------------------------------------------------
910. // The old hl:web rendered a page by WALKING the View tree per request: for every node it asks
911. // what kind it is, for every element it builds the attribute string, and it decides the
912. // indentation of every line again, on every request, for every one of the 121 mounts a
913. // page may hold. Every one of those decisions is a fact about the View.
914. //
915. // So a component's render is compiled ONCE into a list of STEPS — constant text, and a
916. // read with its own closure — and a request is a concatenation. The structure (tags,
917. // static attributes, the readable form's line breaks, which element is a block) is
918. // decided at compile time; only the values are asked for per request.
919. //
920. // KEYED BY THE INDENT IT IS RENDERED AT, because that is the only thing about a
921. // component's HTML that its caller decides: the shell renders at one tab, the page at
922. // the depth the slot stands, a fill compactly (null). An app has a handful of those.
923. serverSteps(key, nodes, indent, classes, slotted) {
924. let ck = key + '|' + (indent == null ? '~' : indent) + '|' + joinList(classes) + '|' + (slotted ? '1' : '0')
925. if (steps[ck] == null) {
926. steps[ck] = blockSteps(classes == null || classes.length == 0 ? nodes : v.withRootClasses(nodes, classes), indent, slotted)
927. }
928. return steps[ck]
929. }
931. // A `slot` THE HOST FILLED COUNTS AS CONTENT, and an empty one does not — the one
932. // thing about a component's shape its caller decides, so it is part of the key.
933. staticVoid = [ 'area' 'base' 'br' 'col' 'embed' 'hr' 'img' 'input' 'link' 'meta' 'source' 'track' 'wbr' ]
934. staticVerbatim = [ 'textarea' 'pre' 'script' 'style' ]
936. blocky(n, slotted) {
937. if (staticVerbatim.includes(n.tag)) { return false }
938. if (n.children.length == 0) { return false }
939. for (c of n.children) {
940. if (c.k == 'text' || c.k == 'field') { return false }
941. if (c.k == 'member' && !(c.name == 'slot' && slotted)) { return false }
942. }
943. return true
944. }
946. steps = {}
947. v = new View
949. joinList(l) {
950. if (l == null) { return '' }
951. let out = ''
952. for (c of l) { out = out + ',' + c }
953. return out
954. }
956. // `render(nodes, …, indent)`: the readable form puts each element on its own line at
957. // `indent`, the compact one writes them end to end.
958. blockSteps(nodes, indent, slotted) {
959. let out = []
960. for (n of nodes) {
961. if (indent != null) {
962. if (n.k == 'el') { push(&out, { k = 's'; v = newline + indent; }) nodeSteps(&out, n, indent, slotted) }
963. else if (n.k == 'component') { nodeSteps(&out, n, indent, slotted) }
964. else if (n.k == 'for') { forSteps(&out, n, indent, slotted) }
965. else if (n.k == 'if') { ifSteps(&out, n, indent, slotted) }
966. else if (n.k == 'member' && n.name == 'slot') { push(&out, { k = 'slotline'; v = newline + indent; }) }
967. else if (n.k != 'on') { nodeSteps(&out, n, indent, slotted) }
968. } else {
969. nodeSteps(&out, n, null, slotted)
970. }
971. }
972. return out
973. }
975. forSteps(&out, n, indent, slotted) {
976. out.push({ k = 'for'; row = n.row; read = readFn(n.list); body = blockSteps(n.body, indent, slotted); })
977. return null
978. }
980. ifSteps(&out, n, indent, slotted) {
981. out.push({ k = 'if'; read = readFn(n.cond); then = blockSteps(n.then, indent, slotted); other = blockSteps(n.other, indent, slotted); })
982. return null
983. }
985. // one node's steps — `html(node, …)`, decided once
986. nodeSteps(&out, n, indent, slotted) {
987. if (n.k == 'text') { push(&out, { k = 's'; v = v.escape(n.text); }) return null }
988. if (n.k == 'on') { return null }
989. if (n.k == 'member' && n.name == 'slot') { out.push({ k = 'slot'; }) return null }
990. if (n.k == 'member' || n.k == 'field') { out.push({ k = 'r'; read = readFn(n); }) return null }
991. if (n.k == 'for') { forSteps(&out, n, indent, slotted) return null }
992. if (n.k == 'if') { ifSteps(&out, n, indent, slotted) return null }
993. if (n.k == 'component') {
994. out.push({ k = 'kid'; path = n.path; cls = n.cls; key = n.key; classes = n.classes; indent = indent;
995. fill = (n.fill == null || n.fill.length == 0) ? null : blockSteps(n.fill, null, slotted); })
996. return null
997. }
998. if (n.k == 'el') { elSteps(&out, n, indent, slotted) return null }
999. push(&out, { k = 's'; v = '<!-- ' + n.tag + ' not rendered yet -->'; })
1000. return null
1001. }
1003. elSteps(&out, n, indent, slotted) {
1004. let attrs = []
1005. let valueRead = null // a textarea's value is its content
1006. let selRead = null // a select's value selects an option
1007. for (a of n.attrs) {
1008. if (n.tag == 'textarea' && a.name == 'value') { valueRead = attrRead(a) }
1009. else if (n.tag == 'select' && a.name == 'value') { selRead = attrRead(a) }
1010. // a bound BOOLEAN attribute is its presence (ticket #33): ` checked=""` or nothing
1011. else if ((a.member != null || a.ref != null) && v.isBoolAttr(a.name)) { attrs.push({ k = 'b'; name = a.name; read = attrRead(a); }) }
1012. else if (a.member != null || a.ref != null) {
1013. push(&attrs, { k = 's'; v = ' ' + a.name + '="'; })
1014. attrs.push({ k = 'r'; read = attrRead(a); })
1015. push(&attrs, { k = 's'; v = v.extraOf(a) + '"'; })
1016. } else {
1017. push(&attrs, { k = 's'; v = ' ' + a.name + '="' + v.escape(a.text) + '"'; })
1018. }
1019. }
1020. if (v.boundValue(n)) { push(&attrs, { k = 's'; v = ' autocomplete="off"'; }) }
1022. // the children, in the form this element takes: a block puts them one per line
1023. let kids = []
1024. if (indent != null && blocky(n, slotted)) {
1025. kids = blockSteps(n.children, indent + tab, slotted)
1026. push(&kids, { k = 's'; v = newline + indent; })
1027. } else {
1028. kids = blockSteps(n.children, null, slotted)
1029. }
1030. if (valueRead != null) { kids = [{ k = 'r'; read = valueRead; }] }
1032. // AN OPTION IS THE ONE ELEMENT WHOSE OWN TAG DEPENDS ON THE VALUE ABOVE IT: it
1033. // carries `selected` when its value is the select's. Everything else is settled.
1034. if (n.tag == 'option') {
1035. out.push({ k = 'opt'; attrs = attrs; body = kids; ov = optionRead(n); })
1036. return null
1037. }
1038. push(&out, { k = 's'; v = '<' + n.tag; })
1039. for (a of attrs) { push(&out, a) }
1040. if (staticVoid.includes(n.tag)) { push(&out, { k = 's'; v = '>'; }) return null }
1041. push(&out, { k = 's'; v = '>'; })
1042. // A SELECT HANDS ITS VALUE TO ITS OPTIONS, however deep they stand: its children
1043. // run under it, and it is the only element that changes anything for them.
1044. if (n.tag == 'select') { out.push({ k = 'sel'; read = selRead; body = kids; }) }
1045. else { for (kk of kids) { push(&out, kk) } }
1046. push(&out, { k = 's'; v = '</' + n.tag + '>'; })
1047. return null
1048. }
1050. // CONSTANT TEXT MERGES. Two literal steps in a row are one string decided at compile
1051. // time — which is what makes a request a concatenation of a handful of pieces instead
1052. // of one per node.
1053. push(&out, step) {
1054. if (step.k == 's' && out.length > 0 && out[out.length - 1].k == 's') {
1055. let last = out[out.length - 1]
1056. last.v = last.v + step.v
1057. out[out.length - 1] = last
1058. return null
1059. }
1060. out.push(step)
1061. return null
1062. }
1064. // ---- the reads, each with its own closure ------------------------------------------
1065. // `view.value`'s rule, split once: a `for` row variable in scope wins over a member of
1066. // the same name, and a field path walks into it. The closure holds the name — there is
1067. // no node to look at per request.
1068. readFn(node) {
1069. if (node == null) { return (inst, rows) => { return null } }
1070. if (node.k == 'text') { let t = v.literalValue(node.kind, node.text) return (inst, rows) => { return t } }
1071. let name = node.name
1072. if (node.k != 'field') {
1073. return (inst, rows) => { return rows[name] != null ? rows[name] : inst[name] }
1074. }
1075. let path = node.path
1076. return (inst, rows) => {
1077. let val = rows[name] != null ? rows[name] : inst[name]
1078. for (f of path) {
1079. if (val == null) { return null }
1080. val = val[f]
1081. }
1082. return val
1083. }
1084. }
1086. attrRead(a) {
1087. if (a.member != null) { return readFn({ k = 'member'; name = a.member; }) }
1088. if (a.ref != null) { return readFn(a.ref) }
1089. let t = a.text
1090. return (inst, rows) => { return t }
1091. }
1093. // an option's own value: its `value` attribute, or null when it has none (the browser
1094. // then reports its text, and the run compares against what it rendered)
1095. optionRead(n) {
1096. for (a of n.attrs) {
1097. if (a.name == 'value') { return attrRead(a) }
1098. }
1099. return null
1100. }
1102. // ---- the run: a concatenation ------------------------------------------------------
1103. // EVERY REGION IS WRITTEN BETWEEN TWO MARKS (tickets #103, #104): an `if` around the
1104. // branch that stands, a `for` around its rows and each row around its own nodes. The
1105. // client claims them as they are and builds the same ones, and a region's nodes are
1106. // exactly what stands between its two marks — nothing it holds has to be remembered
1107. // node by node, and text beside a region can never run into the region's text.
1108. markOpen = '<!--[-->'
1109. markClose = '<!--]-->'
1111. runSteps(list, &inst, &rows, &ctx) {
1112. let out = ''
1113. for (s of list) {
1114. if (s.k == 's') { out = out + s.v }
1115. else if (s.k == 'r') { let f = s.read out = out + v.escape(f(&inst, &rows)) }
1116. else if (s.k == 'b') { let f = s.read if (v.boolOn(f(&inst, &rows))) { out = out + ' ' + s.name + '=""' } }
1117. else if (s.k == 'slot') { if (ctx.slot != null) { out = out + ctx.slot } }
1118. else if (s.k == 'slotline') { if (ctx.slot != null) { out = out + s.v + ctx.slot } }
1119. else if (s.k == 'for') {
1120. let f = s.read
1121. let list2 = f(&inst, &rows)
1122. out = out + markOpen
1123. if (list2 != null) {
1124. let ri = 0
1125. for (entry of list2) {
1126. let inner = rows + {}
1127. inner[s.row] = entry
1128. let rc = v.rowCtx(&ctx, &entry, ri)
1129. out = out + markOpen + runSteps(s.body, &inst, &inner, &rc) + markClose
1130. ri = ri + 1
1131. }
1132. }
1133. out = out + markClose
1134. }
1135. else if (s.k == 'if') {
1136. let f = s.read
1137. if (f(&inst, &rows)) { out = out + markOpen + runSteps(s.then, &inst, &rows, &ctx) + markClose }
1138. else { out = out + markOpen + runSteps(s.other, &inst, &rows, &ctx) + markClose }
1139. }
1140. else if (s.k == 'opt') {
1141. let head = runSteps(s.attrs, &inst, &rows, &ctx)
1142. let body = runSteps(s.body, &inst, &rows, &ctx)
1143. let mark = ''
1144. if (ctx.sel != null) {
1145. let ov = body
1146. if (s.ov != null) { let f = s.ov ov = '' + f(&inst, &rows) }
1147. if (ov == ctx.sel) { mark = ' selected' }
1148. }
1149. out = out + '<option' + head + mark + '>' + body + '</option>'
1150. }
1151. else if (s.k == 'sel') {
1152. let f = s.read
1153. let inner = ctx + {}
1154. inner.sel = f == null ? null : '' + f(&inst, &rows)
1155. out = out + runSteps(s.body, &inst, &rows, &inner)
1156. }
1157. else if (s.k == 'kid') {
1158. let kid = ctx.kids[v.kidKeyIn(s.path, ctx)]
1159. if (kid == null) { out = out + '<!-- ' + s.cls + ' not mounted -->' }
1160. else {
1161. let fillText = s.fill == null ? null : runSteps(s.fill, &inst, &rows, &ctx)
1162. let kidCtx = { slot = fillText; kids = kid.kids; }
1163. let kidInst = kid.page
1164. let empty = {}
1165. out = out + runSteps(serverSteps(s.key, kid.view, s.indent, s.classes, fillText != null), &kidInst, &empty, &kidCtx)
1166. }
1167. }
1168. }
1169. return out
1170. }