tools/lua/template.lua

   1 -- From lua-resty-template (modified to remove external dependencies)
   2 --[[
   3 Copyright (c) 2014 - 2020 Aapo Talvensaari
   4 All rights reserved.
   5
   6 Redistribution and use in source and binary forms, with or without modification,
   7 are permitted provided that the following conditions are met:
   8
   9 * Redistributions of source code must retain the above copyright notice, this
  10   list of conditions and the following disclaimer.
  11
  12 * Redistributions in binary form must reproduce the above copyright notice, this
  13   list of conditions and the following disclaimer in the documentation and/or
  14   other materials provided with the distribution.
  15
  16 * Neither the name of the {organization} nor the names of its
  17   contributors may be used to endorse or promote products derived from
  18   this software without specific prior written permission.
  19
  20 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  21 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  22 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  23 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
  24 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  25 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  27 ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30 ]]--
  31 -- $FreeBSD$
  32
  33 local setmetatable = setmetatable
  34 local loadstring = loadstring
  35 local tostring = tostring
  36 local setfenv = setfenv
  37 local require = require
  38 local concat = table.concat
  39 local assert = assert
  40 local write = io.write
  41 local pcall = pcall
  42 local phase
  43 local open = io.open
  44 local load = load
  45 local type = type
  46 local dump = string.dump
  47 local find = string.find
  48 local gsub = string.gsub
  49 local byte = string.byte
  50 local null
  51 local sub = string.sub
  52 local var
  53
  54 local _VERSION = _VERSION
  55 local _ENV = _ENV -- luacheck: globals _ENV
  56 local _G = _G
  57
  58 local HTML_ENTITIES = {
  59     ["&"] = "&amp;",
  60     ["<"] = "&lt;",
  61     [">"] = "&gt;",
  62     ['"'] = "&quot;",
  63     ["'"] = "&#39;",
  64     ["/"] = "&#47;"
  65 }
  66
  67 local CODE_ENTITIES = {
  68     ["{"] = "&#123;",
  69     ["}"] = "&#125;",
  70     ["&"] = "&amp;",
  71     ["<"] = "&lt;",
  72     [">"] = "&gt;",
  73     ['"'] = "&quot;",
  74     ["'"] = "&#39;",
  75     ["/"] = "&#47;"
  76 }
  77
  78 local VAR_PHASES
  79
  80 local ESC    = byte("\27")
  81 local NUL    = byte("\0")
  82 local HT     = byte("\t")
  83 local VT     = byte("\v")
  84 local LF     = byte("\n")
  85 local SOL    = byte("/")
  86 local BSOL   = byte("\\")
  87 local SP     = byte(" ")
  88 local AST    = byte("*")
  89 local NUM    = byte("#")
  90 local LPAR   = byte("(")
  91 local LSQB   = byte("[")
  92 local LCUB   = byte("{")
  93 local MINUS  = byte("-")
  94 local PERCNT = byte("%")
  95
  96 local EMPTY  = ""
  97
  98 local VIEW_ENV
  99 if _VERSION == "Lua 5.1" then
 100     VIEW_ENV = { __index = function(t, k)
 101         return t.context[k] or t.template[k] or _G[k]
 102     end }
 103 else
 104     VIEW_ENV = { __index = function(t, k)
 105         return t.context[k] or t.template[k] or _ENV[k]
 106     end }
 107 end
 108
 109 local newtab
 110 do
 111     local ok
 112     ok, newtab = pcall(require, "table.new")
 113     if not ok then newtab = function() return {} end end
 114 end
 115
 116 local function enabled(val)
 117     if val == nil then return true end
 118     return val == true or (val == "1" or val == "true" or val == "on")
 119 end
 120
 121 local function trim(s)
 122     return gsub(gsub(s, "^%s+", EMPTY), "%s+$", EMPTY)
 123 end
 124
 125 local function rpos(view, s)
 126     while s > 0 do
 127         local c = byte(view, s, s)
 128         if c == SP or c == HT or c == VT or c == NUL then
 129             s = s - 1
 130         else
 131             break
 132         end
 133     end
 134     return s
 135 end
 136
 137 local function escaped(view, s)
 138     if s > 1 and byte(view, s - 1, s - 1) == BSOL then
 139         if s > 2 and byte(view, s - 2, s - 2) == BSOL then
 140             return false, 1
 141         else
 142             return true, 1
 143         end
 144     end
 145     return false, 0
 146 end
 147
 148 local function read_file(path)
 149     local file, err = open(path, "rb")
 150     if not file then return nil, err end
 151     local content
 152     content, err = file:read "*a"
 153     file:close()
 154     return content, err
 155 end
 156
 157 local function load_view(template)
 158     return function(view, plain)
 159         if plain == true then return view end
 160         local path, root = view, template.root
 161         if root and root ~= EMPTY then
 162             if byte(root, -1) == SOL then root = sub(root, 1, -2) end
 163             if byte(view,  1) == SOL then path = sub(view, 2) end
 164             path = root .. "/" .. path
 165         end
 166         return plain == false and assert(read_file(path)) or read_file(path) or view
 167     end
 168 end
 169
 170 local function load_file(func)
 171     return function(view) return func(view, false) end
 172 end
 173
 174 local function load_string(func)
 175     return function(view) return func(view, true) end
 176 end
 177
 178 local function loader(template)
 179     return function(view)
 180         return assert(load(view, nil, nil, setmetatable({ template = template }, VIEW_ENV)))
 181     end
 182 end
 183
 184 local function visit(visitors, content, tag, name)
 185     if not visitors then
 186         return content
 187     end
 188
 189     for i = 1, visitors.n do
 190         content = visitors[i](content, tag, name)
 191     end
 192
 193     return content
 194 end
 195
 196 local function new(template, safe)
 197     template = template or newtab(0, 26)
 198
 199     template._VERSION    = "2.0"
 200     template.cache       = {}
 201     template.load        = load_view(template)
 202     template.load_file   = load_file(template.load)
 203     template.load_string = load_string(template.load)
 204     template.print       = write
 205
 206     local load_chunk = loader(template)
 207
 208     local caching
 209     if VAR_PHASES and VAR_PHASES[phase()] then
 210         caching = enabled(var.template_cache)
 211     else
 212         caching = true
 213     end
 214
 215     local visitors
 216     function template.visit(func)
 217         if not visitors then
 218             visitors = { func, n = 1 }
 219             return
 220         end
 221         visitors.n = visitors.n + 1
 222         visitors[visitors.n] = func
 223     end
 224
 225     function template.caching(enable)
 226         if enable ~= nil then caching = enable == true end
 227         return caching
 228     end
 229
 230     function template.output(s)
 231         if s == nil or s == null then return EMPTY end
 232         if type(s) == "function" then return template.output(s()) end
 233         return tostring(s)
 234     end
 235
 236     function template.escape(s, c)
 237         if type(s) == "string" then
 238             if c then return gsub(s, "[}{\">/<'&]", CODE_ENTITIES) end
 239             return gsub(s, "[\">/<'&]", HTML_ENTITIES)
 240         end
 241         return template.output(s)
 242     end
 243
 244     function template.new(view, layout)
 245         local vt = type(view)
 246
 247         if vt == "boolean" then return new(nil,  view) end
 248         if vt == "table"   then return new(view, safe) end
 249         if vt == "nil"     then return new(nil,  safe) end
 250
 251         local render
 252         local process
 253         if layout then
 254             if type(layout) == "table" then
 255                 render = function(self, context)
 256                     context = context or self
 257                     context.blocks = context.blocks or {}
 258                     context.view = template.process(view, context)
 259                     layout.blocks = context.blocks or {}
 260                     layout.view = context.view or EMPTY
 261                     layout:render()
 262                 end
 263                 process = function(self, context)
 264                     context = context or self
 265                     context.blocks = context.blocks or {}
 266                     context.view = template.process(view, context)
 267                     layout.blocks = context.blocks or {}
 268                     layout.view = context.view
 269                     return tostring(layout)
 270                 end
 271             else
 272                 render = function(self, context)
 273                     context = context or self
 274                     context.blocks = context.blocks or {}
 275                     context.view = template.process(view, context)
 276                     template.render(layout, context)
 277                 end
 278                 process = function(self, context)
 279                     context = context or self
 280                     context.blocks = context.blocks or {}
 281                     context.view = template.process(view, context)
 282                     return template.process(layout, context)
 283                 end
 284             end
 285         else
 286             render = function(self, context)
 287                 return template.render(view, context or self)
 288             end
 289             process = function(self, context)
 290                 return template.process(view, context or self)
 291             end
 292         end
 293
 294         if safe then
 295             return setmetatable({
 296                 render = function(...)
 297                     local ok, err = pcall(render, ...)
 298                     if not ok then
 299                         return nil, err
 300                     end
 301                 end,
 302                 process = function(...)
 303                     local ok, output = pcall(process, ...)
 304                     if not ok then
 305                         return nil, output
 306                     end
 307                     return output
 308                 end,
 309              }, {
 310                 __tostring = function(...)
 311                     local ok, output = pcall(process, ...)
 312                     if not ok then
 313                         return ""
 314                     end
 315                     return output
 316             end })
 317         end
 318
 319         return setmetatable({
 320             render = render,
 321             process = process
 322         }, {
 323             __tostring = process
 324         })
 325     end
 326
 327     function template.precompile(view, path, strip, plain)
 328         local chunk = dump(template.compile(view, nil, plain), strip ~= false)
 329         if path then
 330             local file = open(path, "wb")
 331             file:write(chunk)
 332             file:close()
 333         end
 334         return chunk
 335     end
 336
 337     function template.precompile_string(view, path, strip)
 338         return template.precompile(view, path, strip, true)
 339     end
 340
 341     function template.precompile_file(view, path, strip)
 342         return template.precompile(view, path, strip, false)
 343     end
 344
 345     function template.compile(view, cache_key, plain)
 346         assert(view, "view was not provided for template.compile(view, cache_key, plain)")
 347         if cache_key == "no-cache" then
 348             return load_chunk(template.parse(view, plain)), false
 349         end
 350         cache_key = cache_key or view
 351         local cache = template.cache
 352         if cache[cache_key] then return cache[cache_key], true end
 353         local func = load_chunk(template.parse(view, plain))
 354         if caching then cache[cache_key] = func end
 355         return func, false
 356     end
 357
 358     function template.compile_file(view, cache_key)
 359         return template.compile(view, cache_key, false)
 360     end
 361
 362     function template.compile_string(view, cache_key)
 363         return template.compile(view, cache_key, true)
 364     end
 365
 366     function template.parse(view, plain)
 367         assert(view, "view was not provided for template.parse(view, plain)")
 368         if plain ~= true then
 369             view = template.load(view, plain)
 370             if byte(view, 1, 1) == ESC then return view end
 371         end
 372         local j = 2
 373         local c = {[[
 374 context=... or {}
 375 local ___,blocks,layout={},blocks or {}
 376 local function include(v, c) return template.process(v, c or context) end
 377 local function echo(...) for i=1,select("#", ...) do ___[#___+1] = tostring(select(i, ...)) end end
 378 ]] }
 379         local i, s = 1, find(view, "{", 1, true)
 380         while s do
 381             local t, p = byte(view, s + 1, s + 1), s + 2
 382             if t == LCUB then
 383                 local e = find(view, "}}", p, true)
 384                 if e then
 385                     local z, w = escaped(view, s)
 386                     if i < s - w then
 387                         c[j] = "___[#___+1]=[=[\n"
 388                         c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 389                         c[j+2] = "]=]\n"
 390                         j=j+3
 391                     end
 392                     if z then
 393                         i = s
 394                     else
 395                         c[j] = "___[#___+1]=template.escape("
 396                         c[j+1] = visit(visitors, trim(sub(view, p, e - 1)), "{")
 397                         c[j+2] = ")\n"
 398                         j=j+3
 399                         s, i = e + 1, e + 2
 400                     end
 401                 end
 402             elseif t == AST then
 403                 local e = find(view, "*}", p, true)
 404                 if e then
 405                     local z, w = escaped(view, s)
 406                     if i < s - w then
 407                         c[j] = "___[#___+1]=[=[\n"
 408                         c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 409                         c[j+2] = "]=]\n"
 410                         j=j+3
 411                     end
 412                     if z then
 413                         i = s
 414                     else
 415                         c[j] = "___[#___+1]=template.output("
 416                         c[j+1] = visit(visitors, trim(sub(view, p, e - 1)), "*")
 417                         c[j+2] = ")\n"
 418                         j=j+3
 419                         s, i = e + 1, e + 2
 420                     end
 421                 end
 422             elseif t == PERCNT then
 423                 local e = find(view, "%}", p, true)
 424                 if e then
 425                     local z, w = escaped(view, s)
 426                     if z then
 427                         if i < s - w then
 428                             c[j] = "___[#___+1]=[=[\n"
 429                             c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 430                             c[j+2] = "]=]\n"
 431                             j=j+3
 432                         end
 433                         i = s
 434                     else
 435                         local n = e + 2
 436                         if byte(view, n, n) == LF then
 437                             n = n + 1
 438                         end
 439                         local r = rpos(view, s - 1)
 440                         if i <= r then
 441                             c[j] = "___[#___+1]=[=[\n"
 442                             c[j+1] = visit(visitors, sub(view, i, r))
 443                             c[j+2] = "]=]\n"
 444                             j=j+3
 445                         end
 446                         c[j] = visit(visitors, trim(sub(view, p, e - 1)), "%")
 447                         c[j+1] = "\n"
 448                         j=j+2
 449                         s, i = n - 1, n
 450                     end
 451                 end
 452             elseif t == LPAR then
 453                 local e = find(view, ")}", p, true)
 454                 if e then
 455                     local z, w = escaped(view, s)
 456                     if i < s - w then
 457                         c[j] = "___[#___+1]=[=[\n"
 458                         c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 459                         c[j+2] = "]=]\n"
 460                         j=j+3
 461                     end
 462                     if z then
 463                         i = s
 464                     else
 465                         local f = visit(visitors, sub(view, p, e - 1), "(")
 466                         local x = find(f, ",", 2, true)
 467                         if x then
 468                             c[j] = "___[#___+1]=include([=["
 469                             c[j+1] = trim(sub(f, 1, x - 1))
 470                             c[j+2] = "]=],"
 471                             c[j+3] = trim(sub(f, x + 1))
 472                             c[j+4] = ")\n"
 473                             j=j+5
 474                         else
 475                             c[j] = "___[#___+1]=include([=["
 476                             c[j+1] = trim(f)
 477                             c[j+2] = "]=])\n"
 478                             j=j+3
 479                         end
 480                         s, i = e + 1, e + 2
 481                     end
 482                 end
 483             elseif t == LSQB then
 484                 local e = find(view, "]}", p, true)
 485                 if e then
 486                     local z, w = escaped(view, s)
 487                     if i < s - w then
 488                         c[j] = "___[#___+1]=[=[\n"
 489                         c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 490                         c[j+2] = "]=]\n"
 491                         j=j+3
 492                     end
 493                     if z then
 494                         i = s
 495                     else
 496                         c[j] = "___[#___+1]=include("
 497                         c[j+1] = visit(visitors, trim(sub(view, p, e - 1)), "[")
 498                         c[j+2] = ")\n"
 499                         j=j+3
 500                         s, i = e + 1, e + 2
 501                     end
 502                 end
 503             elseif t == MINUS then
 504                 local e = find(view, "-}", p, true)
 505                 if e then
 506                     local x, y = find(view, sub(view, s, e + 1), e + 2, true)
 507                     if x then
 508                         local z, w = escaped(view, s)
 509                         if z then
 510                             if i < s - w then
 511                                 c[j] = "___[#___+1]=[=[\n"
 512                                 c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 513                                 c[j+2] = "]=]\n"
 514                                 j=j+3
 515                             end
 516                             i = s
 517                         else
 518                             y = y + 1
 519                             x = x - 1
 520                             if byte(view, y, y) == LF then
 521                                 y = y + 1
 522                             end
 523                             local b = trim(sub(view, p, e - 1))
 524                             if b == "verbatim" or b == "raw" then
 525                                 if i < s - w then
 526                                     c[j] = "___[#___+1]=[=[\n"
 527                                     c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 528                                     c[j+2] = "]=]\n"
 529                                     j=j+3
 530                                 end
 531                                 c[j] = "___[#___+1]=[=["
 532                                 c[j+1] = visit(visitors, sub(view, e + 2, x))
 533                                 c[j+2] = "]=]\n"
 534                                 j=j+3
 535                             else
 536                                 if byte(view, x, x) == LF then
 537                                     x = x - 1
 538                                 end
 539                                 local r = rpos(view, s - 1)
 540                                 if i <= r then
 541                                     c[j] = "___[#___+1]=[=[\n"
 542                                     c[j+1] = visit(visitors, sub(view, i, r))
 543                                     c[j+2] = "]=]\n"
 544                                     j=j+3
 545                                 end
 546                                 c[j] = 'blocks["'
 547                                 c[j+1] = b
 548                                 c[j+2] = '"]=include[=['
 549                                 c[j+3] = visit(visitors, sub(view, e + 2, x), "-", b)
 550                                 c[j+4] = "]=]\n"
 551                                 j=j+5
 552                             end
 553                             s, i = y - 1, y
 554                         end
 555                     end
 556                 end
 557             elseif t == NUM then
 558                 local e = find(view, "#}", p, true)
 559                 if e then
 560                     local z, w = escaped(view, s)
 561                     if i < s - w then
 562                         c[j] = "___[#___+1]=[=[\n"
 563                         c[j+1] = visit(visitors, sub(view, i, s - 1 - w))
 564                         c[j+2] = "]=]\n"
 565                         j=j+3
 566                     end
 567                     if z then
 568                         i = s
 569                     else
 570                         e = e + 2
 571                         if byte(view, e, e) == LF then
 572                             e = e + 1
 573                         end
 574                         s, i = e - 1, e
 575                     end
 576                 end
 577             end
 578             s = find(view, "{", s + 1, true)
 579         end
 580         s = sub(view, i)
 581         if s and s ~= EMPTY then
 582             c[j] = "___[#___+1]=[=[\n"
 583             c[j+1] = visit(visitors, s)
 584             c[j+2] = "]=]\n"
 585             j=j+3
 586         end
 587         c[j] = "return layout and include(layout,setmetatable({view=table.concat(___),blocks=blocks},{__index=context})) or table.concat(___)" -- luacheck: ignore
 588         return concat(c)
 589     end
 590
 591     function template.parse_file(view)
 592         return template.parse(view, false)
 593     end
 594
 595     function template.parse_string(view)
 596         return template.parse(view, true)
 597     end
 598
 599     function template.process(view, context, cache_key, plain)
 600         assert(view, "view was not provided for template.process(view, context, cache_key, plain)")
 601         return template.compile(view, cache_key, plain)(context)
 602     end
 603
 604     function template.process_file(view, context, cache_key)
 605         assert(view, "view was not provided for template.process_file(view, context, cache_key)")
 606         return template.compile(view, cache_key, false)(context)
 607     end
 608
 609     function template.process_string(view, context, cache_key)
 610         assert(view, "view was not provided for template.process_string(view, context, cache_key)")
 611         return template.compile(view, cache_key, true)(context)
 612     end
 613
 614     function template.render(view, context, cache_key, plain)
 615         assert(view, "view was not provided for template.render(view, context, cache_key, plain)")
 616         template.print(template.process(view, context, cache_key, plain))
 617     end
 618
 619     function template.render_file(view, context, cache_key)
 620         assert(view, "view was not provided for template.render_file(view, context, cache_key)")
 621         template.render(view, context, cache_key, false)
 622     end
 623
 624     function template.render_string(view, context, cache_key)
 625         assert(view, "view was not provided for template.render_string(view, context, cache_key)")
 626         template.render(view, context, cache_key, true)
 627     end
 628
 629     if safe then
 630         return setmetatable({}, {
 631             __index = function(_, k)
 632                 if type(template[k]) == "function" then
 633                     return function(...)
 634                         local ok, a, b = pcall(template[k], ...)
 635                         if not ok then
 636                             return nil, a
 637                         end
 638                         return a, b
 639                     end
 640                 end
 641                 return template[k]
 642             end,
 643             __new_index = function(_, k, v)
 644                 template[k] = v
 645             end,
 646         })
 647     end
 648
 649     return template
 650 end
 651
 652 return new()