summaryrefslogtreecommitdiff
path: root/macros/luatex/generic/luaxml/luaxml-domobject.lua
blob: 6d299d41575658648c7aa8032d50412235990ee4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
--- DOM module for LuaXML
-- @module luaxml-domobject
-- @author Michal Hoftich <michal.h21@gmail.com
local dom = {}
local xml = require("luaxml-mod-xml")
local handler = require("luaxml-mod-handler")
local css_query = require("luaxml-cssquery")


local void = {area = true, base = true, br = true, col = true, hr = true, img = true, input = true, link = true, meta = true, param = true}

local escapes = {
  [">"] = "&gt;",
  ["<"] = "&lt;",
  ["&"] = "&amp;",
  ['"'] = "&quot;",
  ["'"] = "&#39;",
  ["`"] = "&#x60;"
}

local function escape(search, text)
  return text:gsub(search, function(ch)
    return escapes[ch] or ""
  end)
end

local function escape_element(text)
  return escape("([<>&])", text)
end

local function escape_attr(text)
  return escape("([<>&\"'`])", text)
end

local actions = {
  TEXT = {text = "%s"},
  COMMENT = {start = "<!-- ", text = "%s", stop = " -->"},
  ELEMENT = {start = "<%s%s>", stop = "</%s>", void = "<%s%s />"},
  DECL = {start = "<?%s %s?>"},
  PI = {start = "<?%s %s?>"},
  DTD = {start = "<!DOCTYPE ", text = "%s" , stop=">"},
  CDATA = {start = "<![CDATA[", text = "%s", stop ="]]>"}
  
}

--- It serializes the DOM object back to the XML.
-- This function is mainly used for internal purposes, it is better to
-- use the `DOM_Object:serialize()`.
-- @param parser DOM object
-- @param current Element which should be serialized
-- @param level 
-- @param output
-- @return table Table with XML strings. It can be concenated using table.concat() function to get XML string corresponding to the DOM_Object.
local function serialize_dom(parser, current,level, output)
  local output = output or {}
  local function get_action(typ, action)
    local ac = actions[typ] or {}
    local format = ac[action] or ""
    return format
  end
  local function insert(format, ...)
    table.insert(output, string.format(format, ...))
  end
  local function prepare_attributes(attr)
    local t = {}
    local attr = attr or {}
    for k, v in pairs(attr) do
      t[#t+1] = string.format("%s='%s'", k, escape_attr(v))
    end
    if #t == 0 then return "" end
    -- add space before attributes
    return " " .. table.concat(t, " ")
  end
  local function start(typ, el, attr)
    local format = get_action(typ, "start")
    insert(format, el, prepare_attributes(attr))
  end
  local function text(typ, text)
    local format = get_action(typ, "text")
    insert(format, escape_element(text))
  end
  local function stop(typ, el)
    local format = get_action(typ, "stop")
    insert(format,el)
  end
  local level = level or 0
  local spaces = string.rep(" ",level)
  local root= current or parser._handler.root
  local name = root._name or "unnamed"
  local xtype = root._type or "untyped"
  local text_content = root._text or ""
  local attributes = root._attr or {}
  -- if xtype == "TEXT" then
  --   print(spaces .."TEXT : " .. root._text)
  -- elseif xtype == "COMMENT" then
  --   print(spaces .. "Comment : ".. root._text)
  -- else
  --   print(spaces .. xtype .. " : " .. name)
  -- end
  -- for k, v in pairs(attributes) do
  --   print(spaces .. " ".. k.."="..v)
  -- end
  if xtype == "DTD" then
    text_content = string.format('%s %s "%s" "%s"', name, attributes["_type"] or "",  attributes._name, attributes._uri )
    -- remove unused fields
    text_content = text_content:gsub('"nil"','')
    text_content = text_content:gsub('%s*$','')
    attributes = {}
  elseif xtype == "ELEMENT" and void[name] and #current._children < 1 then
    local format = get_action(xtype, "void")
    insert(format, name, prepare_attributes(attributes))
    return output
  elseif xtype == "PI" then
    -- it contains spurious _text attribute
    attributes["_text"] = nil
  elseif xtype == "DECL" and name =="xml" then
    -- the xml declaration attributes must be in a correct order
    local encoding = attributes.encoding or "utf-8"
    insert("<?xml version='%s' encoding='%s' ?>", attributes.version, encoding)
    return output
  elseif xtype == "CDATA" then
    -- return content unescaped
    insert(string.format("<![CDATA[%s]]>", text_content))
    return output
  end

  start(xtype, name, attributes)
  text(xtype,text_content) 
  local children = root._children or {}
  for _, child in ipairs(children) do
    output = serialize_dom(parser,child, level + 1, output)
  end
  stop(xtype, name)
  return output
end

--- XML parsing function
-- Parse the XML text and create the DOM object.
-- @return DOM_Object
local parse = function(
  xmltext --- String to be parsed
  ,voidElements --- hash table with void elements
 )
  local domHandler = handler.domHandler()
  ---  @type DOM_Object
  local DOM_Object = xml.xmlParser(domHandler)
  -- preserve whitespace
  DOM_Object.options.stripWS = nil
  -- don't try to expand entities
  DOM_Object.options.expandEntities = nil
  local voidElements = voidElements or void
  DOM_Object._handler.options.voidElements = voidElements
  DOM_Object:parse(xmltext)
  DOM_Object.current = DOM_Object._handler.root
  DOM_Object.__index = DOM_Object
  DOM_Object.css_query = css_query()

  local function save_methods(element)
    setmetatable(element,DOM_Object)
    local children = element._children or {}
    for _, x in ipairs(children) do
      save_methods(x)
    end
  end
  local parser = setmetatable({}, DOM_Object)

  --- Returns root element of the DOM_Object 
  -- @return DOM_Object 
  function DOM_Object:root_node()
    return self._handler.root
  end


  --- Get current node type
  -- @param  el [optional] node to get the type of
  function DOM_Object:get_node_type( 
    el --- [optional] element to test
    )
    local el = el or self
    return el._type
  end

  --- Test if the current node is an element.
  -- You can pass different element as parameter
  -- @return boolean
  function DOM_Object:is_element(
    el --- [optional] element to test
    )
    local el = el or self
    return self:get_node_type(el) == "ELEMENT" -- @bool
  end

  
  --- Test if current node is text
  -- @return boolean
  function DOM_Object:is_text(
    el --- [optional] element to test
    )
    local el = el or self
    return self:get_node_type(el) == "TEXT"
  end

  local lower = string.lower

  --- Return name of the current element
  -- @return string
  function DOM_Object:get_element_name(
    el --- [optional] element to test
    )
    local el = el or self
    return el._name or "unnamed"
  end

  --- Get value of an attribute
  -- @return string
  function DOM_Object:get_attribute(
    name --- Attribute name
    )
    local el = self
    if self:is_element(el) then
      local attr = el._attr or {}
      return attr[name]
    end
  end

  --- Set value of an attribute
  -- @return boolean
  function DOM_Object:set_attribute( 
    name --- Attribute name
    , value --- Value to be set
    )
    local el = self
    if self:is_element(el) then
      el._attr[name] = value
      return true
    end
  end
  

  --- Serialize the current node back to XML
  -- @return string
  function DOM_Object:serialize(
    current --- [optional] element to be serialized
    )
    local current = current
    -- if no current element is added and self is not plain parser object
    -- (_type is then nil), use the current object as serialized root
    if not current and self._type then
      current = self
    end
    return table.concat(serialize_dom(self, current))
  end

  --- Get text content from the node and all of it's children
  -- @return string
  function DOM_Object:get_text(
    current --- [optional] element which should be converted to text
    )
    local current = current or self
    local text = {}
    if current:is_text() then return current._text or "" end
    for _, el in ipairs(current:get_children()) do
      if el:is_text() then
        text[#text+1] = el._text or ""
      elseif el:is_element() then
        text[#text+1] = el:get_text()
      end
    end
    return table.concat(text)
  end



  --- Retrieve elements from the given path.
  -- The path is list of elements separated by space,
  -- starting from the top element of the current element
  -- @return table of elements which match the path
  function DOM_Object:get_path(
    path --- path to be traversed
    , current --- [optional] element which should be traversed. Default element is the root element of the DOM_Object
    )
    local function traverse_path(path_elements, current, t)
      local t = t or {}
      if #path_elements == 0 then 
        -- for _, x in ipairs(current._children or {}) do
          -- table.insert(t,x)
        -- end
        table.insert(t,current)
        return t
      end
      local current_path = table.remove(path_elements, 1)
      for _, x in ipairs(self:get_children(current)) do
        if self:is_element(x) then
          local name = string.lower(self:get_element_name(x))
          if name == current_path then
            t = traverse_path(path_elements, x, t)
          end
        end
      end
      return t
    end
    local current = current or self:root_node() -- self._handler.root
    local path_elements = {}
    local path = string.lower(path)
    for el in path:gmatch("([^%s]+)") do table.insert(path_elements, el) end
    return traverse_path(path_elements, current)
  end

  --- Select elements chidlren using CSS selector syntax
  -- @return table with elements matching the selector.
  function DOM_Object:query_selector(
    selector --- String using the CSS selector syntax
    )
    local css_query = self.css_query
    local css_parts = css_query:prepare_selector(selector)
    return css_query:get_selector_path(self, css_parts)
  end

  --- Get table with children of the current element
  -- @return table with children of the selected element
  function DOM_Object:get_children(
    el --- [optional] element to be selected
    )
    local el  = el or self
    local children = el._children or {}
    return children
  end

  --- Get the parent element
  -- @return DOM_Object parent element
  function DOM_Object:get_parent( 
    el --- [optional] element to be selected
    )
    local el = el or self
    return el._parent
  end

  --- Execute function on the current element and all it's children elements.
  -- The traversing of child elements of a given node can be disabled when the executed
  -- function returns false.
  -- @return nothing
  function DOM_Object:traverse_elements(
    fn, --- function which will be executed on the current element and all it's children
    current --- [optional] element to be selected
    )
    local current = current or self --
    -- Following situation may happen when this method is called directly on the parsed object
    if not current:get_node_type() then
      current = self:root_node() 
    end
    local status = true
    if self:is_element(current) or self:get_node_type(current) == "ROOT"then
      local status = fn(current)
      -- don't traverse child nodes when the user function return false
      if status ~= false then
        for _, child in ipairs(self:get_children(current)) do
          self:traverse_elements(fn, child)
        end
      end
    end
  end

  --- Execute function on list of elements returned by DOM_Object:get_path()
  function DOM_Object:traverse_node_list( 
    nodelist --- table with nodes selected by DOM_Object:get_path()
    , fn --- function to be executed
    )
    local nodelist = nodelist or {}
    for _, node in ipairs(nodelist) do
      for _, element in ipairs(node._children) do
        fn(element)
      end
    end
  end

  --- Replace the current node with new one
  -- @return boolean, message
  function DOM_Object:replace_node(
     new --- element which should replace the current element
    )
    local old = self
    local parent = self:get_parent(old)
    local id,msg = self:find_element_pos( old)
    if id then
      parent._children[id] = new
      return true
    end
    return false, msg
  end

  --- Add child node to the current node
  function DOM_Object:add_child_node( 
    child, --- element to be inserted as a current node child
    position --- [optional] position at which should the node be inserted
    )
    local parent = self
    child._parent = parent
    if position then
      table.insert(parent._children, position, child)
    else
      table.insert(parent._children, child)
    end
  end


  --- Create copy of the current node
  -- @return DOM_Object element
  function DOM_Object:copy_node( 
    element --- [optional] element to be copied
    )
    local element = element or self
    local t = {}
    for k, v in pairs(element) do
      if type(v) == "table" and k~="_parent" then
        t[k] = self:copy_node(v)
      else
        t[k] = v
      end
    end
    save_methods(t)
    return t
  end


  --- Create a new element
  -- @return DOM_Object element
  function DOM_Object:create_element(
    name, -- New tag name
    attributes, -- Table with attributes
    parent -- [optional] element which should be saved as the element's parent
    )
    local parent = parent or self
    local new = {}
    new._type = "ELEMENT"
    new._name = name
    new._attr = attributes or {}
    new._children = {}
    new._parent = parent
    save_methods(new)
    return new
  end

  --- Create new text node
  -- @return DOM_Object text object
  function DOM_Object:create_text_node( 
    text, -- string
    parent -- [optional] element which should be saved as the element's parent
    )
    local parent = parent or self
    local new = {}
    new._type = "TEXT"
    new._parent = parent
    new._text = text
    save_methods(new)
    return new
  end

  --- Delete current node
  function DOM_Object:remove_node(
    element -- [optional] element to be removed
    )
    local element = element or self
    local parent = self:get_parent(element)
    local pos = self:find_element_pos(element)
    -- if pos then table.remove(parent._children, pos) end
    if pos then 
      -- table.remove(parent._children, pos) 
      parent._children[pos] = setmetatable({_type = "removed"}, DOM_Object)
    end
  end

  --- Find the element position in the current node list
  -- @return integer position of the current element in the element table
  function DOM_Object:find_element_pos(
    el -- [optional] element which should be looked up
    )
    local el = el or self
    local parent = self:get_parent(el)
    if not self:is_element(parent) and self:get_node_type(parent) ~= "ROOT" then return nil, "The parent isn't element" end
    for i, x in ipairs(parent._children) do
      if x == el then return i end
    end
    return false, "Cannot find element"
  end

  --- Get node list which current node is part of
  -- @return table with elements
  function DOM_Object:get_siblings(
    el -- [optional] element for which the sibling element list should be retrieved
    )
    local el = el or self
    local parent = el:get_parent()
    if parent:is_element() then
      return parent:get_children()
    end
  end

  --- Get sibling node of the current node
  -- @param change Distance from the current node
  -- @return DOM_Object node
  function DOM_Object:get_sibling_node( change)
    local el = self
    local pos = el:find_element_pos()
    local siblings = el:get_siblings()
    if pos and siblings then
      return siblings[pos + change]
    end
  end

  --- Get next node
  -- @return DOM_Object node
  function DOM_Object:get_next_node(
    el --- [optional] node to be used
    )
    local el = el or self
    return el:get_sibling_node(1)
  end

  --- Get previous node
  -- @return DOM_Object node
  function DOM_Object:get_prev_node(
    el -- [optional] node to be used
    )
    local el = el or self
    return el:get_sibling_node(-1)
  end


  -- include the methods to all xml nodes
  save_methods(parser._handler.root)
  -- parser:
  return parser
end

--- @export
return {
  parse = parse, 
  serialize_dom= serialize_dom
}