aboutsummaryrefslogtreecommitdiffstats
path: root/teal-src/util/datamapper.tl
blob: 23f5ecaaa338d21f3cd6b6efd88a24e70ac00130 (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
-- Copyright (C) 2021 Kim Alvefur
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
-- Based on
-- https://json-schema.org/draft/2020-12/json-schema-core.html
-- https://json-schema.org/draft/2020-12/json-schema-validation.html
-- http://spec.openapis.org/oas/v3.0.1#xmlObject
-- https://github.com/OAI/OpenAPI-Specification/issues/630 (text:true)
--
-- XML Object Extensions:
-- text to refer to the text content at the same time as attributes
-- x_name_is_value for enum fields where the <tag-name/> is the value
-- x_single_attribute for <tag attr="this"/>
--
-- TODO pointers
-- TODO cleanup / refactor
-- TODO s/number/integer/ once we have appropriate math.type() compat
--

local st = require "util.stanza";
local json = require"util.json"
local pointer = require"util.jsonpointer";

local json_type_name = json.json_type_name;
local json_schema_object = require "util.jsonschema"
local type schema_t = boolean | json_schema_object

local function toboolean ( s : string ) : boolean
	if s == "true" or s == "1" then
		return true
	elseif s == "false" or s == "0" then
		return false
	elseif s then
		return true
	end
end

local function totype(t : json_type_name, s : string) : any
	if not s then return nil end
	if t == "string" then
		return s;
	elseif t == "boolean" then
		return toboolean(s)
	elseif t == "number" or t == "integer" then
		return tonumber(s)
	end
end

local enum value_goes
	"in_tag_name"
	"in_text"
	"in_text_tag"
	"in_attribute"
	"in_single_attribute"
	"in_children"
	"in_wrapper"
end

local function resolve_schema(schema  : schema_t, root : json_schema_object) : schema_t
	if schema is json_schema_object then
		if schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then
			return pointer.resolve(root as table, schema["$ref"]:sub(2)) as schema_t;
		end
	end
	return schema;
end

local function guess_schema_type(schema : json_schema_object) : json_type_name
	local schema_types = schema.type
	if schema_types is json_type_name then
		return schema_types
	elseif schema_types ~= nil then
		error "schema has unsupported 'type' property"
	elseif schema.properties then
		return "object"
	elseif schema.items then
		return "array"
	end
	return "string" -- default assumption
end

local function unpack_propschema( propschema : schema_t, propname : string, current_ns : string )
		: json_type_name, value_goes, string, string, string, string, { any }
	local proptype : json_type_name = "string"
	local value_where : value_goes = propname and "in_text_tag" or "in_text"
	local name = propname
	local namespace : string
	local prefix : string
	local single_attribute : string
	local enums : { any }

	if propschema is json_schema_object then
		proptype = guess_schema_type(propschema);
	elseif propschema is string then -- Teal says this can never be a string, but it could before so best be sure
		error("schema as string is not supported: "..propschema.." {"..current_ns.."}"..propname)
	end

	if proptype == "object" or proptype == "array" then
		value_where = "in_children"
	end

	if propschema is json_schema_object then
		local xml = propschema.xml
		if xml then
			if xml.name then
				name = xml.name
			end
			if xml.namespace and xml.namespace ~= current_ns then
				namespace = xml.namespace
			end
			if xml.prefix then
				prefix = xml.prefix
			end
			if proptype == "array" and xml.wrapped then
				value_where = "in_wrapper"
			elseif xml.attribute then
				value_where = "in_attribute"
			elseif xml.text then
				value_where = "in_text"
			elseif xml.x_name_is_value then
				value_where = "in_tag_name"
			elseif xml.x_single_attribute then
				single_attribute = xml.x_single_attribute
				value_where = "in_single_attribute"
			end
		end
		if propschema["const"] then
			enums = { propschema["const"] }
		elseif propschema["enum"] then
			enums = propschema["enum"]
		end
	end

	return proptype, value_where, name, namespace, prefix, single_attribute, enums
end

local parse_object : function (schema : schema_t, s : st.stanza_t, root : json_schema_object) : { string : any }
local parse_array : function (schema : schema_t, s : st.stanza_t, root : json_schema_object) : { any }

local function extract_value (s : st.stanza_t, value_where : value_goes, proptype : json.json_type_name, name : string, namespace : string, prefix : string, single_attribute : string, enums : { any }) : string
	if value_where == "in_tag_name" then
		local c : st.stanza_t
		if proptype == "boolean" then
			c = s:get_child(name, namespace);
		elseif enums and proptype == "string" then
			-- XXX O(n²) ?
			-- Probably better to flip the table and loop over :childtags(nil, ns), should be 2xO(n)
			-- BUT works first, optimize later
			for i = 1, #enums do
				c = s:get_child(enums[i] as string, namespace);
				if c then break end
			end
		else
			c = s:get_child(nil, namespace);
		end
		if c then
			return c.name;
		end
	elseif value_where == "in_attribute" then
		local attr = name
		if prefix then
			attr = prefix .. ':' .. name
		elseif namespace and namespace ~= s.attr.xmlns then
			attr = namespace .. "\1" .. name
		end
		return s.attr[attr]

	elseif value_where == "in_text" then
		return s:get_text()

	elseif value_where == "in_single_attribute" then
		local c = s:get_child(name, namespace)
		return c and c.attr[single_attribute]
	elseif value_where == "in_text_tag" then
		return s:get_child_text(name, namespace)
	end
end

function parse_object (schema : schema_t, s : st.stanza_t, root : json_schema_object) : { string : any }
	local out : { string : any } = {}
	schema = resolve_schema(schema, root)
	if schema is json_schema_object and schema.properties then
		for prop, propschema in pairs(schema.properties) do
			propschema = resolve_schema(propschema, root)

			local proptype, value_where, name, namespace, prefix, single_attribute, enums = unpack_propschema(propschema, prop, s.attr.xmlns)

			if value_where == "in_children" and propschema is json_schema_object then
				if proptype == "object" then
					local c = s:get_child(name, namespace)
					if c then
						out[prop] = parse_object(propschema, c, root);
					end
				elseif proptype == "array" then
					local a = parse_array(propschema, s, root);
					if a and a[1] ~= nil then
						out[prop] = a;
					end
				else
					error "unreachable"
				end
			elseif value_where == "in_wrapper" and propschema is json_schema_object and proptype == "array" then
				local wrapper = s:get_child(name, namespace);
				if wrapper then
					out[prop] = parse_array(propschema, wrapper, root);
				end
			else
				local value : string = extract_value (s, value_where, proptype, name, namespace, prefix, single_attribute, enums)

				out[prop] = totype(proptype, value)
			end
		end
	end

	return out
end

function parse_array (schema : json_schema_object, s : st.stanza_t, root : json_schema_object) : { any }
	local itemschema : schema_t = resolve_schema(schema.items, root);
	local proptype, value_where, child_name, namespace, prefix, single_attribute, enums = unpack_propschema(itemschema, nil, s.attr.xmlns)
	local attr_name : string
	if value_where == "in_single_attribute" then -- FIXME this shouldn't be needed
		value_where = "in_attribute";
		attr_name = single_attribute;
	end
	local out : { any } = {}

	if proptype == "object" then
		if itemschema is json_schema_object then
			for c in s:childtags(child_name, namespace) do
				table.insert(out, parse_object(itemschema, c, root));
			end
		else
			error "array items must be schema object"
		end
	elseif proptype == "array" then
		if itemschema is json_schema_object then
			for c in s:childtags(child_name, namespace) do
				table.insert(out, parse_array(itemschema, c, root));
			end
		end
	else
		for c in s:childtags(child_name, namespace) do
			local value : string = extract_value (c, value_where, proptype, attr_name or child_name, namespace, prefix, single_attribute, enums)

			table.insert(out, totype(proptype, value));
		end
	end
	return out;
end

local function parse (schema : json_schema_object, s : st.stanza_t) : table
	local s_type = guess_schema_type(schema)
	if s_type == "object" then
		return parse_object(schema, s, schema)
	elseif s_type == "array" then
		return parse_array(schema, s, schema)
	else
		error "top-level scalars unsupported"
	end
end

local function toxmlstring(proptype : json_type_name, v : any) : string
	if proptype == "string" and v is string then
		return  v
	elseif proptype == "number" and v is number then
		return  string.format("%g", v)
	elseif proptype == "integer" and v is number then -- TODO is integer
		return  string.format("%d", v)
	elseif proptype == "boolean" then
		return  v and "1" or "0"
	end
end

local unparse : function (json_schema_object, table, string, string, st.stanza_t, json_schema_object) : st.stanza_t

local function unparse_property(out : st.stanza_t, v : any, proptype : json_type_name, propschema : schema_t, value_where : value_goes, name : string, namespace : string, current_ns : string, prefix : string, single_attribute : string, root : json_schema_object)

	if value_where == "in_attribute" then
		local attr = name
		if prefix then
			attr = prefix .. ':' .. name
		elseif namespace and namespace ~= current_ns then
			attr = namespace .. "\1" .. name
		end

		out.attr[attr] = toxmlstring(proptype, v)
	elseif value_where == "in_text" then
		out:text(toxmlstring(proptype, v))
	elseif value_where == "in_single_attribute" then
		assert(single_attribute)
		local propattr : { string : string } = {}

		if namespace and namespace ~= current_ns then
			propattr.xmlns = namespace
		end

		propattr[single_attribute] = toxmlstring(proptype, v)
		out:tag(name, propattr):up();

	else
		local propattr : { string : string }
		if namespace ~= current_ns then
			propattr = { xmlns = namespace }
		end
		if value_where == "in_tag_name" then
			if proptype == "string" and v is string then
				out:tag(v, propattr):up();
			elseif proptype == "boolean" and v == true then
				out:tag(name, propattr):up();
			end
		elseif proptype == "object" and propschema is json_schema_object and v is table then
			local c = unparse(propschema, v, name, namespace, nil, root);
			if c then
				out:add_direct_child(c);
			end
		elseif proptype == "array" and propschema is json_schema_object and v is table then
			if value_where == "in_wrapper" then
				local c = unparse(propschema, v, name, namespace, nil, root);
				if c then
					out:add_direct_child(c);
				end
			else
				unparse(propschema, v, name, namespace, out, root);
			end
		else
			out:text_tag(name, toxmlstring(proptype, v), propattr)
		end
	end
end

function unparse ( schema : json_schema_object, t : table, current_name : string, current_ns : string, ctx : st.stanza_t, root : json_schema_object ) : st.stanza_t

	if root == nil then root = schema end

	if schema.xml then
		if schema.xml.name then
			current_name = schema.xml.name
		end
		if schema.xml.namespace then
			current_ns = schema.xml.namespace
		end
		-- TODO prefix?
	end

	local out = ctx or st.stanza(current_name, { xmlns = current_ns })

	local s_type = guess_schema_type(schema)
	if s_type == "object" then

		for prop, propschema in pairs(schema.properties) do
			propschema = resolve_schema(propschema, root)
			local v = t[prop]

			if v ~= nil then
				local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(propschema, prop, current_ns)
				unparse_property(out, v, proptype, propschema, value_where, name, namespace, current_ns, prefix, single_attribute, root)
			end
		end
		return out;

	elseif s_type == "array" then
		local itemschema = resolve_schema(schema.items, root)
		local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(itemschema, current_name, current_ns)
		for _, item in ipairs(t as { string }) do
			unparse_property(out, item, proptype, itemschema, value_where, name, namespace, current_ns, prefix, single_attribute, root)
		end
		return out;
	end
end

return {
	parse = parse,
	unparse = unparse,
}