File

util/template.lua @ 12580:a9dbf657c894 0.12

util.datamapper: Improve handling of schemas with non-obvious "type" The JSON Schema specification says that schemas are objects or booleans, and that the 'type' property is optional and can be an array. This module previously allowed bare type names as schemas and did not really handle booleans. It now handles missing 'type' properties and boolean 'true' as a schema. Objects and arrays are guessed based on the presence of 'properties' or 'items' field.
author Kim Alvefur <zash@zash.se>
date Fri, 08 Jul 2022 17:32:48 +0200
parent 8555:4f0f5b49bb03
child 12975:d10957394a3c
line wrap: on
line source

-- luacheck: ignore 213/i
local stanza_mt = require "util.stanza".stanza_mt;
local setmetatable = setmetatable;
local pairs = pairs;
local ipairs = ipairs;
local error = error;
local envload = require "util.envload".envload;
local debug = debug;
local t_remove = table.remove;
local parse_xml = require "util.xml".parse;

local _ENV = nil;
-- luacheck: std none

local function trim_xml(stanza)
	for i=#stanza,1,-1 do
		local child = stanza[i];
		if child.name then
			trim_xml(child);
		else
			child = child:gsub("^%s*", ""):gsub("%s*$", "");
			stanza[i] = child;
			if child == "" then t_remove(stanza, i); end
		end
	end
end

local function create_string_string(str)
	str = ("%q"):format(str);
	str = str:gsub("{([^}]*)}", function(s)
		return '"..(data["'..s..'"]or"").."';
	end);
	return str;
end
local function create_attr_string(attr, xmlns)
	local str = '{';
	for name,value in pairs(attr) do
		if name ~= "xmlns" or value ~= xmlns then
			str = str..("[%q]=%s;"):format(name, create_string_string(value));
		end
	end
	return str..'}';
end
local function create_clone_string(stanza, lookup, xmlns)
	if not lookup[stanza] then
		local s = ('setmetatable({name=%q,attr=%s,tags={'):format(stanza.name, create_attr_string(stanza.attr, xmlns));
		-- add tags
		for i,tag in ipairs(stanza.tags) do
			s = s..create_clone_string(tag, lookup, stanza.attr.xmlns)..";";
		end
		s = s..'};';
		-- add children
		for i,child in ipairs(stanza) do
			if child.name then
				s = s..create_clone_string(child, lookup, stanza.attr.xmlns)..";";
			else
				s = s..create_string_string(child)..";"
			end
		end
		s = s..'}, stanza_mt)';
		s = s:gsub('%.%.""', ""):gsub('([=;])""%.%.', "%1"):gsub(';"";', ";"); -- strip empty strings
		local n = #lookup + 1;
		lookup[n] = s;
		lookup[stanza] = "_"..n;
	end
	return lookup[stanza];
end
local function create_cloner(stanza, chunkname)
	local lookup = {};
	local name = create_clone_string(stanza, lookup, "");
	local src = "local setmetatable,stanza_mt=...;return function(data)";
	for i=1,#lookup do
		src = src.."local _"..i.."="..lookup[i]..";";
	end
	src = src.."return "..name..";end";
	local f,err = envload(src, chunkname);
	if not f then error(err); end
	return f(setmetatable, stanza_mt);
end

local template_mt = { __tostring = function(t) return t.name end };
local function create_template(templates, text)
	local stanza, err = parse_xml(text);
	if not stanza then error(err); end
	trim_xml(stanza);

	local info = debug.getinfo(3, "Sl");
	info = info and ("template(%s:%d)"):format(info.short_src:match("[^\\/]*$"), info.currentline) or "template(unknown)";

	local template = setmetatable({ apply = create_cloner(stanza, info), name = info, text = text }, template_mt);
	templates[text] = template;
	return template;
end

local templates = setmetatable({}, { __mode = 'k', __index = create_template });
return function(text)
	return templates[text];
end;