tethys-feature-service/node_modules/proj4/lib/parseCode.js
2023-10-02 15:04:02 +02:00

63 lines
1.5 KiB
JavaScript

import defs from './defs';
import wkt from 'wkt-parser';
import projStr from './projString';
import match from './match';
function testObj(code){
return typeof code === 'string';
}
function testDef(code){
return code in defs;
}
var codeWords = ['PROJECTEDCRS', 'PROJCRS', 'GEOGCS','GEOCCS','PROJCS','LOCAL_CS', 'GEODCRS', 'GEODETICCRS', 'GEODETICDATUM', 'ENGCRS', 'ENGINEERINGCRS'];
function testWKT(code){
return codeWords.some(function (word) {
return code.indexOf(word) > -1;
});
}
var codes = ['3857', '900913', '3785', '102113'];
function checkMercator(item) {
var auth = match(item, 'authority');
if (!auth) {
return;
}
var code = match(auth, 'epsg');
return code && codes.indexOf(code) > -1;
}
function checkProjStr(item) {
var ext = match(item, 'extension');
if (!ext) {
return;
}
return match(ext, 'proj4');
}
function testProj(code){
return code[0] === '+';
}
function parse(code){
if (testObj(code)) {
//check to see if this is a WKT string
if (testDef(code)) {
return defs[code];
}
if (testWKT(code)) {
var out = wkt(code);
// test of spetial case, due to this being a very common and often malformed
if (checkMercator(out)) {
return defs['EPSG:3857'];
}
var maybeProjStr = checkProjStr(out);
if (maybeProjStr) {
return projStr(maybeProjStr);
}
return out;
}
if (testProj(code)) {
return projStr(code);
}
}else{
return code;
}
}
export default parse;