Parsing JSON using php jsonpath

I'm trying to parse a JSON in PHP using jsonpath ....

My JSON is coming from this

(it's quite too long to cut/paste here but you can see it in a browser session ....)

The JSON is a valid JSON (I've verified it using ... ).

I've tried the jsonpath expression using and all seems works fine, but when I put all in my PHP code sample below ....

<?php ini_set('display_errors', 'On'); error_reporting(E_ALL); require_once('json.php'); // JSON parser require_once('jsonpath-0.8.0.php'); // JSONPath evaluator $url = ' $ch = curl_init(); curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE); curl_setopt($ch, CURLOPT_HEADER, 0); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE); curl_setopt($ch, CURLOPT_PROXY, ''); $data = curl_exec($ch); curl_close($ch); $parser = new Services_JSON(SERVICES_JSON_LOOSE_TYPE); $o = $parser->decode($data); $xpath_for_parsing = '$..aziende[?(@.descrizione=="A.S.U.I. - Trieste")]..prontoSoccorsi[?(@.descrizione=="Pronto Soccorso e Terapia Urgenza Trieste")]..dipartimenti[?(@.descrizione=="Pronto Soccorso Maggiore")]..codiciColore[?(@.descrizione=="Bianco")]..situazionePazienti..numeroPazientiInAttesa'; $match1 = jsonPath($o, $xpath_for_parsing); //print_r($match1); $match1_encoded = $parser->encode($match1); print_r($match1_encoded); $match1_decoded = json_decode($match1_encoded); //print_r($match1_decoded); if ($match1_decoded[0] != '') { return $match1_decoded[0]; } else { return "N.D."; }
?>

... no values are printed .. only a "false" value.

Something goes wrong in my jsonpath expression when I put it in my PHP code: ths error that coming out is the follow

Warning: Missing argument 3 for JsonPath::evalx(), called in /var/www/html/OpenProntoSoccorso/Test/jsonpath-0.8.0.php on line 84 and defined in /var/www/html/OpenProntoSoccorso/Test/jsonpath-0.8.0.php on line 101
Notice: Use of undefined constant descrizione - assumed 'descrizione' in /var/www/html/OpenProntoSoccorso/Test/jsonpath-0.8.0.php(104) : eval()'d code on line 1

Probably I've to escape / quoting my jsonpath to use it in PHP but I don't know how ... any suggestion is appreciated ...

NOTE: I need to use jsonpath expressions like ?(@.descrizione=="A.S.U.I. - Trieste") and I can't use "positional" json path ...

I've also tried to use jsonpath-0.8.3.php coming from here , but nothing change ...

Suggestions?

Thank you in advance ...

5 Answers

I would suggest trying to use a different library for JsonPath, if the one you are working with has a bug and the 3rd party service states no error in query.

Here are a few:

• FlowCommunications/JSONPath
• Peekmo/JsonPath
• mtdowling/JmesPath

I am pretty sure there are more. Hope that helps.

you can use json_decode to convert it to a native php array, then you can use hhb_xml_encode ( from ) to convert the array to an xml, then you can use DOMDocument::loadHTML to convert the XML to a DOMDocument, then you can use DOMXPath::query to search through it with XPaths...

example:

<?php
declare(strict_types = 1);
header ( "content-type: text/plain;charset=utf8" );
require_once ('hhb_.inc.php');
$json_raw = (new hhb_curl ( '', true ))->exec ( ' )->getStdOut ();
$parsed = json_decode ( $json_raw, true );
// var_dump ( $parsed );
$xml = hhb_xml_encode ( $parsed );
// var_dump($xml);
$dom = @DOMDocument::loadHTML ( $xml );
$dom->formatOutput = true;
$xp = new DOMXPath ( $dom );
$elements_for_parsing = $xp->query ( '//aziende/descrizione[text()=' . xpath_quote ( 'A.S.U.I. - Trieste' ) . ']|//prontosoccorsi/descrizione[text()=' . xpath_quote ( 'Pronto Soccorso e Terapia Urgenza Trieste' ) . ']|//dipartimenti/descrizione[text()=' . xpath_quote ( 'Pronto Soccorso Maggiore' ) . ']|//codicicolore/descrizione[text()=' . xpath_quote ( 'Bianco' ) . ']|//situazionepazienti|//numeroPazientiInAttesa' );
// var_dump ( $elements_for_parsing,$dom->saveXML() );
foreach ( $elements_for_parsing as $ele ) { var_dump ( $ele->textContent );
}
// based on
function xpath_quote(string $value): string { if (false === strpos ( $value, '"' )) { return '"' . $value . '"'; } if (false === strpos ( $value, '\'' )) { return '\'' . $value . '\''; } // if the value contains both single and double quotes, construct an // expression that concatenates all non-double-quote substrings with // the quotes, e.g.: // // concat("'foo'", '"', "bar") $sb = 'concat('; $substrings = explode ( '"', $value ); for($i = 0; $i < count ( $substrings ); ++ $i) { $needComma = ($i > 0); if ($substrings [$i] !== '') { if ($i > 0) { $sb .= ', '; } $sb .= '"' . $substrings [$i] . '"'; $needComma = true; } if ($i < (count ( $substrings ) - 1)) { if ($needComma) { $sb .= ', '; } $sb .= "'\"'"; } } $sb .= ')'; return $sb;
}
function hhb_xml_encode(array $arr, string $name_for_numeric_keys = 'val'): string { if (empty ( $arr )) { // avoid having a special case for <root/> and <root></root> i guess return ''; } $is_iterable_compat = function ($v): bool { // php 7.0 compat for php7.1+'s is_itrable return is_array ( $v ) || ($v instanceof \Traversable); }; $isAssoc = function (array $arr): bool { // thanks to Mark Amery for this if (array () === $arr) return false; return array_keys ( $arr ) !== range ( 0, count ( $arr ) - 1 ); }; $endsWith = function (string $haystack, string $needle): bool { // thanks to MrHus $length = strlen ( $needle ); if ($length == 0) { return true; } return (substr ( $haystack, - $length ) === $needle); }; $formatXML = function (string $xml) use ($endsWith): string { // there seems to be a bug with formatOutput on DOMDocuments that have used importNode with $deep=true // on PHP 7.0.15... $domd = new DOMDocument ( '1.0', 'UTF-8' ); $domd->preserveWhiteSpace = false; $domd->formatOutput = true; $domd->loadXML ( '<root>' . $xml . '</root>' ); $ret = trim ( $domd->saveXML ( $domd->getElementsByTagName ( "root" )->item ( 0 ) ) ); assert ( 0 === strpos ( $ret, '<root>' ) ); assert ( $endsWith ( $ret, '</root>' ) ); $full = trim ( substr ( $ret, strlen ( '<root>' ), - strlen ( '</root>' ) ) ); $ret = ''; // ... seems each line except the first line starts with 2 ugly spaces, // presumably its the <root> element that starts with no spaces at all. foreach ( explode ( "\n", $full ) as $line ) { if (substr ( $line, 0, 2 ) === ' ') { $ret .= substr ( $line, 2 ) . "\n"; } else { $ret .= $line . "\n"; } } $ret = trim ( $ret ); return $ret; }; // $arr = new RecursiveArrayIterator ( $arr ); // $iterator = new RecursiveIteratorIterator ( $arr, RecursiveIteratorIterator::SELF_FIRST ); $iterator = $arr; $domd = new DOMDocument (); $root = $domd->createElement ( 'root' ); foreach ( $iterator as $key => $val ) { // var_dump ( $key, $val ); $ele = $domd->createElement ( is_int ( $key ) ? $name_for_numeric_keys : $key ); if (! empty ( $val ) || $val === '0') { if ($is_iterable_compat ( $val )) { $asoc = $isAssoc ( $val ); $tmp = hhb_xml_encode ( $val, is_int ( $key ) ? $name_for_numeric_keys : $key ); // var_dump ( $tmp ); // die (); $tmp = @DOMDocument::loadXML ( '<root>' . $tmp . '</root>' ); foreach ( $tmp->getElementsByTagName ( "root" )->item ( 0 )->childNodes ?? [ ] as $tmp2 ) { $tmp3 = $domd->importNode ( $tmp2, true ); if ($asoc) { $ele->appendChild ( $tmp3 ); } else { $root->appendChild ( $tmp3 ); } } unset ( $tmp, $tmp2, $tmp3 ); if (! $asoc) { // echo 'REMOVING';die(); // $ele->parentNode->removeChild($ele); continue; } } else { $ele->textContent = $val; } } $root->appendChild ( $ele ); } $domd->preserveWhiteSpace = false; $domd->formatOutput = true; $ret = trim ( $domd->saveXML ( $root ) ); assert ( 0 === strpos ( $ret, '<root>' ) ); assert ( $endsWith ( $ret, '</root>' ) ); $ret = trim ( substr ( $ret, strlen ( '<root>' ), - strlen ( '</root>' ) ) ); // seems to be a bug with formatOutput on DOMDocuments that have used importNode with $deep=true.. $ret = $formatXML ( $ret ); return $ret;
}

ps, the lines require_once ('hhb_.inc.php'); $json_raw = (new hhb_curl ( '', true ))->exec ( ' )->getStdOut (); are just fetching the url and putting the json in $json_raw (using gzip compressed transfer to speed things up btw), replace it with whatever you want to fetch it into $json_raw , the actual curl library i used is from

currently it prints:

string(18) "A.S.U.I. - Trieste"
string(41) "Pronto Soccorso e Terapia Urgenza Trieste"
string(9) "121200:14"
string(10) "181400:254"
string(6) "Bianco"
string(7) "200:292"
string(5) "00:00"
string(24) "Pronto Soccorso Maggiore"
string(7) "3300:15"
string(6) "Bianco"
string(8) "6200:584"
string(5) "00:00"
string(5) "00:00"
string(8) "4100:353"
string(6) "Bianco"
string(7) "100:051"
string(5) "00:00"
string(5) "00:00"
string(7) "1100:15"
string(8) "6402:012"
string(6) "Bianco"
string(7) "402:274"
string(5) "00:00"
string(9) "11900:202"
string(9) "11401:427"
string(6) "Bianco"
string(8) "2102:051"
string(5) "00:00"
string(7) "3300:08"
string(8) "7401:423"
string(6) "Bianco"
string(8) "8402:104"
string(5) "00:00"
string(6) "Bianco"
string(5) "00:00"
string(5) "00:00"
string(5) "00:00"
string(5) "00:00"
string(7) "1100:04"
string(10) "121000:512"
string(6) "Bianco"
string(8) "5400:461"
string(5) "00:00"
string(5) "00:00"
string(5) "00:00"
string(6) "Bianco"
string(5) "00:00"
string(5) "00:00"
string(9) "121200:18"
string(9) "11800:593"
string(6) "Bianco"
string(8) "6401:272"
string(5) "00:00"
string(6) "Bianco"
string(7) "1100:04"
string(5) "00:00"
string(5) "00:00"
string(5) "00:00"
string(7) "2200:05"
string(9) "10801:102"
string(6) "Bianco"
string(8) "8201:166"
string(5) "00:00"
string(8) "3200:071"
string(7) "100:261"
string(6) "Bianco"
string(5) "00:00"
string(5) "00:00"
string(7) "1100:00"
string(9) "151500:26"
string(10) "161301:123"
string(6) "Bianco"
string(8) "9500:434"
string(7) "1100:00"
string(7) "2200:13"
string(6) "Bianco"
string(7) "200:342"
string(5) "00:00"
string(6) "Bianco"
string(7) "1100:24"
string(5) "00:00"
string(5) "00:00"
string(5) "00:00"
string(7) "1100:04"
string(8) "9700:222"
string(10) "171500:582"
string(6) "Bianco"
string(7) "200:512"
string(7) "1100:40"
string(7) "1100:22"
string(6) "Bianco"
string(8) "3100:062"
string(5) "00:00"
string(5) "00:00"
string(5) "00:00"
string(6) "Bianco"
string(5) "00:00"
string(5) "00:00"
string(7) "1100:22"
string(8) "7500:302"
string(6) "Bianco"
string(5) "00:00"
string(5) "00:00"
string(7) "1100:06"
string(6) "Bianco"
string(7) "1100:00"
string(5) "00:00"
string(5) "00:00"

hope that's what you were looking for, i was guessing by the "xpath" you provided.

xpath is too complicated for your task and overkill in general...

just use the standard json_decode(), get the equivalent PHP object and navigate it using stardard for/while loops and regexes

Also I think your question is misleading, your problem is not parsing a JSON (that's done by json_decode() automatically), your problem is extracting some data from it using xpath.. I suggest to have a refactor of your question showing exactly what goes wrong and what's your intent

If you need to descent into a precise JSON node (or set of nodes), why you don't do it by means of for loops and regexes?

I've solved changing library implementation for JsonPath: now I use Skyscanner JsonPath implementation (ref. ).

Some troubles on installation (for me, I never used composer before ...), but the skyskanner team supported me (ref. ) and now I've this PHP code ....

<?php ini_set('display_errors', 'On'); error_reporting(E_ALL); include "./tmp/vendor/autoload.php"; $url = ' //#Set CURL parameters: pay attention to the PROXY config !!!! $ch = curl_init(); curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE); curl_setopt($ch, CURLOPT_HEADER, 0); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE); curl_setopt($ch, CURLOPT_PROXY, ''); $data = curl_exec($ch); curl_close($ch); $jsonObject = new JsonPath\JsonObject($data); $jsonPathExpr = "$..aziende[?(@.descrizione==\"A.S.U.I. - Trieste\")]..prontoSoccorsi[?(@.descrizione==\"Pronto Soccorso e Terapia Urgenza Trieste\")]..dipartimenti[?(@.descrizione==\"Pronto Soccorso Maggiore\")]..codiciColore[?(@.descrizione==\"Verde\")]..situazionePazienti..numeroPazientiInAttesa"; $r = $jsonObject->get($jsonPathExpr); //print json_encode($r); print json_encode($r[0]);
?>

in ./tmp I've what I obtain from composer

... that works fine and in this way I can do my json query, potentially, without knowing its exact structure

<?php // PRINT SI JSON ORIGINAL
define("DIRPATH", dirname($_SERVER["SCRIPT_FILENAME"]) . '/');
define("WEBPATH", ' . $_SERVER['SERVER_ADDR'] . dirname($_SERVER['PHP_SELF']) . '/');
//define("WEBPORT", ' . $_SERVER['SERVER_ADDR'] . ':' . $_SERVER['SERVER_PORT'] . dirname($_SERVER['PHP_SELF']) . '/');
//define("imgpath", DIRPATH . 'image/');
//$png = file_get_contents(');
$jsondata = file_get_contents(');
header("Content-type: application/ld+json; charset=utf-8");	$print = json_decode($jsondata);	print_r($print);
?>
<?php // PRINT ME KATEGORI
define("DIRPATH", dirname($_SERVER["SCRIPT_FILENAME"]) . '/');
define("WEBPATH", ' . $_SERVER['SERVER_ADDR'] . dirname($_SERVER['PHP_SELF']) . '/');
//define("WEBPORT", ' . $_SERVER['SERVER_ADDR'] . ':' . $_SERVER['SERVER_PORT'] . dirname($_SERVER['PHP_SELF']) . '/');
//define("imgpath", DIRPATH . 'image/');
//$png = file_get_contents(');
$jsondata = file_get_contents(');
header("Content-type: application/ld+json; charset=utf-8");	$print = json_decode($jsondata);	//print_r($print);	$items = '';	// KETU FILLON LISTA	foreach ($print->{'aziende'} as $item) {	$items .= '
' . $item->id . '
' . $item->descrizione . '
';
};
?>
<?php echo $items; ?>