How to get text within td element from remote webpage via PHP - php

Question

I have a temperature monitor set up, and I would like to use some of the data for other things (cron jobs, etc). The data from the sensor can be accessed from our local network (192.168.123.123). The element in question is:
<td id="1E5410ECC9D90FC3-entity-0-measurement-0" class="">69.08</td>
<!-- I NEED THE 69.08 -->
I can't do it via ajax since I get the Allow-Access-Origin error (CORS).
I tried this:
$url = 'http://192.168.123.123';
$content = file_get_contents($url);
$first = explode( '<div id="1E5410ECC9D90FC3-entity-0-measurement-0">' , $content );
$second = explode("</div>" , $first[0] );
echo $second[0];
but I got this:
��UMS�0��+��$���94С�2����؋-�%#Ʉ�뻲���Bۓ%����ݷr��m4�yyF*_+ry���ӈP������S��|��&�ȵ�2���}��V�7ǜO��dz�[�� (�!�_2��$�/�p/ g�=B� D����<��1�#�=h���J�˨�'��I^ ��g7��=�=��^�0��ϔ����p�Q��L��I�%TF�Q�) ������;c��o$��a����g��mWr�ܹ��;�(��bE��O�i� ��y�҉)f=�6=�,2� �#I��s����>����kNƕt/W2^��# Xp�3^݅$ѵ��T U�ʲ�#f��db�ԁ%��b�`G|��D�{񠐏sι1�� ]#2ZH�(1;&�h8��^0er��3���D�Q�5B�u� ^!5X:�{a U\:߰0�~Ɍ�3+S�^1��qB:�g����C>�.�P~n��$\֢D����%J+�b�ELc�Gq���K �]��xV��j�[���Ԧ��nAɍ��<�ZT#���zc�Q(f܁�(~�^�ZKwk:8�·n>��(=�"aB)�Fl5�b]/�_�$���_��ɴ��9�H}��B [#�V�ԅp��r�g�A�j���2����Ju*������{�bY�,O4�����M��B�#�e���,� ��_֔���o����
How can I properly get the 'td' text within the specific div id?

Answer 1

You are trying to retrieve data from <td id="1E5410ECC9D90FC3-entity-0-measurement-0" class=""> not <div id="1E5410ECC9D90FC3-entity-0-measurement-0">, so not from a <div>, so just change it into:
$url = 'http://192.168.123.123';
$content = file_get_contents($url);
$first = explode( '<td id="1E5410ECC9D90FC3-entity-0-measurement-0">' , $content );
$second = explode("</td>" , $first[0] );
echo $second[0];
Or am I crazy?

Answer 2

Step 1:
I suggest using php's curl library to manage and configure your web request/response.
Using this mechanism allows you to better manage/control encoding, compression and encryption.
http://php.net/manual/en/book.curl.php
// create curl resource
$ch = curl_init();
// set url
curl_setopt($ch, CURLOPT_URL, "http://192.168.123.123");
//return the transfer as a string
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
// $output contains the output string
$output = curl_exec($ch);
// close curl resource to free up system resources
curl_close($ch);
Step 2:
Let's extract the details out of the returned response string from the web server. I suggest PHP's PCRE function preg_match to extract the needed data.
http://php.net/manual/en/ref.pcre.php
// Looking for <td id="1E5410ECC9D90FC3-entity-0-measurement-0" class="">69.08</td>
$pattern = '/id="1E5410ECC9D90FC3-entity-0-measurement-0".*>([\d]{1,2}?\.[\d]{1,2})<\//';
// run the regex match and collect the hit
preg_match($pattern, $output, $matches);
// print_r of the array
/*
Array
(
[0] => id="1E5410ECC9D90FC3-entity-0-measurement-0" class="">69.08</
[1] => 69.08
)
*/
// Print out the result to check
echo $matches[1];