How can openlayers tell if the point is online?

as mentioned in the question, how can openlayers tell if the point is online? I only found the judgment point whether it is in the noodle or not, but I didn"t find it whether it was on the line

.
Aug.23,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e46bd2-4cf78.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e46bd2-4cf78.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?