Everyone knows that having broken links on your website negatively affects your SEO rankings. Checking all entries manually can take a significant amount of time, given that periodic checks are also required. Starting from version 1.0.4 of phpListings, we've decided to automate the link checking process by adding a built-in link checking tool, which periodically checks active listing website links, identifies broken ones, and warns the site administrator or the owner of the listing about the problem. Knowing about the specific requests of some directory websites that use phpListings, we have added many configuration settings to fine-tune the checker.
By default, the link checking tool is disabled and websites are checked only syntactically on listing submission or update. To enable the automatic link checking system you need to visit the Administrator Panel - Settings - Settings - Other - Broken Link Checker and enable the "Enable Periodic Checker" option. On the same page, you can specify the frequency of checks in days ("Days Between Checks" option, initially 7, that is, once a week), the delay in hours between rechecking of a link that was identified as broken ("Hours Between Retries on Failure" option, initially set to 6 hours) and the maximum number of attempts between these rechecks ("Maximum Number of Retries" option, that is set to 8 by default).
The algorithm of the checker is quite simple. With a frequency of 7 days (configurable option), the tool visits the site of each active listing and, depending on the returned error code, decides on the link status. The site is considered to be active if, when trying to visit the link, the server returned an error code in the range of 1 to 399. In any other situation, the site is considered to be broken and the system starts periodic checking of this website every 6 hours (configurable option) to make sure that the site is really broken. The maximum number of these checks is initially set to 8 (configurable option) and when this number of checks is reached, the system can be set to delete the listing website automatically or just stop any further attempts waiting for the administrator to fix or remove the link. It is also possible to send an email notification to the administrator and (or) the owner of the listing after a definite unsuccessful checking attempt.
Check results are available under the Administrator panel - Content - Listing Type - Broken Website Links, separate for each listing type. On this page you can find all listings with the link identified as broken, the current number of re-validation attempts for every listing, the date of the last verification, and the error code returned by the server. You, as the administrator user, can correct the listing website link or remove it.
It should be noted that this checker only works with the "Website" built-in listing form field and is not suitable for custom form fields of the "Website" type.
Websites protected by the Cloudflare service cannot be verified in most cases and will appear as broken. The IP address of your server must be whitelisted in the site's Cloudflare settings panel for the verification process to be successful.