Broken Link Detector 4
The Broken Link Detector plugin identifies and, where possible, fixes broken links in both content and metadata. Key features include:
- Probing both internal and external URLs stored in content and metadata to verify their validity.
 - Generating a list of broken links, viewable by editors in the admin panel.
 - Allowing administrators to create a blacklist of domains that should be excluded from the link-checking process.
 - Displaying a warning (via a tooltip) for images that cannot be fetched from blacklisted external domains.
 
Admin UI
This plugin adds two admin menu options:
Tools > Broken links summary
This page presents a summary of all links that was found to be broken in the last classification. This page is avabile for users that can edit posts.
Settings > Broken links settings
This page gives an administrator the ability to configure the plugin. A whitelist of domains is provided, and the ability to enable context detection feature.
Cron actions
This plugin does not utilize the built on WordPress cron functionality. We instead recommend to setup the cli actions in the native unix crons.
Cli documentation
Broken link detector does not rely on scheduled actions due to its resource intensive nature. Instead a set of cli actions is provided to maintain the link registry.
Cli commands
All broken links cli commands are placed under broken-link-detector prefix. To get a up to date index of all options please use the following command:
                      wp broken-link-detector --info
                    
Install, Uninstall & Reinstall
This command allows you to install, reinstall or uninstall the database table required for broken link registry.
                      wp broken-link-detector database --[install, uninstall, reinstall]
                    
Find links
This command will scan your sites content and meta data for links, and register them in the link registry. The links will not show up in the summary, util they have been classified as broken. The flags in this command is optional, and will default to true.
                      wp broken-link-detector find-links --meta=true --content=true
                    
Classify Links
This command will asses and classify each found link to check if the link is valid or not. This is a resource intensive action, therefore a limit can be applied to classify a subset of links. This function utilizes the confuration value in recheckInterval, to prevent calls to frequent of external services.
                      wp broken-link-detector classify-links --limit=[NUMBER]
                    
Filter Documentation
                      This document provides an overview of the available filters within the BrokenLinkDetector\Config class. All filters are prefixed with BrokenLinkDetector/Config.
                    
Filters
                      BrokenLinkDetector/Config/getDatabaseVersionKey
                    
                    
                      Description:
                      Filter the key used for the database version.
                    
                      Default Value:
                      'broken_link_detector_db_version'
                    
                      BrokenLinkDetector/Config/getDatabaseVersion
                    
                    
                      Description:
                      Filter the current database version from the options table.
                    
                      Default Value:
                      '2.0.0'
                    
                      BrokenLinkDetector/Config/getTableName
                    
                    
                      Description:
                      Filter the name of the table that stores broken links.
                    
                      Default Value:
                      'broken_links_detector'
                    
                      BrokenLinkDetector/Config/getPluginUrl
                    
                    
                      Description:
                      Filter the plugin URL.
                    
                      Default Value:
                      The value provided during object construction for pluginUrl.
                    
                      BrokenLinkDetector/Config/getPluginPath
                    
                    
                      Description:
                      Filter the plugin path.
                    
                      Default Value:
                      The value provided during object construction for pluginPath.
                    
                      BrokenLinkDetector/Config/getPluginFieldsPath
                    
                    
                      Description:
                      Filter the path where fields are located.
                    
                      Default Value:
                      The plugin path appended with source/fields.
                    
                      BrokenLinkDetector/Config/getTextDomain
                    
                    
                      Description:
                      Filter the text domain.
                    
                      Default Value:
                      'broken-link-detector'
                    
                      BrokenLinkDetector/Config/linkUpdaterBannedPostTypes
                    
                    
                      Description:
                      Filter the post types where link repair (link updater) should not run.
                    
                      Default Value:
                      ['attachment', 'revision', 'acf', 'acf-field', 'acf-field-group']
                    
                      BrokenLinkDetector/Config/linkDetectBannedPostTypes
                    
                    
                      Description:
                      Filter the post types that should not be checked for broken links.
                    
                      Default Value:
                      ['attachment', 'revision', 'acf', 'acf-field', 'acf-field-group']
                    
                      BrokenLinkDetector/Config/linkDetectAllowedPostStatuses
                    
                    
                      Description:
                      Filter the post types that should not be checked for broken links based on status.
                    
                      Default Value:
                      ['publish', 'private', 'password']
                    
                      BrokenLinkDetector/Config/responseCodesConsideredBroken
                    
                    
                      Description:
                      Filter the response codes that are considered broken.
                    
                      Default Value:
                      [400, 403, 404, 410, 500, 502, 503, 504]
                    
                      BrokenLinkDetector/Config/checkIfDnsRespondsBeforeProbingUrl
                    
                    
                      Description:
                      Filter to determine if DNS should respond before probing the URL.
                    
                      Default Value:
                      true
                    
                      BrokenLinkDetector/Config/getMaxRedirects
                    
                    
                      Description:
                      Filter the number of redirects to follow.
                    
                      Default Value:
                      5
                    
                      BrokenLinkDetector/Config/getTimeout
                    
                    
                      Description:
                      Filter the timeout for the request.
                    
                      Default Value:
                      5
                    
                      BrokenLinkDetector/Config/getRecheckInterval
                    
                    
                      Description:
                      Filter the interval for rechecking broken links in minutes.
                    
                      Default Value:
                      720
                    
                      BrokenLinkDetector/Config/getDomainsThatShouldNotBeChecked
                    
                    
                      Description:
                      Filter the domains that should not be checked for broken links. These will be registered, but always return null.
                    
                      Default Value:
                      An empty array if no domains are set in ACF fields.
                    
                      BrokenLinkDetector/Config/isContextCheckEnabled
                    
                    
                      Description:
                      Filter to enable/disable context check based on configuration and URL.
                    
                      Default Value:
                      false
                    
                      BrokenLinkDetector/Config/getContextCheckUrl
                    
                    
                      Description:
                      Filter the URL to probe for the context check.
                    
                      Default Value:
                      The value from the ACF field or an empty string if not set.
                    
                      BrokenLinkDetector/Config/getContextCheckTimeout
                    
                    
                      Description:
                      Filter the timeout in milliseconds for the context check.
                    
                      Default Value:
                      3000
                    
                      BrokenLinkDetector/Config/getContextCheckDomainsToDisable
                    
                    
                      Description:
                      Filter the domains that should be disabled when the context check fails.
                    
                      Default Value:
                      The domains retrieved by the getDomainsThatShouldNotBeChecked method.
                    
                      BrokenLinkDetector/Config/getContextCheckSuccessClass
                    
                    
                      Description:
                      Filter the class to be applied for a successful context check.
                    
                      Default Value:
                      'context-check-avabile'
                    
                      BrokenLinkDetector/Config/getContextCheckFailedClass
                    
                    
                      Description:
                      Filter the class to be applied for a failed context check.
                    
                      Default Value:
                      'context-check-unavabile'
                    
                      BrokenLinkDetector/Config/getContextCheckTooltipText
                    
                    
                      Description:
                      Filter the tooltip text for a disabled link due to context failure.
                    
                      Default Value:
                      The value from the ACF field or 'Link unavabile' if not set.
                    
                      BrokenLinkDetector/Config/getCommandNamespace
                    
                    
                      Description:
                      Filter the namespace for the WP CLI command.
                    
                      Default Value:
                      'broken-link-detector'
                    
Example Usage
To modify the filter for the database version key, you can use the following code in your plugin or theme:
add_filter('BrokenLinkDetector/Config/getDatabaseVersionKey', function($versionKey) {
    return 'custom_version_key';
});