使用jquery-week-calendar报错：Cannot read property 'classes' of undefined

Hey there, let's tackle this error you're hitting while using jquery-week-calendar with your set of jQuery plugins. Here are the most likely causes and fixes to try out:

1. Version Incompatibility Between jQuery UI and jquery-week-calendar-ui #

You're using jquery-ui: 1.12.1 alongside jquery-week-calendar-ui: latest—the latest version of the week calendar UI component might rely on changes in newer jQuery UI versions that aren't present in 1.12.1. The classes property it's trying to access probably got moved or restructured in newer jQuery UI releases, or the latest week calendar expects a different setup from the 1.12.1 UI.

Fixes: #

• Downgrade jquery-week-calendar-ui: Look for a version of the week calendar UI that explicitly states compatibility with jQuery UI 1.x (like the 0.9.x stable releases, which are known to work well with older jQuery UI versions).
• Upgrade jQuery UI: If possible, bump jQuery UI to a more recent stable version (just make sure to test all your other plugins—like jquery-steps, jquery-mousewheel, etc.—to ensure they play nice with the newer UI version).

2. Missing or Malformed Initialization Configuration #

The jquery-week-calendar requires a proper configuration object when initializing. If your config is missing critical classes-related properties, or you're referencing an undefined config object, this error can pop up.

Fixes: #

• Double-check your calendar initialization code to ensure it includes the necessary classes setup. For example:

$('#your-calendar-element').weekCalendar({
  classes: {
    calendar: 'wc-calendar',
    header: 'wc-header',
    event: 'wc-event',
    // Add other required class mappings here
  },
  // Include your other calendar settings below
});

• If you're extending a default config, make sure that default config is being loaded correctly and hasn't been overwritten by another script.

3. Incorrect Script Loading Order #

If jquery-week-calendar-ui loads before jquery-ui, it won't be able to access the jQuery UI objects it depends on—leading to that undefined error when it tries to read classes.

Fixes: #

• Load your scripts in this strict order:
  • jquery: 3.1.1 (always first!)
  • jquery-ui: 1.12.1 (make sure you're loading all core components like widget, mouse, etc.—the week calendar relies on these)
  • All other jQuery plugins (jquery-mousewheel, jquery-typeahead, jquery-mask-plugin, etc.)
  • jquery-week-calendar-ui
  • Your custom initialization script

Bonus Troubleshooting Step #

Open your browser's DevTools > Sources tab, jump to the error line (scripts.bundle.js:12672:11129), and check exactly which object is missing the classes property. This will give you a more precise idea of whether it's a UI component, a config object, or something else causing the issue.

内容的提问来源于stack exchange，提问作者DarioTecchia