dianping/cat · error · Error

prompt requires a callback

Error message

prompt requires a callback

What it means

bootbox.prompt requires a callback function, mandatory for the same reason as confirm: the entered value is only delivered via callback (string, or false/null when cancelled/dismissed). Validation runs after the title check and throws when options.callback is missing or not a function.

Source

Thrown at cat-home/src/main/webapp/assets/js/uncompressed/bootbox.js:440

          each(checkedItems, function(_, item) {
            value.push($(item).val());
          });
          break;
      }

      return options.callback(value);
    };

    options.show = false;

    // prompt specific validation
    if (!options.title) {
      throw new Error("prompt requires a title");
    }

    if (!$.isFunction(options.callback)) {
      throw new Error("prompt requires a callback");
    }

    if (!templates.inputs[options.inputType]) {
      throw new Error("invalid prompt type");
    }

    // create the input based on the supplied type
    input = $(templates.inputs[options.inputType]);

    switch (options.inputType) {
      case "text":
      case "textarea":
      case "email":
      case "date":
      case "time":
      case "number":
      case "password":
        input.val(options.value);

View on GitHub (pinned to e815e74d4c)

Solutions

1. Pass a function as the second argument (or callback property): bootbox.prompt('Your name:', function(v){ ... }).
2. Handle cancellation inside the callback: result === false or null means dismissed — code accordingly.
3. Do not rely on the return value for the user input; capture it in the callback closure.

Example fix

// before
var name = bootbox.prompt('Enter your name:'); // no callback, throws

// after
bootbox.prompt('Enter your name:', function (name) {
  if (name === null) return; // dismissed
  save(name);
});

if (typeof cb !== 'function') cb = function () {};
bootbox.prompt('Enter a value:', cb);

function isPromptCallback(fn) {
  return typeof fn === 'function';
}

When it happens

Trigger: bootbox.prompt('Your name:'); bootbox.prompt('Your name:', 'save'); bootbox.prompt({title: 'Your name:'}) with no callback; passing an unbound method reference that is undefined.

Common situations: Assuming prompt returns the value synchronously (it does not — pre-bootbox-5 it returns a jQuery/XHR-like dialog object); refactoring that dropped the callback; mixing up argument order (callback first, title second).

Related errors

• confirm requires a callback
• prompt requires a title
• Please specify a message
• alert requires callback property to be a function when provi
• invalid prompt type

AI-assisted analysis of dianping/cat@e815e74d4c (2026-08-14). Data as JSON: /api/errors/e711942927a0d7d2. Report an issue: GitHub.