Semantic-Org/Semantic-UI · warning

{name} cannot contain "{ruleValue}"

Error message

{name} cannot contain  "{ruleValue}"

What it means

Default prompt for the Semantic UI Form `doesntContain` rule (settings.rules.doesntContain, form.js:1472). Here the prompt key (form.js:1268) and the rule function name MATCH, so it resolves correctly. Requires the value to NOT contain `{ruleValue}` (case-insensitive substring). Note the literal message contains a DOUBLE space (`'cannot contain "'`) — a typo in the source that surfaces verbatim to users.

Source

Thrown at src/definitions/behaviors/form.js:1268

    unspecifiedField : 'This field'
  },

  prompt: {
    empty                : '{name} must have a value',
    checked              : '{name} must be checked',
    email                : '{name} must be a valid e-mail',
    url                  : '{name} must be a valid url',
    regExp               : '{name} is not formatted correctly',
    integer              : '{name} must be an integer',
    decimal              : '{name} must be a decimal number',
    number               : '{name} must be set to a number',
    is                   : '{name} must be "{ruleValue}"',
    isExactly            : '{name} must be exactly "{ruleValue}"',
    not                  : '{name} cannot be set to "{ruleValue}"',
    notExactly           : '{name} cannot be set to exactly "{ruleValue}"',
    contain              : '{name} must contain "{ruleValue}"',
    containExactly       : '{name} must contain exactly "{ruleValue}"',
    doesntContain        : '{name} cannot contain  "{ruleValue}"',
    doesntContainExactly : '{name} cannot contain exactly "{ruleValue}"',
    minLength            : '{name} must be at least {ruleValue} characters',
    length               : '{name} must be at least {ruleValue} characters',
    exactLength          : '{name} must be exactly {ruleValue} characters',
    maxLength            : '{name} cannot be longer than {ruleValue} characters',
    match                : '{name} must match {ruleValue} field',
    different            : '{name} must have a different value than {ruleValue} field',
    creditCard           : '{name} must be a valid credit card number',
    minCount             : '{name} must have at least {ruleValue} choices',
    exactCount           : '{name} must have exactly {ruleValue} choices',
    maxCount             : '{name} must have {ruleValue} or less choices'
  },

  selector : {
    checkbox   : 'input[type="checkbox"], input[type="radio"]',
    clear      : '.clear',
    field      : 'input, textarea, select',
    group      : '.field',

View on GitHub (pinned to 597843ab84)

Solutions

1. Remove the forbidden substring from the value.
2. If case-sensitivity is intended, use `doesntContainExactly`.
3. Override the prompt to fix the double-space typo: `{type:'doesntContain[spam]', prompt:'Value cannot contain "spam"'}`.

Example fix

// before - default ships with a double-space typo
rules: [{ type: 'doesntContain[spam]' }]  // renders '... cannot contain  "spam"'

// after - corrected custom prompt
rules: [{ type: 'doesntContain[spam]', prompt: 'Value cannot contain "spam"' }]

const banned = 'spam';
if (($field.val() || '').toLowerCase().indexOf(banned.toLowerCase()) !== -1) { /* warn */ }

const containsBannedCI = (v, t) => String(v).toLowerCase().indexOf(String(t).toLowerCase()) !== -1;

When it happens

Trigger: `{type:'doesntContain[spam]'}` with input `spam@example.com` or `This is spam` → contains `spam` case-insensitively → prompt shown (with the double space).

Common situations: Blocking banned words in comments/usernames; users noticing the odd double-space rendering in the UI.

Related errors

• {name} must contain "{ruleValue}"
• {name} must contain exactly "{ruleValue}"
• {name} cannot contain exactly "{ruleValue}"
• {name} must be a valid url
• {name} is not formatted correctly

AI-assisted analysis of Semantic-Org/Semantic-UI@597843ab84 (2026-08-13). Data as JSON: /api/errors/1db7609625e82c03. Report an issue: GitHub.