q-input has value then only Rules will apply

user_13506448 0
Viewed 4119

If q-input has value != '' then only i want to apply the Rules like required 8 number maximum. In the below code it gives me the required input error even it's null.

<q-input
    filled
    name="landline"
    label="Landline Phone Number"
    v-model="user.landline"
    placeholder="Landline Phone Number"
    ref="landlinePhoneNumber"
    type="number"
    :maxlength="8"
    :rules="[val => val!='' && val.length > 7 || 'Landline Required 8 digit']"
/>
quasar quasar-framework vue.js
2 Answers

Try to add prop lazy-rules. By default, it's set to 'ondemand', which means that validation will be triggered only when the component’s validate() method is manually called or when the wrapper QForm submits itself. More info

user_124649000

You have to return true when the field is null first, then validate only if it's not null. Also, add the prop lazy-rules so that it only validates when the form field loses focus.

Here is how I did it in Vue 3, using composable and TypeScript. The form field component:

<q-input
        class="q-mt-md"
        filled
        v-model="id_number"
        label="ID Number "
        type="text"
        hint="Optional/Leave blank if not available"
        lazy-rules
        :rules="[(val) => isNumberBlankOrValid(val) || 'Invalid ID Number']"
      />

The method isNumberBlankOrValid called from the field above:

    const isNumberBlankOrValid = (val: string) => {
    if (val.length === 0) {
      return true
    }
    return isValidNumber(val)
  }

The isValidNumber for other fields that must be filled:

const isValidNumber = (val: string) => val && isNumeric(val)

The isNumeric method is a simple regex for validating numbers:

const isNumeric =  (value: string) => {
  return /^\d+$/.test(value)
}
user_32249600
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