# wire.validate

Validate data entered or selected by users using the `wire.validate` method.  The method will return `null` if the validation was successful.  It will return an error message if it was not.

## Parameters

| Name   | Description                           |
| ------ | ------------------------------------- |
| value  | The value to be validated.            |
| config | The configuration for the validation. |

## Config Properties

Use the following properties on the second parameter `config` to configure the validation.

| Name     | Description                                                                                                                            |
| -------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| type     | The type of validation to be performed.  See valid values [below](/wirebootstrap/reference/wire/wire.ui.validate.md#validation-types). |
| error    | Error message to be returned if the validation fails.                                                                                  |
| required | Determines whether the `value` passed into the `validate` method is required.                                                          |

## Validation Types

The following details the valid values of the type configuration property along with the additional configuration for each.

### Number

Use the `number` type to be sure a value is a valid number.

```javascript
// returns null
const error = wire.validate(10, {    
    type: "number"
});
```

Use `gt` with  the `number` type to be sure a value is greater than a specific value.

```javascript
// returns value in error
const error = wire.validate(10, {    
    type: "number", 
    gt: 20
    error: "Please enter a number greater than 20"
});
```

### Value

Use the `value` type to verify that a value is within a list of `values`.

```javascript
// returns null
const error = wire.validate("Y", {    
    type: "value", 
    values: [ "Y", "N" ]
});
```

Use `case` with the `value` type to specify whether the check against the `values` list should be case sensitive.  The `case` condition defaults to `false`.

```javascript
// returns default error message for 'value' type
const error = wire.validate("y", {    
    type: "value", 
    case: true,
    values: [ "Y", "N" ]
});
```

### Date

Use the `date` type to verify that a value is a valid date.  

```javascript
// returns null
const error = wire.validate("01-15-1986", {    
    type: "date" 
});
```

### Phone Number

Use the `phone` type to verify a value is a valid phone number.  

```javascript
// returns null
const error = wire.validate("201-555-1212", {    
    type: "phone" 
});
```

### Email Address

Use the `email` type to verify that a value is a valid email address.  

```javascript
// returns null
const error = wire.validate("jkratz@gmail.com", {    
    type: "email" 
});
```

### Regular Expression

Use the `regex` type to verify that a value meets a regular expression condition.  Set the expression into the `exp` property.  

The following checks for a valid phone number.

```javascript
// returns null
const error = wire.validate("201-555-1212", {    
    type: "regex",
    exp: "^\\(?([0-9]{3})\\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$" 
});
```

{% hint style="info" %}
Note, the site <https://www.regextester.com/> is a useful site for testing regular expressions for use with this type of validation.
{% endhint %}

### Custom

When all else fails, use the `custom` type to validate a value using a custom function.  Use the `validate` property to define the custom function.  This function takes the same parameters as the `validate` function itself and should return the same error if the validation is not successful.

The following uses the [moment.js](https://momentjs.com/) library to do a custom date validation.

```javascript
// returns null
const error = wire.validate("011586", {    
    type: "custom" 
    validate: (value, config) => {
        if(!moment(value, 'MMDDYY', true).isValid())
            return "Must be in format 'mmddyy' (i.e. 081587)";
    }
});
```

#### Value

When using the `custom` validation type, the value passed in can also be an object. &#x20;

```javascript
const data = {date: "011586", checkMe: false };

const error = wire.validate(data, {    
    type: "custom" 
    validate: (value, config) => {
        if(value.checkMe && !moment(value.date, 'MMDDYY', true).isValid())
            return "Must be in format 'mmddyy' (i.e. 081587)";
    }
});
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.wirebootstrap.com/wirebootstrap/reference/wire/wire.ui.validate.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.