Download link: 
➡ Click here: Vue js form validation
You can play with this example here: See the Pen by Raymond Camden on. Input and textarea components For this article, I presume that you have a Vue. How do we tell VeeValidate that it can use this new rule we just created?
Suppose we want the name to be between 5 to 20 characters. Promise : null } GitHub. This boolean value is what is checked to see if the form is valid or not. Currently, there are over 20 ring rules available in the plugin. Min and max are both inclusive. My checkForm logic which is run on submit remember checks for name and age only as movie is optional. The easiest case is to simply add type metadata, which might be useful in choosing correct xi string later on. To render the ContactForm component, we must add it in our App root component. Now create a new vue js project there by using the following command. Like the name input, this also has a span input attached in similar fashion. Using Custom Validation For the autobus example, the second text field age was switched to email which will be validated with a bit of custom logic.
Installation instructions and other documentation can be found at. This documentation presents every builtin validator with short description and presents an example custom validator implementation to help understanding them and writing your own as easy as possible. Basic usage You can import the library and use as a Vue plugin to enable the functionality globally on all components containing validation configuration.
Form Validation - Consider applying a class e.
Vue js is growing rapidly. The increasing list of great features and performance makes it one of the best JavaScript frameworks. It has a smaller learning curve too that makes it a great choice for building UX User Experience. In this article, we will learn vue js form validation. We will use to make things look pretty. Vue js form validation First of all, if you are new to Vue I would suggest you check. It will help you to get started with Vue js. However, if you are a React or Angular developer then I would suggest you have a look at. We will use npm as Vue CLI provides a great way to play with it. So open up the command prompt and go to your desired directory. Now create a new vue js project there by using the following command. You will find a folder called src within the root directory of your project. Go inside of it and there will be a folder called components. Now create a new component called Home. Now inside of the template tags create a form. I am using Bootstrap 4 and its predefined classes to make things easier. You can install it directly using npm and import it within your main. Validate I have added markup for a simple comment form with 3 required fields. Bootstrap provides an is-invalid class that helps in showing field with the error. So we will need to add this class when the field is invalid. Vue provides a great way to bind classes with data variables. Suppose we have a nameError variable within data. If the variable is true the is-invalid class will be added to the field automatically. Now you can add v-bind property to other fields with emailError and commentError variables. We have almost completed the template part but. Have not we missed something? Adding the required variables export default name: 'home', data return nameError: false, emailError: false, commentError: false, Inside of the script, we have added 3 boolean variables. Initially, they are set to false so that invalid class will not be added before validation. Ohh ups we have missed something again!. We need to deal with the user input. The two-way data binding of Vue makes it really easy to manipulate user inputs. Finally, do the same with the rest of the fields. So we can now manipulate inputs and define our validate method logic. However, you may notice we have not thought of error messages yet. Generally, you can handle this in many different ways. I will explain the easier one. Defining the validation logic Extend the script and add the method as follows. Suppose we want the name to be between 5 to 20 characters. Then we can add the following validation logic. Notice that I have added the message as a string you can use an array if it will contain more than one error messages. You can create your own simple validation rules like this one. However, I have added an embedded code below you can use that for reference. Now we have added a message to the validation error. As the name is our first field so in order to display the error message of the name we will need to fetch index 0 of errors array. Initially, the errors array is empty so a v-if directive is added to display the vue js form validation message if index 0 exists. You can follows this same procedure to display the error message for other fields too. Extending the features First of all, imagine what will happen if you try to validate more than once. The previous error messages are still in the errors array right!. So in order to solve this issue, you can simply set errors array to empty at the first line of our validate method. We must specify what will happen if the field is validated and has no errors. We can do this with a simple else statement as follows. This will help you to get rid of overlapping classes. At the last line, we have changed the class of error message block to valid-feedback. You will be able to see the following output once its ready.