TypeError: Cannot read property 'validate' of undefined?

import Joi from “joi-browser”;

import Form from “./common/form”;

export default class LoginForm extends Form {

state = {

data: { username: "", password: "" },

errors: {},

};

schema = {

username: Joi.string().required().label("Username"),

password: Joi.string().required().label("Password"),

};

doSubmit = () => {

// call the server

console.log("Form Submitted");

};

render() {

return (

  <div>

    <h1>Login</h1>

    <form onSubmit={this.handleSubmit}>

      {this.renderInput("username", "Username")}

      {this.renderInput("password", "Password", "password")}

      {this.renderButton("Login")}

    </form>

  </div>

);

}

}

Form.jsx

import React, { Component } from “react”;

import { Joi } from “joi-browser”;

import Input from “./input”;

export default class Form extends Component {

state = {

data: {},

errors: {},

};

validate = () => {

const options = {

  abortEarly: false,

};

const { error } = Joi.validate(this.state.data, this.schema, options);

if (!error) return null;

const errors = {};

for (let item of error.details) errors[item.path[0]] = item.message;

return errors;

/* const errors = {};

const { data } = this.state;

if (data.username.trim() === "")

  errors.username = "Username is required";

if (data.password.trim() === "")

  errors.password = "Password is required";

return Object.keys(errors).length === 0 ? null : errors;

*/

};

validateProperty = ({ name, value }) => {

const obj = { [name]: value };

const schema = { [name]: this.schema[name] };

const { error } = Joi.validate(obj, schema);

return error ? error.details[0].message : null;

};

handleSubmit = (e) => {

e.preventDefault();

const errors = this.validate();

this.setState({ errors: errors || {} });

if (errors) return;

this.doSubmit();

};

handleChange = ({ currentTarget: input }) => {

const errors = { ...this.state.errors };

const errorMessage = this.validateProperty(input);

if (errorMessage) errors[input.name] = errorMessage;

else delete errors[input.name];

const data = { ...this.state.data };

data[input.name] = input.value;

// data[e.currentTarget.name] = e.currentTarget.value;

this.setState({ data, errors });

//handle single input

/*

const data = { ...this.state.data };

data.username = e.currentTarget.value;

this.setState({ data });

*/

};

renderButton(label) {

return (

  <button disabled={this.validate()} className="btn btn-primary">

    {label}

  </button>

);

}

renderInput(name, label, type = “text”) {

const { data, errors } = this.state;

return (

  <Input

    type={type}

    name={name}

    value={data[name]}

    label={label}

    onChange={this.handleChange}

    error={errors[name]}

  />

);

}

}

“Cannot read property ‘validate’ of undefined”? Anyone can help in finding the error.

Is there any more to that error? For example a stack trace that might help us figure out which variable is undefined? What have you tried so far?

@programmingwithmosh can you please help us here? Having the same issue!

@shan72023 any luck solving this?

Hey guys. I had the exact same issue and couldn’t figure it out for half an hour. The problem is with the import of Joi inf form.jsx. you are using
import { Joi } from “joi-browser”;
you need be using
import Joi from “joi-browser”;

This is because VSCode assumes you want the named export and not the default export but you actually need the default export to access the validate method.

Hope this helps!

1 Like

Hi,

If you’re using more up-to-date version of Joi package, the syntax has been changed so it might be the reason that you’re getting this error:

This was it this should be resolved

This solved my problem. Thanks!