TypeScript Vue Form

Proof of concept package hacked together quickly, not recommended to use during production yet...

Premise / idea

I wanted to create an implementation of vform using TypeScript. After delving into the vform code, I discovered it used Object.assign() to add the properties from the form data directly to the class. This provided an interesting problem in TypeScript, which led me to develop this package using a slightly different approach to vform

Rather than tacking the properties on to the object, I went for a different approach. I maintain a property of the original data, and a one just of the changes, then use Object.defineProperty() to add a getter and setter for each key on the data. One thing this does not do right now is handle nested data or arrays, while I have no doubt that it will be possible, for this proof of concept I didn't feel like it was needed.

Request Handler

The next thing I did was to do away with the dependency for axios, and instead require users to set their request handler function themselves, enabling them to implement whatever http client of their choosing.

The request handler needs to follow the contract

import VForm, { RequestMethod, RequestException, ResponseData, RequestHandler } from '@willishq/ts-vform';

const form = new VForm({
    name: 'Andrew'
});

form.setRequestHandler(async function<T>(method: RequestMethod, url: string, data: Partial<T>): Promise<ResponseData<T>> {
    return {
        method, url, data
    };
});

Using with Vue

Coming soon...

Using with Nuxt.js

create a plugin for VForm

import VForm, { RequestMethod, RequestException, ResponseData, RequestHandler } from '@willishq/ts-vform';


export default ({app}, inject) => {

    const requestHandler: RequestHandler = async <T>(method: RequestMethod, url: string, data: RequestData<T>): Promise<ResponseData<T>> => {
        try {
            // makeRequest
            return {}
        } catch (e) {
            if (e.statusCode === 422) {
                const errors: ValidationErrors = {
                    statusCode: 422,
                    message: 'Validation Failed',
                    errors: {
                        // parse errors into valid structure, ie:
                        // name: ['must me set', 'must be andrew']
                    }
                };
                throw errors;
            }
        }
    }

    inject('vform', <M>(params: M) => {
        const form:VForm<M> = new VForm(params);
        form.setRequestHandler(requestHandler);
        return form;
    });

}

which can be used in your components like so

<template>
    <div>
        <p v-if="form.flashMessage()" v-text="form.flashMessage()"/>
        <input type="email" v-model="form.email">
        <div v-if="form.hasError('email')">
            <span v-for="message in form.getErrors('email')" v-text="message" />
        </div>
        <input type="password" v-model="form.password">
        <div v-if="form.hasError('password')">
            <span v-for="message in form.getErrors('password')" v-text="message" />
        </div>
        <button @click="submit">Login<button>
    </div>
</template>

<script lang="ts">
interface LoginModel {
    username: string,
    password: string
}

@Component
export default class LoginForm extends Vue {
    public form: VForm = this.$form<LoginModel>({
        email: '',
        password: ''
    });

    public async submit() {
        try {
            let response = await this.form.post('auth/login');
            // redirect user to next page
        } catch (e) {
            // silent?
        }
    }
}
</script>