From 97eb6f9febc180efb94ade2bb695b8a36727ce5a Mon Sep 17 00:00:00 2001 From: asabeneh Date: Tue, 13 Oct 2020 01:53:50 +0300 Subject: [PATCH] day_12 has been cleaned --- 12_Day_Forms/12_forms.md | 5 +- .../13_uncontrolled_input.md | 895 ++ .../.gitignore | 23 + .../README.md | 5 + .../package.json | 34 + .../public/index.html | 111 + .../src/data/countries.js | 2013 +++ .../src/data/ten_most_highest_populations.js | 13 + .../src/images/asabeneh.jpg | Bin 0 -> 20817 bytes .../src/images/css_logo.png | Bin 0 -> 84176 bytes .../src/images/html_logo.png | Bin 0 -> 18060 bytes .../src/images/js_logo.png | Bin 0 -> 11783 bytes .../src/images/react_logo.png | Bin 0 -> 41477 bytes .../src/index.js | 326 + .../yarn.lock | 10849 ++++++++++++++++ 15 files changed, 14272 insertions(+), 2 deletions(-) create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input.md create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/.gitignore create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/README.md create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/package.json create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/public/index.html create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/data/countries.js create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/data/ten_most_highest_populations.js create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/images/asabeneh.jpg create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/images/css_logo.png create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/images/html_logo.png create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/images/js_logo.png create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/images/react_logo.png create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/src/index.js create mode 100644 13_Day_Controlled_Versus_Uncontrolled_Input/13_uncontrolled_input_boilerplate/yarn.lock diff --git a/12_Day_Forms/12_forms.md b/12_Day_Forms/12_forms.md index ace0ce2..2972c0d 100644 --- a/12_Day_Forms/12_forms.md +++ b/12_Day_Forms/12_forms.md @@ -91,7 +91,8 @@ So far we did not get any data from input field. Now, it is time to learn how to The input element has many attributes such as value, name, id, placeholder, type and event handler. In addition, we can link a label and an input field using an id of input field and htmlFor of the label.If label and input are linked it will focus the input when we click on label. Look at the example give below. ```js -class App extends React.Component { +import React, { Component } from 'react' +class App extends Component { // declaring state // initial state state = { @@ -107,7 +108,7 @@ class App extends React.Component { const firstName = this.state.firstName return (
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+ +[<< Day 12](../12_Day_Forms/12_forms.md) | [Day 14 >>]() + +![30 Days of React banner](../images/30_days_of_react_banner_day_13.jpg) + +- [Uncotrolled Inputs](#uncotrolled-inputs) + - [Getting data from an input field](#getting-data-from-an-input-field) + - [Getting multiple input data from form](#getting-multiple-input-data-from-form) + - [Get data from different input field types](#get-data-from-different-input-field-types) + - [Form Validation](#form-validation) + - [What is validation?](#what-is-validation) + - [What is the purpose of validation](#what-is-the-purpose-of-validation) + - [Validation Types](#validation-types) +- [Exercises](#exercises) + - [Exercises: Level 1](#exercises-level-1) + - [Exercises: Level 2](#exercises-level-2) + - [Exercises: Level 3](#exercises-level-3) + +# Uncotrolled Inputs + +In the previous day challenge we have covered controlled inputs. In react most of the time we use controlled inputs as recommended on the official [documentation of React](https://reactjs.org/docs/uncontrolled-components.html). To write un + +```html + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +``` + +Another HTML fields to get data from a form are textarea and select with options elements. + +```html + + + +``` + +Now, you know most of the fields we need to get data from a form. Let's start with an input with type text field. In the previous day, we saw different types of events and today we will focus on more of _onChange_ event type which triggers whenever an input field data changes. Input field has by default a memory to store input data but in this section we control that using state and we implement a controlled input. Today we will implement a controlled input. We will cover uncontrolled input in a separate section. + +## Getting data from an input field + +So far we did not get any data from input field. Now, it is time to learn how to get data from an input field. We need on input field, event listener (onChange) and state to get data from a controlled input. See the example below. The h1 element below the input tag display what we write on the input. Check live [demo](https://codepen.io/Asabeneh/full/OJVpyqm). + +The input element has many attributes such as value, name, id, placeholder, type and event handler. In addition, we can link a label and an input field using an id of input field and htmlFor of the label.If label and input are linked it will focus the input when we click on label. Look at the example give below. + +```js +class App extends React.Component { + // declaring state + // initial state + state = { + firstName: '', + } + handleChange = (e) => { + const value = e.target.value + this.setState({ firstName: value }) + } + + render() { + // accessing the state value and this value will injected to the input in the value attribute + const firstName = this.state.firstName + return ( +
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+ ) + } +} +``` + +We usually use form to handle use information. Let us move to form section and make use the form element. + +## Getting multiple input data from form + +In this section we will develop a small form which collect user information. Our user is a student. We use a parent form element and certain number of input elements to collect user information. In addition to that we will have event listener for the form (onSubmit) and for the inputs (onChange). See the following example try to see the commonts too. You can also check the live [demo](https://codepen.io/Asabeneh/full/eYNvJda). + +```js +class App extends React.Component { + // declaring state + state = { + firstName: '', + lastName: '', + country: '', + title: '', + } + handleChange = (e) => { + /* + // we can get the name and value like this but we can also destructure it from e.target + const name = e.target.name + const value = e.target.value + */ + const { name, value } = e.target + // [variablename] this we can make a value stored in a certain variable could be a key for an object, in this case a key for the state + this.setState({ [name]: value }) + } + handleSubmit = (e) => { + // stops the default behavior of form element specifically refreshing of page + e.preventDefault() + console.log(this.state) + } + + render() { + // accessing the state value by destrutcturing the state + const { firstName, lastName, title, country } = this.state + return ( +
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+ ) + } +} +``` + +The above form handles only text types but do have different input field types. Let's do another form which handle all the different input field types. + +## Get data from different input field types + +```js +// index.js +import React, { Component } from 'react' +import ReactDOM from 'react-dom' + +const options = [ + { + value: '', + label: '-- Select Country--', + }, + { + value: 'Finland', + label: 'Finland', + }, + { + value: 'Sweden', + label: 'Sweden', + }, + { + value: 'Norway', + label: 'Norway', + }, + { + value: 'Denmark', + label: 'Denmark', + }, +] + +// mapping the options to list(array) of JSX options + +const selectOptions = options.map(({ value, label }) => ( + +)) + +class App extends React.Component { + // declaring state + state = { + firstName: '', + lastName: '', + email: '', + country: '', + tel: '', + dateOfBirth: '', + favoriteColor: '', + weight: '', + gender: '', + file: '', + bio: '', + skills: { + html: false, + css: false, + javascript: false, + }, + } + handleChange = (e) => { + /* + // we can get the name and value like this but we can also destructure it from e.target + const name = e.target.name + const value = e.target.value + */ + const { name, value, type, checked } = e.target + // [variablename] this we can make a value stored in a certain variable could be a key for an object, in this case a key for the state + + if (type === 'checkbox') { + this.setState({ + skills: { ...this.state.skills, [name]: checked }, + }) + } else if (type === 'file') { + console.log(type, 'cehck here') + this.setState({ [name]: e.target.files[0] }) + } else { + this.setState({ [name]: value }) + } + } + handleSubmit = (e) => { + // stops the default behavior of form element specifically refreshing of page + e.preventDefault() + const { + firstName, + lastName, + email, + tel, + dateOfBirth, + favoriteColor, + weight, + country, + gender, + bio, + file, + skills, + } = this.state + + const formattedSkills = [] + for (const key in skills) { + console.log(key) + if (skills[key]) { + formattedSkills.push(key.toUpperCase()) + } + } + const data = { + firstName, + lastName, + email, + tel, + dateOfBirth, + favoriteColor, + weight, + country, + gender, + bio, + file, + skills: formattedSkills, + } + console.log(data) + } + + render() { + // accessing the state value by destrutcturing the state + const { + firstName, + lastName, + email, + tel, + dateOfBirth, + favoriteColor, + weight, + country, + gender, + bio, + } = this.state + return ( +
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