In this tutorial we are going to create a customer feedback form using Reactive forms with Angular 7.
1. Intro – Model Driven Forms or Reactive Forms
Reactive forms helps us manage the state of a form at a given point in time. It helps us to write some executable code when any value or state changes. It helps us to write complex validation rules in code. It has direct access to the data model of our form. The logic which we implement in model driven forms can be tested. And thus unit test can be done. Reactive forms are used to implement more advance forms. Template driven forms are mainly for simpler implementations.
ng new feedback-form
2. Create a Form Component
create a component: ng g c feedback-form
3. ReactiveFormsModule && FormGroup
app.module.ts file import ReactiveFormsModule import { ReactiveFormsModule } from ‘@angular/forms’;
feedback-form.component.ts import { FormGroup } from ‘@angular/forms’; Form group represents the entire form that we are going to build.
FormBuilder is used to build the form. import { FormGroup } from ‘@angular/forms’;
4. HTML and CSS
styles.css, feedback-form.component and app.component
5. Creating FormControl
FormGroup represents the entire form. And the individual form elements will be represented by FormControl. Thus, FormControl is the building block of a FormGroup. import { FormGroup, FormBuilder, FormControl } from ‘@angular/forms’;
6. Creating nested form groups
Creating form groups inside form groups for holding similar form control elements e.g a group of checkboxes
7. Creating Form Controls inside nested form groups
8. Creating Form Controls for radio buttons
Radio buttons is just a single input. Thus we are not having a different form group for this. While checkbox has multiple inputs with multiple values, so having a form group to wrap them around.
9. Creating Form Array for dynamic elements
A Form Array is also like Form Group and can be used to create multiple form control elements. This is unique in the way that we can create/add/delete form control elements inside it.
10. Creating Add/Delete functions
11. Pre filling data in form
In HTML we use “value” attribute. Thus giving the same data from value of an input into form control will set it as default selection.
12. Pre filling data in form with setValue in ngOnInit
13. reset()
Any form group or form control or form array can be cleared with reset()
14. Showing form data on HTML
json pipe used to view HTML data for easier coding
15. Submit Feedback Form
(ngSubmit)
WIRING FORMGROUP FROM TS INTO HTML
16. formControlName
It links formcontrol created in ts with input file in html. This also takes care of two way binding of input.
17. formArrayName and looping through form array controls
Adding/removing more feedbacks
18. formGroupName and formControlName for nested form groups in checkboxes
19. Adding formControlName to select
We can use [ngValue] from [ngSelect] to save object in a select also instead of just a string. Thus makes coding easier.
20. Adding formControlName to textarea
21. Adding formControlName to radio buttons
Note that better to replace name with formControlName or. Name and formControlName should be same.
22. Hiding the detailed feedback section if gender is male
Use get handler to get any formcontrol value in HTML template
23. Change classes
ng-untouched – if input has not been touched even once ng-touched – if input is once touched or focused ng-pristine – if input’s value has not been changed even once ng-dirty – if input’s value has changed atleast once
24. Using valueChanges event to subscribe to change event of an input
valueChanges.subscribe and .get() handler
25. Using Validators
26. Validators.required with error message
27. Array of validations
Validators.required, Validators.minLength to get errors data: use the errors property from the formscontrol object
28. Complex/Custom Validators
Show error message if customer has a Washing Machine product and tries to choose Proper Installation option
29. Disabling submit button if form is not valid
30. Build and move to server
ng build change base href=”/projects/ui/customer-feedback-form/”
In this tutorial we are going to learn about Angular CLI commands that we can use to boost our productivity while creating an angular application.
1. Intro and Commands
Check version of node js installed : node –version Check version of npm installed : npm –version Install angular: npm install -g @angular/cli
2. Creating a project
Create a project: ng new my-project Move into the project folder: cd my-project Launch the default code editor: code .
3. Running the scripts from package.json file
Use the command “npm run” to run any script Start server: npm run start to run ng serve from package.json file in our case Build project for production: npm run build to run ng build
4. Building project for dev and production
npm run build –env=prod npm run build –env=dev
5. Creating a project with Advanced options
Previously set up routing: ng new my-project-one –routing (This will create a new routing module inside app folder) Use scss instead of css: ng new my-project-two –style=scss (This will create scss files instead of css files) Have multiple options: ng new my-project-two –style=scss –routing ng new my-project-two –style=scss –routing –prefix=bg
6. Working with assets folder
npm run build always moves all the assets files also. Lets copy one image into src/assets and npm run build – it will copy the file in to build folder How to control which files to move or not from assets: Move only img2 folder files from src assets to destination assets “assets”: [ “src/favicon.ico”, { “glob”: “**/*”, “input”: “src/assets/img2”, “output”: “assets/img2” } ], Always a better idea to have all files from assets and controllable files or folders from a new folder eg: misc-assets
ng serve: Builds the files in memory and launches on a port. Also refreshes automatically when there is any code change Change package.json file ng serve –open: After launching the app, open it in browser: ng serve –port=9099 –open: Compile, build the files and Launch app on port 9099 and open in browser
9. ng generate component
ng generate –help (To see all the options we have) ng g c recipe-item –dry-run (To see what will happen if you run the command) ng g c recipe-item –flat –dry-run (–flat option the components are directly created under app folder without it’s own folder) ng g c recipe-item (To actually render the component folder) Note that this component is used in app module
10. ng generate module
ng g m main-items (Generate a module) ng g c main-items/recipe-main-item –module=main-items
11. ng generate directive
ng g d main-items/directives/custominput –module=main-items (ng gen dir path modulename)
12. ng g service
ng g s my-services/recipe-api
13. ng g pipe
ng g p pipes/addcommas (The pipe is added by default to app.module) ng g p pipes/removecommas –module=main-items
14. ng generate class
ng g class class/recipe
15. ng generate interface and enums
Interfaces helps us define data types for our data with the help of data (No need of creating classes, if there is no logic) ng g interface interfaces/recipe ng g enum enums/recipe-type
16. ng generate guard
(Route Guard helps us protect certain routes) ng generate guard payment Import the guard in app module providers And modify the guard code.
17. ng test
karma is used to test our application by default. And to run the tests it uses the default browser i.e. chrome. (karma.conf.js) Run the command ng test. It will fail e.g. if in app.component.html, the h1 title tag has a different text then what’s mentioned in app.component.spec.ts
ng test –code-coverage To get a detailed report of code coverage in coverage folder. It will tell which codes were run during test and which were not. Note that the codes to execute or not are decided by test cases in spec.ts file.
ChromeHeadless By default full fledged chrome is launched in order to perform the test. But in order to save some load we can use the ChromeHeadless option in browser for karma.conf.js and run the test silently in chrome without launching it.
End to End Test: ng e2e Run the above command and launch the app on chrome. It will auto run the app and finish the testing for us.
18. Building Angular Application
Angular cli uses the command: ng build with webpack and does the following things for us: Compile typescript files, build all packages, minify files, compiling scss to css, inlining css, adding scoped css, moving assets etc.
ng build output: dist folder By default it runs in development mode (Thus non optimized files in dist folder) ng build –prod (It will now have optimized files in dist folder)
Add another script in package.json file npm run build:prod
React is a JavaScript framework created by Facebook to help web developers build single page applications quickly. In this tutorial we are going to create a full stack to do or task manager application from scratch with react.
We will build an angular github profile search application from scratch using Angular 4. We will set up all of the components and services for our project.
