Angular 2 formdata append object - Weebly

[Pages:3]Continue

Angular 2 formdata append object

For example, in this tutorial, we see how to upload multiple image files using FormData, HttpClient (multipart/form data), Angular 10/8, and TypeScript. We'll see how to use Angular Material ProgressBar to indicate activity when uploading images and how to use HttpClient along with the RxJS map() method to listen to file upload process events. Follow this tutorial to find out to have the following skills: How to upload one and more image files to TypeScript and Square 10 How to configure HttpClient for angular 10 project, How to use HttpClient to send POST requests multipart/form-data, How to listen to file upload process events using HttpClient, How to use FormData forms to create TypeScript, How to use Angular Material MatProgressBar component to indicate the percentage of file upload in real time. How to use different RxJS operators like map() and catchError(). Steps in this tutorial: Step 1 -- Step 2 of the rectangular CLI v8. Card, button, and ProgressBar components We do not create a server application for file upload because this is not covered in the tutorial. Instead, will use a service to upload and share files online. Learn about the short introduction to FormData. What is FormData? FormData is a data structure that can be used to store key value pairs. It is designed to store form data and can be used with javascript to create an object that is equivalent to an HTML form. This is most useful when you need to send form data to RESTful API endpoints, such as uploading one or more files using the XMLHttpRequest interface or any HTTP client library. You can create a FormData object by using the new operator to create the FormData interface as follows: const formData = new FormData() The formData reference refers to an instance of FormData. You can invite a number of methods on the object to add and collaborate on data pairs. Each pair has a key and value. These are the methods available on FormData objects: append() : used to append a key-value pair to the object. If the key already exists, the value appends the original value to the key, delete(): used to delete the key-value pair, entries(): Returns an Iterator object that you can use to loop through the list of key value pairs in the object, get(): used to return the value of the key. If you append multiple values, returns the first value, getAll(): returns all values for a key, has(): to verify that there is a key, keys(): returns an Iterator object that lists the available keys in the object, set(): adds a value to the object with the specified key. overrides the value, if a key already exists, values(): returns an Iterator object to the values of the FormData object. Now let's move on to the tutorial, starting with the prerequisites. Prerequisites In this tutorial, we create an example application with square field 10, so some prerequisites are required: Node A. JS and npm installed TypeScript are development environments with basic knowledge. In particular, knowledge of object-oriented concepts, such as TypeScript classes and decorators. Local development machine with 8.9+ node, together with NPM 5.5.1+ installation. Nodes are needed for the Angular CLI, as most frontend devices are nowadays. Simply go to the download page of the official website and download the binaries of the operating system. You can also provide specific system instructions for installing the node with package manager. However, the recommended method is to use NVM - Node Version Manager - a POSIX-compatible bash script to manage multiple active Node.js versions. Note: If you don't want to install the local environment for Square Development, but still want to try the code in this tutorial, you can use Stackblitz, an online IDE for front-line development, to create an Angular project that is compatible with Angular CLI. Angular 10 Tutorial, Step 1 -- Set angular CLI v8 In this step we install the latest Angular CLI 8 version (at the time of writing the tutorial). Note: These instructions also apply to Angular 10. Angular CLI is the official tool for initialising and cooperating with Angular projects. To install, open a new command-line interface and run the following command: $ npm install -g @angular/cli When you write the presentation, the angle/cli v8.3.2 will be installed on the system. The next step is to learn how to initialize a new example project from the terminal. Step 2 - Initialize a new Angular 10 project After installing Angular CLI, we create our example project. Go back to the terminal and run the following commands: $ cd ~ $ ng new angular-upload-example The CLI will ask you a few questions - If you want to add Angular routing? Type y in the Yes and Which style sheet formats? Select CSS. This instructs the CLI to automatically set up route planning in our project, so we only need to add component paths to implement navigation in our app. Then locate the project folder and run the local development server with the following commands: $ cd angular-upload-example $ ng serve The local development server will start listening to the address. Open your web browser and find the address to get the app started. This is a screenshot at this point: Now let the developer server run and start a new terminal with the following CLI commands. Step 3 -- Set up Angular 10 HttpClient after initialization Angular project using Angular CLI, continue setting httpclientiin in our example. HttpClient lives in a separate angular module, so we will need to import the main application module before we can use it. Open the example project with a code editor or IDE. I'm going to use visual studio code. Then open src/app/app.module.ts, import the HttpClientModule file, and add it to the module import array as follows: import { BrowserModule } from @angular/platform-browser; import { NgModule } @angular/core; import { AppRoutingModule } from './app-routing.module'; Import {AppComponent } from './ponent'; import { HttpClientModule } @angular/common/http; @NgModule({ declarations: [ AppComponent, ], import: [ BrowserModule, AppRoutingModule, HttpClientModule ], providers: [], bootstrap: [AppComponent] }) export class AppModule { } That's all, now you're ready to use the HttpClient service in your project, but first you need to create two, home and approximately, components of our application. Step 4 - Create angular components After you set up Angular HttpClient, create the angular components that control the application user interface. Go back to a new terminal and run the following commands: $ cd ~/angular-upload-example $ ng create component at home CLI created four files for the component and added it to the declaration array in src/ app/app.module.ts. Then create the approximate component with the following command: $ ng creates a component about Next, open src/app/about/ponent.html, and add the following code: <p style=padding: 13px;> Angular 8 tutorial & example - How to upload multiple image files FormData & HttpClient </p> We leave the home part here for the next steps. Step 5 -- Add angular routing After you create angular components, add them to your router. Open src/app/app-routing.module.ts, the routing configuration, and import the components, and then add the following routes: import { NgModule } from the @angular/core file; import { Routes, RouterModule } from @angular/router; import { HomeComponent } from './home/ponent'; import { AboutComponent } from './about/ponent'; const routes: Routes = [ { path: '', redirectTo: 'home', pathMatch: 'full'}, { path: 'home', component: HomeComponent }, { path: 'about', component: AboutComponent }, ]; @NgModule({ import: [RouterModule.forRoot(routes)], export: [RouterModule] }) export class AppRoutingModule { } Step 6 -- Set Angular 10 Material After you add routing to the various components of the application, see how to add square material to the user interface style. Angular material provides material design components that allow developers to create professional surfaces. Go to your terminal and run the following command from the root folder of the project: $ ng add @angular/material The system will ask you to choose a theme, let's go to Indigo / Pink. The other questions - Set HammerJS gesture recognition? and setup setting browser animations Angular material? To select the default answers, press Enter on the keyboard. Then open the src/styles.css file and add a theme: @import ~@angular/material/prebuilt-themes/indigo-pink.css; Each Angular Material component exists in the separate module, which must be imported before the component can be used. Open src/app/app.module.ts and add the following import files: import { MatToolbarModule, MatIconModule, MatCardModule, MatButtonModule, MatProgressBarModule } from @angular/material; These are the modules we imported: MatIcon makes it easier to use vector icons in your app. MatToolbar, which contains a container for headers, addresses, or actions. A MatCard that contains a content store for text, photos, and actions in the context of a single subject. MatButton, which contains a native or element with a <button> <a> material design style and ink frills. MatProgressBar, which includes a horizontal progress bar to indicate progress and activity. Next, you must add these modules to the import array: @NgModule({ declarations: [ AppComponent, HomeComponent, AboutComponent ], import: [ BrowserModule, AppRoutingModule, HttpClientModule, BrowserAnimationsModule, MatToolbarModule, MatIconModule, MatButtonModule, MatCardModule, MatProgressBarModule ], providers: [], bootstrap: [AppComponent] }) export class App {Module } Next's add a toolbar. Open the src/app/ponent.html file and add the following code: <mat-toolbar color=primary><h1> ngImageUpload </h1><button mat-button= routerlink=/>Home</button> <button mat-button= routerlink=/about>About</button> </mat-toolbar> <routeroutlet></router-outlet> We created our shell application, which has a top bar with two navigation buttons for your home and components. As a plug into our tutorial to this point: We've installed Angular CLI, initialized a new project, and created a couple of component routing, I've configured HttpClient and Square Material for the project, and added an app shell that includes a topbar and navigation. To create Angular 10 File Upload Service Now, create a square service that includes uploading code image files in your project. Go back to the terminal and run the following command to create a new service: generate $ng service upload Next, open src/app/upload.service.ts, and start importing : import { HttpClient, HttpEvent, HttpEventResponse, HttpEventType } from '@angular/common/http'; import { map } by rxjs/operators; Then inject HttpClient and specify the SERVER_URL variable that contains the file upload server address: @Injectable({ providedIn: 'root' }) export class UploadService { SERVER_URL: string = constructor(private httpClient: HttpClient) { } Next, add the upload() method, which simply calls the HttpClient post() method to send an HTTP POST request to the file in the upload file.</a></button> to the file.</a></button> nyilv?nos felt?lt?s(formData) { vissza this.httpClient.post<any>(ez. SERVER_URL, formData, { reportProgress: true, observe: 'events' }); } 9. Nyissa meg az src/app/home/ponent.ts f?jlt, ?s kezdje a k?vetkez import?l?ssal: import { Component, OnInit, ViewChild, ElementRef } a @angular/core f?jlb?l; import { HttpEventType, HttpErrorResponse } a @angular/common/http-bl; a } import?l?sa az rxjs-bl; import { catchError, map } az rxjs/operators r?sz?rl; import { UploadService } a '.. /upload.service; Ezut?n defini?lja a fileUpload ?s a files v?ltoz?kat, ?s adja be az UploadService-t a k?vetkezk?ppen: @Component({ selector: 'app-home', templateUrl: './ponent.html', styleUrls: [./ponent.css'] }) export oszt?ly HomeComponent implements OnInit { @ViewChild(fileUpload, {static: false}) fileUpload: ElementRef;files = []; constructor(private uploadService: UploadService) { Next, defini?lja a uploadFile() met?dust: uploadFile(file) { const formData = new FormData(); formData.append('file', file.data); file.inProgress = true; this.uploadService.upload(formData).pipe( map(event => { switch (event.type) { case HttpEventType.UploadProgress: file.progress = Math.round(event.loaded * 100 / event.total); break; case HttpEventType.Response: return event; } }), catchError((hiba: HttpErrorResponse) => { file.inProgress = false; return of('${file.data.name} upload failed.'); }).) subscribe((event: any) => { if (typeof (event) === 'object') { console.log(event.body); } }); } L?trehoztunk egy formaadatot, ?s a f?jlt egy f?jl nev mezh?z fzt?k. A kulcs nev?nek ott kell lennie, ahol a kiszolg?l? elv?rja, hogy megtal?lja a f?jlt m?s b?lcsk?nt, a kiszolg?l? nem lesz k?pes kibontani a f?jlt. Ezut?n elk?ldt?k az rlap adatait a szervernek az UploadService Upload() met?dus?nak megh?v?s?val. Ezut?n defini?lja a uploadFiles() met?dust, amely t?bb k?pf?jl felt?lt?s?re haszn?lhat?: private uploadFiles() { this.fileUpload.nativeElement.value = ''; this.files.forEach(file=>{ this.uploadFile(file); }); } Ezut?n adja meg az onClick() met?dust: onClick() { const fileUpload = this.fileUpload.nativeElement;fileUpload.onchange = () => { for (let index = 0; index < fileupload.files.length;= index++)= {= const= file=fileUpload.files[index]; this.files.push({= data:= file,= inprogress:= false,= progress:= 0});= }= this.uploadfiles();= };= fileupload.click();= }= next,= we= need= to= create= the= html= template= of= our= image= upload= ui.= open= the= src/app/home/ponent.html= file= and= add= the= following= content:=><div style=text-align:center; margin-top: 100px; ><mat-card style=margin-top:10px; width: 50%;><mat-card-content><ul><li *ngfor=let file of files><mat-progress-bar [value]=file.progress></mat-progress-bar> <span id=file-label> </span></li></ul> </mat-card-content></mat-card></div></any><button mat-button= color=warn (click)=onClick()> <mat-icon>file_upload</mat-icon> upload</button><input type=file #fileupload= id=fileUpload name=fileUpload multiple=multiple accept=image/* style=display:none;> Then open src/app/home/ponent .css and add the following CSS code: ul, li { margin: 0; padding: 0; list-style: none; } This is a screenshot of our application when uploading four image files: Conclusion As a wrap-up of our Angular 10 tutorial, we saw how to upload one and more image files to the server using HttpClient to send POST requests to FormData. We used various angular materials, such as MatCard, MatButton, MatIcon, and MatProgressBar, to create a user interface layout. Layout.

chuck close movie worksheet , origami_dove_printable_instructions.pdf , orc arcadia wi , doobie brothers song reactions , delonghi rialto manual , terraria save editor apk , mid day meal programme pdf , 81192254594.pdf , mary_j_blige_my_life_album_download_zip.pdf , a hope in the unseen pdf , unblocked_games_a_small_car_2.pdf , modern combat versus hack pc 2019 ,

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download