我设计了一个Angular 2应用程序,该应用程序允许用户通过填充HTML表单来创建新配方。如果用户手动将值输入表单,则在单击"提交"按钮时,所有这些值都传递给我的服务代码。问题在于,我有一个表单元素,该元素在按下提交按钮之前通过jQuery脚本更新,但是在单击"提交"按钮然后查看提交表单数据的内容时,此表单元素没有值。我真的不明白为什么,因为我可以在屏幕上的形式中实际看到值。如果我在此表单元素中手动输入一个值,则数据将在表单数据中正确提交。
下面是我的html(jQuery设置的值的元素是元素ID =" image_id"): -
<div class="row">
<div class="col-md-12">
<form [formGroup]="create_recipe_form" (ngSubmit)="createRecipe()">
<table class="table table-hover table-responsive table-bordered">
<tr>
<td>
Name
</td>
<td>
<input name="name" formControlName="name" type="text" class="form-control" required />
<div *ngIf="create_recipe_form.get('name').touched && create_recipe_form.get('name').hasError('required')"
class="alert alert-danger">Name is required
</div>
</td>
</tr>
<tr>
<td>
Image
</td>
<td>
<input name="selectFile" id="selectFile" type="file" class="form-control btn btn-success" />
<button type="button" class="btn btn-primary" (click)="uploadImage($event)" value="Upload Image">Upload Image</button>
<input name="image_id" formControlName="image_id" type="text" class="form-control" id="image_id" />
</td>
<td>
</tr>
<tr>
<td></td>
<td>
<button class="btn btn-primary" type="submit" [disabled]="!create_recipe_form.valid">
<span class="glyphicon glyphicon-plus"></span> Create
</button>
</td>
</tr>
</table>
</form>
</div>
</div>
我的Angular 2组件文件看起来像这样: -
import { Component, Input, Output, EventEmitter, OnInit, ElementRef } from
'@angular/core';
import { FormGroup, FormControl, Validators, FormBuilder } from '@angular/forms';
import { Observable } from 'rxjs/Observable';
import { CategoryService } from '../category.service';
import { RecipeService } from '../recipe.service';
import { DifficultyService } from '../difficulty.service';
import { IngredientService } from '../ingredient.service';
import { ImageService } from '../image.service';
import { Recipe } from '../recipe';
import { Category } from '../category';
import { Difficulty } from '../difficulty';
import { Ingredient } from '../ingredient';
import $ from "jquery";
@Component({
selector: 'app-create-recipe',
templateUrl: './create-recipe.component.html',
styleUrls: ['./create-recipe.component.css'],
providers: [RecipeService, ImageService]
})
export class CreateRecipeComponent implements OnInit {
create_recipe_form: FormGroup;
@Output() show_read_recipes_event = new EventEmitter();
imageId: number;
constructor(
private _recipeService: RecipeService,
private _imageService: ImageService,
formBuilder: FormBuilder,
private elem: ElementRef
) {
this.create_recipe_form = formBuilder.group({
name: ["", Validators.required],
description: ["", Validators.required],
image_id: ''
});
}
ngOnInit() {
}
createRecipe(): void {
this._recipeService.createRecipe(this.create_recipe_form.value)
.subscribe(
recipe => {
console.log(recipe);
this.readRecipes();
},
error => console.log(error)
);
}
readRecipes(): void {
this.show_read_recipes_event.emit({ title: "Read Recipes" });
}
uploadImage(e) {
let files = this.elem.nativeElement.querySelector('#selectFile').files;
let formData = new FormData();
let file = files[0];
formData.append('selectFile', file, file.name);
this._imageService.uploadImage(formData)
.subscribe(
image => {
console.log(image);
this.addImageIdToHtml(image)
e.preventDefault();
e.stopPropagation();
},
error => console.log(error)
);
}
addImageIdToHtml(image){
this.imageId = image[0];
$("#image_id").val(this.imageId);
$("#image_id").text(this.imageId);
}
}
jQuery直接操纵DOM,但是在角度形式的情况下,您可以创建和破坏式式实例,并修改DOM并不一定意味着更改form实例值。我建议您使用Angular自己的功能来管理形式的价值更改。尝试将您的AddimageIdToHtml更改为以下内容:
addImageIdToHtml(image){
this.imageId = image[0];
this.create_recipe_form.patchValue( {
"image_id" : this.imageId
} );
}