验证 angular 表单和 Json（已实施基本验证）

Question

当我们将鼠标悬停在 table 的第一列上时，会出现一个工具提示，然后单击工具提示垫对话框中的按钮会打开。

该对话框包含 2 个部分左侧和编辑 json 和。左边是选中哪一行，右边显示的是对应的数据json。

1) 基本表单验证有效，但我需要显示一些消息（如果表单无效）以防用户编辑 json 并尝试单击按钮。（尝试使用 blur [ngModelOption] [ngFormOption] onUpdate 属性但无法实现）

对于 json 部分，基本验证也有效，但对于以下几点，如何提供验证：

1) 如果我将密钥设为空字符串，它不会验证。

2) 我怎样才能强制指定一个特定的密钥。

Stackblitz link https://stackblitz.com/edit/angular-mat-tooltip-qxxgcp?file=app%2Falert-dialog%2Falert-dialog.component.html

警报摘录-dialog.component.ts

<form #jsonform="ngForm" (ngSubmit)="onAddNewAlert()">
            <json-input [(ngModel)]="data.data[incomingSelectedAlert].conditionals" name="result"></json-input>
            <button type="submit" class="btn btn-success alertButtonSubmit" [disabled]="jsonform.invalid">Add As New Alert</button>
</form>

json-input.component （我有 NG_VALIDATORS 和 valdidate 函数执行基本的 json 验证）

@Component({
selector: 'json-input',
template:
    `
    <style>
     textarea {
     height: 421px;
     width: 480px;
     resize: none;
    }
    </style>
    <textarea
      [value]="jsonString" 
      (change)="onChange($event)" 
      (keyup)="onChange($event)">
    </textarea>
    `,
providers: [
{
  provide: NG_VALUE_ACCESSOR,
  useExisting: forwardRef(() => JsonInputComponent),
  multi: true,
},
{
  provide: NG_VALIDATORS,
  useExisting: forwardRef(() => JsonInputComponent),
  multi: true,
}]       
})
export class JsonInputComponent implements ControlValueAccessor, Validator {
private jsonString: string;
private parseError: boolean;
private data: any;

// this is the initial value set to the component
public writeValue(obj: any) {
    if (obj) {
        this.data = obj;
        // this will format it with 4 character spacing
        this.jsonString = JSON.stringify(this.data, undefined, 4); 
    }
}

// registers 'fn' that will be fired wheb changes are made
// this is how we emit the changes back to the form
public registerOnChange(fn: any) {
    this.propagateChange = fn;
}

// validates the form, returns null when valid else the validation object
// in this case we're checking if the json parsing has passed or failed from the onChange method
public validate(c: FormControl) {
    return (!this.parseError) ? null : {
        jsonParseError: {
            valid: false,
        },
    };
}

// not used, used for touch input
public registerOnTouched() { }

// change events from the textarea
private onChange(event) {

    // get value from text area
    let newValue = event.target.value;

    try {
        // parse it to json
        this.data = JSON.parse(newValue);
        this.parseError = false;
    } catch (ex) {
        // set parse error if it fails
        this.parseError = true;
    }

    // update the form
    this.propagateChange(this.data);
}

// the method set in registerOnChange to emit changes back to the form
private propagateChange = (_: any) => { };
}

Answer 1

我已经通过以下步骤完成了您需要的操作：

将 json 表单转换为反应式表单而不是模板表单（使用模板表单并在 TypeScript 代码中检索 NgForm 指令不是一个好习惯）
将 forbiddenFields（包含空字符串，因为它是 JS 中的实际有效键）和 mandatoryFields 添加到 JsonInputComponent
```
mandatoryFields: string[] = ["conditionals", "offset", "alert"];
forbiddenFields: string[] = [""];
```

在onChange函数中实现字段检查：

private onChange(event) {
    // get value from text area
    let newValue = event.target.value;

    try {
        // parse it to json

        this.data = JSON.parse(newValue);
        const datakeys = Object.keys(this.data);

        const containsForbiddenFields = datakeys.some(x => this.forbiddenFields.indexOf(x) >= 0);
        const containsMandatoryFields = this.mandatoryFields.every(x => datakeys.indexOf(x) >= 0);
        this.parseError = containsForbiddenFields || !containsMandatoryFields;
    } catch (ex) {
        // set parse error if it fails
        this.parseError = true;
    }

    // update the form
    this.propagateChange(this.data);
}

对于完整的工作解决方案，这里是分叉的 Stackblitz

Answer 2

我已按照以下步骤操作并根据要求更新了您的代码，它似乎工作正常：

For adding validations to check empty string and mandatory keys in nested objects, I have added logic on ngOnInit() method when value of form changes in AlertDialogComponent with the help of control value accessor.

添加了这些变量以验证表单并获取 JSON 对象的键，

isFormValid = true;
mandatoryField = ['conditionals', 'offset', 'alert', 'mTitle'];
allMandatoryFieldsExists: boolean;

在这里附上我的解决方案和主要代码，Stackblitz

this.jsonform.statusChanges.subscribe(() => {
        let data = this.jsonform.value.result;
        let keys = [];
        if(data) {            
          for(var i in data) {
            keys.push(i);
            if(i === 'offset' && data[i] === '') {
              this.isFormValid = false;
              return;
            } else {
              this.isFormValid = true;
            }

            if(i === 'conditionals') {
              for(var j in data[i][0]) {
                keys.push(j);
                if(data[i][0][j] === '') {
                  this.isFormValid = false;
                  return;
                } else {
                  this.isFormValid = true;
                }
              }
            }

            if(i === 'alert') {
              for(var j in data[i]) {
                keys.push(j);
                if(data[i][j] === '') {
                  this.isFormValid = false;
                  return;
                } else {
                  this.isFormValid = true;
                }
              }
            }
          }

          this.allMandatoryFieldsExists = this.mandatoryField.every(x => keys.indexOf(x) >= 0);
        }

        if(this.jsonform.dirty && (!this.isFormValid || !this.allMandatoryFieldsExists)){
            console.log("form is dirty and not valid")
            // this.alertService.error("Json not correct. Please fix!");
        }else{
            console.log("form is dirty but valid")
        }
      });

验证 angular 表单和 Json（已实施基本验证）

To Validate angular form and Json(Basic validaton already implemented)

javascript

json

angular

angular-material2