Angular Mat-Table with Dynamic Columns generate and Data should be populated in horizontal way

Question

I have a requirement where I need to populate the mat-table with the below mentioned Array of JSON object in horizontal format.

Please find the input array :-

[{
        "SAMPLERULEID": 69,
        "SAMPLERULENAME": "Sample1",
        "SAMPLERULECONDITIONS": [{
                "SAMPLERULECONDITIONID": 148,
                "SAMPLERULEID": 69,
                "SAMPLERULENAME": "Sample1",
                "CONDITIONFIELDID": 1,
                "DISPLAYNAME": "Country",
                "OPERATOR": "=",
                "COUNT": 10
            },
            {
                "SAMPLERULECONDITIONID": 149,
                "SAMPLERULEID": 69,
                "SAMPLERULENAME": "Sample1",
                "CONDITIONFIELDID": 2,
                "DISPLAYNAME": "State",
                "OPERATOR": "=",
                "COUNT": 11
            },
            {
                "SAMPLERULECONDITIONID": 150,
                "SAMPLERULEID": 69,
                "SAMPLERULENAME": "Sample1",
                "CONDITIONFIELDID": 3,
                "DISPLAYNAME": "City",
                "OPERATOR": "=",
            },
            {
                "SAMPLERULECONDITIONID": 151,
                "SAMPLERULEID": 69,
                "SAMPLERULENAME": "Sample1",
                "CONDITIONFIELDID": 4,
                "DISPLAYNAME": "Town",
                "OPERATOR": "IS NULL"
            }
        ],
    },
    {
        "SAMPLERULEID": 80,
        "SAMPLERULENAME": "Sample123",
        "SAMPLERULECONDITIONS": [{
            "SAMPLERULECONDITIONID": 208,
            "SAMPLERULEID": 80,
            "SAMPLERULENAME": "Sample123",
            "CONDITIONFIELDID": 92,
            "DISPLAYNAME": "Date",
            "OPERATOR": "IS NOT NULL",
            "COUNT": 12
        }],
    },
    {
        "SAMPLERULEID": 74,
        "SAMPLERULENAME": "Sample2",
        "SAMPLERULECONDITIONS": [{
                "SAMPLERULECONDITIONID": 153,
                "SAMPLERULEID": 74,
                "SAMPLERULENAME": "Sample2",
                "CONDITIONFIELDID": 89,
                "DISPLAYNAME": "Primary",
                "OPERATOR": "IS NOT NULL",
                "COUNT": 5
            },
            {
                "SAMPLERULECONDITIONID": 156,
                "SAMPLERULEID": 74,
                "SAMPLERULENAME": "Sample2",
                "CONDITIONFIELDID": 90,
                "DISPLAYNAME": "Secondary",
                "OPERATOR": ">",
                "COUNT": 9
            },
            {
                "SAMPLERULECONDITIONID": 157,
                "SAMPLERULEID": 74,
                "SAMPLERULENAME": "Sample2",
                "CONDITIONFIELDID": 89,
                "DISPLAYNAME": "Third",
                "OPERATOR": "IS NULL",
                "COUNT": 99
            }
        ],
    }
]

and Needed the Mat-table output in the below format..

here the column names are generated dynamically depending upon the array by incrementing count by 1 for condition string.

Please find the .ts file...

  export class SamplePocComponent implements OnInit {
    
      lstRulesCheck: MatTableDataSource<any>;
    
  displayedColumns3: string[] = [
    'SAMPLERULENAME','DISPLAYNAME',
  ];
    
      displayedColumns4: any[] = ['SAMPLERULENAME'];
    
      payload: any[] = []; // This is the input XML which is posted in top of the discussion
    
      count: number;
    
      constructor() {}
    
      ngOnInit() {
        this.getSampleRules();
      }
    
      getSampleRules() {
    
        this.lstRulesCheck = new MatTableDataSource(this.payload);
    
        this.payload.forEach((element) => {
          if(element.SAMPLERULECONDITIONS[0] !== undefined) {
            if(element.SAMPLERULECONDITIONS.length > 0) {
              if(this.count > element.SAMPLERULECONDITIONS.length){
              } else {
                this.count = element.SAMPLERULECONDITIONS.length;
              }
            }
          }
        })
    
        for (let i = 1; i <= this.count; i++) {
          this.displayedColumns4.push('condition'+ i);
        }
      }
     getVal(col, payload) {

if (payload.SAMPLERULECONDITIONS[0] !== undefined) {
  this.value = col.substring(9) - 1;

  this.one = "";
  this.two = "";
  this.three = "";

  if (payload.SAMPLERULECONDITIONS && payload.SAMPLERULECONDITIONS[this.value] && payload.SAMPLERULECONDITIONS[this.value].DISPLAYNAME) {
    this.one = payload.SAMPLERULECONDITIONS[this.value].DISPLAYNAME;
  }
  if (payload.SAMPLERULECONDITIONS && payload.SAMPLERULECONDITIONS[this.value] && payload.SAMPLERULECONDITIONS[this.value].OPERATOR) {
    this.two = payload.SAMPLERULECONDITIONS[this.value].OPERATOR;
  }
  if (payload.SAMPLERULECONDITIONS && payload.SAMPLERULECONDITIONS[this.value] && payload.SAMPLERULECONDITIONS[this.value].COUNT) {
    this.three = payload.SAMPLERULECONDITIONS[this.value].COUNT;
  }


  //return this.one + this.two + this.three;

  if(this.one !== "" || this.two !== "" || this.three !== ""){
    return `<td mat-cell> ${this.one}</td>
    <td mat-cell> ${this.two}</td>
    <td mat-cell> ${this.three} </td>`
  } else {
    return "";
  }  
}

}

    }

Please find the Mat-table code.. As of now I am able to print only Sample Name..

<table mat-table [dataSource]="lstRulesCheck" class="mat-elevation-z8">
                <ng-container *ngFor="let col of displayedColumns4" [matColumnDef]="col">
        <th mat-header-cell *matHeaderCellDef> {{col}} </th>
        <ng-container *ngIf="col === 'SAMPLERULENAME'">
            <td mat-cell *matCellDef="let element1"> {{element1.SAMPLERULENAME}} </td>
        </ng-container>
        <ng-container *ngIf="col !== 'SAMPLERULENAME'">
            <td mat-cell style="word-break: break-all; max-width: 30px;padding-left: 5px;" *matCellDef="let element" [innerHTML]="getVal(col,element)"></td>
        </ng-container>
    </ng-container>

        <tr mat-header-row *matHeaderRowDef="displayedColumns4;sticky: true"></tr>
        <tr mat-row *matRowDef="let row; columns: displayedColumns4;"></tr>

    </table>

I am facing issue while adding the dynamic column names and data needs to be divided depending upon columns.

Could you please help me to achieve the above requirement (screenshot).

Answer 1

Implemented the below HTML file to have the columns generate dynamically and modified the ts file to get the corresponding data.

  getValue(element, colname){

    // if (element && element.SAMPLERULECONDITIONS[0] !== undefined) {
      var lastChar = colname.substr(colname.length - 1) - 1;      
      colname = colname.slice(0, -1); 

      if (element.SAMPLERULECONDITIONS && element.SAMPLERULECONDITIONS[lastChar]) {
        return (element["SAMPLERULECONDITIONS"][lastChar][colname]);
      }
   }

Corresponding HTML File :- Still I need to add Action tag at the end with EDIT and Delete row

<div class="data" #TABLE>
    <table mat-table [dataSource]="lstRulesCheck" class="mat-elevation-z8">
        <ng-container *ngFor="let col of displayedColumns1; let i = index" [matColumnDef]="col">
            <ng-container *ngIf="col === 'SAMPLERULENAME'">
                <th mat-header-cell *matHeaderCellDef> </th>
                <td mat-cell *matCellDef="let element"> {{element.SAMPLERULENAME}} </td>
            </ng-container>

            <ng-container *ngIf="col !== 'SAMPLERULENAME'">
                <th mat-header-cell *matHeaderCellDef> </th>
                <td mat-cell *matCellDef="let element">
                    {{getValue(element, col)}}
                </td>
            </ng-container>

        </ng-container>

        <ng-container *ngFor="let groupName of displayedGroupColumns; let i = index; let f=first"
            [matColumnDef]="groupName">

            <ng-container *ngIf="f; else colSpan">
                <th mat-header-cell *matHeaderCellDef [attr.colspan]="1">
                    Name
                </th>
            </ng-container>
            
            <ng-template #colSpan>
                <th mat-header-cell *matHeaderCellDef style="text-align: center;" [attr.colspan]="3">
                    {{groupName}}
                </th>
            </ng-template>
        </ng-container>

        <tr mat-header-row *matHeaderRowDef="displayedGroupColumns"></tr>
        <tr mat-row *matRowDef="let row; columns: displayedColumns1;"></tr>
    </table>
</div>

Answer 2

displayedColumns: string[] = ['SAMPLERULENAME','DISPLAYNAME1','OPERATOR1','COUNT1','DISPLAYNAME2','OPERATOR2','COUNT2','DISPLAYNAME3','OPERATOR3','COUNT3','DISPLAYNAME4','OPERATOR4','COUNT4'];
  dataSource = ELEMENT_DATA;

  getValue(element, colname){
   console.log(element);
   var lastChar = colname.substr(colname.length - 1);
   console.log(lastChar);
   colname = colname.slice(0, -1); 
   console.log(colname);
   
   if(element["SAMPLERULECONDITIONS" + lastChar]){
    return (element["SAMPLERULECONDITIONS" + lastChar][colname]);
   }
  }

<table mat-table [dataSource]="dataSource" class="mat-elevation-z8">

<!-- Position Column -->

<ng-container *ngFor="let col of displayedColumns; let i = index" [matColumnDef]="col">

<ng-container  *ngIf="col === 'SAMPLERULENAME'" matColumnDef="SAMPLERULENAME">
<th mat-header-cell *matHeaderCellDef> </th>
<td mat-cell *matCellDef="let element"> {{element.SAMPLERULENAME}} </td>
</ng-container>

<ng-container *ngIf="col !== 'SAMPLERULENAME'">
    <th mat-header-cell *matHeaderCellDef>  </th>
    <td mat-cell *matCellDef="let element">
    {{getValue(element, col)}}
    </td>      
  </ng-container>  
  
</ng-container>

<!-- Header row first group -->
<ng-container matColumnDef="header-row-first-group">
<th mat-header-cell *matHeaderCellDef 
    [style.text-align]="center"
    [attr.colspan]="1"> 
  Name
</th>
</ng-container>

<!-- Header row second group -->
<ng-container matColumnDef="header-row-second-group">
<th mat-header-cell *matHeaderCellDef [attr.colspan]="3"> Second group </th>
</ng-container>

<!-- Header row 3 group -->
<ng-container matColumnDef="header-row-3-group">
<th mat-header-cell *matHeaderCellDef [attr.colspan]="3"> Condition1 </th>
</ng-container>

<!-- Header row 4 group -->
<ng-container matColumnDef="header-row-4-group">
<th mat-header-cell *matHeaderCellDef [attr.colspan]="3">Condition2 </th>
</ng-container>

<!-- Header row 4 group -->
<ng-container matColumnDef="header-row-5-group">
<th mat-header-cell *matHeaderCellDef [attr.colspan]="3"> Condition3 </th>
</ng-container>



<tr mat-header-row *matHeaderRowDef="['header-row-first-group', 'header-row-second-group','header-row-3-group','header-row-4-group','header-row-5-group']"></tr>


<tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
</table>

<!-- Copyright 2018 Google Inc. All Rights Reserved.
  Use of this source code is governed by an MIT-style license that
  can be found in the LICENSE file at http://angular.io/license -->

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