Adding elements to an array is not functioning as expected in TypeScript

Question

Adding elements to an array is not functioning as expected in TypeScript

I have successfully implemented a table using MatTableModule in Angular with Typescript.

Everything works perfectly when I assign values to the datasource like this:

let dataRow = {name: dealerInfo.name, address: dealerInfo.address, town: dealerInfo.town, contact: dealerInfo.contact};
this.dataSource = [dataRow];

However, when attempting to add rows dynamically by using push(), it doesn't work and the data is not displayed in the HTML. Here's what I tried:

let dataRow = {name: dealerInfo.name, address: dealerInfo.address, town: dealerInfo.town, contact: dealerInfo.contact};
this.dataSource.push(dataRow);

This is how my data source is currently defined:

dataSource: any [] = [];

What is the correct way to add elements dynamically to the data source?

angular typescript angular-material

Answer 1

Answer №1

When creating a MatTableDatasource, it is important to follow the correct procedure by initializing an instance of it and passing it as the [dataSource] property

dataSource: MatTableDataSource<any> = new MatTableDataSource<any>();

You can provide initial data in the constructor and then add more data using the data property

this.dataSource.data.push(dealerInfo);

Instead of using any, consider creating an interface for better type safety

export interface TableRow {
    name: string;
    ...
}

and

new MatTableDataSource<TableRow>();

To learn more about DataSources:

DataSource

In most practical scenarios, providing the table with a DataSource instance is the ideal approach to handle data efficiently. The DataSource plays a crucial role in managing sorting, filtering, pagination, and data retrieval specific to the application.

Answer 2

When creating a MatTableDatasource, it is important to follow the correct procedure by initializing an instance of it and passing it as the [dataSource] property

dataSource: MatTableDataSource<any> = new MatTableDataSource<any>();

You can provide initial data in the constructor and then add more data using the data property

this.dataSource.data.push(dealerInfo);

Instead of using any, consider creating an interface for better type safety

export interface TableRow {
    name: string;
    ...
}

and

new MatTableDataSource<TableRow>();

To learn more about DataSources:

DataSource

In most practical scenarios, providing the table with a DataSource instance is the ideal approach to handle data efficiently. The DataSource plays a crucial role in managing sorting, filtering, pagination, and data retrieval specific to the application.

Answer 3

Answer №2

Thanks to the assistance of @baao, I was able to successfully resolve the issue by implementing the following solution:

// Variables declaration.
rowDataArr: RowData[] = [];
dataSource: MatTableDataSource<RowData> = new MatTableDataSource<RowData>();

After receiving data from the backend, I performed the following actions:

valuesFromBackend.forEach(rowData=> {
this.rowDataArr.push(rowData);
});
this.dataSource.data = this.rowDataArr;

Answer 4

Thanks to the assistance of @baao, I was able to successfully resolve the issue by implementing the following solution:

// Variables declaration.
rowDataArr: RowData[] = [];
dataSource: MatTableDataSource<RowData> = new MatTableDataSource<RowData>();

After receiving data from the backend, I performed the following actions:

valuesFromBackend.forEach(rowData=> {
this.rowDataArr.push(rowData);
});
this.dataSource.data = this.rowDataArr;

Adding elements to an array is not functioning as expected in TypeScript

Answer №1

Answer №2

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