What is the process for managing multiple selections using checkbox code?

Question

What is the process for managing multiple selections using checkbox code?

I have been following the official tutorial for ag-grid and I've reached a point where I need to manipulate information related to selected checkboxes. However, the documentation lacks detail on how the code actually functions. It might be understandable since it's not their responsibility to provide in-depth explanations. But as someone with limited experience working with Angular technology, I find it challenging to truly grasp the workings of the code!

The html file instructs me to add the following:

<button (click)="getSelectedRows()">Get Selected Rows</button>

And in app.component.ts, I need to include this:

getSelectedRows() {  
        const selectedNodes = this.agGrid.api.getSelectedNodes();   
        const selectedData = selectedNodes.map(node => node.data);   
        const selectedDataStringPresentation = selectedData.map( node => node.make + ' ' + node.model).join(', ');   
        alert('Selected nodes: ${selectedDataStringPresentation}');   
    }

If there is someone who can explain what exactly the typescript code is doing, that would be greatly appreciated. Thank you!

javascript angular typescript ag-grid ag-grid-ng2

Answer 1

Answer №1

It appears that agGrid is the platform where your simulated data is stored, retrieving an array of information from elsewhere.
The array selectedData is generated by converting (without modifying the original array) the selectedNodes array and extracting only the data property from each node.
selectedDataStringPresentation performs a similar operation, but this time it compiles formatted strings by combining the make and model properties of each object in selectedData.

You may be overlooking the implementation of ES6 (JavaScript standard) functions used in this context, particularly the map() function.

You can reference the official documentation for the map() function on arrays here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map

In essence, the map() function cycles through an array, applying a specified function to each element and returning the results as a new array.

To illustrate with selectedData, you can interpret the process like this:

Iterate through each object in selectedNodes, extract the data property, and store in a new array.

This feature proves handy when handling distinct arrays with varied purposes. For instance, if you have a service containing a catalog of objects and receive an array of IDs representing those objects from a backend service, you can employ the map() function to effortlessly convert the array of IDs into an array of corresponding objects from your service.

Answer 2

It appears that agGrid is the platform where your simulated data is stored, retrieving an array of information from elsewhere.
The array selectedData is generated by converting (without modifying the original array) the selectedNodes array and extracting only the data property from each node.
selectedDataStringPresentation performs a similar operation, but this time it compiles formatted strings by combining the make and model properties of each object in selectedData.

You may be overlooking the implementation of ES6 (JavaScript standard) functions used in this context, particularly the map() function.

You can reference the official documentation for the map() function on arrays here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map

In essence, the map() function cycles through an array, applying a specified function to each element and returning the results as a new array.

To illustrate with selectedData, you can interpret the process like this:

Iterate through each object in selectedNodes, extract the data property, and store in a new array.

This feature proves handy when handling distinct arrays with varied purposes. For instance, if you have a service containing a catalog of objects and receive an array of IDs representing those objects from a backend service, you can employ the map() function to effortlessly convert the array of IDs into an array of corresponding objects from your service.

Answer 3

Answer №2

Oh no! @Alex Beugnet beat me to the punch with an upvote. Nevertheless, I'll still post my response since I was in the middle of composing it.

Before diving into Enable Selection section of the guide, let's check your familiarity with TypeScript. Apologies if this seems basic, but clarity is key for understanding the logic behind your question.

In the "Enable Selection" part of the guide, you're essentially enabling multiple row selection in the grid and getting data from those selected rows upon button click.

To better understand what's happening with the getMultipleRows() function, visualize it using the Debugger in browsers like Chrome Developer Tools (press F12). It's highly recommended for grasping the underlying logic.

const selectedNodes

Let's say we select two rows - Porsche Boxster 72000 and Ford Mondeo 32000. Clicking 'Get Selected Rows' triggers the getSelectedRows() function:

const selectedNodes = this.agGrid.api.getSelectedNodes();

This line assigns the constant variable 'selectedNodes' RowNodes from AgGrid. By utilizing the AgGridNg2 method getSelectedNodes(), you receive an array in the form of:

[RowNode, RowNode] //(one for each selected row)

Each RowNode contains various properties as provided by AgGrid, but focus solely on the 'data' property for now.

const SelectedData

const selectedData = selectedNodes.map(node => node.data);

'selectedData' becomes an array of RowNode.data, extracting the data property from RowNodes into a new array. You can think of it as:

let selectedData = [];

for (let i = 0; i <= selectedNodes.length - 1; i++){
    selectedData[i] = selectedNodes[i].data;
}

The 'selectedData' would appear as:

[
    {
        make: "Porsche",
        model: "Boxster",
        price: 72000,
    },
    {
        make: "Ford",
        model: "Mondeo",
        price: 32000
    }
]

const selectedDataStringPresentation

const selectedDataStringPresentation = selectedData.map( node => node.make + ' ' + node.model).join(', ');

This step concatenates Make and Model from selectedData array into a single element with commas. Resulting in "Porsche Boxter, Ford Mondeo".

Lastly,

alert('Selected nodes: ${selectedDataStringPresentation}');

An alert will display the selectedDataStringPresentation array in the browser for viewing.

Answer 4

Oh no! @Alex Beugnet beat me to the punch with an upvote. Nevertheless, I'll still post my response since I was in the middle of composing it.

Before diving into Enable Selection section of the guide, let's check your familiarity with TypeScript. Apologies if this seems basic, but clarity is key for understanding the logic behind your question.

In the "Enable Selection" part of the guide, you're essentially enabling multiple row selection in the grid and getting data from those selected rows upon button click.

To better understand what's happening with the getMultipleRows() function, visualize it using the Debugger in browsers like Chrome Developer Tools (press F12). It's highly recommended for grasping the underlying logic.

const selectedNodes

Let's say we select two rows - Porsche Boxster 72000 and Ford Mondeo 32000. Clicking 'Get Selected Rows' triggers the getSelectedRows() function:

const selectedNodes = this.agGrid.api.getSelectedNodes();

This line assigns the constant variable 'selectedNodes' RowNodes from AgGrid. By utilizing the AgGridNg2 method getSelectedNodes(), you receive an array in the form of:

[RowNode, RowNode] //(one for each selected row)

Each RowNode contains various properties as provided by AgGrid, but focus solely on the 'data' property for now.

const SelectedData

const selectedData = selectedNodes.map(node => node.data);

'selectedData' becomes an array of RowNode.data, extracting the data property from RowNodes into a new array. You can think of it as:

let selectedData = [];

for (let i = 0; i <= selectedNodes.length - 1; i++){
    selectedData[i] = selectedNodes[i].data;
}

The 'selectedData' would appear as:

[
    {
        make: "Porsche",
        model: "Boxster",
        price: 72000,
    },
    {
        make: "Ford",
        model: "Mondeo",
        price: 32000
    }
]

const selectedDataStringPresentation

const selectedDataStringPresentation = selectedData.map( node => node.make + ' ' + node.model).join(', ');

This step concatenates Make and Model from selectedData array into a single element with commas. Resulting in "Porsche Boxter, Ford Mondeo".

Lastly,

alert('Selected nodes: ${selectedDataStringPresentation}');

An alert will display the selectedDataStringPresentation array in the browser for viewing.

What is the process for managing multiple selections using checkbox code?

Answer №1

Answer №2

const selectedNodes

const SelectedData

const selectedDataStringPresentation

Similar questions

Create efficient images using Node.js and express using sharp or canvas

There seems to be an issue with Kurento-rtsp2webrtc functionality on AWS

Angular material table footer calculations

Utilize Server Side Includes in your JavaScript code

What could be causing the concave walls in my ray casting engine when applying fisheye correction?

The Jest snapshot test fails to capture any styling applied to children components

Having a single quote within a double quote can cause issues with JavaScript code

Having trouble finding module: Unable to locate 'fs' - yet another hurdle with NextJS

What are some effective ways to integrate the WordPress API with ReactJS?

Peer dependency conflict detected: @angular/[email protected]

After the recent update to rc2, the Angular2 quickstart app has suddenly stopped functioning as expected

Issue with playing audio file using HowlerJS

pagination functionality incorporated into element ui tables

When using Websocket, an error message stating "Invalid frame header" will be triggered if a close message of 130 or more characters is sent

Implementation of chained if-else if statements using dot.js

Can anyone help me understand the meaning of this unfamiliar icon in WebStorm's autocomplete feature

The improved approach to implementing guards in Angular

Activate animation upon scrolling to specific element using Material-UI

Tips on filtering an array in a JSON response based on certain conditions in Angular 7

A guide to declaring MongoDB models in TypeScript across multiple files