Showing posts with label Lightning Web Components. Show all posts
Showing posts with label Lightning Web Components. Show all posts

Wednesday, 12 August 2020

Lightning Datatable Sorting in Lightning Web Components

Last time we talk about Lightning Datatable in Lightning Web Components (LWC). In this post we will talk about lightning datatable example with sorting in lightning web components. We can achieve the column sorting with the help of onsort attribute in datatable.

Lightning-datatable

Lightning datatable provides an onsort attribute which allow us to implement the sorting in lightning datatable. To enable the sorting on row you need to set sortable to true for the column and set sorted-By to match the fieldName attribute on the column. 


Use onsort event handler to update the table with the new column index and sort direction. The sort event returns the following parameter.
  1. fieldName : The fieldName that controls the sorting.
  2. sortDirection : The sorting direction. Valid options include 'asc' and 'desc'.

We can implement the sorting in LWC with following ways :-
  1. sorting locally 
  2. via apex call.

Local Sorting


We mostly implement this type of sorting when we know data elements in lightning datatable is small and limited

  1. Create Apex Class : To select certain contacts using SOQL, use an Apex method. Check this post to learn about how to Call Apex Methods in LWC.
    LWCDataTableSortingExample
    public with sharing class LWCDataTableSortingExample {
        @AuraEnabled(Cacheable=true)
        public static List <Contact> getContacts() {
            List<Contact> contList = [ SELECT Id, FirstName, LastName, Phone, Email
                                       FROM Contact
                                       LIMIT 10 ];
            return contList;
        }   
    }
  2. Create Lightning web component : Create one Lightning web component in your developer org or sandbox.
    dataTableSortingLWC.html
    <template>
        <lightning-card title="Data Sorting in Lightning Datatable in LWC" icon-name="standard:contact" >
            <br/>
            <div style="width: auto;">
                <template if:true={data}>
                    <lightning-datatable data={data}
                                         columns={columns}
                                         key-field="id"
                                         sorted-by={sortBy}
                                         sorted-direction={sortDirection}
                                         onsort={doSorting}

                                         hide-checkbox-column="true"></lightning-datatable>
                </template>
            </div>
        </lightning-card>
    </template>
    • In lightning datatable use sorted-by and sorted-direction attribute to define the direction and sorted column.
    • use onsort event to call javascript function to sort your local data.

    dataTableSortingLWC.js
    import {LightningElement, wire, track} from 'lwc';
    import getContacts from '@salesforce/apex/LWCDataTableSortingExample.getContacts';

    // datatable columns with row actions. Set sortable = true
    const columns = [ { label: 'FirstName', fieldName: 'FirstName', sortable: "true"},
                      { label: 'LastName', fieldName: 'LastName', sortable: "true"},
                      { label: 'Phone', fieldName: 'Phone', type: 'phone', sortable: "true"},
                      { label: 'Email', fieldName: 'Email', type: 'email', sortable: "true" },];

    export default class DataTableSortingLWC extends LightningElement {
        @track data;
        @track columns = columns;
        @track sortBy;
        @track sortDirection;
     
        @wire(getContacts)
        contacts(result) {
            if (result.data) {
                this.data = result.data;
                this.error = undefined;
            } else if (result.error) {
                this.error = result.error;
                this.data = undefined;
            }
        }

        doSorting(event) {
            this.sortBy = event.detail.fieldName;
            this.sortDirection = event.detail.sortDirection;
            this.sortData(this.sortBy, this.sortDirection);
        }

        sortData(fieldname, direction) {
            let parseData = JSON.parse(JSON.stringify(this.data));
            // Return the value stored in the field
            let keyValue = (a) => {
                return a[fieldname];
            };
            // cheking reverse direction
            let isReverse = direction === 'asc' ? 1: -1;
            // sorting data
            parseData.sort((x, y) => {
                x = keyValue(x) ? keyValue(x) : ''; // handling null values
                y = keyValue(y) ? keyValue(y) : '';
                // sorting values based on direction
                return isReverse * ((x > y) - (y > x));
            });
            this.data = parseData;
        }  
      
    }
    •  On which column you want to enable the sorting use sortable: "true"
    • Call your javaScript sorting method from onSorting event.
    dataTableSortingLWC.js-meta.xml
    <?xml version="1.0" encoding="UTF-8"?>
    <LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata" fqn="dataTableSortingLWC">
        <apiVersion>46.0</apiVersion>
        <isExposed>true</isExposed>
        <targets>
            <target>lightning__AppPage</target>
            <target>lightning__RecordPage</target>
            <target>lightning__HomePage</target>
        </targets>
    </LightningComponentBundle>
        

Sorting by Apex Call


We also have another way of data sorting with Apex class.

  1. Create Apex Class : Update your apex method and include sord column and sort order.

    public with sharing class LWCDataTableSortingExample {
        @AuraEnabled(Cacheable=true)
        public static List <Contact> getContacts(String field, String sortOrder) {
            String query;
            query  = 'SELECT Id, FirstName, LastName, Phone, Email FROM Contact';
            if(field != null && sortOrder !=null){
                query += ' ORDER BY '+field+' '+sortOrder;
            }

            return Database.query(query);
        }
    }
  2. Create Lightning web components :- No change required in html file.

    <template>
        <lightning-card title="Data Sorting in Lightning Datatable in LWC" icon-name="standard:contact" >
            <br/>
            <div style="width: auto;">
                <template if:true={data}>
                    <lightning-datatable data={data}
                                         columns={columns}
                                         key-field="id"
                                         sorted-by={sortBy}
                                         sorted-direction={sortDirection}
                                         onsort={doSorting}
                                         hide-checkbox-column="true"></lightning-datatable>
                </template>
            </div>
        </lightning-card>
    </template>


    import {LightningElement, wire, track} from 'lwc';
    import getContacts from '@salesforce/apex/LWCDataTableSortingExample.getContacts';

    // datatable columns with row actions. Set sortable = true
    const columns = [ { label: 'FirstName', fieldName: 'FirstName', sortable: "true"},
                      { label: 'LastName', fieldName: 'LastName', sortable: "true"},
                      { label: 'Phone', fieldName: 'Phone', type: 'phone', sortable: "true"},
                      { label: 'Email', fieldName: 'Email', type: 'email', sortable: "true" },];

    export default class DataTableSortingLWC extends LightningElement {
        @track data;
        @track columns = columns;
        @track sortBy='FirstName';
        @track sortDirection='asc';
     
        // retrieving the data using wire service
        @wire(getContacts,{field : '$sortBy',sortOrder : '$sortDirection'})
        contacts(result) {
            if (result.data) {
                this.data = result.data;
                this.error = undefined;
            } else if (result.error) {
                this.error = result.error;
                this.data = undefined;
            }
        }
        doSorting(event) {
            // calling sortdata function to sort the data based on direction and selected field
            this.sortBy = event.detail.fieldName;
            this.sortDirection = event.detail.sortDirection;
        }
    }
    •  Retrieving the data using wire service. Wire will automatically call your apex class when sort field or direction will change
    • Call onSorting method when sort event will fire. 

If you want to load to many record on one single page then use Lazy loading in dataTable.

Monday, 27 July 2020

Share Custom labels between Lightning Web Components

We know how to use custom label in lightning web components. What about if you have large list of labels and you want to to use in multiple LWC components? In this post we will talk about best practice to import bulk custom label in LWC and how to create utility class to import same set of label in multiple Lightning web components.

You can create a utility component that imports all the labels and then exposes them bundled together in one object via a method. Then your main component will have a cleaner list of imports.

Step 1) Create Utility Class.


Create a Lightning web component that contains only a single Js file. Like below structure

labelUtility
   ├──labelUtility.js
   └──labelUtility.js-meta.xml

Lets create one common label Utility component.

labelUtility.js
import header from '@salesforce/label/c.Header';
import title from '@salesforce/label/c.title';

const label = {
    header: header,
    title: title
};

export {label};
  • The module should only have a JS file & Metadata file in it, otherwise it will not work.
  • Just like with any Lightning web component, the folder name and the filename must be identical
  • Imports all the labels and then exposes them bundled together with export.

Step 2) How to use shared label Utility


Create new Lightning web component and import Js file with import statement like below

import { label  } from 'c/labelUtility';

Let see the full code.

import { LightningElement,track } from 'lwc';
import { label  } from 'c/labelUtility';
export default class CustomLabelDemo extends LightningElement {
    @track myLabel=label;
}     
  • Import JS file with import

<template>
    <lightning-card  title={myLabel.title} variant="narrow" icon-name="standard:opportunity">
        <p>{myLabel.header}</p>
    </lightning-card>
</template>   


Please share your feedback and comment if there is any better way to implement or your like this post.





Tuesday, 21 July 2020

Custom Label in Lightning Web Components (LWC)

In this post we will talk about how to use custom label in lightning web components (LWC). Custom labels are text values stored in Salesforce that can be translated into any language that Salesforce supports. We use custom labels to create multilingual applications. Let see how to access custom Label in Lightning Web Components.

To import a label in a Lightning Web Component, use @salesforce/label in an import statement

import labelName from '@salesforce/label/label-reference';
  1. labelName: It is name that refers to the label in LWC.
  2. labelReference: The name of the label in your org.
Custom Labels In Lightning Web Component(LWC) Example

create lightning web component in your sandbox or developer org.

customLabelDemo.html
<template>
    <lightning-card  title={label.title} variant="narrow" icon-name="standard:opportunity">
        <p>{label.header}</p>
    </lightning-card>
</template>
  • To use the labels in the template, use the same {property} syntax that you use to reference any JavaScript property

customLabelDemo.js
import { LightningElement } from 'lwc';
import header from '@salesforce/label/c.Header';
import title from '@salesforce/label/c.Title';
export default class CustomLabelDemo extends LightningElement {

    label = {
        header,
        title
    };
}
  • Use import statement to get the label in Lwc.
  • Then Expose the labels to use in the template using property
customLabelDemo.js-meta.xml
<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>48.0</apiVersion>
    <isExposed>true</isExposed>
    <targets>
        <target>lightning__AppPage</target>
        <target>lightning__RecordPage</target>
        <target>lightning__HomePage</target>
    </targets>
</LightningComponentBundle>

Result



Tuesday, 16 June 2020

Navigation Service in Lightning Web Components | Mixin


The Lightning navigation service allows you to navigate in Lightning Experience, Lightning Communities and the Salesforce app. To generate a URL or navigate to a page reference, use the lightning-navigation service wire adapters and functions.

A PageReference is a JavaScript object that describes the page type, its attributes, and the state of the page.

Step 1) Import lightning/navigation
import { NavigationMixin } from 'lightning/navigation';

Step 2) Apply the NavigationMixin function to your component’s base class.

export default class MyCustomElement extends NavigationMixin(LightningElement) {
}

Step 3) Call the navigation service’s [NavigationMixin.Navigate] function to dispatch the navigation request and open the New Course Delivery modal dialog.

onAddNewDelivery() {
     this[NavigationMixin.Navigate]({
         type: 'standard__objectPage',
         attributes: {
             objectApiName: 'Student__c',
             actionName: 'new'
         }
     });
 }

What is a Mixin?

A mixin lets us add functionality to a class without extending it. Useful when a class already extends a parent class, because a class can only extend a single parent.


Check this recording after 1st hours.





Thursday, 2 April 2020

Lightning Web Components Naming Convention

In this post we will talk about Lightning Web Components Naming Convention rules. We will also talk about example of PascalCase, camelCase or kebab-case and how those naming convention rules works in LWC.

Components Bundles

Lightning web component bundles include all below files by default. Its also have some Optional component like CSS, SVG Icon.




Lets see what is the naming convention :

Naming Convention / Rules for Components Bundles

  • Component name Must begin with a lowercase letter
  • Name must contain only alphanumeric or underscore characters
    • Can’t contain a hyphen (dash)
  • Must be unique in the namespace (No other Aura or LWC can have this name)
  • Can’t include whitespace
  • Can’t end with an underscore
  • Can’t contain two consecutive underscores
  • Folder and files names must have same “prefix name”.

HTML File


Use camel case to name your component and use kebab-case to reference a component in the markup. For example



JavaScript File


Java Script Class name should be in PascalCase like below example :

CSS File


  • Needs to be created in the component bundle
  • Has the same name as the component
  • Uses standard CSS syntax
  • Unlike Aura, no need for .THIS

What is the different between camelCase, PascalCase and kebab-case ?


camelCase : Each word in the middle of the respective phrase begins with a capital letter. for example apexHours.
PascalCase: It is same like Camel Case where first letter always is capitalized. for example ApexHours. 
kebab-case: Respective phrase will be transferred to all lowercase with hyphen(-) separating words. for example apex-hours.

Case Name camelCase PascalCase kebab-case
Example helloWorld HelloWorld hello-world
Where to use Folder
File Names
Property name in JS
Class in Java Script Component reference in markup
HTML attribure name

 
 
Please check below post on Lightning Web Components:-

Thanks.
Amit Chaudhary

Friday, 3 January 2020

Lightning Datatable Sorting in Lightning Web Components

Lightning Datatable Sorting in Lightning Web Components
Last time we talk about Lightning Datatable in Lightning Web Components (LWC). In this post we will talk about lightning datatable example with sorting. We know lightning-datatable component displays in tabular data and each column can be displayed based on the data type. We can also achieve the column sorting with the help of onsort attribute in datatable. I hope VsCode is already setup on you machine and you know how to create Lightning Web Component. If not please check our Get started with Salesforce lightning web components post.

Lightning-datatable

Lightning datatable provides an onsort attribute which allow us to implement the sorting in lightning datatable. To enable the sorting on row you need to set sortable to true for the column and set sorted-By to match the fieldName attribute on the column. 

Use onsort event handler to update the table with the new column index and sort direction. The sort event returns the following parameter.
  1. fieldName    The fieldName that controls the sorting.
  2. sortDirection    The sorting direction. Valid options include 'asc' and 'desc'.
 You can implement sorting locally or via apex call.

Local Sorting:

We mostly implement this type of sorting when we know data elements in lightning datatable is small and limited.

1) Create Apex Class. 

To select certain contacts using SOQL, use an Apex method. Check this post to learn about how to Call Apex Methods in LWC.

LWCDataTableSortingExample:
public with sharing class LWCDataTableSortingExample {
    @AuraEnabled(Cacheable=true)
    public static List <Contact> getContacts() {
        List<Contact> contList = [ SELECT Id, FirstName, LastName, Phone, Email
                                   FROM Contact
                                   LIMIT 10 ];
        return contList;
    }     
}

2) Create Lightning web component.

dataTableSortingLWC.html
<template>
    <lightning-card title="Data Sorting in Lightning Datatable in LWC" icon-name="standard:contact" >
        <br/>
        <div style="width: auto;">
            <template if:true={data}>
                <lightning-datatable data={data}
                                     columns={columns}
                                     key-field="id"
                                     sorted-by={sortBy}
                                     sorted-direction={sortDirection}
                                     onsort={doSorting}
                                     hide-checkbox-column="true"></lightning-datatable>
            </template>
        </div>
    </lightning-card>
</template>


dataTableSortingLWC.js
import {LightningElement, wire, track} from 'lwc';
import getContacts from '@salesforce/apex/LWCDataTableSortingExample.getContacts';

// datatable columns with row actions. Set sortable = true
const columns = [ { label: 'FirstName', fieldName: 'FirstName', sortable: "true"},
                  { label: 'LastName', fieldName: 'LastName', sortable: "true"},
                  { label: 'Phone', fieldName: 'Phone', type: 'phone', sortable: "true"},
                  { label: 'Email', fieldName: 'Email', type: 'email', sortable: "true" },];

export default class DataTableSortingLWC extends LightningElement {
    @track data;
    @track columns = columns;
    @track sortBy;
    @track sortDirection;
  
    @wire(getContacts)
    contacts(result) {
        if (result.data) {
            this.data = result.data;
            this.error = undefined;
        } else if (result.error) {
            this.error = result.error;
            this.data = undefined;
        }
    }

    doSorting(event) {
        this.sortBy = event.detail.fieldName;
        this.sortDirection = event.detail.sortDirection;
        this.sortData(this.sortBy, this.sortDirection);
    }

    sortData(fieldname, direction) {
        let parseData = JSON.parse(JSON.stringify(this.data));
        // Return the value stored in the field
        let keyValue = (a) => {
            return a[fieldname];
        };
        // cheking reverse direction
        let isReverse = direction === 'asc' ? 1: -1;
        // sorting data
        parseData.sort((x, y) => {
            x = keyValue(x) ? keyValue(x) : ''; // handling null values
            y = keyValue(y) ? keyValue(y) : '';
            // sorting values based on direction
            return isReverse * ((x > y) - (y > x));
        });
        this.data = parseData;
    }      
}

dataTableSortingLWC.js-meta.xml
<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata" fqn="dataTableSortingLWC">
    <apiVersion>46.0</apiVersion>
    <isExposed>true</isExposed>
    <targets>
        <target>lightning__AppPage</target>
        <target>lightning__RecordPage</target>
        <target>lightning__HomePage</target>
    </targets>
</LightningComponentBundle>

 

Sorting by Apex Call:

We also have another way of data sorting with Apex class.

1) Create Apex Class. 

LWCDataTableSortingExample:
public with sharing class LWCDataTableSortingExample {
    @AuraEnabled(Cacheable=true)
    public static List <Contact> getContacts(String field, String sortOrder) {
        String query;
        query  = 'SELECT Id, FirstName, LastName, Phone, Email FROM Contact';
        if(field != null && sortOrder !=null){
            query += ' ORDER BY '+field+' '+sortOrder;
        }
        return Database.query(query);
    }
}

2) Create Lightning web component.

dataTableSortingLWC.html
<template>
    <lightning-card title="Data Sorting by Apex" icon-name="standard:contact" >
        <br/>
        <div style="width: auto;">
            <template if:true={data}>
                <lightning-datatable data={data}
                                     columns={columns}
                                     key-field="id"
                                     sorted-by={sortBy}
                                     sorted-direction={sortDirection}
                                     onsort={doSorting}
                                     hide-checkbox-column="true"></lightning-datatable>
            </template>
        </div>
    </lightning-card>
</template>

dataTableSortingLWC.js
import {LightningElement, wire, track} from 'lwc';
import getContacts from '@salesforce/apex/LWCDataTableSortingExample.getContacts';

// datatable columns with row actions
const columns = [ { label: 'FirstName', fieldName: 'FirstName', sortable: "true"},
                  { label: 'LastName', fieldName: 'LastName', sortable: "true"},
                  { label: 'Phone', fieldName: 'Phone', type: 'phone', sortable: "true"},
                  { label: 'Email', fieldName: 'Email', type: 'email', sortable: "true" },];

export default class DataTableSortingLWC extends LightningElement {
    // reactive variable
    @track data;
    @track columns = columns;
    @track sortBy='FirstName'
    @track sortDirection='asc';
  
    // retrieving the data using wire service
    @wire(getContacts,{field : '$sortBy',sortOrder : '$sortDirection'})
    contacts(result) {
        if (result.data) {
            this.data = result.data;
            this.error = undefined;
        } else if (result.error) {
            this.error = result.error;
            this.data = undefined;
        }
    }

    doSorting(event) {
        // calling sortdata function to sort the data based on direction and selected field
        this.sortBy = event.detail.fieldName;
        this.sortDirection = event.detail.sortDirection;
        this.sortData(this.sortBy, this.sortDirection);
    }

    sortData(fieldname, direction) {
        let parseData = JSON.parse(JSON.stringify(this.data));
        // Return the value stored in the field
        let keyValue = (a) => {
            return a[fieldname];
        };
        // cheking reverse direction
        let isReverse = direction === 'asc' ? 1: -1;
        // sorting data
        parseData.sort((x, y) => {
            x = keyValue(x) ? keyValue(x) : ''; // handling null values
            y = keyValue(y) ? keyValue(y) : '';
            // sorting values based on direction
            return isReverse * ((x > y) - (y > x));
        });

        // set the sorted data to data table data
        this.data = parseData;
    }      
}


Please check below post on Lightning Web Components:-

Thanks
Amit Chaudhary