Ensure the initial word (or potentially all words) of a statement is in uppercase in Angular 2+

Question

Ensure the initial word (or potentially all words) of a statement is in uppercase in Angular 2+

Struggling with capitalizing words in an Angular 2 template (referred to as view) led to an error in the console and the application failing to load, displaying a blank page:

Error: Uncaught (in promise): Error: Template parse errors: The pipe 'capitalize' could not be found

The objective is as follows, using examples below with a hardcoded string instead of a variable in the Angular 2 component:

Capitalize only the first word of the sentence if no argument is provided.

 {{ 'heLlo woRld' | capitalize }} // outputs "HeLlo woRld" - Only "H" is capitalized

Capitalize all words of the string by passing the argument 'all'.

{{ 'heLlo woRld' | capitalize:'all' }} // outputs "HeLlo WoRld" - Both "H" and "W" are capitalized

Additional edge cases to consider:

 {{ 'a' | capitalize }}                   // outputs "A"

 {{ 'a' | capitalize:'all' }}             // outputs "A"

 {{ '' | capitalize }}                    // outputs nothing

 {{ '' | capitalize:'all' }}              // outputs nothing

 {{ null | capitalize }}                  // outputs nothing

 {{ null | capitalize:'all' }}            // outputs nothing

Keep in mind that the solution should be JS-based without the use of third-party libraries like jQuery, underscore, or lodash. It should adhere to Typescript and ES6 standards.

javascript typescript ecmascript-6 angular2-template angular2-pipe

Answer 1

Answer №1

Initially, I had the assumption that angular 2 comes equipped with a pre-built "capitalize" pipe just like it has the "uppercase" pipe readily available. To tackle this issue, I decided to create my own "capitalize" pipe:

Start by creating a file named: capitalize.pipe.ts

If you're using angular-cli, you have the option to generate the aforementioned file using the command: ng g pipe capitalize

NOTE: Don't forget to make adjustments in your module file (e.g., home.module.ts) to incorporate the newly created/generated pipe.

Proceed to modify the newly created/generated file in the following manner:

import { Pipe, PipeTransform } from '@angular/core';

// To adhere to DRY principles, establish a reusable function that converts a 
// (word or sentence) to title case

const toTitleCase = (value) => {
  return value.substring(0, 1).toUpperCase() + value.substring(1);
  // alternatively, you can also utilize: 
  // return value.charAt(0).toUpperCase() + value.slice(1);
};

@Pipe({
  name: 'capitalize'
})
export class CapitalizePipe implements PipeTransform {

  transform(value: any, args?: any): any {
    if (value) {
      if (args === 'all') {
        return value.split(' ').map(toTitleCase).join(' ');
      } else {
        return toTitleCase(value);
      }
    }
    return value;
  }

}

Once the above steps are completed, you can seamlessly utilize the pipe in your template (also known as view) as shown below:

{{ 'heLlo woRld' | capitalize }} // generates "HeLlo woRld" - Only the first letter "H" is capitalized

{{ 'heLlo woRld' | capitalize:'all' }} // produces "HeLlo WoRld" - Both the letters "H" and "W" are capitalized

Answer 2

Initially, I had the assumption that angular 2 comes equipped with a pre-built "capitalize" pipe just like it has the "uppercase" pipe readily available. To tackle this issue, I decided to create my own "capitalize" pipe:

Start by creating a file named: capitalize.pipe.ts

If you're using angular-cli, you have the option to generate the aforementioned file using the command: ng g pipe capitalize

NOTE: Don't forget to make adjustments in your module file (e.g., home.module.ts) to incorporate the newly created/generated pipe.

Proceed to modify the newly created/generated file in the following manner:

import { Pipe, PipeTransform } from '@angular/core';

// To adhere to DRY principles, establish a reusable function that converts a 
// (word or sentence) to title case

const toTitleCase = (value) => {
  return value.substring(0, 1).toUpperCase() + value.substring(1);
  // alternatively, you can also utilize: 
  // return value.charAt(0).toUpperCase() + value.slice(1);
};

@Pipe({
  name: 'capitalize'
})
export class CapitalizePipe implements PipeTransform {

  transform(value: any, args?: any): any {
    if (value) {
      if (args === 'all') {
        return value.split(' ').map(toTitleCase).join(' ');
      } else {
        return toTitleCase(value);
      }
    }
    return value;
  }

}

Once the above steps are completed, you can seamlessly utilize the pipe in your template (also known as view) as shown below:

{{ 'heLlo woRld' | capitalize }} // generates "HeLlo woRld" - Only the first letter "H" is capitalized

{{ 'heLlo woRld' | capitalize:'all' }} // produces "HeLlo WoRld" - Both the letters "H" and "W" are capitalized

Answer 3

Answer №2

Transforming the first letter of every word to uppercase:

function capitalWords(str){
    str=str.split(" ")
    for(var i=0 ; i<str.length ;i++){
        str[i]= str[i][0].toUpperCase()+str[i].substring(1)
    }
    return str.join(" ")
}


console.log(capitalWords("and this is a test !"))

Answer 4

Transforming the first letter of every word to uppercase:

function capitalWords(str){
    str=str.split(" ")
    for(var i=0 ; i<str.length ;i++){
        str[i]= str[i][0].toUpperCase()+str[i].substring(1)
    }
    return str.join(" ")
}


console.log(capitalWords("and this is a test !"))

Ensure the initial word (or potentially all words) of a statement is in uppercase in Angular 2+

Answer №1

Answer №2

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