How to use pipe in ts not HTML

问题:

I adding text into html element from ts

like this

this.legend.append('text')
  .attr('x', legendRectSize + legendSpacing)
  .attr('y', legendRectSize - legendSpacing)
  .text(function(d) { return d; });

this will create html like

<text>Data will come here</text>

I want to use pipe to convert this data into some form how can I do that from ts code ?

and as I am creating this HTML dynamically I cannot use pipe like this

<text>{{Data will come here | pipename}} </text>

I am looking for somethig like

this.legend.append('text')
  .attr('x', legendRectSize + legendSpacing)
  .attr('y', legendRectSize - legendSpacing)
  .text(function(d) { return d; }).applypipe('pipename');

回答1:

First import your pipe in component. And then use your pipe in your component. Like this..

pipe.ts

/**
 * filter checkbox list
 */
@Pipe({ name: 'filter', pure: true })
export class FilterPipe{
  transform(items: any[], args: any): any {
    let filter = args.toString();
    if(filter !== undefined && filter.length !== null){
        if(filter.length === 0 || items.length ===0){
            return items;
        }else{
            return filter ? items.filter(item=> item.title.toLocaleLowerCase().indexOf(filter) != -1) : items;
        }
    }
  }
}

component.ts (Use in your typescript code)

const filterPipe = new FilterPipe();
const fiteredArr = filterPipe.transform(chkArray,txtSearch);

xyz.html (Use in your html file)

<ul>
    <li *ngFor="todo for todos | filter:'txtsearch'"> {{todo.name}} </li>
</ul>

回答2:

import pipe in the component

import { PipeName } from './pipename'

include it in the provides

@Component({
    selector: 'pipe-using-component',
    templateUrl: './pipe-using-component.html',
    providers: [
        PipeName
    ],
})

inject it in the constructor

export class PipeUsingComponent {
  constructor(private pipeName: PipeName)
   }

   var requiredResult = this.pipeName.transform(passvalue);
}

回答3:

If Pipename is your custom pipe then if you want to use the same in your ts file then you can use below code

import {Pipename} from './pipename';

Pipename.prototype.transform(arguments);//this is how u can use your custom pipe

回答4:

In your .ts

import {YourPipe} from '/pipePath';


let value = new YourPipe().transform(param);