Angular translate service, interpolate params in nested json

You can also do this by using the translate pipe, so that you can remove the additional service dependency to your component.

<p *ngIf="!item?.isRemovable">
{{'i18n.dashboard.heading' 
| translate:{'TEXTTOFIND': 'STRINGTOREPLACE'} }}
</p>

Just make sure that your key i18n.test.key has this TEXTTOFIND interpolated. Something like below.

"heading": "This is with the interpolated {{TEXTTOFIND}} text."

Note the {{}} in the heading string and the STRINGTOREPLACE can be anything you wish.

According to the source of ngx-translate interpolation works only on strings:

export abstract class TranslateParser {
/**
 * Interpolates a string to replace parameters
 * "This is a {{ key }}" ==> "This is a value", with params = { key: "value" }
 * @param expr
 * @param params
 * @returns {string}
 */
abstract interpolate(expr: string | Function, params?: any): string;

This means you might need to use an array of keys instead of a non-leaf element:

this.translateService.get([
    'SampleField.Validation.MIN', 
    'SampleField.Validation.MAX'
  ], {
  // using hard coded value just as a sample
  min: 0, max: 2000
}).subscribe(translation => {
  console.log(translation);
});