React-intl, use api with Typescript

Updated:

After reading the docs about upgrade to 3.x, I found it has a simpler way, just use useIntl hook:

Sample code:

import { FormattedMessage, useIntl } from 'react-intl'


type Props = {
  placeholder: string,
}

function MyComponent({ placeholder }: Props) {
  const intl = useIntl()

  return (
    <input placeholder={intl.formateMessage({id: placeholder})} type="text"/>
  )
}

export default MyComponent

---

Old:

In the react-intl new version (3.12.0), we don't need @types/react-intl anymore, react-intl has its own type definition, and InjectedIntlProps doesn't exist anymore, it is named WrappedComponentProps instead.

My sample code:

import { FormattedMessage, injectIntl, WrappedComponentProps } from 'react-intl'

type Props = {
  placeholder: string,
} & WrappedComponentProps

function MyComponent({ placeholder, intl }: Props) {

  return (
    <input placeholder={intl.formateMessage({id: placeholder})} type="text"/>
  )
}

export default injectIntl(MyComponent)

The problem was due to the version of the typescript definition. When using @types/react-intl": "^2.2.0", it works like a charm.

(edit) Few changes needed to make it work :

//index.tsx
<IntlProvider locale={`fr-FR`} messages={messages_fr}>
  <NameForm/>
</IntlProvider>,

//nameForm.tsx
interface NameFormProps extends InjectedIntlProps {
  placeholder: string,
}

class NameForm extends React.Component<NameFormProps, {}> {

  render() {
    let namePlaceholder = this.props.intl.formatMessage({
       id: this.props.placeholder,
       defaultMessage: "name"
      });

    return (
      <form>
        <input placeholder={namePlaceholder} type="text"/>
      </form>
    );
}

export default injectIntl(NameForm);

While working with the same problem, I found that neither including InjectedIntlProps as a member, as mentioned in the question, nor extending from it, as mentioned in another answer, satisfies the type checker. When extending from InjectedIntlProps, the call to injectIntl checked, but using the resulting component in JSX expected me to provide an intl property. The following strategy resolved this though:

    interface NameFormProps {
        // Include all custom properties here.
    }

    class NameForm extends React.Component<NameFormProps & InjectedIntlProps, {}> {
        // Class body.
    }

    export default injectIntl(NameForm);

Neither of the existing solutions worked for me. Instead it was due to injectIntl inferring the properties to include InjectedIntlProps.

To fix it, I had to explicitly tell injectIntl what props the wrapped component should have:

interface NameFormProps {
}

class NameForm extends React.Component<NameFormProps & InjectedIntlProps> {
}

export default injectIntl<NameFormProps>(NameForm);

If there are no props, it needs to be changed slightly:

class NameForm extends React.Component<InjectedIntlProps> {
}

export default injectIntl<{}>(NameForm);