React Native – Image Require Module using Dynamic Names

I’m currently building a test app using React Native. The Image module thus far has been working fine.

For example, if I had an image named avatar, the below code snippet works fine.

<Image source={require('image!avatar')} />

But if I change it to a dynamic string, I get

<Image source={require('image!' + 'avatar')} />

I get the error:

Requiring unknown module "image!avatar". If you are sure the module is there, try restarting the packager.

Obviously, this is a contrived example, but dynamic image names are important. Does React Native not support dynamic image names?

Answer

This is covered in the documentation under the section “Static Resources“:

The only allowed way to refer to an image in the bundle is to literally write require(‘image!name-of-the-asset’) in the source.

// GOOD
<Image source={require('image!my-icon')} />

// BAD
var icon = this.props.active ? 'my-icon-active' : 'my-icon-inactive';
<Image source={require('image!' + icon)} />

// GOOD
var icon = this.props.active ? require('image!my-icon-active') : require('image!my-icon-inactive');
<Image source={icon} />

However you also need to remember to add your images to an xcassets bundle in your app in Xcode, though it seems from your comment you’ve done that already.

http://facebook.github.io/react-native/docs/image.html#adding-static-resources-to-your-app-using-images-xcassets