Question

Is there a way to convert a byte array to base64 in a Freemarker template? Something like:

<img src="data:image/jpeg;base64,${photo.data?base64}" />

Thanks.

Answer 1

There’s no built-in way in the current release. (But of course you can call your own method to do it.)

The object whose methods you want to call must be put into the data-model (i.e. the template context). (For statics: freemarker.org/docs/pgui_misc_beanwrapper.html#autoid_55)

But, for easier maintenance, I prefer this: create class com.foo.Base64EncoderMethod implements TemplateMethodModelEx (that calls Base64.encodeBase64 internally), then create a template lib/utils.ftl (if you don’t already have something like that) and in that, call <#assign base64Encode = 'com.foo.Base64EncoderMethod'?new()>. Then in the templates, call <#import '/lib/utils.ftl' as u> and ${u.base64Encode(photo.data)}