What are the main differences between StringTemplate and FreeMarker?

Question

The net seems to be full of comparisons between Velocity and FreeMarker, and they seem to be reasonably equivalent. But there seems to be almost no comparisons between StringTemplate and FreeMarker!

So, what are the main differences between StringTemplate and FreeMarker?

My usage for them would be to generate HTML pages only. Out of the two, I would've expected FreeMarker to be the more suitable and more capable, as that seems to the more common one - but through a quick glance it seems that StringTemplate actually has more suitable features!

It would be great if someone who has used both would have time to comment - for the actual specifics, I can just read the documentation side by side, but I'd like something to get started with.

Corri

A quick clarification! I am not interested in the obvious differences - that StringTemplate is functional and has no loops etc and FreeMarker is almost a full blown programming language! I'm interested in concrete feature differences that come up during usage - where one thing is easily possible with one but really difficult with the other. – Corri

Answer 1

I designed ST to build jGuru after getting sick of the "code in template" model of JSP. Velocity and friends (i.e., every other engine i think) give you more power than you need. I used basically four features to build jGuru.com (as described in paper). More features are unnecessary and lead you to entangle your model into the template. If you're building a one-off prototype, that's ok and any engine is fine. Code in templates is ok in that case since you don't care about maintenance.

Another thing people seem to ignore: how the hell can a graphics designer read code in templates? They can't. So, how can they work on the templates then? Even changing the order of some elements can break your model. You really need the separation to work in commercial environment, unless you want a site that looks like a coder built the html ;)

Dither

You don't know enough about ST to be commenting! ;-) But seriously though, I was more interested in the other features, besides the model-view separation. Stuff like template inheritance, which is present in ST but not in FM, atleast not in the same way. It seems very odd that nobody seems to take StringTemplate in to consideration when comparing FreeMarker, Velocity or even XSLT. – Corri

hiya. yeah, inheritance is critical to avoid duplicating templates. I use it extensively in ANTLR code generation. I have basic, say, Java templates to generate parsers. If you want trees, I have to inject tree construction code and w/o duplicating entire Java group. If you turn on -debug, I need to inject debug event triggers. Sometimes both! Inheritance lets you describe the difference between plain Java output and Java output with debug/tree actions. – Dither

Inheritance is the thing that makes ST tempting! Otherwise, i don't like the overly strict mvc, as we have no mythical graphics designers that can't resist MVC changes and can't understand very simple VTL. – Patrick

It is, however, difficult to recommend using StringTemplate in a Servlet environment, because it is not threadsafe, nor is there any public commitment to making it so. – Sergei

Answer 2

The main difference is that StringTemplate strictly enforces model-view separation and you can't put logic in the templates and FreeMarker lets you put full of logic in the templates.. This at least at the beginning make it more difficult to use but it's more scalable. For example if you are generating code and you have no logic in the templates generating another port for another language is less tedious because you haven't to replicate logic in each template.

There's a paper from Terence Parr that explains the benefits from model-view separation

Lilongwe

Thanks, but do read my clarification on the question - the answer didn't really tell me anything I didn't know already. – Corri

paper link is broken now – Mesial