Are there any good tutorials for using sitemesh in a grails application?

Question

I'm a pretty experienced Grails developer, but most of my experience has been with using grails for serving up JSON/XML to a flex app and some relatively simple HTML websites.

I've been diving deeper into using the sitemesh integration in grails and I'm struggling a little to find best practices for some more complex configurations, and I'm curious if there are any good tutorials or examples out there. The original Sitemesh website isn't that useful as the tags it talks about aren't directly exposed in grails.

A google search is mostly showing old mailing list posts and some vanilla sitemesh stuff which is helping me to move a little further along, but it's a lot of trial and error.

I fully understand how the basic g:layoutTitle, g:layoutHead, and g:layoutBody tags work. Those are easy and well documented.

The kinds of things that I'd like to see examples for:

• g:applyLayout - the documentation on this is weak and I don't fully understand the uses suggested in the main docs. How is this different than setting the meta name='layout' content='foo' property?

• g:pageProperty - some better examples on how to pull and use properties into the main template by setting the values as meta tags in the page that's being decorated. The grails docs on pageProperty show only the onload attribute from the body being brought forward. I think you can also use meta tag values here as well, anything else?

• can you use multiple levels of sitemesh layouts? My testing seems to make me think that I can't, but that seems to reduce reusability. I think that the answer here is some usage of the g:applyLayout, but that's where I'm struggling the most.

Solution 1

Well, I can answer a bit:

Your first and third questions are related, as you can't chain layouts using the meta tag.

Your final page should have a meta tag as you suggest, but if you want to layer a layout on top of another layout, you put a g:applyLayout tag at the top of the child layout, pointing at the parent.

In your edit.gsp, you'd have:

<meta name="layout" content="editTemplate" />

and in editTemplate.gsp, you'd have:

<g:applyLayout name="baseTemplate" >
<!-- the html for the editTemplate -->
</g:applyLayout>

so edit.gsp would use editTemplate.gsp, which would use baseTemplate.gsp as a base layout. You can chain those as needed.

I haven't used g:pageProperty at all, so I can't throw you better examples there, sorry.

Solution 2

The Sitemesh together with Grails is a very very powerful feature. The more I use it - the more I love it. You can decorate any part of our web site: you can have layout for error messages, tooltips, news lines, comments, etc, etc. Just to note that you can do even that with in your pages and have multiple levels of decoration (no <content> needed):

/view/layout/inline-error-message.gsp

<span class="errorMessageInSomeFancyBox">
    <span class="errorIcon"></span>
    <g:layoutBody />
<span>

/views/book/create.gsp

<%-- let's decorate our error message with some fancy box --%>
<g:applyLayout name="inline-error-message">${some.error.message}</g:applyLayout>

Comments

[npiv]

This should get you going example wise Grails Goodness - Applying layouts in layouts

[Tomasz Kalkosiński]

It's the same as templates with g:render. Is there any difference?

[igor]

This implementation is much cleaner if you have literally hundreds of templates. You don't want to end up with hundreds of g:renders and have many many properties in "${quotes}". This is easier to read and maintain. For small web site it does not make a difference.