Conditional processing within a Sightly/HTL component dependent upon position within a page - aem

Question

I've recently begun as an Ops dev on an AEM project, and we have a component (a table, that has a title, some copy and a field where the author can author some HTML to represent the contents of a table, with and elements. This, for whatever reason, has to sit within a component, called ArticleContainer. The title should have an H1 tag if the table is at the top of the page, and an H2 tag if it's anywhere lower down. I've tried using data-sly-test thus:
<sly data-sly-test.topOfPage="${table.firstPosition==true}">
<h1 data-sly-test="${table.headerCopy}" class="heading fontH2 headingLinear headingThick">
<span class="tableHeadingWrapper">${table.headerCopy # context='html'}</span>
</h1>
</sly>
<sly data-sly-test="${!topOfPage}">
<h2 data-sly-test="${table.headerCopy}" class="heading fontH2 headingLinear headingThick">
<span class="tableHeadingWrapper">${table.headerCopy # context='html'}</span>
</h2>
</sly>
Now, this kind of processing has worked elsewhere where the component doesn't sit within a container, but it seems that if it's in a container it always picks up the non-topOfPage condition. I assume there might be a way to maybe do the test within the container component & pass it down into the table component? How would one go about this, or if it's not possible, is there another method by which one might achieve this?

Answer 1

There are two things here:
What does table.firstPosition return? You should be able to debug this in your Sling Model or POJO and probably need to adjust the logic to account for intermediary containers.
HTL/Sightly has a data-sly-element that allows you to change the HTML element based on an expression, you could make your code shorter (and easier to maintain):
<h1 data-sly-test="${table.headerCopy}" data-sly-element="${table.firstPosition ? 'h1' : 'h2'}" class="heading fontH2 headingLinear headingThick">
<span class="tableHeadingWrapper">${table.headerCopy # context='html'}</span>
</h1>