DXA 1.7 : Render Component Content TBB 'expandLinkDepth'

Question

Multimedia Component A with metadata fields.
Multimedia Component A is linked in Component B.
Component B is linked in Component A.
CT A (embedded) with expandLinkDepth '2'.
Component A & CT A(embedded) is added in Page A and published.

DXA 1.7 webapplication is setup in such a way it should use CT output with expandLinkDepth '2'.

We have a scenario where Multimedia Component metadata fields are not available in DXA Models to display in page.

By increasing expandLinkDepth to '3', CT renders multimedia metadata in JSON output. we can able to get the multimedia metadata values in DXA models.

Will there be any impact on increasing the link levels in CM side TBB? any other options available in CD side to achieve the scenario?

Answer 1

In general, increasing expandLinkDepth can result in more data being embedded in published Pages and DCPs. Whether it does so and to which extent completely depends on your content model (how deep do your component links go?). The effect of increasing expandLinkDepth may vary from no difference at all to an exponential growth in data size.

Including unneccessary data results in longer rendering time, larger transport Packages and more time needed to retrieve/deserialize the data. So, you want to keep this setting as low as possible, so that you include just the amount of data you need in your implementation.

By default, you don’t have very granular control over the expand depth, so you will have to set it to the maximum depth you need in your implementation. If you find you have a few exceptions where you need a deeper expansion than in other places, you could consider using a copy of the “Render Page/Component Content” TBB with a different expandLinkDepth setting.

Since DXA 2.0, you can choose whether you want link expansion to happen on CM-side or on CD-side (in the DXA Model Service/Extension). This gives more granular control over link expansion.