_repr_html_ causes GETs

[jsignell]

Kind of hard to figure out where this issue should go since the code in question is in pystac itself. But the repercussions are more obvious on the pystac-client side.

The issue is that _repr_html_ implicitly triggers 5 GETs:

Just using pystac it looks like there are only two requests:

but I added the logging myself (#1096) so I might have missed some calls.

[gadomski]

Stuff like this is usually related to link resolution, especially w.r.t. getting the root (see: #960). But haven't looked at this specific issue yet, I'll update if/when I do.

[jsignell]

I think it comes from these bits in the jinja template:

pystac/pystac/html/Macros.jinja2

Lines 38 to 65 in ac95270

	{% macro items(parent) -%}
	{% if parent.get_items()|is_nonempty_generator %}
	<details>
	<summary style="margin-bottom: 10px; margin-top: 10px">
	<h4 style="margin-bottom: 0px; display: inline;">Items</h4>
	</summary>
	<i> Only the first item shown </i>
	{% for item in parent.get_items()|first %}
	{{ item._repr_html_() }}
	{% endfor %}
	</details>
	{% endif %}
	{%- endmacro %}
	{% macro children(parent) -%}
	{% if parent.get_children()|is_nonempty_generator %}
	<details>
	<summary style="margin-bottom: 10px; margin-top: 10px">
	<h4 style="margin-bottom: 0px; display: inline;">Children</h4>
	</summary>
	<i> Only the first child shown </i>
	{% for child in parent.get_children()|first %}
	{{ child._repr_html_() }}
	{% endfor %}
	</details>
	{% endif %}
	{%- endmacro %}

specifically these: parent.get_items()|first parent.get_children()|first

[gadomski]

Transferring to pystac as it's all related to code in that repo.

Two comments:

• High level, this seems like intentional behavior to produce rich HTML representations, so I'm not sure it's a bug/problem.
• Lower level, those double-requests (for the search and for the root) seem problematic and probably are a bug.

[jsignell]

I have an extreme proposal. Opening a PR now