I try to get content asset is online or not. I know that when we change online attribute to no from sandbox we won't see asset but currently asset is inside a modal, so that modal shows up with no content. That's why I try to check whether asset is online or not.
<div class="base_modal ${isOnline ? '' : 'd-none'}">
<iscontentasset aid="my_asset" />
</div>
I tried to call isOnline() function in isml but it is not worked.
Try this.
<isset name="myAsset" value="${require("dw/content/ContentMgr").getContent("my_asset")}" scope="page" />
<isif condition="${myAsset && myAsset.online}">
<iscontentasset aid="${myAsset.ID}" />
</isif>
You can also try replacing "iscontentasset" with "isprint"
<isprint value="${myAsset.custom && myAsset.custom.body && myAsset.custom.body.markup}" encoding="off"/>