In Adobe Campaign Standard how do you use data from a collection link in an email? For example I want to send an email using data from a transaction table, one customer may have 1 transaction, another may have 100 and others have anything in between. In Classic I could use a content block and query targetData.<name of collection link> .length to get how many transactions the customer had and then loop through these in the content block to build the email.
You can create a content block in ACS as well. To add the logic, you can refer to the "Order Confirmation - Products Collection" oob content block with syntax "context.rtEvent.ctx.products.length". It refers to the " rtEvent_EVTwe_SHOP_OrderConfirmation" schema (Administration > Development > Diagnosis > Data schemas). Similarly based on your custom resource schema, you can add logic in a custom content block.