Block preview — block preview window
Block preview — a preview window that shows the result of the block in real time. It is the same on the settings screens for recommendation and dynamic blocks and is opened by the “Open in modal” button.
Why is this needed
When you are configuring a block (strategy, filters, audience) — you want to immediately understand which products will appear in the output with such settings. The block preview allows you to check this without publishing the block on the site, without leaving the admin panel.
Basic tab — product list
The window consists of three tabs: Basic | Explanation | Investigate.
The first tab is Basic. It shows a table of products that will appear in the block output with the current settings:
- Products are automatically loaded as you scroll down the table.
- The table includes previews of the cards (name, image, tag, brief metadata).
- For the Similar products block, the preview is built based on the saved block — there is a hint on the screen saying “The preview is generated based on the saved block — form changes will be applied after saving.” To see the result of the edits, save the block first.
Explanation tab — why the product is in the output
The second tab is Explanation. It answers the question “why this particular product made it into the block”: under each product card, badges are displayed with the reasons for the selection — for example, “Ordered together,” “Attributes matched,” “Same category,” “In trending ranking,” “Viewed,” “Substituted as popular.”
The badges are ordered by meaning: first, fallback for popular items, then selection (why the product is here at all), then ranking (why it is in this position), and finally downgrading (for example, “Lower — price difference” — the product was dropped due to a price difference).
Explanation explains the output for each product — what worked for a specific card. Investigate shows the picture for the entire request — which audience rule was applied, what warnings the system issued, whether fallback was enabled. If there are no selection reasons, the tab will show a message like “No data for explanation” — this is normal, for example, for an empty preview.
Investigate tab — diagnostics
The third tab is Investigate — it is needed for debugging. Here you can see what happened “under the hood” during the output formation:
| Section on screen | What it means |
|---|---|
| Audience rule applied | Which audience rule was triggered for the current request. See Audience Filter. |
| Warnings | Diagnostics — for example, “attribute set is empty,” “fallback selected products not from the chosen category.” |
| Fallback used | Flag: whether the fallback path (backup display of trending products) was triggered. |
| Request context | Request context — what the system received when building the preview (user ID, cart, selected categories, etc.). |
If there is no data for a particular section, that section will not be displayed on the Investigate tab — this is not an error.
Simulate user (ID) — preview "on behalf of" the user
On the block settings screen in the Context for preview section, the context for which the preview is built is set. The field depends on the type of block:
| Block type | Preview context field |
|---|---|
| Trending, Recently viewed, Personal recommendations, Repeat purchase | Simulate user (ID) |
| Cart complement, Cart similar | Test cart (product IDs) |
| Wishlist similar | Test wishlist (product IDs) |
| Frequently ordered, Similar products (automatic mode) | Test product ID |
For personalized blocks, this field is Simulate user (ID) (in the diagnostics of the Investigate tab, this value is referred to as simulatedUserId). Enter the ID of any user — the preview will generate results as if the request came from them. This is convenient for:
- Checking personal recommendations (Personal recommendations, Repeat purchase) for a specific client;
- Reproducing complaints like “I have the wrong products in the block” — enter their ID and see what they will see.
Without specifying Simulate user (ID), the preview uses your own admin context, and for personalized blocks, the output may be empty or irrelevant.
Access right blocks.preview
Access to the block preview is controlled by a separate right blocks.preview in the rights tree.
This allows:
- Assigning a role that edits blocks without access to the preview (for example, for content managers “form-only”).
- Hiding sensitive data from some admins that may be revealed through Investigate (Request context section).
Give blocks.preview to those who configure and check the output of blocks. To content managers — only if they need to see the actual output of the block before publication.