Significantly optimizes the component rendering strategy within the form
state endpoint by precisely rendering only the fields that require it.
This cuts down on server processing and network response sizes when
invoking form state requests **that manipulate array and block rows
which contain server components**, such as rich text fields, custom row
labels, etc. (results listed below).
Here's a breakdown of the issue:
Previously, when manipulating array and block fields, _all_ rows would
render any server components that might exist within them, including
rich text fields. This means that subsequent changes to these fields
would potentially _re-render_ those same components even if they don't
require it.
For example, if you have an array field with a rich text field within
it, adding the first row would cause the rich text field to render,
which is expected. However, when you add a second row, the rich text
field within the first row would render again unnecessarily along with
the new row.
This is especially noticeable for fields with many rows, where every
single row processes its server components and returns RSC data. And
this does not only affect nested rich text fields, but any custom
component defined on the field level, as these are handled in the same
way.
The reason this was necessary in the first place was to ensure that the
server components receive the proper data when they are rendered, such
as the row index and the row's data. Changing one of these rows could
cause the server component to receive the wrong data if it was not
freshly rendered.
While this is still a requirement that rows receive up-to-date props, it
is no longer necessary to render everything.
Here's a breakdown of the actual fix:
This change ensures that only the fields that are actually being
manipulated will be rendered, rather than all rows. The existing rows
will remain in memory on the client, while the newly rendered components
will return from the server. For example, if you add a new row to an
array field, only the new row will render its server components.
To do this, we send the path of the field that is being manipulated to
the server. The server can then use this path to determine for itself
which fields have already been rendered and which ones need required
rendering.
## Results
The following results were gathered by booting up the `form-state` test
suite and seeding 100 array rows, each containing a rich text field. To
invoke a form state request, we navigate to a document within the
"posts" collection, then add a new array row to the list. The result is
then saved to the file system for comparison.
| Test Suite | Collection | Number of Rows | Before | After | Percentage
Change |
|------|------|---------|--------|--------|--------|
| `form-state` | `posts` | 101 | 1.9MB / 266ms | 80KB / 70ms | ~96%
smaller / ~75% faster |
---------
Co-authored-by: James <james@trbl.design>
Co-authored-by: Alessio Gravili <alessio@gravili.de>
Continuation of #11867. When rendering custom fields nested within
arrays or blocks, such as the Lexical rich text editor which is treated
as a custom field, these fields will sometimes disappear when form state
requests are invoked sequentially. This is especially reproducible on
slow networks.
This is different from the previous PR in that this issue is caused by
adding _rows_ back-to-back, whereas the previous issue was caused when
adding a single row followed by a change to another field.
Here's a screen recording demonstrating the issue:
https://github.com/user-attachments/assets/5ecfa9ec-b747-49ed-8618-df282e64519d
The problem is that `requiresRender` is never sent in the form state
request for row 2. This is because the [task
queue](https://github.com/payloadcms/payload/pull/11579) processes tasks
within a single `useEffect`. This forces React to batch the results of
these tasks into a single rendering cycle. So if request 1 sets state
that request 2 relies on, request 2 will never use that state since
they'll execute within the same lifecycle.
Here's a play-by-play of the current behavior:
1. The "add row" event is dispatched
a. This sets `requiresRender: true` in form state
1. A form state request is sent with `requiresRender: true`
1. While that request is processing, another "add row" event is
dispatched
a. This sets `requiresRender: true` in form state
b. This adds a form state request into the queue
1. The initial form state request finishes
a. This sets `requiresRender: false` in form state
1. The next form state request that was queued up in 3b is sent with
`requiresRender: false`
a. THIS IS EXPECTED, BUT SHOULD ACTUALLY BE `true`!!
To fix this this, we need to ensure that the `requiresRender` property
is persisted into the second request instead of overridden. To do this,
we can add a new `serverPropsToIgnore` to form state which is read when
the processing results from the server. So if `requiresRender` exists in
`serverPropsToIgnore`, we do not merge it. This works because we
actually mutate form state in between requests. So request 2 can read
the results from request 1 without going through an additional rendering
cycle.
Here's a play-by-play of the fix:
1. The "add row" event is dispatched
a. This sets `requiresRender: true` in form state
b. This adds a task in the queue to mutate form state with
`requiresRender: true`
1. A form state request is sent with `requiresRender: true`
1. While that request is processing, another "add row" event is
dispatched
a. This sets `requiresRender: true` in form state AND
`serverPropsToIgnore: [ "requiresRender" ]`
c. This adds a form state request into the queue
1. The initial form state request finishes
a. This returns `requiresRender: false` from the form state endpoint BUT
IS IGNORED
1. The next form state request that was queued up in 3c is sent with
`requiresRender: true`
