Persistent Data

Store your Web Viewer HTML so it survives a clone, using FileMaker 26's Configure Persistent Data feature.

FileMaker 26 introduces Configure Persistent Data, a feature that lets specific data survive when a file is cloned. ProofKit 3.0 uses it to keep your embedded Web Viewer HTML inside the FileMaker file through a clone — and therefore through a data migration.

Requires FileMaker 26+

Persistent data is a FileMaker 26 feature. On earlier versions, the embedded Web Viewer code still does not survive a clone, and the workarounds in Deployment Methods still apply.

The problem this solves

The default embedded deployment stores the Web Viewer app as data in a FileMaker field. That is simple and works offline, but it has historically had one big drawback: a clone strips all record data, so the HTML is gone.

This matters because most production deployments and data migrations work by taking a clone of your development file and migrating live data into it. The embedded HTML, being record data, did not make it across — which is why teams reached for sidecar files, migration-only utility files, or hosted deployments to work around it.

How deployment writes the HTML

When you install the ProofKit 3.0 add-on, you get two versions of the Web Viewer calculation to choose from: the original table-and-record version, and a new version that retrieves the HTML from persistent data.

Every time you deploy, ProofKit saves the bundled HTML into a record in a table, exactly as before. In addition, if you are developing on FileMaker 26 or later, it also saves the HTML to a persistent data bucket.

Because both copies are written on deploy, it is up to you to decide which one your end users load:

Persistent data method — recommended when all of your users are on FileMaker 26.
Table-and-record method — required while any of your users are on a version earlier than FileMaker 26.

Use the persistent data method

If every user is on FileMaker 26, use the persistent data Web Viewer. It survives clones and data migrations with no extra copy step.

Create a new layout for the Web Viewer app.

Drag the ProofKit add-on from the left sidebar onto the layout.

This places a Web Viewer with the new calculation that includes the persistent data retrieval methods.

Resize the Web Viewer to fill the layout so it stretches to the full layout size.

Tell it which app to load using one of two options:

Hard-code the app name directly inside the Web Viewer calculation, or
Set the global field for the app name before navigating the user to this layout.

Supporting users before FileMaker 26

If some of your users are not yet on FileMaker 26, keep using the table-and-record method, which requires the HTML to live in a record in a table.

If you use data migrations, remember that this record data does not survive a clone. When you update the HTML, you may need to copy it over manually or run a post-migration script to move the latest HTML into the migrated file.

Removing pre-FileMaker 26 support

Once all of your users are on FileMaker 26 and you no longer need the table-and-record method:

Delete the name and HTML fields from the ProofKit apps table.
Update the deploy_html script so it no longer tries to save to those fields.

After this, deployments write only to persistent data.

Deployment Methods — how the embedded, hosted, and downloaded options compare.
Upgrade to 3.0 — moving an existing project onto the new add-on.