Advanced

Model File Import / Export

Save and restore complete model configurations as .tmm files

.tmm is the local model file format for Dreapex TMM. It saves the current structure, optics, sweep configuration, and optimizer settings into a single JSON file that can be reopened in any future version of Dreapex TMM.

Use case	Description
Project archive	Save multiple candidate designs as separate `.tmm` files for offline archiving
Cross-machine migration	Replaces manually copying `localStorage`; transfer via cloud storage or email
Backup before risky operations	Safety net before loading a Case Library entry or importing a URL config
Peer review	Send `.tmm` plus result screenshots to a colleague for one-click reproduction

Entry Points

Two icon buttons on the right side of the top toolbar:

Icon	Action	testid
`pi pi-file-import`	Import a local `.tmm` file	`layout-toolbar-import-model`
`pi pi-download`	Export the current model as a `.tmm` file	`layout-toolbar-export-model`

File Format

Item	Value
Extension	`.tmm`
Content	Pretty-printed JSON with 2-space indentation, readable in any text editor
Top-level shape	`{ version, savedAt, data }`, identical to the browser `localStorage` autosave format
`data` field	Contains five modules: `structure / optics / surroundings / sweepList / optimizer`
Not included	`Results` (recomputable), `Settings` (user preferences), `Logs`, UI state

{
  "version": 1,
  "savedAt": "2026-04-21T00:12:34.567Z",
  "data": {
    "structure":    [ ... ],
    "optics":       { ... },
    "surroundings": { ... },
    "sweepList":    [ ... ],
    "optimizer": {
      "objectives":         [ ... ],
      "variables":          [ ... ],
      "algorithmSettings":  { ... }
    }
  }
}

Export Flow

Click the pi pi-download button in the toolbar.
The browser downloads the file immediately. Default name: tmm-project-{YYYY-MM-DD}.tmm.
A toast confirms: Downloaded {fileName}.

No extra validation runs before export. Even if the current model has configuration issues (for example, a missing material), it can still be exported — useful for offline troubleshooting.

Import Flow

Click the pi pi-file-import button in the toolbar.
Pick a .tmm or .json file in the file picker.
Files larger than 10 MB are rejected with a File too large toast.
JSON is parsed; failure shows Not valid JSON.
Version pre-check runs based on the version field; migrations run if needed.
A confirmation dialog appears: "This will replace the current model. Continue?"
After confirmation, the model is written to the store and a toast confirms: Loaded model from file.

Failure case	Message	Suggested fix
Not JSON	`Not valid JSON`	Check the first lines in a text editor for corruption
Missing `version` field	`Not a TMM project file`	Confirm the file was exported from Dreapex TMM
Newer than the app	`File is from a newer version of TMM; please upgrade`	Upgrade Dreapex TMM, or ask the sender to export a backward-compatible file
Shape mismatch / migration failed	`File is corrupted or incompatible with current schema`	Inspect each `data` module in a text editor to locate the issue
Partial module fallback	Warning toast, defaults substituted	After loading, verify `Optics` / `Sweep` / `Optimizer`

Backward Compatibility Promise

A .tmm file saved today opens in any future schema version of Dreapex TMM.

How:

Every snapshot entering the store (.tmm / URL config / localStorage) goes through a version-aware migration pipeline;
Older versions are migrated step-by-step to the current version;
Final shape is validated against the current schema.

The version number is written into the version field at export time. On import, files newer than the app's supported version are rejected. Before sharing a model with someone on an older app version, verify their version is compatible.

Relationship to Other Persistence

Mechanism	Scope	Trigger	When to use
`.tmm` file	Model snapshot	Manual export / import	Project archive, cross-machine migration, offline review
`localStorage` autosave	Model snapshot	Automatic on edit	In-browser safety net for accidental closes / restarts
URL config sharing	Model snapshot + selected Settings	Explicit URL generation	Remote collaboration, paste-link reproduction
Case Library	9 fixed built-in models	Manual selection	Quick entry into a working model; not persisted

When the goal is to transfer the exact UI state to a colleague, prefer .tmm files: bounded size, no URL-length limit, and the file content is independent of any attachment-handling on the path.

For URL-based sharing, see URL Config Sharing.

Case Library

One-click access to nine built-in classic thin-film examples

URL Config Sharing

Load complete model configurations from a single URL