Struct WasmModel 

pub struct WasmModel { /* private fields */ }

WebAssembly wrapper around the core 3MF Model.

This struct provides JavaScript-accessible methods for working with 3MF files in the browser. It wraps lib3mf_core::Model and exposes a subset of its functionality through WASM bindings.

Primary API Surface

The main way to use this from JavaScript:

1. Parse a 3MF file from bytes using WasmModel::from_bytes()
2. Query model properties: unit(), object_count()

JavaScript Usage

const model = WasmModel.from_bytes(fileBytes);
console.log(`Unit: ${model.unit()}`);
console.log(`Objects: ${model.object_count()}`);

Full Workflow Example

import init, { WasmModel, set_panic_hook } from './lib3mf_wasm.js';

await init();
set_panic_hook();

// Load from file input
const file = document.getElementById('file-input').files[0];
const buffer = await file.arrayBuffer();
const model = WasmModel.from_bytes(new Uint8Array(buffer));

// Display basic info
document.getElementById('unit').textContent = model.unit();
document.getElementById('count').textContent = model.object_count();

Implementations

impl WasmModel

pub fn new() -> WasmModel

Create a new empty 3MF Model.

This creates a model with default values (millimeters unit, no objects, empty build). In most cases, you should use WasmModel::from_bytes() instead to parse an existing 3MF file.

JavaScript Usage

const model = new WasmModel();
// Model is empty - unit is Millimeter by default

Note

This constructor has limited utility since the WASM bindings don’t currently expose model-building APIs. It’s primarily for internal use and testing.

impl WasmModel

pub fn from_bytes(data: &[u8]) -> Result<WasmModel, JsError>

Parse a 3MF file from a byte array (e.g. from a file upload).

This is the primary way to load 3MF files in the browser. It handles the full parsing pipeline:

1. Interprets bytes as a ZIP archive
2. Parses OPC relationships to locate the model XML
3. Parses the XML into the in-memory model structure
4. Returns a WasmModel ready for inspection

Arguments

• data - The bytes of the .3mf file (ZIP archive). Typically obtained from a browser file input via FileReader or File.arrayBuffer().

Returns

Returns a WasmModel on success, or throws a JavaScript error on failure.

Errors

This function can fail in several ways:

• Invalid ZIP: The bytes don’t represent a valid ZIP archive
• Missing model part: The archive lacks a valid OPC relationship to a 3D model
• Malformed XML: The model XML is invalid or doesn’t conform to the 3MF schema
• Parser errors: Semantic errors in the 3MF structure (invalid references, etc.)

Errors are returned as JavaScript exceptions with descriptive messages.

Example (Rust)

use lib3mf_wasm::WasmModel;

let file_bytes = std::fs::read("model.3mf")?;
let model = WasmModel::from_bytes(&file_bytes)?;

JavaScript Usage

try {
    const buffer = await file.arrayBuffer();
    const model = WasmModel.from_bytes(new Uint8Array(buffer));
    console.log("Parsed successfully");
} catch (error) {
    console.error(`Parse failed: ${error}`);
}

pub fn unit(&self) -> String

Get the unit of measurement used in the model.

Returns the unit as a string for display in JavaScript.

Possible Return Values

• "Millimeter" (default, most common)
• "Centimeter"
• "Inch"
• "Foot"
• "Meter"
• "MicroMeter"

JavaScript Usage

const unit = model.unit();
console.log(`Model uses ${unit} units`);

pub fn object_count(&self) -> usize

Get the total number of objects in the model resources.

This counts all objects in the model’s resource collection, not just objects referenced by build items.

JavaScript Usage

const count = model.object_count();
console.log(`Model contains ${count} objects`);

Note

Build items may reference the same object multiple times (instances), so the number of build items may differ from the object count.

Trait Implementations

impl Default for WasmModel

Default implementation delegates to new().

fn default() -> Self

Returns the “default value” for a type.

impl From<WasmModel> for JsValue

fn from(value: WasmModel) -> Self

Converts to this type from the input type.

impl FromWasmAbi for WasmModel

type Abi = u32

The Wasm ABI type that this converts from when coming back out from the ABI boundary.

unsafe fn from_abi(js: u32) -> Self

Recover a Self from Self::Abi.

impl IntoWasmAbi for WasmModel

type Abi = u32

The Wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self) -> u32

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl LongRefFromWasmAbi for WasmModel

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRef<WasmModel>

Same as RefFromWasmAbi::Anchor

unsafe fn long_ref_from_abi(js: Self::Abi) -> Self::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl OptionFromWasmAbi for WasmModel

fn is_none(abi: &Self::Abi) -> bool

Tests whether the argument is a “none” instance. If so it will be deserialized as None, and otherwise it will be passed to FromWasmAbi.

impl OptionIntoWasmAbi for WasmModel

fn none() -> Self::Abi

Returns an ABI instance indicating “none”, which JS will interpret as the None branch of this option.

impl RefFromWasmAbi for WasmModel

type Abi = u32

The Wasm ABI type references to Self are recovered from.

type Anchor = RcRef<WasmModel>

The type that holds the reference to Self for the duration of the invocation of the function that has an &Self parameter. This is required to ensure that the lifetimes don’t persist beyond one function call, and so that they remain anonymous.

unsafe fn ref_from_abi(js: Self::Abi) -> Self::Anchor

Recover a Self::Anchor from Self::Abi.

impl RefMutFromWasmAbi for WasmModel

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRefMut<WasmModel>

Same as RefFromWasmAbi::Anchor

unsafe fn ref_mut_from_abi(js: Self::Abi) -> Self::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl TryFromJsValue for WasmModel

fn try_from_js_value(value: JsValue) -> Result<Self, JsValue>

Performs the conversion.

fn try_from_js_value_ref(value: &JsValue) -> Option<Self>

Performs the conversion.

impl VectorFromWasmAbi for WasmModel

type Abi = <Box<[JsValue]> as FromWasmAbi>::Abi

unsafe fn vector_from_abi(js: Self::Abi) -> Box<[WasmModel]>

impl VectorIntoWasmAbi for WasmModel

type Abi = <Box<[JsValue]> as IntoWasmAbi>::Abi

fn vector_into_abi(vector: Box<[WasmModel]>) -> Self::Abi

impl WasmDescribe for WasmModel

fn describe()

impl WasmDescribeVector for WasmModel

fn describe_vector()

impl SupportsConstructor for WasmModel

impl SupportsInstanceProperty for WasmModel

impl SupportsStaticProperty for WasmModel