wikimedia/mediawiki-extensions-UploadWizard

( function () {
    /**
     * Represents an object which configures an html5 FormData object to upload.
     * Large files are uploaded in chunks.
     *
     * @class
     * @param {mw.UploadWizardUpload} upload
     * @param {mw.Api} api
     */
    mw.ApiUploadFormDataHandler = function ( upload, api ) {
        mw.ApiUploadHandler.call( this, upload, api );

        this.formData = {
            action: 'upload',
            stash: 1,
            format: 'json'
        };

        this.transport = new mw.FormDataTransport(
            this.api,
            this.formData
        ).on( 'update-stage', ( stage ) => {
            upload.ui.setStatus( 'mwe-upwiz-' + stage );
        } );
    };

    OO.inheritClass( mw.ApiUploadFormDataHandler, mw.ApiUploadHandler );

    mw.ApiUploadFormDataHandler.prototype.abort = function () {
        this.transport.abort();
    };

    /**
     * @return {jQuery.Promise}
     */
    mw.ApiUploadFormDataHandler.prototype.submit = function () {
        var handler = this;

        return this.configureEditToken().then( () => {
            handler.beginTime = Date.now();
            handler.upload.ui.setStatus( 'mwe-upwiz-transport-started' );
            handler.upload.ui.showTransportProgress();

            return handler.transport.upload( handler.upload.file, handler.upload.title.getMainText() )
                .progress( ( fraction ) => {
                    if ( handler.upload.state === 'aborted' ) {
                        handler.abort();
                        return;
                    }

                    if ( fraction !== null ) {
                        handler.upload.setTransportProgress( fraction );
                    }
                } );
        } );
    };

    /**
     * Obtain a fresh edit token.
     * If successful, store token and call a callback.
     *
     * @return {jQuery.Promise}
     */
    mw.ApiUploadFormDataHandler.prototype.configureEditToken = function () {
        var handler = this;

        return this.api.getEditToken().then( ( token ) => {
            handler.formData.token = token;
        } );
    };
}() );