wip(lab): Work on porting lab/workbenck to named exports

sites/shared/components/workbench/exporting/export-handler.mjs

@@ -0,0 +1,127 @@
+import Worker from 'web-worker'
+import fileSaver from 'file-saver'
+import { themePlugin } from '@freesewing/plugin-theme'
+import { pagesPlugin } from '../layout/print/plugin.mjs'
+import { capitalize } from 'shared/utils.mjs'
+
+export const exportTypes = {
+  exportForPrinting: ['a4', 'a3', 'a2', 'a1', 'a0', 'letter', 'tabloid'],
+  exportForEditing: ['svg', 'pdf'],
+  exportAsData: ['json', 'yaml', 'github gist'],
+}
+
+export const defaultPdfSettings = {
+  size: 'a4',
+  orientation: 'portrait',
+  margin: 10,
+  coverPage: true,
+}
+
+/**
+ * Handle exporting the draft or gist
+ * format: format to export to
+ * gist: the gist
+ * design: the pattern constructor for the design to be exported
+ * t: a translation function to attach to the draft
+ * app: an app instance
+ * onComplete: business to perform after a successful export
+ * onError: business to perform on error
+ * */
+export const handleExport = async (format, gist, design, t, app, onComplete, onError) => {
+  // start the loading indicator
+  app.startLoading()
+
+  // get a worker going
+  const worker = new Worker(new URL('./export-worker.js', import.meta.url), { type: 'module' })
+
+  // listen for the worker's message back
+  worker.addEventListener('message', (e) => {
+    // on success
+    if (e.data.success) {
+      // save it out
+      if (e.data.blob) {
+        const fileType = exportTypes.exportForPrinting.indexOf(format) === -1 ? format : 'pdf'
+        fileSaver.saveAs(e.data.blob, `freesewing-${gist.design || 'gist'}.${fileType}`)
+      }
+      // do additional business
+      onComplete && onComplete(e)
+    }
+    // on error
+    else {
+      console.log(e.data.error)
+      onError && onError(e)
+    }
+
+    // stop the loader
+    app.stopLoading()
+  })
+
+  // pdf settings
+  const settings = {
+    ...defaultPdfSettings,
+    ...(gist._state.layout?.forPrinting?.page || {}),
+  }
+
+  // arguments to pass to the worker
+  const workerArgs = { format, gist, settings }
+
+  // data passed to the worker must be JSON serializable, so we can't pass functions or prototypes
+  // that means if it's not a data export there's more work to do before we can hand off to the worker
+  if (exportTypes.exportAsData.indexOf(format) === -1) {
+    gist.embed = false
+    // make a pattern instance for export rendering
+    const layout = gist.layouts?.printingLayout || gist.layout || true
+    let pattern = new design({ ...gist, layout })
+
+    // add the theme and translation to the pattern
+    pattern.use(themePlugin, { stripped: format !== 'svg', skipGrid: ['pages'] })
+    pattern.use(
+      {
+        hooks: {
+          insertText: (locale, text, { t }) => t(text),
+        },
+      },
+      { t }
+    )
+
+    // a specified size should override the gist one
+    if (format !== 'pdf') {
+      settings.size = format
+    }
+
+    try {
+      // add pages to pdf exports
+      if (format !== 'svg') {
+        pattern.use(
+          pagesPlugin({
+            ...settings,
+            printStyle: true,
+            renderBlanks: false,
+            setPatternSize: true,
+          })
+        )
+
+        // add the strings that are used on the cover page
+        workerArgs.strings = {
+          design: capitalize(pattern.designConfig.data.name.replace('@freesewing/', '')),
+          tagline: t('common:sloganCome') + '. ' + t('common:sloganStay'),
+          url: window.location.href,
+        }
+      }
+
+      // draft and render the pattern
+      pattern.draft()
+      workerArgs.svg = pattern.render()
+
+      // add the svg and pages data to the worker args
+      workerArgs.pages = pattern.setStores[pattern.activeSet].get('pages')
+
+      // post a message to the worker with all needed data
+      worker.postMessage(workerArgs)
+    } catch (err) {
+      console.log(err)
+      app.stopLoading()
+      onError && onError(err)
+    }
+  }
+}