FEATURE: support uploads for themes

This allows themes to bundle various assets

app/assets/javascripts/admin/controllers/modals/admin-add-upload.js.es6

@@ -0,0 +1,43 @@
+import ModalFunctionality from 'discourse/mixins/modal-functionality';
+import { ajax } from 'discourse/lib/ajax';
+// import computed from 'ember-addons/ember-computed-decorators';
+import { popupAjaxError } from 'discourse/lib/ajax-error';
+
+export default Ember.Controller.extend(ModalFunctionality, {
+  adminCustomizeThemesShow: Ember.inject.controller(),
+
+  actions: {
+    updateName() {
+      let name = this.get('name');
+      if (Em.isEmpty(name)) {
+        name = $('#file-input')[0].files[0].name;
+        this.set('name', name.split(".")[0]);
+      }
+    },
+    upload() {
+
+      let options = {
+        type: 'POST'
+      };
+
+      options.processData = false;
+      options.contentType = false;
+      options.data = new FormData();
+      let file = $('#file-input')[0].files[0];
+      options.data.append('file', file);
+
+      ajax('/admin/themes/upload_asset', options).then(result=>{
+        let upload = {
+          upload_id: result.upload_id,
+          name: this.get('name'),
+          original_filename: file.name
+        };
+        this.get('adminCustomizeThemesShow').send('addUpload', upload);
+        this.send('closeModal');
+      }).catch(e => {
+        popupAjaxError(e);
+      });
+
+    }
+  }
+});