1 files changed, 114 insertions, 0 deletions
diff --git a/app/assets/javascripts/blob/balsamiq/balsamiq_viewer.js b/app/assets/javascripts/blob/balsamiq/balsamiq_viewer.js
new file mode 100644
index 00000000000..c17877a276d
--- /dev/null
+++ b/app/assets/javascripts/blob/balsamiq/balsamiq_viewer.js
@@ -0,0 +1,114 @@
+import sqljs from 'sql.js';
+import { template as _template } from 'underscore';
+
+const PREVIEW_TEMPLATE = _template(`
+  <div class="panel panel-default">
+    <div class="panel-heading"><%- name %></div>
+    <div class="panel-body">
+      <img class="img-thumbnail" src="data:image/png;base64,<%- image %>"/>
+    </div>
+  </div>
+`);
+
+class BalsamiqViewer {
+  constructor(viewer) {
+    this.viewer = viewer;
+  }
+
+  loadFile(endpoint) {
+    return new Promise((resolve, reject) => {
+      const xhr = new XMLHttpRequest();
+
+      xhr.open('GET', endpoint, true);
+      xhr.responseType = 'arraybuffer';
+      xhr.onload = loadEvent => this.fileLoaded(loadEvent, resolve, reject);
+      xhr.onerror = reject;
+
+      xhr.send();
+    });
+  }
+
+  fileLoaded(loadEvent, resolve, reject) {
+    if (loadEvent.target.status !== 200) return reject();
+
+    this.renderFile(loadEvent);
+
+    return resolve();
+  }
+
+  renderFile(loadEvent) {
+    const container = document.createElement('ul');
+
+    this.initDatabase(loadEvent.target.response);
+
+    const previews = this.getPreviews();
+    previews.forEach((preview) => {
+      const renderedPreview = this.renderPreview(preview);
+
+      container.appendChild(renderedPreview);
+    });
+
+    container.classList.add('list-inline');
+    container.classList.add('previews');
+
+    this.viewer.appendChild(container);
+  }
+
+  initDatabase(data) {
+    const previewBinary = new Uint8Array(data);
+
+    this.database = new sqljs.Database(previewBinary);
+  }
+
+  getPreviews() {
+    const thumbnails = this.database.exec('SELECT * FROM thumbnails');
+
+    return thumbnails[0].values.map(BalsamiqViewer.parsePreview);
+  }
+
+  getResource(resourceID) {
+    const resources = this.database.exec(`SELECT * FROM resources WHERE id = '${resourceID}'`);
+
+    return resources[0];
+  }
+
+  renderPreview(preview) {
+    const previewElement = document.createElement('li');
+
+    previewElement.classList.add('preview');
+    previewElement.innerHTML = this.renderTemplate(preview);
+
+    return previewElement;
+  }
+
+  renderTemplate(preview) {
+    const resource = this.getResource(preview.resourceID);
+    const name = BalsamiqViewer.parseTitle(resource);
+    const image = preview.image;
+
+    const template = PREVIEW_TEMPLATE({
+      name,
+      image,
+    });
+
+    return template;
+  }
+
+  static parsePreview(preview) {
+    return JSON.parse(preview[1]);
+  }
+
+  /*
+   * resource = {
+   *   columns: ['ID', 'BRANCHID', 'ATTRIBUTES', 'DATA'],
+   *   values: [['id', 'branchId', 'attributes', 'data']],
+   * }
+   *
+   * 'attributes' being a JSON string containing the `name` property.
+   */
+  static parseTitle(resource) {
+    return JSON.parse(resource.values[0][2]).name;
+  }
+}
+
+export default BalsamiqViewer;