Implement some flow and cleanup API call for file manager

resources/assets/scripts/api/http.js

@@ -0,0 +1,25 @@
+// @flow
+import axios from 'axios';
+import type { AxiosInstance } from 'axios';
+
+// This token is set in the bootstrap.js file at the beginning of the request
+// and is carried through from there.
+// const token: string = '';
+
+const http: AxiosInstance = axios.create({
+    'X-Requested-With': 'XMLHttpRequest',
+    'Accept': 'application/json',
+    'Content-Type': 'application/json',
+});
+
+// If we have a phpdebugbar instance registered at this point in time go
+// ahead and route the response data through to it so things show up.
+if (typeof window.phpdebugbar !== 'undefined') {
+    http.interceptors.response.use(response => {
+        window.phpdebugbar.ajaxHandler.handle(response.request);
+
+        return response;
+    });
+}
+
+export default http;

resources/assets/scripts/api/server/getDirectoryContents.js

@@ -0,0 +1,50 @@
+// @flow
+import http from './../http';
+import filter from 'lodash/filter';
+import isObject from 'lodash/isObject';
+import route from '../../../../../vendor/tightenco/ziggy/src/js/route';
+
+export interface DirectoryContentsResponse {
+    files: Object,
+    directories: Object,
+    editable: Array<string>,
+}
+
+/**
+ * Get the contents of a specific directory for a given server.
+ *
+ * @param {String} server
+ * @param {String} directory
+ * @return {Promise<DirectoryContentsResponse>}
+ */
+export function getDirectoryContents(server: string, directory: string): Promise<DirectoryContentsResponse> {
+    return new Promise((resolve, reject) => {
+        http.get(route('server.files', { server, directory }))
+            .then((response) => {
+                return resolve({
+                    files: filter(response.data.contents, function (o) {
+                        return o.file;
+                    }),
+                    directories: filter(response.data.contents, function (o) {
+                        return o.directory;
+                    }),
+                    editable: response.data.editable,
+                });
+            })
+            .catch(err => {
+                if (err.response && err.response.status === 404) {
+                    return reject('The directory you requested could not be located on the server');
+                }
+
+                if (err.response.data && isObject(err.response.data.errors)) {
+                    err.response.data.errors.forEach(error => {
+                        return reject(error.detail);
+                    });
+                }
+
+                return reject(err);
+            });
+    });
+}
+
+export default getDirectoryContents;