feat(rest): add support for transforming JSON and XML responses

src/rest/AbstractHTTP.ts

@@ -6,6 +6,10 @@ import {OnmsHTTPOptions} from '../api/OnmsHTTPOptions';
 import {OnmsResult} from '../api/OnmsResult';
 import {OnmsServer} from '../api/OnmsServer';
 
+// tslint:disable-next-line
+const X2JS = require('x2js');
+const xmlParser = new X2JS();
+
 /**
  * Implementation of the OnmsHTTP interface using Axios: https://github.com/mzabriskie/axios
  * @module AxiosHTTP
@@ -45,6 +49,39 @@ export abstract class AbstractHTTP implements IOnmsHTTP {
   /** make an HTTP get call -- this should be overridden by the implementation */
   public abstract get(url: string, options?: OnmsHTTPOptions): Promise<OnmsResult<any>>;
 
+  /** a convenience method for implementers to use to turn JSON into a javascript object */
+  protected transformJSON(data: any) {
+    if (typeof data === 'string') {
+      return JSON.parse(data);
+    } else {
+      // assume it's already parsed
+      return data;
+    }
+  }
+
+  /** a convenience method for implementers to use to turn XML into a javascript object */
+  protected transformXML(data: any) {
+    if (typeof data === 'string') {
+      return xmlParser.xml2js(data);
+    } else {
+      // assume it's already parsed
+      return data;
+    }
+  }
+
+  /** combine all options from the given options, the current server, and the default options */
+  protected getOptions(options?: OnmsHTTPOptions) {
+    let ret = Object.assign({auth: {}}, this.options);
+    if (this.timeout) {
+      ret.timeout = this.timeout;
+    }
+    if (this.serverObj && this.serverObj.auth) {
+      ret.auth = Object.assign(ret.auth, this.serverObj.auth);
+    }
+    ret = Object.assign(ret, options);
+    return ret;
+  }
+
   /** useful for performing an action (like clearing caches) when the server is set */
   protected onSetServer() {
     // do nothing by default