UI: Maintain HTTP Headers from all API requests as JSON-API meta data

ui-v2/app/adapters/application.js

@@ -13,6 +13,7 @@ export const REQUEST_DELETE = 'deleteRecord';
 
 export const DATACENTER_QUERY_PARAM = 'dc';
 
+import { HEADERS_SYMBOL as HTTP_HEADERS_SYMBOL } from 'consul-ui/utils/http/consul';
 export default Adapter.extend({
   namespace: 'v1',
   repo: service('settings'),
@@ -22,6 +23,24 @@ export default Adapter.extend({
       ...this._super(...arguments),
     };
   },
+  handleResponse: function(status, headers, response, requestData) {
+    // The ember-data RESTAdapter drops the headers after this call,
+    // and there is no where else to get to these
+    // save them to response[HTTP_HEADERS_SYMBOL] for the moment
+    // so we can save them as meta in the serializer...
+    if (
+      (typeof response == 'object' && response.constructor == Object) ||
+      Array.isArray(response)
+    ) {
+      // lowercase everything incase we get browser inconsistencies
+      const lower = {};
+      Object.keys(headers).forEach(function(key) {
+        lower[key.toLowerCase()] = headers[key];
+      });
+      response[HTTP_HEADERS_SYMBOL] = lower;
+    }
+    return this._super(status, headers, response, requestData);
+  },
   handleBooleanResponse: function(url, response, primary, slug) {
     return {
       // consider a check for a boolean, also for future me,

ui-v2/app/serializers/application.js

@@ -1,19 +1,59 @@
 import Serializer from 'ember-data/serializers/rest';
 
+import { get } from '@ember/object';
+import {
+  HEADERS_SYMBOL as HTTP_HEADERS_SYMBOL,
+  HEADERS_INDEX as HTTP_HEADERS_INDEX,
+  HEADERS_DIGEST as HTTP_HEADERS_DIGEST,
+} from 'consul-ui/utils/http/consul';
 export default Serializer.extend({
   // this could get confusing if you tried to override
   // say `normalizeQueryResponse`
   // TODO: consider creating a method for each one of the `normalize...Response` family
   normalizeResponse: function(store, primaryModelClass, payload, id, requestType) {
-    return this._super(
+    // Pick the meta/headers back off the payload and cleanup
+    // before we go through serializing
+    const headers = payload[HTTP_HEADERS_SYMBOL] || {};
+    delete payload[HTTP_HEADERS_SYMBOL];
+    const normalizedPayload = this.normalizePayload(payload, id, requestType);
+    const response = this._super(
       store,
       primaryModelClass,
       {
-        [primaryModelClass.modelName]: this.normalizePayload(payload, id, requestType),
+        [primaryModelClass.modelName]: normalizedPayload,
       },
       id,
       requestType
     );
+    // put the meta onto the response, here this is ok
+    // as JSON-API allows this and our specific data is now in
+    // response[primaryModelClass.modelName]
+    // so we aren't in danger of overwriting anything
+    // (which was the reason for the Symbol-like property earlier)
+    // use a method modelled on ember-data methods so we have the opportunity to
+    // do this on a per-model level
+    response.meta = this.normalizeMeta(
+      store,
+      primaryModelClass,
+      headers,
+      normalizedPayload,
+      id,
+      requestType
+    );
+    return response;
+  },
+  normalizeMeta: function(store, primaryModelClass, headers, payload, id, requestType) {
+    const meta = {
+      index: headers[HTTP_HEADERS_INDEX],
+      digest: headers[HTTP_HEADERS_DIGEST],
+      date: headers['date'],
+    };
+    if (requestType === 'query') {
+      meta.ids = payload.map(item => {
+        return get(item, this.primaryKey);
+      });
+    }
+    return meta;
   },
   normalizePayload: function(payload, id, requestType) {
     return payload;

ui-v2/app/utils/http/consul.js

@@ -0,0 +1,3 @@
+export const HEADERS_SYMBOL = '__consul_ui_http_headers__';
+export const HEADERS_INDEX = 'x-consul-index';
+export const HEADERS_DIGEST = 'x-consul-contenthash';