Merge pull request #48 from contentstack/feat/Release-Preview-Implementation

feat: implements release preview

Author: nadeem-cs

src/lib/contentstack.ts

@@ -3,7 +3,7 @@ import { InternalAxiosRequestConfig, AxiosRequestHeaders, AxiosResponse } from '
 import { handleRequest } from './cache';
 import { Stack as StackClass } from './stack';
 import { Policy, StackConfig } from './types';
-import { getHost } from './utils';
+import * as Utility from './utils';
 export * as Utils from '@contentstack/utils';
 
 let version = '{{VERSION}}';
@@ -40,7 +40,7 @@ export function stack(config: StackConfig): StackClass {
     live_preview: {} as any
   };
 
-  defaultConfig.defaultHostname = config.host || getHost(config.region, config.host);
+  defaultConfig.defaultHostname = config.host || Utility.getHost(config.region, config.host);
   config.host = defaultConfig.defaultHostname;
 
   if (config.apiKey) {
@@ -59,6 +59,21 @@ export function stack(config: StackConfig): StackClass {
     throw new Error('Environment for Stack is required');
   }
 
+  if (config.live_preview) {
+    if (Utility.isBrowser()) {
+      const params = new URL(document.location.toString()).searchParams;
+      if (params.has('live_preview')) {
+          config.live_preview.live_preview = params.get('live_preview') || config.live_preview.live_preview;
+      }
+      if (params.has('release_id')) {
+          defaultConfig.headers['release_id'] = params.get('release_id');
+      }
+      if (params.has('preview_timestamp')) {
+          defaultConfig.headers['preview_timestamp'] = params.get('preview_timestamp');
+      }
+    }
+  }
+
   if (config.branch) {
     defaultConfig.headers.branch = config.branch;
   }

src/lib/stack.ts

@@ -153,5 +153,12 @@ export class Stack {
       }
       this._client.stackConfig.live_preview = livePreviewParams;
     }
+
+    if (query.hasOwnProperty('release_id')) {
+      this._client.defaults.headers['release_id'] = query.release_id;
+    }
+    if (query.hasOwnProperty('preview_timestamp')) {
+      this._client.defaults.headers['preview_timestamp'] = query.preview_timestamp;
+    }
   }
 }

src/lib/types.ts

@@ -261,6 +261,8 @@ export interface LivePreviewQuery {
   live_preview: string
   contentTypeUid: string
   entryUid?: any;
+  preview_timestamp?: string
+  release_id?: string
 }
 
 export type LivePreview = {

src/lib/utils.ts

@@ -10,3 +10,7 @@ export function getHost(region: Region = Region.US, host?: string) {
 
   return url;
 }
+
+export function isBrowser() {
+  return (typeof window !== "undefined");
+}