From 0bc13911487a51a229e24c9288dcf3644f5d3532 Mon Sep 17 00:00:00 2001
From: Enix <enixcoda@gmail.com>
Date: Fri, 1 Nov 2019 18:40:01 +0800
Subject: [PATCH] feat: add force cache

---
 packages/pjax/index.d.ts          | 5 +++++
 packages/pjax/index.js            | 2 +-
 packages/pjax/lib/send-request.js | 9 +++++++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/packages/pjax/index.d.ts b/packages/pjax/index.d.ts
index 1e78099..13769ec 100644
--- a/packages/pjax/index.d.ts
+++ b/packages/pjax/index.d.ts
@@ -179,6 +179,11 @@ declare namespace Pjax {
       requestParams?: IRequestParams[];
       formData?: FormData;
     }
+
+    /**
+     * Cache accessed pages
+     */
+    forceCache?: boolean
   }
 
   export type Switch = (oldEl: Element, newEl: Element, options?: IOptions, switchesOptions?: StringKeyedObject) => void;
diff --git a/packages/pjax/index.js b/packages/pjax/index.js
index b528d85..889cb6f 100644
--- a/packages/pjax/index.js
+++ b/packages/pjax/index.js
@@ -23,7 +23,7 @@ var Pjax = function(options) {
   this.log("Pjax options", this.options);
 
   if (this.options.scrollRestoration && "scrollRestoration" in history) {
-    history.scrollRestoration = "manual";
+    history.scrollRestoration = "auto";
   }
 
   this.maxUid = this.lastUid = newUid();
diff --git a/packages/pjax/lib/send-request.js b/packages/pjax/lib/send-request.js
index ad7b1b1..7d282cf 100644
--- a/packages/pjax/lib/send-request.js
+++ b/packages/pjax/lib/send-request.js
@@ -1,8 +1,11 @@
 var updateQueryString = require("./util/update-query-string");
 
+const cache = new Map();
+
 module.exports = function(location, options, callback) {
   options = options || {};
   var queryString;
+  var forceCache = options.forceCache || false;
   var requestOptions = options.requestOptions || {};
   var requestMethod = (requestOptions.requestMethod || "GET").toUpperCase();
   var requestParams = requestOptions.requestParams || null;
@@ -11,9 +14,15 @@ module.exports = function(location, options, callback) {
   var request = new XMLHttpRequest();
   var timeout = options.timeout || 0;
 
+  if (forceCache && cache.has(location)) {
+    callback(cache.get(location), request, location, options);
+    return;
+  }
+
   request.onreadystatechange = function() {
     if (request.readyState === 4) {
       if (request.status === 200) {
+        if (forceCache) cache.set(location, request.responseText);
         callback(request.responseText, request, location, options);
       } else if (request.status !== 0) {
         callback(null, request, location, options);