From 27f5851458242cd8be8c35eff3621c462a514385 Mon Sep 17 00:00:00 2001
From: Eddy Ernesto del Valle Pino <xigmatron@gmail.com>
Date: Thu, 20 Jun 2019 09:39:39 +0200
Subject: [PATCH] Add support for push state

---
 reactor/channels.py           |  4 ++++
 reactor/component.py          | 14 +++++++++++---
 reactor/static/reactor.coffee | 29 ++++++++++++++++++++++++++++-
 3 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/reactor/channels.py b/reactor/channels.py
index b0b9d44..285e332 100644
--- a/reactor/channels.py
+++ b/reactor/channels.py
@@ -109,3 +109,7 @@ def remove(self, event):
     def redirect(self, event):
         log.debug(f"<<< REDIRECT {event['url']}")
         self.send_json(dict(event, type='redirect'))
+
+    def push_state(self, event):
+        log.debug(f"<<< PUSH-STATE {event['url']}")
+        self.send_json(dict(event, type='push_state'))
diff --git a/reactor/component.py b/reactor/component.py
index f7dd6c2..cf3b985 100644
--- a/reactor/component.py
+++ b/reactor/component.py
@@ -95,6 +95,7 @@ def build(cls, tag_name, *args, **kwargs):
     def __init__(self, context, id=None):
         self._context = context
         self._destroy_sent = False
+        self._redirect_sent = False
         self._redirected_to = None
         self._last_sent_html = ''
         self._diff = diff_match_patch()
@@ -152,10 +153,15 @@ def send_destroy(self):
             id=self.id,
         )
 
-    def send_redirect(self, url):
+    def send_redirect(self, url, push_state=True):
         url = reverse(url)
         if self._channel_name:
-            send_to_channel(self._channel_name, 'redirect', url=url)
+            if push_state:
+                action = 'push_state'
+            else:
+                action = 'redirect'
+            send_to_channel(self._channel_name, action, url=url)
+            self._redirect_sent = True
         else:
             self._redirected_to = url
 
@@ -184,7 +190,9 @@ def render_diff(self):
             ]
 
     def render(self):
-        if self._destroy_sent:
+        if self._redirect_sent:
+            html = self._last_sent_html
+        elif self._destroy_sent:
             html = ''
         elif self._redirected_to:
             html = (
diff --git a/reactor/static/reactor.coffee b/reactor/static/reactor.coffee
index 4591c4c..d25d54a 100644
--- a/reactor/static/reactor.coffee
+++ b/reactor/static/reactor.coffee
@@ -87,7 +87,9 @@ reactor_channel.on 'close', ->
 reactor_channel.on 'message', ({type, id, html_diff, url}) ->
   console.log '<<<', type.toUpperCase(), id or url
   if type is 'redirect'
-    location.assign url
+    window.location.assign url
+  else if type is 'push_state'
+    push_state url
   else
     el = document.getElementById(id)
     if el?
@@ -241,4 +243,29 @@ debounce = (delay_name, delay) -> (...args) ->
   clearTimeout _timeouts[delay_name]
   _timeouts[delay_name] = setTimeout (=> send(...args)), delay
 
+push_state = (url) ->
+  if history.pushState?
+    history.pushState {}, '', url
+    load_page url
+  else
+    window.location.assign url
+
+window.onpopstate = ->
+  load_page window.location.href
+
+load_page = (url) ->
+  utf8_decoder = new TextDecoder("utf-8")
+  fetch(url).then (response) ->
+    reader = await response.body.getReader()
+    done = false
+    result = []
+    while not done
+      {done, value} = await reader.read()
+      value = if value then utf8_decoder.decode(value) else ''
+      result.push value
+    html = result.join('').trim()
+    window.requestAnimationFrame ->
+      morphdom(document.documentElement, html)
+      document.querySelector('[autofocus]')?.focus()
+
 reactor_channel.open()