puriketu memo

Tuesday, November 8, 2011

High speeding technique for Ajax post

When you use this technique, your user feels as fast as client app.

The conventional method

Set onClick = 'update(this);' to element
Post with update()
Wait for callback function
Update UI with callback function

→User has to wait for callback function.(S)he feels slow.

This technique

Set onClick = 'update(this);' to element
Before post with update(),update UI
Wait for callback function
If post is failed,reset UI and handle error with callback function

→User doesn't have to wait for callback function.(S)he feels fast.

#If app's updateing often fails and a user overlook errors and resetting UI, (s)he has discontent.

Best practice

Callback function works only for resetting UI and handling error so you can commonize it.

Note

The conventional method is popular method.Why?I think the reason is callback function is too convinient.

'Language defines thinking'--This is Sapir-Whorf hypothesis.I suggest that callback function defines programmer's thinking.

In Fuzzy system,for example SNS,Game, you might want to use this technique.

Especially in Game,fast response is essential.

Thursday, March 24, 2011

tweepy memo

Last login: Thu Mar 24 16:25:31 on ttys000

/Users/prk29% easy_install tweepy

Searching for tweepy

Reading http://pypi.python.org/simple/tweepy/

Reading http://github.com/joshthecoder/tweepy

Best match: tweepy 1.7.1

Downloading http://pypi.python.org/packages/2.6/t/tweepy/tweepy-1.7.1-py2.6.egg#md5=920800078a8820cbc75c0ca2527dbe60

Processing tweepy-1.7.1-py2.6.egg

Moving tweepy-1.7.1-py2.6.egg to /Library/Python/2.6/site-packages

Adding tweepy 1.7.1 to easy-install.pth file

Installed /Library/Python/2.6/site-packages/tweepy-1.7.1-py2.6.egg

Processing dependencies for tweepy

Finished processing dependencies for tweepy

/Users/prk29%

Monday, February 7, 2011

How to use Goole App Engine Channel API

Overview:
Channel API is the API to synchronize clients in real time.
The procedure is following.
1.Client side:request a Channel API token and client ID from GAE.
2.GAE side:create the token and return it to the client.
3.Client side:open the client's channel with the token.
4.GAE side:send message to the client with the client ID, not the token.
5.Client side:get message.
1.Client side:request a Channel API token and client ID from GAE.
html:
<span id="token" style="display:none;">none-token</span>
javascipt:
function take_token() {
   console.debug('taking a token');
   $.get("/ChannelAPI", {}, function(results){
$("#token").text(results.token)//save token to "#token".
make_channel(results.token)
   },"json");
}
2.GAE side:create the token and return it to the client.
def get(self):
client_id = "user1"
token = channel.create_channel(client_id)
self.response.headers.add_header('Content-Type', 'application/json; charset=utf-8')
self.response.out.write(simplejson.dumps({'token': token}))
3.Client side:open the client's channel with the token.
function make_channel(token){
   channel = new goog.appengine.Channel(token);
   socket = channel.open();
   socket.onopen = onOpened;
   socket.onmessage = onMessage;
   socket.onerror = onError;
   socket.onclose = onClose;
}
4.GAE side:send message to the client with the client ID, not the token.
def post(self):
channel.send_message("user1", simplejson.dumps({"tokens":tokens}))
5.Client side:get message.
function onMessage(message){
a = new Array()
   console.debug('received a message: ', message);
   console.debug("receive a message.data:",message.data);
   var obj = JSON.parse(message.data);
   console.debug(obj.tokens)
   console.debug(obj.tokens[0])
}

Thursday, February 3, 2011

How to post data with jQuery on PhoneGap

I can not post data to GAE with XMLHttpRequest on iPhone.However,I can with jQuery and JSONP on Safari and iPhone,but I can not on Chrome.

That code is following.

HTML side:

<head>
<title>puriketu memo</title>
<meta name="viewport" content="user-scalable=no, width=device-width" />
<link rel="stylesheet" type="text/css" href="iphone.css" media="only screen and (max-width: 480px)" />

<script type="text/javascript" src="http://localhost:8082/js/jquery.js"></script>
<script type="text/javascript" src="http://localhost:8082/js/iphone.js"></script>

</head>

javascript side:

$.post(
request,
{"content":"content a"},
function(data, status) {
alert("post success");
}
);

);

reference:

XMLHttpRequest Cross-domain issue

As soon as you sent the code, I have tested it and it did not work in my Chrome, Firefox or Android device. So, I came home last night and tested your code on Safari and my iPhone app, it works without any issues, actually my original code also worked without any issues in Safari and iPhone.

How to get data from Google App Engine with XMLHttpRequest on PhoneGap

There is a cross domain issue when we implement this program.
Follow the code disolves it.

javascript side:

var url = request; // ex)"http://localhost:8080"

var xhr = new XMLHttpRequest();

xhr.open("GET", url, true);

xhr.onreadystatechange = function(){

if ( xhr.readyState == 4 ) {

if ( xhr.status == 200 ) {

var response = JSON.parse(xhr.responseText);

$.each(response,function(i,r){

alert(r.content);

});

alert("get success!");

} else {

alert(xhr.responseText);

alert("lose");

}

};

xhr.send(null);

Google App Engine side:

class MainHandler(webapp.RequestHandler):

def get(self):

self.response.headers['Access-Control-Allow-Origin'] = '*'

self.response.headers['Access-Control-Allow-Headers'] = '*'

self.response.headers['Access-Control-Allow-Methods'] = 'GET'

self.response.headers['Content-Type'] = 'text/plain;charset=UTF-8'

tweets = db.GqlQuery('SELECT * FROM Tweet')

results = []

for tweet in tweets:

result = {}

result['content'] = tweet.content

results.append(result)

self.response.out.write(simplejson.dumps(results))

reference:
XMLHttpRequest Cross-domain issue

As soon as you sent the code, I have tested it and it did not work in my Chrome, Firefox or Android device. So, I came home last night and tested your code on Safari and my iPhone app, it works without any issues, actually my original code also worked without any issues in Safari and iPhone.

Saturday, January 29, 2011

How to get data from Google App Engine for python with jQuery

GAE side:

import simplejson

...

class HistoryHandler(webapp.RequestHandler):

def get(self):

viewerid = self.request.get('viewerid')

query = "SELECT * FROM dbmodel where viewerid = '" + viewerid + "'"

datas = db.GqlQuery(query)

result = []

for data in datas:

r = {}

r["key"] = data.key().id()

r["unreadflag"] = data.unreadflag

result.append(r)

self.response.out.write(simplejson.dumps(result))

jQuery side:

$.get('http://xxxxxxxx.appspot.com/historydata signed', {viewerid : viewerid}, function(results) {

if(results.length == 0){

...

}

else{

//when results is an object, this "i" is a hash key.

//when results is an array, this "i" is an index.

$.each(results, function(i, r) {

alert(r.unreadflag);

});

}

}, 'json');

P.S.

My English is not good enough.

If there is a mistake and an anxious point,teach me softly.

How to post data to Google App Engine for python with jQuery

jQuery side:

$.post(

"http://xxxxxxxxxxxxxxxxx.appspot.com/introdata",

{"viewerid": viewerid, "fromid": from, "toid": to, "introreason": reason},

function(data, status) {

$("#oktext").css('font-size', '12px').css("font-weight", "bold").css("color", "red").fadeIn(2000);

$("#oktext").fadeOut(5000);

}

);

GAE side:

from django.utils import simplejson

...

class AddHandler(webapp.RequestHandler):

...

def post(self):

viewerid = self.request.get('viewerid')

data = introData(viewerid=viewerid)

data.fromid = self.request.get('fromid')

data.toid = self.request.get('toid')

data.introreason = self.request.get('introreason')

data.unreadflag = '1'

data.put()

...

def main():

application = webapp.WSGIApplication(

[

('/introdata',AddHandler),

...

],

debug=True)

wsgiref.handlers.CGIHandler().run(application)

if __name__ == '__main__':

main()