I am calling a simple query with findOne, so far the data in users.db is:
{"id":40, "is_admin":1,"name":"John Smith"},
{"id":43, "is_admin":1,"name":"Laura Smith"}
// Users
var users = new Datastore({ filename: 'db/users.db' });
var id_user = 43;
console.log("-------------geting users db");
//
users.loadDatabase(function (err) {
console.log("------------- users db loaded--", id_user);
// find user by id
users.findOne({ id: id_user }, function (err, a,b,c) {
console.log(a,b,c); // displays null undefined undefined
});
});
Any idea why is returning null?
I think function being passed in findOne should take 2 parameters. First parameter will be the result of query and
second parameter will be error if something goes wrong . First parameter will be Null if there is no match in db .otherwise it should return the match result.
Function(result, error ){
}
It will be you function prototype
I tested your code in my app
db.findOne({ "c2cId":"292" }, function (err, a,b,c) {
console.log(a,b,c);
});
It return one doc and undefined, undefined.
If you use findOne I guess you just want to find the first doc, so looking at the
doc at
You can see there is only two parameters err and the doc
Concerning the null: in your query are you using a variable named id? or is it the key, in last case you should use quotes....
Related
I have a list of people (first and last name) who I want to follow, but I don't want to Google or search them via Twitter separately. What is the best way to get the Twitter handles? Some GitHub repos or tutorials are also fine.
Twitter offers a "User Search" API request.
If you want to search for a user named "Ada Lovelace" you will need to send an OAuth'd request to
https://api.twitter.com/1.1/users/search.json?q=Ada%20Lovelace
You will get back a list of results. There may be many people who share the same first and last name.
As for how to do it, that rather depends on the programming language you want to use.
If you just want a clickable link, use https://twitter.com/search?q=Terence%20Eden
So firstly this question is off-topic but I will try write an answer for you. You could use the twitter api for this but that might be a little overkill if you just want to do this for you.
I made you an API
I made an API just for you using KimonoLabs. You can use this and just make a script that loops through your list and requests this api every time, then return a list of the results. Here is the API endpoint:
https://www.kimonolabs.com/api/duwxgie4?apikey=D6UKiTtKU93kv0YJj8i3kFBAbsIjdSTC&q=PERSON%20NAME
The &q= is the paramater for the person's name. To seperate the first and last name use %20, like so: Robert%20Keus
The documentation for this api is here:
https://www.kimonolabs.com/apis/duwxgie4
Let me know if you need any help,
Luca
Latest answer # 2016
First Solution: I wrote following node.js script. You need access_token and id of pulicly published google doc spreadsheet. For testing purpose I have provided sample spreadsheet's link and its id in following code.
var Twit = require('twit'),
async = require('async');
var T = new Twit({
consumer_key: 'xxxxxxxx',
consumer_secret: 'xxxxxxxxxxxxxxxxxxxxxxxxxx',
access_token: 'xxxxxxxxxxx',
access_token_secret: 'xxxxxxxxxxxxxxxxxxxxxxxxx',
timeout_ms: 60*1000 // optional HTTP request timeout to apply to all requests.
});
//https://docs.google.com/spreadsheets/d/1n7DxgJTTHZ9w3xwiHokUhXMLkBwpP5c9ZLFmsYFDCic/edit?usp=sharing
var GoogleSpreadsheet = require("google-spreadsheet"),
_ = require('underscore');
var sheetId = req.params.sheet || "1n7DxgJTTHZ9w3xwiHokUhXMLkBwpP5c9ZLFmsYFDCic",
sheet = new GoogleSpreadsheet(sheetId);
async.waterfall([
function (cb) {
sheet.getRows(1, {}, function (err, rows) {
if (err) { res.send(err); return;};
var names = [];
_.each(rows, function (row) {
names.push(row.first + " " + row.last);
});
cb(null, names);
});
},
function (names, callback1) {
async.map(names, function(name, cb){
T.get('users/search', { q: name, page: 1 }, function (err, data, response) {
if(data.length)
cb(null, {screen_name: data[0].screen_name, name:data[0].name});
else
cb(null, {screen_name: "no_data_retrieved", name: name});
});
}, function (err, results) {
callback1(null, results);
});
},
function (users, callback) {
console.log(users); //**YOU GET ALL DESIRED DATA HERE**
}
], function (err, result) {
//handle in memory data
});
Second Solution: Clone node-cheat twitter-screen-names, run npm install and shoot node server, Now get all twitter usernames as json in browser.
Happy Helping!
I'm using Node-Neo4j client for my db. I want to create unique node, but I couldn't find how to do that in the documentation of Node-Neo4j. I used the logic below to check if a node exists or not:
person_param = {'name': namesurname, 'userid': userid };
person_node = db.createNode(person_param);
if (!person_node.exists){
person_node.save(function(err, result){
//if(err) and if(!err) stuff
});
}
But, from what I understand, createNode creates a new node from scratch, and when I use exists on it, it just checks if the newly created node saved into database or not.
How can I check if a node with supplied properties already exists in db or not?
Thanks in advance.
The only solution I can think of, is the following:
Create your properties object
Query the Neo4J instance for those properties
If a result is returned use that
otherwise save it
In code:
var person_param = {'name': namesurname, 'userid': userid };
// Build a Cypher query
var query = [
'MATCH (user: {name: {name}, id: {userid}})',
'RETURN user'
].join('\n');
// use your params in the query
var params = person_param;
// Send the Cypher query
db.query(query, params, function (err, results) {
if (err) throw err;
// no node with such properties found
if(!results.length){
saveNode(params, callback)
} else {
// carry on with your code...
}
});
function saveNode(person_param, callback){
var person_node = db.createNode(person_param);
person_node.save(function(err, result){
//if(err) and if(!err) stuff
// call the callback here
});
}
The downside of this approach is that you need to build a Cypher query for each type of node you have, because there's no way (as far as I know) to pass both properties name and values to Cypher.
In my web app , I am showing rates of stocks.I am using jquery autocomplete to show options while entring stocks name. But I have built local copy of javascript array. I want to show the options from this local array , If search term is not found in local array then ajax call must be made to get the list from server side.
Thanks !!!
//Local array
var local_array=["option1","option2"];
//jqueryUI call of autocomplete function
$('#search_stock').autocomplete({
source:function(){
if(search term is found in local array)
{
show suggestion from local array.
}
else
{
make ajax call to show suggestions of stock names.
}
}
});
UPDATE
Here's the actual code
$(function() {
var cache = {'option1':'option1','option2':'option2'}, lastXhr;
$( "#stock_rates" ).autocomplete({
minLength: 2,
source: function( request, response ) {
var term = request.term;
if ( term in cache ) {
response( cache[ term ] );
return;
}
lastXhr = $.getJSON( "stock_rates.php", request, function( data, status, xhr ) {
cache[ term ] = data;
if ( xhr === lastXhr ) { response( data ); }
});
}
});
});
The example pages for jQuery UI autocomplete have an example of exactly this issue.
http://jqueryui.com/demos/autocomplete/#remote-with-cache. Click the 'View Source' link on that page to see the code for the example.
The key part is that 'source' takes arguments.
source: function(request, response){
You need to read request, either fetch the value from your cache, or do a request, and then call the response function and pass it the matched values.
Update
Your problem now is that the format that you are storing in your cache is wrong. The cache just stores data as it would be returned from your getJSON call, indexed by the search term. It is up to you do to do the prefix checking and such.
To continue the way you are trying now, you'll either need to populate the cache properly.
var cache = {
"o": ['option1', 'option2'],
"op": ['option1', 'option2'],
// ....
"option1": ['option1'],
"option2": ['option2']
};
Otherwise, you could store the data differently and put more logic in your 'source' function to do the prefix checking on a static array or something. That all really depends on the data you are caching though.
Use search event of autocomplete and check your condition in that event and based on that return true or false if you want to make a ajax call respectively.
Below is the sample code.
$('#search_stock').autocomplete({
search:function(event,ui){
if(search term is found in local array)
{
return false;
}
else
{
return true;
}
}
});
var display_message="";
$('input:checked').each(function(index) {
var profile_id=$(this).val();
$.ajax({
type: 'post',
url: 'myUrl',
data: data,
success: function(data) {
if(data=="ok")
display_message = display_message + data +", ";
}
});
});
alert(display_message);
alert(display_message);
if($.trim(display_message)!=""){
jAlert("Your birthdate already exits in "+display_message.substring(0, display_message.length - 2)+".", "Bdate");
return false;
}
in this code, i use two alert-box for display display_message variable value.
when i run successfully this code, in 1st alert-box i get blank value and second alert-box i get value which i needed, then it will go in if condition.
if i doesn't use alert box then it will always take null value in display_message variable and never enters into the if condition. so what i need to change to run this code without alert box?
You are making an asynchronous call via AJAX, but your code is executing synchronously. So it is returning before the AJAX call completes. The first alert box just gives the function time to catch up. You need to handle all this code in your success callback.
var display_message="";
$('input:checked').each(function(index) {
var profile_id=$(this).val();
$.ajax({
type: 'post',
url: 'myUrl',
data: data,
success: function(data) {
if(data=="ok")
display_message = display_message + data +", ";
if($.trim(display_message)!=""){
jAlert("Your birthdate already exits in "+display_message.substring(0, display_message.length - 2)+".", "Bdate");
return false;
}
});
});
You want all your ajax queries to finish and return results, right?
Then this is a synchronization problem.
I would suggest this approach (code is simplified for clarity).
var inputs_processed = -1;
var inputs_to_process = -1;
function queryData() {
inputs_to_process = $('input:checked').length;
$('input:checked').each(function() {
$.ajax({success: function(data) {
inputs_processed += 1;
// build up that message
}});
});
}
function displayResult() {
if (inputs_processed == inputs_to_process) {
// display result
} else {
// not all queries finished yet. Wait.
setTimeout(displayResult, 500);
}
}
queryData();
displayResult();
Basically, you know how many requests should be made and you don't display result until that number of requests returns.
Why your data is "data"? I cant see any variable called data is declared here. You should pass in the value you want to use as the parameter into the data options.
Edit: This is why u getting the null value. data is not initialize into anything. Only after the success function, your "data" will have the value since you declare the return value with the same name
I built an ajax chat in one of my mvc website. everything is working fine. I am using polling. At certain interval i am using $.post to get the messages from the db. But there is a problem. The message retrieved using $.post keeps on repeating. here is my javascript code and controller method.
var t;
function GetMessages() {
var LastMsgRec = $("#hdnLastMsgRec").val();
var RoomId = $("#hdnRoomId").val();
//Get all the messages associated with this roomId
$.post("/Chat/GetMessages", { roomId: RoomId, lastRecMsg: LastMsgRec }, function(Data) {
if (Data.Messages.length != 0) {
$("#messagesCont").append(Data.Messages);
if (Data.newUser.length != 0)
$("#usersUl").append(Data.newUser);
$("#messagesCont").attr({ scrollTop: $("#messagesCont").attr("scrollHeight") - $('#messagesCont').height() });
$("#userListCont").attr({ scrollTop: $("#userListCont").attr("scrollHeight") - $('#userListCont').height() });
}
else {
}
$("#hdnLastMsgRec").val(Data.LastMsgRec);
}, "json");
t = setTimeout("GetMessages()", 3000);
}
and here is my controller method to get the data:
public JsonResult GetMessages(int roomId,DateTime lastRecMsg)
{
StringBuilder messagesSb = new StringBuilder();
StringBuilder newUserSb = new StringBuilder();
List<Message> msgs = (dc.Messages).Where(m => m.RoomID == roomId && m.TimeStamp > lastRecMsg).ToList();
if (msgs.Count == 0)
{
return Json(new { Messages = "", LastMsgRec = System.DateTime.Now.ToString() });
}
foreach (Message item in msgs)
{
messagesSb.Append(string.Format(messageTemplate,item.User.Username,item.Text));
if (item.Text == "Just logged in!")
newUserSb.Append(string.Format(newUserTemplate,item.User.Username));
}
return Json(new {Messages = messagesSb.ToString(),LastMsgRec = System.DateTime.Now.ToString(),newUser = newUserSb.ToString().Length == 0 ?"":newUserSb.ToString()});
}
Everything is working absloutely perfect. But i some messages getting repeated. The first time page loads i am retrieving the data and call GetMessages() function. I am loading the value of field hdnLastMsgRec the first time page loads and after the value for this field are set by the javascript.
I think the message keeps on repeating because of asynchronous calls. I don't know, may be you guys can help me solve this.
or you can suggest better way to implement this.
Kaivalya is correct about the caching, but I'd also suggest that your design could and should be altered just a tad.
I made a very similar app recently, and what I found was that my design was greatly enhanced by letting the controllers work with the fairly standard PRG pattern (post-redirect-get). Why enhanced? well, because POST methods are built to add stuff to an app, GET methods are supposed to be used to get information without side effects. Your polling should be just getting new messages w/o side effects.
So rather than your $.post call expecting data and handling the callback, what I'd recommend is having your controller expose a method for creating new chat messages via POST and then another method that get the last X chat messages, or the messages since a certain timestamp or whatever.
The javascript callback from the post action, then can update some variables (e.g. the last message id, timestamp of the last message, or even the whole URL of the next message based on the info contained in a redirect, whatever).
The $.post would fire only in response to user input (e..g type in a box, hit 'send') Then, you have (separately) a $.get call from jquery that's set up to poll like you said, and all it does is fetch the latest chat messages and it's callback updates the chat UI with them.
I got my answer here: ASP.NET AJAX CHAT
The names below i am referring to are from above link.
i think the actual problem was with the timestamp thing and asynchronous behaviour of $.post. after calling "GetMessages()" method, even if the previous request to retrive chat message was not complete anathor call to same method used to fire due to setting timeout for "GetMessages()" method outside the $.post method. In my question you can see that timeout for "GetMessages()" method is set outside the $.post method. Now i set the timeout for "GetMessages()" method inside the $.post method. so that next call to "GetMessages()" only occur after 3 seconds of completion of current $.post method. I have posted the code below.
var t;
function GetMessages() {
var LastMsgRec = $("#hdnLastMsgRec").val();
var RoomId = $("#hdnRoomId").val();
//Get all the messages associated with this roomId
$.post("/Chat/GetMessages", { roomId: RoomId, lastRecMsg: LastMsgRec }, function(Data) {
if (Data.LastMsgRec.length != 0)
$("#hdnLastMsgRec").val(Data.LastMsgRec);
if (Data.Messages.length != 0) {
$("#messagesCont").append(Data.Messages);
if (Data.newUser.length != 0)
$("#usersUl").append(Data.newUser);
$("#messagesCont").attr({ scrollTop: $("#messagesCont").attr("scrollHeight") - $('#messagesCont').height() });
$("#userListCont").attr({ scrollTop: $("#userListCont").attr("scrollHeight") - $('#userListCont').height() });
}
else {
}
t = setTimeout("GetMessages()", 3000);
}, "json");
}
I addition to that i also changed few things. As suggested by ignatandrei i placed $("#hdnLastMsgRec").val(Data.LastMsgRec); immediately after function(Data) {.
and also
as said by MikeSW i changed the data retrieval process. Previously i was extracting data on the basis of timespan(retrieve all the data associated with
this room id that has greater timespan than last data retrieved message timespan) but now i keep track of the messageid. Now i retrieve only those data that
has message id greater than last retrieved message id.
and guess what no repeataion and perfectly working chat application so far on my intranet.
I still got to see it's performance when deployed on internet.
i think it solved my problem.
i will still test the system and let u guys know if there is any problem.
By default $.post() caches the results
You can either call $.ajaxSetup ({ cache: false}); before JS GetMessages function call to ensure caching is disabled or change the $.post to $.ajax and set cache attribute to false. In the end $.post() is a short cut to this:
$.ajax({
type: 'POST',
url: url,
data: data,
success: success
dataType: dataType
});