In express 4.x:

    req.get(&#39;Referrer&#39;)

This will also check [both spellings](https://stackoverflow.com/a/3087656/179015) of referrer so you do not have to do:

     req.headers.referrer || req.headers.referer

Here is the [documentation](http://expressjs.com/en/4x/api.html#req.get)


If you mean how do you get it when running an express server, then it&#39;s done using the [header](http://expressjs.com/guide.html#req.header%28%29) method on your request:

    req.headers.referer;
    // =&gt; &quot;http://google.com&quot;

I&#180;m trying to find the corners on a image, I don&#180;t need the contours, only the 4 corners. I will change the perspective using 4 corners.

I&#180;m using Opencv, but I need to know the steps to find the corners and what function I will use.

My images will be like this:(without red points, I will paint the points after)
![enter image description here][1]


EDITED:

After suggested steps, I writed the code: (Note: I&#180;m not using pure OpenCv, I&#180;m using javaCV, but the logic it&#180;s the same).

	// Load two images and allocate other structures (I&#180;m using other image)
        IplImage colored = cvLoadImage(
                &quot;res/scanteste.jpg&quot;,
                CV_LOAD_IMAGE_UNCHANGED);

![enter image description here][2]

        IplImage gray = cvCreateImage(cvGetSize(colored), IPL_DEPTH_8U, 1);
        IplImage smooth = cvCreateImage(cvGetSize(colored), IPL_DEPTH_8U, 1);

        //Step 1 - Convert from RGB to grayscale (cvCvtColor)
        cvCvtColor(colored, gray, CV_RGB2GRAY);


![enter image description here][3]


       
        //2 Smooth (cvSmooth)
        cvSmooth( gray, smooth, CV_BLUR, 9, 9, 2, 2); 
  
![enter image description here][4]

        //3 - cvThreshold  - What values?
        cvThreshold(gray,gray, 155, 255, CV_THRESH_BINARY);

![enter image description here][5]

        //4 - Detect edges (cvCanny) -What values?
    	int N = 7;
    	int aperature_size = N;
    	double lowThresh = 20;
    	double highThresh = 40;    	
        cvCanny( gray, gray, lowThresh*N*N, highThresh*N*N, aperature_size );	




![enter image description here][6]


        //5 - Find contours (cvFindContours)
        int total = 0;
        CvSeq contour2 = new CvSeq(null);
        CvMemStorage storage2 = cvCreateMemStorage(0);
        CvMemStorage storageHull = cvCreateMemStorage(0);
        total = cvFindContours(gray, storage2, contour2, Loader.sizeof(CvContour.class), CV_RETR_CCOMP, CV_CHAIN_APPROX_NONE);
        if(total &gt; 1){
              while (contour2 != null &amp;&amp; !contour2.isNull()) {
                  if (contour2.elem_size() &gt; 0) {
                	//6 - Approximate contours with linear features (cvApproxPoly)
                      CvSeq points = cvApproxPoly(contour2,Loader.sizeof(CvContour.class), storage2, CV_POLY_APPROX_DP,cvContourPerimeter(contour2)*0.005, 0);
                      cvDrawContours(gray, points,CvScalar.BLUE, CvScalar.BLUE, -1, 1, CV_AA);

                  }
                  contour2 = contour2.h_next();
              }

        } 

![enter image description here][7]


So, I want to find the cornes, but I don&#180;t know how to use corners function like cvCornerHarris and others.


  [1]: http://i.stack.imgur.com/9CtnW.jpg
  [2]: http://i.stack.imgur.com/ag0Sa.jpg
  [3]: http://i.stack.imgur.com/xCFht.png
  [4]: http://i.stack.imgur.com/sgBAi.png
  [5]: http://i.stack.imgur.com/79WA4.png
  [6]: http://i.stack.imgur.com/01VZ0.png
  [7]: http://i.stack.imgur.com/Zj35W.png

How to find corners on a Image using OpenCv

We have a test database and some test logins that we would like to give db_owner access to through a script. Usually we would have to go into logins and right click on the username and go to user mapping and select the database to associate it with and give it owner access and click &lt;kbd&gt;OK&lt;/kbd&gt;.


SQL Server giving logins(users) db_owner access to database

How do I find the a referring sites URL in node?

I&#39;m using express, would I find this in the headers on connect or something?

Thanks!

How do I find the a referring sites URL in node?

How do I find the a referring sites URL in node?
I'm using express, would I find this in the headers on connect or something?
Thanks!

Let&#39;s say I want to reload `www.domain.com/abc?num=4`

But I want to reload `www.domain.com/abc` ONLY (without everything after the question mark)

How do I reload the page without the query parameters?

I was wondering if there&#39;s a way to do something like a PHP `foreach` loop in JavaScript. The functionality I&#39;m looking for is something like this PHP Snippet:

    foreach($data as $key =&gt; $value) { }

I was looking at the JS `for..in` loop, but there seems to be no way to specify the `as`. If I do this with a &#39;normal&#39; for loop (`for(var i = 0; i &lt; data.length; i++`), is there a way to grab the key =&gt; value pairs?

For..In loops in JavaScript - key value pairs

I&#39;ve tried searching for people with similar questions, but haven&#39;t found anything.

I have two dates in JavaScript, both set to the same value... Equality Testing fails on ==, but &gt;= and &lt;= evaluate true.

Below is the code I have in play:


    var startDate = new Date( 2011, 7, 30, 0, 0, 0, 0 );
    
    var dt = new Date( 2011, 7, 30, 0, 0, 0, 0 );
    
    if( startDate == dt )
    	document.write(&#39;They Equal&lt;br /&gt;&#39;);
    	
    if( startDate &gt; dt )
    	document.write(&#39;Start Date is &gt; dt&lt;br /&gt;&#39;);
    	
    if( startDate &gt;= dt )
    	document.write(&#39;Start Date is &gt;= dt&lt;br /&gt;&#39;);
    
    if( startDate &lt; dt )
    	document.write(&#39;Start Date is &lt; dt&lt;br /&gt;&#39;);
    	
    if( startDate &lt;= dt )
    	document.write(&#39;Start Date is &lt;= dt&lt;br /&gt;&#39;);
    	
    if( dt == startDate )
    	document.write(&#39;They Equal&lt;br /&gt;&#39;);
    	
    if( dt &gt; startDate )
    	document.write(&#39;dt &gt; startDate&lt;br /&gt;&#39;);
    	
    if( dt &gt;= startDate )
    	document.write(&#39;dt &gt;= Start Date &lt;br /&gt;&#39;);
    
    if( dt &lt; startDate )
    	document.write(&#39;dt &lt; Start Date &lt;br /&gt;&#39;);
    	
    if( dt &lt;= startDate )
    	document.write(&#39;dt &lt;= Start Date &lt;br /&gt;&#39;);	
    	
    document.write( dt );
    document.write( &#39;&lt;br /&gt;&#39;);
    document.write( startDate );

Has anyone encountered anything like this, or am I doing something fundamentally wrong?

I tested this is Internet Explorer (9), Firefox 5+, and Chrome.

**Update:**

So two people posted great answers to my problem, and I thank both of you: xdazz and DaveRandom. I had read an earlier post on stackoverflow.com on a similar question and a guy said that date objects could be compared like any others, and any other example I found always did a &lt; or &gt; type of compare, never a full equality so I wasn&#39;t able to make the connection as to why I was doing it wrong.

Thanks to you two, and the others that posted similar answers.


JavaScript Date Comparisons Don&#39;t Equal

Are trailing commas standard in JavaScript, or do most browsers like Chrome and Firefox just tolerate them?

I thought they were standard, but IE8 puked after encountering one—of course IE not supporting something hardly means it’s not standard.

Here’s an example of what I mean (after the last element of the books array):

    var viewModel = {
        books: ko.observableArray([
            { title: &quot;..&quot;, display: function() { return &quot;..&quot;; } },
            { title: &quot;..&quot;, display: function() { return &quot;..&quot;; } },
            { title: &quot;..&quot;, display: function() { return &quot;..&quot;; } }, // &lt;--right there
        ]),
        currentTemplate: ko.observable(&quot;bookTemplate1&quot;),
        displayTemplate: function() { return viewModel.currentTemplate(); }
    };

Are trailing commas in arrays and objects part of the spec?

Are there any good Node.js (server-side JavaScript) unit testing frameworks currently out there?

I&#39;m looking for something a little deeper than the provided Assert module.


Node.js unit testing

The RFC2617 says to encode the username and password to base64 but don&#39;t say what character encoding to use when creating the octets for input into the base64 algorithm.

Should I assume US-ASCII or UTF8?  Or has someone settled this question somewhere already?

What encoding should I use for HTTP Basic Authentication?

I&#39;m trying to create a static file server in nodejs more as an exercise to understand node than as a perfect server. I&#39;m well aware of projects like Connect and node-static and fully intend to use those libraries for more production-ready code, but I also like to understand the basics of what I&#39;m working with. With that in mind, I&#39;ve coded up a small server.js:

    var http = require(&#39;http&#39;),
        url = require(&#39;url&#39;),
        path = require(&#39;path&#39;),
        fs = require(&#39;fs&#39;);
    var mimeTypes = {
        &quot;html&quot;: &quot;text/html&quot;,
        &quot;jpeg&quot;: &quot;image/jpeg&quot;,
        &quot;jpg&quot;: &quot;image/jpeg&quot;,
        &quot;png&quot;: &quot;image/png&quot;,
        &quot;js&quot;: &quot;text/javascript&quot;,
        &quot;css&quot;: &quot;text/css&quot;};

    http.createServer(function(req, res) {
        var uri = url.parse(req.url).pathname;
        var filename = path.join(process.cwd(), uri);
        path.exists(filename, function(exists) {
            if(!exists) {
                console.log(&quot;not exists: &quot; + filename);
                res.writeHead(200, {&#39;Content-Type&#39;: &#39;text/plain&#39;});
                res.write(&#39;404 Not Found\n&#39;);
                res.end();
            }
            var mimeType = mimeTypes[path.extname(filename).split(&quot;.&quot;)[1]];
            res.writeHead(200, mimeType);

            var fileStream = fs.createReadStream(filename);
            fileStream.pipe(res);

        }); //end path.exists
    }).listen(1337);

My question is twofold 

 1. Is this the &quot;right&quot; way to go about creating and streaming basic html etc in node or is there a better/more elegant/more robust method ?

 2. Is the .pipe() in node basically just doing the following?

.
    
    var fileStream = fs.createReadStream(filename);
    fileStream.on(&#39;data&#39;, function (data) {
        res.write(data);
    });
    fileStream.on(&#39;end&#39;, function() {
        res.end();
    });

Thanks everyone!

Basic static file server in NodeJS

I&#39;m writing a web service that returns a base64-encoded PDF file, so my plan is to add two headers to the response:

    Content-Type: application/pdf
    Content-Transfer-Encoding: base64

My question is: Is `Content-Transfer-Encoding` a valid HTTP header?  I think it might only be for MIME.  If not, how should I craft my HTTP response to represent the fact that I&#39;m returning a base64-encoded PDF?  Thanks.

**EDIT:** 

It looks like HTTP does not support this header.  From [RFC2616 Section 14][1]:

&gt; Note: while the definition of Content-MD5 is exactly the same for HTTP
&gt; as in RFC 1864 for MIME entity-bodies, there are several ways in which
&gt; the application of Content-MD5 to HTTP entity-bodies differs from its
&gt; application to MIME entity-bodies. One is that **HTTP, unlike MIME, does
&gt; not use Content-Transfer-Encoding**, and does use Transfer-Encoding and
&gt; Content-Encoding.

Any ideas for what I should set my headers to?  Thanks.

**EDIT 2**

Many of the code samples found in the comments of this PHP reference manual page seem to suggest that it actually *is* a valid HTTP header:

http://php.net/manual/en/function.header.php

  [1]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html

Is Content-Transfer-Encoding an HTTP header?

I want to add a &quot;Check for update&quot; button in apps so that when someone clicks it, it will display a toast message / progress dialog for checking the app&#39;s version. 

If new version is found the apps will auto download it to the phone and let user to  manually install the updated apps.

Or any others method will do as long as it can check for latest version and notify the user to update.

--------

**Update:** Now you can do this inside your app using https://developer.android.com/guide/playcore/in-app-updates


How to allow users to check for the latest app version from inside the app?

I have some disabled inputs in a form and I want to send them to a server, but Chrome excludes them from the request. 

Is there any workaround for this without adding a hidden field? 

    &lt;form action=&quot;/Media/Add&quot;&gt;
        &lt;input type=&quot;hidden&quot; name=&quot;Id&quot; value=&quot;123&quot; /&gt;

        &lt;!-- this does not appear in request --&gt;
        &lt;input type=&quot;textbox&quot; name=&quot;Percentage&quot; value=&quot;100&quot; disabled=&quot;disabled&quot; /&gt; 

    &lt;/form&gt;

Disabled form inputs do not appear in the request

Perhaps it&#39;s the time, perhaps it&#39;s me drowning in sparse documentation and not being able to wrap my head around the concept of updating in Mongoose :)

Here&#39;s the deal: 

I have a contact schema and model (shortened properties):

    var mongoose = require(&#39;mongoose&#39;),
        Schema = mongoose.Schema;
    
    var mongooseTypes = require(&quot;mongoose-types&quot;),
        useTimestamps = mongooseTypes.useTimestamps;
    
    
    var ContactSchema = new Schema({
        phone: {
            type: String,
            index: {
                unique: true,
                dropDups: true
            }
        },
        status: {
            type: String,
            lowercase: true,
            trim: true,
            default: &#39;on&#39;
        }
    });
    ContactSchema.plugin(useTimestamps);
    var Contact = mongoose.model(&#39;Contact&#39;, ContactSchema);

I receive a request from the client, containing the fields I need and use my model thusly:

    mongoose.connect(connectionString);
    var contact = new Contact({
        phone: request.phone,
        status: request.status
    });

And now we reach the problem:

 1. If I call `contact.save(function(err){...})` I&#39;ll receive an error if the contact with the same phone number already exists (as expected - unique)
 2. I can&#39;t call `update()` on contact, since that method does not exist on a document
 3. If I call update on the model:  
`Contact.update({phone:request.phone}, contact, {upsert: true}, function(err{...})`  
I get into an infinite loop of some sorts, since the Mongoose update implementation clearly doesn&#39;t want an object as the second parameter.
 4. If I do the same, but in the second parameter I pass an associative array of the request properties `{status: request.status, phone: request.phone ...}` it works - but then I have no reference to the specific contact and cannot find out its `createdAt` and `updatedAt` properties.

So the bottom line, after all I tried: given a document `contact`, how do I update it if it exists, or add it if it doesn&#39;t?

Thanks for your time.




How do I update/upsert a document in Mongoose?

How can I download a file that is in my server to my machine accessing a page in a nodeJS server?

I&#39;m using the ExpressJS and I&#39;ve been trying this:

    app.get(&#39;/download&#39;, function(req, res){

	  var file = fs.readFileSync(__dirname + &#39;/upload-folder/dramaticpenguin.MOV&#39;, &#39;binary&#39;);

      res.setHeader(&#39;Content-Length&#39;, file.length);
	  res.write(file, &#39;binary&#39;);
	  res.end();
    });

But I can&#39;t get the file name and the file type ( or extension ). Can anyone help me with that?

Download a file from NodeJS Server using Express

I have downloaded Windows Binary (.exe) of nodejs from [the main page][1]. 

How can I install and use `npm` (Node package manager)?


  [1]: https://nodejs.org/download/

How to use npm with node.exe?

Almost every Express app I see has an `app.use` statement for middleware but I haven&#39;t found a clear, concise explanation of what middleware actually is and what the `app.use` statement is doing. Even the express docs themselves are a bit vague on this. Can you explain these concepts for me please?

What does middleware and app.use actually mean in Expressjs?

I&#39;ve been trying to get HTTPS set up with a node.js project I&#39;m working on.  I&#39;ve essentially followed the [node.js documentation][1] for this example:

    // curl -k https://localhost:8000/
    var https = require(&#39;https&#39;);
    var fs = require(&#39;fs&#39;);
    
    var options = {
      key: fs.readFileSync(&#39;test/fixtures/keys/agent2-key.pem&#39;),
      cert: fs.readFileSync(&#39;test/fixtures/keys/agent2-cert.pem&#39;)
    };
    
    https.createServer(options, function (req, res) {
      res.writeHead(200);
      res.end(&quot;hello world\n&quot;);
    }).listen(8000);

Now, when I do 

    curl -k https://localhost:8000/
I get 

    hello world

as expected.  But if I do 

    curl -k http://localhost:8000/

I get 

    curl: (52) Empty reply from server

In retrospect this seems obvious that it would work this way, but at the same time, people who eventually visit my project aren&#39;t going to type in **https**://yadayada, and I want all traffic to be https from the moment they hit the site.  

How can I get node (and Express as that is the framework I&#39;m using) to hand off all incoming traffic to https, regardless of whether or not it was specified?  I haven&#39;t been able to find any documentation that has addressed this.  Or is it just assumed that in a production environment, node has something that sits in front of it (e.g. nginx) that handles this kind of redirection?

This is my first foray into web development, so please forgive my ignorance if this is something obvious.


  [1]: http://nodejs.org/docs/v0.4.11/api/https.html

Automatic HTTPS connection/redirect with node.js/express

So, I may be missing something simple here, but I can&#39;t seem to find a way to get the hostname that a request object I&#39;m sending a response to was requested from.

Is it possible to figure out what hostname the user is currently visiting from node.js?

Get hostname of current request in node.js Express

is possible in mongo db to select collection&#39;s documents like in SQL :

    SELECT * FROM collection WHERE _id IN (1,2,3,4);

or if i have a `_id array` i must select one by one and then recompose the `array/object` of results?


Content Type	Original Author	Original Content on Stackoverflow
Question	fancy	View Question on Stackoverflow
Solution 1 - Javascript	Ross	View Answer on Stackoverflow
Solution 2 - Javascript	emboss	View Answer on Stackoverflow

How do I find the a referring sites URL in node?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

SQL Server giving logins(users) db_owner access to database

How to find corners on a Image using OpenCv

Attributions