HATEOAS is a concept of *application architecture*. It defines the way in which application clients interact with the server, by navigating hypermedia links they find inside resource models returned by the server.

To *implement* HATEOAS you need some standard way of representing resources, that will contain hypermedia information (links to related resources), for example, something like this:

    {
        &quot;links&quot;: {
            &quot;self&quot;: { &quot;href&quot;: &quot;http://api.com/items&quot; },
            &quot;item&quot;: [
                { &quot;href&quot;: &quot;http://api.com/items/1&quot; },
                { &quot;href&quot;: &quot;http://api.com/items/2&quot; }
            ]
        },
        &quot;data&quot;: [
                { &quot;itemName&quot;: &quot;a&quot; }, 
                { &quot;itemName&quot;: &quot;b&quot; } 
        ] 
    }

HAL is one of such standards. It is a specific format of resource presentation, that can be used to implement HATEOAS. 

You can fully implement HATEOAS without following HAL at all if you prefer to follow another standard or use your own.

In order to stage python project within our corporation I need to make an installable distribution. 

This should include:

 - An egg or whl for my project
 - An egg or whl for every dependency of the project
 - (optionally) produce a requirements.txt file listing all the installable components for this release

Is there an easy plug in, (e.g. an alternative to bdist_wheel) that will not only compile one wheel but also that project&#39;s components?

Obviously I can script this, but I was hoping that there might be a short-cut that builds the package + dependencies in fewer steps.

This needs to work on Python 2.7 on Windows + Linux.

Build a wheel/egg and all dependencies for a python project

I&#39;m writing an opencv program and I found a script on another stackoverflow question: https://stackoverflow.com/questions/14752006/computer-vision-masking-a-human-hand/14756351#14756351

When I run the scripted answer, I get the following error:

    Traceback (most recent call last):
        File &quot;skinimagecontour.py&quot;, line 13, in &lt;module&gt;
        contours, _ = cv2.findContours(skin_ycrcb, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    ValueError: too many values to unpack

The code:

    import sys
    import numpy
    import cv2

    im = cv2.imread(&#39;Photos/test.jpg&#39;)
    im_ycrcb = cv2.cvtColor(im, cv2.COLOR_BGR2YCR_CB)

    skin_ycrcb_mint = numpy.array((0, 133, 77))
    skin_ycrcb_maxt = numpy.array((255, 173, 127))
    skin_ycrcb = cv2.inRange(im_ycrcb, skin_ycrcb_mint, skin_ycrcb_maxt)
    cv2.imwrite(&#39;Photos/output2.jpg&#39;, skin_ycrcb) # Second image

    contours, _ = cv2.findContours(skin_ycrcb, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    for i, c in enumerate(contours):
        area = cv2.contourArea(c)
        if area &gt; 1000:
            cv2.drawContours(im, contours, i, (255, 0, 0), 3)
    cv2.imwrite(&#39;Photos/output3.jpg&#39;, im)

Any help is appreciated!

OpenCV Python: cv2.findContours - ValueError: too many values to unpack

[HATEOAS][1] (Hypermedia as the Engine of Application State) and [HAL][2] (Hypertext Application Language) seem to be related but are not exactly the same. What is the relationship and difference between HATEOAS and HAL?


  [1]: http://en.wikipedia.org/wiki/HATEOAS
  [2]: http://en.wikipedia.org/wiki/Hypertext_Application_Language

Relationship and difference between HAL and HATEOAS

<p><a href="http://en.wikipedia.org/wiki/HATEOAS" target="_blank" rel="noopener noreferrer">HATEOAS</a> (Hypermedia as the Engine of Application State) and <a href="http://en.wikipedia.org/wiki/Hypertext_Application_Language" target="_blank" rel="noopener noreferrer">HAL</a> (Hypertext Application Language) seem to be related but are not exactly the same. What is the relationship and difference between HATEOAS and HAL?</p>


Let&#39;s say I have an API where you can get users:

    GET /RESTAPI/user/

And you can delete users by:

    DELETE /RESTAPI/user/123

What is the *RESTful convention* on what the DELETE&#39;s response body should contain?
I expected it should be the new list of all users which now doesn&#39;t contain the user with id 123 anymore.

Googling around didn&#39;t get me any satisfying answers. I only found opinions on how to do that, **but isn&#39;t there a strict definition of RESTful Services**?


This is NOT a duplicate of https://stackoverflow.com/questions/7955469/what-should-a-restful-api-post-delete-return-in-the-body and https://stackoverflow.com/questions/4268707/what-rest-put-post-delete-calls-should-return-by-a-convention
since this questions asks for a strict definition regarding DELETE. Those questions were answered by loose opinions only.

RESTful - What should a DELETE response body contain

I am playing around with Nodejs and express by building a small rest API. My question is, what is the good practice/best way to set the code status, as well as the response data?

Let me explain with a little bit of code (I will not put the node and express code necessary to start the server, just the router methods that are concerned):

    router.get(&#39;/users/:id&#39;, function(req, res, next) {
      var user = users.getUserById(req.params.id);
      res.json(user);
    });


    exports.getUserById = function(id) {
      for (var i = 0; i &lt; users.length; i++) {
        if (users[i].id == id) return users[i];
      }
    };

The code below works perfectly, and when sending a request with Postman, I get the following result:
![enter image description here][1]

As you can see, the status shows 200, which is OK. But is this the best way to do this? Is there a case where I should have to set the status myself, as well as the returned JSON? Or is that always handled by express?

For example, I just made a quick test and slightly modified the get method above:

    router.get(&#39;/users/:id&#39;, function(req, res, next) {
      var user = users.getUserById(req.params.id);
      if (user == null || user == &#39;undefined&#39;) {
        res.status(404);
      }
      res.json(user);
    });

As you can see, if the user is not found in the array, I will just set a status of 404.

Resources/advices to learn more about this topic are more than welcome.


  [1]: http://i.stack.imgur.com/0EMs8.png

Proper way to set response status and JSON content in a REST API made with nodejs and express

I’ve been trying to access this particular REST service from a PHP page I’ve created on our server.  I narrowed the problem down to these two lines.  So my PHP page looks like this:

    &lt;?php
	$response = file_get_contents(&quot;https://maps.co.weber.ut.us/arcgis/rest/services/SDE_composite_locator/GeocodeServer/findAddressCandidates?Street=&amp;SingleLine=3042+N+1050+W&amp;outFields=*&amp;outSR=102100&amp;searchExtent=&amp;f=json&quot;);
	
	echo $response; ?&gt;

The page dies on line 2 with the following errors:

&gt; - Warning: file_get_contents(): SSL operation failed with code 1.
   OpenSSL Error messages: error:14090086:SSL
   routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed in
   ...php on line 2
 - Warning: file_get_contents(): Failed to enable crypto in ...php on
   line 2
 - Warning:
   file_get_contents(`https://maps.co.weber.ut.us/arcgis/rest/services/SDE_composite_locator/GeocodeServer/findAddressCandidates?Street=&amp;SingleLine=3042+N+1050+W&amp;outFields=*&amp;outSR=102100&amp;searchExtent=&amp;f=json`):
   failed to open stream: operation failed in ...php on line 2


We’re using a Gentoo server.  We recently upgraded to PHP version 5.6.  It was after the upgrade when this problem appeared.    

I found when I replace the REST service with an address like `https://www.google.com`; my page works just fine.  


In an earlier attempt I set `“verify_peer”=&gt;false`, and passed that in as an argument to file_get_contents, as described here:  https://stackoverflow.com/questions/15076819/file-get-contents-ignoring-verify-peer-false  But like the writer noted; it made no difference.  

I’ve asked one of our server administrators if these lines in our php.ini file exist:

 - extension=php_openssl.dll
 - allow_url_fopen = On


He told me that since we’re on Gentoo, openssl is compiled when we build; and it’s not set in the php.ini file.  

I also confirmed that `allow_url_fopen` is working.  Due to the specialized nature of this problem; I’m not finding a lot of information for help.  Have any of you come across something like this?  Thanks.  

file_get_contents(): SSL operation failed with code 1, Failed to enable crypto

I am facing issues while consuming JAX-RS services as JSON.

Below I have added my code.

This is my service class:

    //Sets the path to base URL + /hello
    @Path(&quot;/hello&quot;) 
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public class Hello {

	    @GET
    	@Produces(&quot;application/json&quot;)
    	public Student getStudent() {
		
	    	Student s = new Student();
		    s.first_name = &quot;Test First Name !!!&quot;;
    		s.last_name = &quot;Test Last Name!!!&quot;;
		
	    	return s;
	    }

`Student` class which I am trying to get from service:
  
    @XmlRootElement
    public class Student implements Serializable {
    	
    	public String first_name;
    	public String last_name;
    	
    	public String getFirst_name() {
    		return first_name;
    	}
    
    	public void setFirst_name(String first_name) {
    		this.first_name = first_name;
    	}
    
    	public String getLast_name() {
    		return last_name;
    	}
    
    	public void setLast_name(String last_name) {
    		this.last_name = last_name;
    	}
    
    	public Student()
    	{
    		first_name = &quot;Fahad&quot;;
    		last_name = &quot;Mullaji&quot;;
    	}
    }

Web XML on service side.

&lt;!-- language: lang-xml --&gt;

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
    &lt;web-app xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
    	xmlns=&quot;http://java.sun.com/xml/ns/javaee&quot;
    	xsi:schemaLocation=&quot;http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd&quot;
    	id=&quot;WebApp_ID&quot; version=&quot;3.0&quot;&gt;
    	&lt;display-name&gt;com.vogella.jersey.first&lt;/display-name&gt;
    	&lt;servlet&gt;
    		&lt;servlet-name&gt;Jersey REST Service&lt;/servlet-name&gt;
    		&lt;servlet-class&gt;org.glassfish.jersey.servlet.ServletContainer&lt;/servlet-class&gt;
    		&lt;!-- Register resources and providers under com.vogella.jersey.first package. --&gt;
    		&lt;init-param&gt;
    			&lt;param-name&gt;jersey.config.server.provider.packages&lt;/param-name&gt;
    			&lt;param-value&gt;com.vogella.jersey.first&lt;/param-value&gt;
    		&lt;/init-param&gt;
    		&lt;init-param&gt;
    			&lt;param-name&gt;com.sun.jersey.api.json.POJOMappingFeature&lt;/param-name&gt;
    			&lt;param-value&gt;true&lt;/param-value&gt;
    		&lt;/init-param&gt;
    
    		&lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
    	&lt;/servlet&gt;
    	&lt;servlet-mapping&gt;
    		&lt;servlet-name&gt;Jersey REST Service&lt;/servlet-name&gt;
    		&lt;url-pattern&gt;/rest/*&lt;/url-pattern&gt;
    	&lt;/servlet-mapping&gt;
    &lt;/web-app&gt; 

I don&#39;t know how to fix this issue.
I am using SOAP UI for testing JSON response but I guess that it should not matter.

Many places I read that I need to add the code below. But I don&#39;t know where. I am not using Maven for building.

    &lt;dependency&gt;
        &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
        &lt;artifactId&gt;jersey-media-moxy&lt;/artifactId&gt;
    &lt;/dependency&gt;

Server is looking for function to parse `Student` object to JSON but it is not able to find function or jar file for it. 
I have added jar of Genson, Moxy, RESTEasy and Jackson but I think that&#39;s the problem.
I think I am missing mapping somewhere.

MessageBodyWriter not found for media type=application/json

We are planning to make a new application with spring 4.0.6 version. We use controller that can return &quot;XML&quot; or &quot;JSON&quot;. 
In the previous project we have successfully implemented Jersey with Spring for REST support using JAX-RS API, but after reading a few articles and suggestions from seniors they said spring is providing pretty good REST support. 

Some of the points that really confused me if I use Spring REST support without using JAX-RS and Jersey are:

1. How marshaling and unmarshaling done in Spring MVC ?

2. Is it necessary for marshaling or unmarshaling need to use jax-rs. 

3. If marshaling and unmarshaling are automatically handled by spring then how does it know about xmlRootElements.

I am still confused if Spring proving very good support of REST then why do people still go with Jersey for REST?
Really looking to know more in details.

If I said anything wrong please ignore it.
Explanation with example is really helpful.

Thanks in advance!!

Spring 4 vs Jersey for REST web services

I have two cloned repositories of two very similar open-source projects, which I have been working on in different instances in Sublime Text 2 to arrive at my desired result. Code from both of these projects was used. I have been using Git as version control for my project, but have not included the original projects. Thus, I would like to be able to quickly compare the contents of two files of the original project and compare the differences between them and my project.

I was hoping that Sublime Text 2 would have a &quot;Compare File&quot; feature, but I can&#39;t seem to find anything related to it in the settings or online. A third-party ST2 package to accomplish this task would also work well. **Is such a task possible to do within the ST2 text editor?** 

Comparing the contents of two files in Sublime Text

I am writing an app that needs to be quite accurate in dates and I wonder how can I compare LocalDate instances.. for now I was using something like:

    LocalDate localdate1 = LocalDate().now();
    LocalDate localdate2 = someService.getSomeDate();
    localdate1.equals(localdate2);

But I noticed that my app is giving me some confusing results, and I think it is because of the date comparing.

I am thinking about obtaining the time from 1970&#39; in long and compare those two, but I must be easier, I am sure of it


How to compare LocalDate instances Java 8

I want to compare values from two different files.  
In Notepad++ version 5.0.3 we had shortcut button &lt;kbd&gt;Alt&lt;/kbd&gt;+&lt;kbd&gt;d&lt;/kbd&gt; but in version 6.6.8 I cannot find any option to compare.

Also let me know which version is most stable.

How to compare two files in Notepad++

Is there an easy way to compare two `[String: AnyObject]` dictionaries in swift, since it doesn&#39;t accept the `==` operator? 

By comparing two dictionaries, I mean checking that they have the same exact keys and for every key they have the same values.

How do I compare two dictionaries in Swift?

As you know, [`java.util.Objects`][1] is 

&gt; This class consists of static utility methods for operating on objects.

One of such methods is `Objects.isNull()`.

My understanding is that `Objects.isNull()` would remove the chance of accidentally assigning a null value to object by omitting the second `=`.

However, the API Note states:

&gt; This method exists to be used as a Predicate, filter(Objects::isNull)

Would there be any reason/circumstance for which I should use `object == null` over `Objects.isNull()` in an **if statement**?

Should `Objects.isNull()` be confined to Predicates exclusively?

  [1]: https://docs.oracle.com/javase/8/docs/api/java/util/Objects.html

java.util.Objects.isNull vs object == null

I am currently creating a REST-API for a project and have been reading article upon article about best practices. Many seem to be against DTOs and simply just expose the domain model, while others seem to think DTOs (or User Models or whatever you want to call it) are bad practice. Personally, I thought that [this article][1] made a lot of sense.

However, I also understand the drawbacks of DTOs with all the extra mapping code, domain models that might be 100% identical to their DTO-counterpart and so on. 

Our API is mostly created so that other clients may consume data, however if we do it right we would also like to use it for our own web GUI if possible. 

The thing is that we might not want to expose all the domain data to the other client users. Much of the data will only make sense in our own web application. Also, we might not want to expose all data about an object in all scenarios, especially relationships to other objects and so on. For example, if we expose a list of a particular object we would not necessarily want to expose the entire object hierarchy; so that the object&#39;s children will not be exposed, but can be discovered through links (hateoas). 

How should I go about solving this problem? I was thinking about using Jackson mixins on our domain models to control what data would be exposed given different scenarios. Or should we just use DTOs all the way - even given its drawbacks and controversy? 


  [1]: https://www.ibm.com/developerworks/community/blogs/barcia/entry/data_models_for_api_s_are_not_canonical_or_domain_models_they_are_your_user_model?lang=en

Content Type	Original Author	Original Content on Stackoverflow
Question	Lee Chee Kiam	View Question on Stackoverflow
Solution 1 - Rest	astreltsov	View Answer on Stackoverflow

Relationship and difference between HAL and HATEOAS

Rest Problem Overview

Rest Solutions

Solution 1 - Rest

OpenCV Python: cv2.findContours - ValueError: too many values to unpack

Build a wheel/egg and all dependencies for a python project

Attributions