{"id":125,"date":"2018-03-22T09:48:00","date_gmt":"2018-03-22T08:48:00","guid":{"rendered":"https:\/\/kindsonthegenius.com\/blog\/2018\/03\/22\/restful-web-services-tutorial-2-setting-up-a-rest-client\/"},"modified":"2020-11-05T14:12:05","modified_gmt":"2020-11-05T13:12:05","slug":"restful-web-services-tutorial-2-setting-up-a-rest-client","status":"publish","type":"post","link":"https:\/\/kindsonthegenius.com\/blog\/restful-web-services-tutorial-2-setting-up-a-rest-client\/","title":{"rendered":"RESTful Web Services Tutorial 2 – Setting up a REST Client"},"content":{"rendered":"
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In this lesson, we would cover the following<\/p>\n
    \n
  1. Review of Tutorial 1<\/a><\/li>\n
  2. Overview of REST Client<\/a><\/li>\n
  3. Setup of Postman REST Client<\/a><\/li>\n
  4. Getting used to Advanced REST Interface <\/a> <\/li>\n
  5. Performing GET Operations<\/a><\/li>\n
  6. Next Steps <\/a><\/li>\n<\/ol>\n
    <\/a><\/div>\n

    <\/p>\n

    1. Review of Tutorial 1<\/a><\/h3>\n

    <\/b>
     In Tutorial 1, we build a REST Web service from the scratch using Visual Studio and C#. It was quite a straight forward procedure. In case, you need to review it, that would be fine so you can get used to it.
    Also, if you have not taken     Tutorial 1<\/a>, you need to go back and take it because you need it to get a clearer understanding of this Tutorial 2.<\/p>\n

    <\/ins>
    <\/p>\n

    2. Overview of REST Client<\/h3>\n

    <\/b>
    I am sure that by now the concept of REST web service is very clear, a service that is accessible over HTTP and conforms to the REST architechtural style.<\/p>\n

    So the question is,
    “what is the difference between a REST web service and other services?”<\/span>
    the differnce is that for a service to be considered a REST web service, it should conform to the following 4 criteria<\/p>\n

      \n
    1. it must have resource-based URLs – Level 1<\/b><\/span><\/li>\n
    2. it must use the correct HTTP verbs (GET, PUT, POST, DELETE) – Level 2<\/span><\/b><\/li>\n
    3. it must return the right status-codes – Level 2<\/span><\/b><\/li>\n
    4. it must be HATEOAS-compliant – Level 3<\/b><\/span><\/li>\n<\/ol>\n

      This four criteria make up the Richardson’s Maturity Model<\/a>. You can read it up here<\/a>.<\/p>\n

      For us to test these wether our API meets up these four criteria, just thebrowser would not do. We need a REST Client application<\/p>\n

      <\/p>\n

      3. Setup of Advanced REST Client<\/h3>\n

      <\/b>
      In this demo, we are going to use Advanced Rest Client from now till the rest of this tutorial. Advanced Rest Client is a free application provided as a plugin to Chrome browser. <\/p>\n

      Visit the Chrome Store on this link https:\/\/chrome.google.com\/webstore\/category\/extensions<\/a>
      Search for Advanced REST Client. Then select it.
      The window is shown as in Figure 1<\/p>\n

      <\/a><\/div>\n
      Figure 1: Advanced REST Client <\/div>\n

      Click on Add To Chrome on the upper left (Blue Button). It downloads and adds as an extention to chrome.
      You will see another tab opens and you can see Advanced Rest Client (a blue Icon) in the list of apps as shown in Figure 2<\/p>\n

       <\/a><\/div>\n
      Figure 2 – Advanced REST Client Added to Chrome<\/div>\n

      Click on it and then Click on Launch App in the next window that opens
      The Advanced REST Client window opens as shown in Figure 3<\/p>\n

      <\/a><\/div>\n
      Figure 3: Advanced REST Client Window <\/div>\n

      Let’s now take some time to get used to the Advanced REST Client interface<\/p>\n

      <\/ins>
      <\/p>\n

      4. Getting used to Advanced REST Interface<\/h3>\n

      <\/b>
      Take not of the following parts of the Window
      Method List: This is the list of HTTP methods. The first item here is GET but you could drop down to see a list of other methods. You need to select this depending on the type of request you want to make<\/p>\n

      Request URL<\/i>: <\/b>This is where you enter the URL containing the API you want to access. The Request URL ends with the port number if ther is a port number<\/p>\n

      Path<\/b>:<\/i> This is path that to a resource which may come after the Request URL. This path is everything following the port number.<\/p>\n

      Query Parameters:<\/b> This is URL query parameters. It is used if the request contains query paramters.<\/p>\n

      For example<\/p>\n

      http:\/\/kindsonthegenius.blogspot.hu\/getpost?id=50<\/span><\/div>\n

      In the above example the URL parameter is id and the value is 50.<\/p>\n

      Send Button<\/b><\/i>: Click to sent the request<\/p>\n

      Headers<\/b><\/i>: HTTP headers define the operating parameters or a HTTP transaction.For example, encoding and character set.<\/p>\n

      Body<\/i>: <\/b>Request body. This tab shows for POST, PUT and DELETE request types. It appears between the Headers tabe and the variables tab.<\/p>\n

      Varibles<\/b><\/i>: This is needed if there are additional variables needed to be sent along with the request<\/p>\n

      <\/p>\n

      5. Performing GET Operations<\/h3>\n

      <\/b>
      You could see how it works by entering www.google.com in the request URL section and pressing Send. You will observe that you have a response of 200 OK.<\/p>\n

      We are now going to use Advanced REST Client to test the API we built in Tutorial 1<\/a>.
      Open the Solution we created in       Tutorial 1<\/a><\/p>\n

      (Download the Solution from here)<\/a><\/p>\n

      Run it and make sure it it running<\/p>\n

      We would carry out to REST API requests:<\/i><\/p>\n