Thursday, April 21, 2016

[Analytics Dashboard] How to Create a Gadget Using External Data Set.


In this blog post I am guiding you to create a dashboard gadget using an external database.

As the example gadget I implemented a graph to display the blogger audience count by month.
Here I create a MySQL database called test. And I create a sample database table as follows.



Here I am using WSO2 DAS 3.0.0 version for the implementation. First you need to place the MySQL JDBC driver in  following path.

<DAS Home Path>/repository/Components/lib

Then you need to create an API to access the external database. The API should place in the
<DAS Home Path>/repository/deployment/server/jaggeryapps/portal/controllers/apis folder.
The API should implement using JAGGERY [1].


Here is my sample API code.

testAPI.jag

       
<%
//make the db connection 
var db = new Database("jdbc:mysql://localhost:3306/UnifiedDashboards", "root", "");
//function to get data from the db
function bloggerData() {
    //db query to get month and the pageviews data set from db
    var query_blogger_data = "SELECT * FROM test;";
    var bloggerDataSet = db.query(query_blogger_data);     
    print(bloggerDataSet);
    return bloggerDataSet;
}
bloggerData();
db.close();
%>

This API returns the dataset from external db.

Here I make API call via POST method in javascript code. And then in the success function I convert the data set in to JSON format and bind the data set with the graph.The code snippet  is as follows.

$.post("/portal/controllers/apis/api/testAPI.jag", function (dataSet) {
var data=JSON.parse(dataSet);
dataBind(data);
});

Now you need to create the gadget to visualize these data. You can follow the steps in [2] to create the gadget.
You can download sample gadget [3] which I implemented. Here I used a third party library[4] to draw the graph.

Flow Chart Diagram of the Gadget.





 UI of the Gadget.


References.






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Saturday, April 2, 2016

Retrieve Repository Details from Git Hub API Using WSO2 GitHub Connector.



In this blog post I'm going to explain how to retrieve all the repository details for specified organization from Git Hub API using WSO2 GitHub Connector[1].

For this task following WSO2 GitHub Connector method can be used. 

       
<github.listOrganizationRepositories configKey="GH">
<org>wso2</org>
<type>public</type>
<page>1<page>
</github.listOrganizationRepositories>

Parameters :


org : Organization name
type : Type of the repository. Eg: public,private,forks etc. Default option is All
page : Page number 

But GitHub API uses pagination[2]. Therefore using the above method you can retrieve data only for the given page number . In other words there is no direct API call found to retrieve all the repository details for specified organization at once. To overcome this I successfully implemented the following ESB proxy service. Using this proxy service you can retrieve all the repository details for specified organization.
First you need to download WSO2 GitHub Connector [1] and add it to WSO2 ESB [4]. Then create a custom proxy service in ESB .

Proxy

 

       
<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="Demo"
       transports="https,http"
       statistics="disable"
       trace="disable"
       startOnLoad="true">
   <target>
      <inSequence>
         <github.listOrganizationRepositories configKey="GH">
               <org>wso2</org>
         </github.listOrganizationRepositories>
         <property name="link"
                   expression="get-property('transport','Link')"
                   scope="default"
                   type="STRING"/>
         <script language="js">
                var link = mc.getProperty('link');
                var lastPage=1;
                var pageLink=link.split(",");
               
                for(var i in pageLink)
                {
                 if(pageLink[i].indexOf("last")!=-1){
                        
                         var result=pageLink[i].match(/page=(\d+)/);
                          lastPage=result[1];
                         break;
                 }
                }
                
                mc.setProperty("lastPage", lastPage);
                var pageNumberDataSet =new XML('<pages></pages>');
                var pageNumberChild;
                var num;
                
                for(var i=0 ;i < lastPage;i++)
                {
                      
                     num=i+1;
                     pageNumberChild= new XML('<pageNumber>' + num + '</pageNumber>');
                     pageNumberDataSet.prependChild(pageNumberChild);
                   
                }
              
                 mc.setProperty("pageNumberDataSet",pageNumberDataSet);
          </script>

         <property name="pageNumberDataSet"
                   expression="get-property('pageNumberDataSet')"
                   scope="default"
                   type="STRING"/>
         <payloadFactory media-type="xml">
            <format>
               <root xmlns="">$1</root>
            </format>
            <args>
               <arg evaluator="xml" expression="get-property('pageNumberDataSet')"/>
            </args>
         </payloadFactory>
         
         <iterate continueParent="true"
                  id="pageNumberIteratorInRepoList"
                  expression="//root/pages/pageNumber"
                  sequential="true">
            <target>
               <sequence>
                  <property name="pageNum"
                            expression="//pageNumber/text()"
                            scope="default"
                            type="STRING"/>
                  <github.listOrganizationRepositories configKey="GH">
                     <org>wso2</org>
                     <page>{$ctx:pageNum}</page>
                  </github.listOrganizationRepositories>
                  <log level="full"/>
               </sequence>
            </target>
         </iterate>
      </inSequence>
   </target>
   <description/>
</proxy>

Description 

 

       
<github.listOrganizationRepositories configKey="GH">
<org>wso2</org>
</github.listOrganizationRepositories>


From the above connector method I got the link for the next page and last page as shown below.

Link: <https://api.github.com/resource?page=2>; rel="next",
      <https://api.github.com/resource?page=5>; rel="last"

Then I assigned the link header to a property called 'link'. 
       
<property name="link"
expression="get-property('transport','Link')"
scope="default"
type="STRING"/>




Then I split the link header and got the last page number inside the  script mediator. And then create a XML payload using page numbers. XML payload format is as shown below.
       
<root>
<pages>
<pageNumber>1</pageNumber>
<pageNumber>2</pageNumber>
</pages>
</root>
Then I iterate through the above payload using Iterator mediator. To do this you need to use the XPath expression as //root/pages/pageNumber.

Then I used the following GitHub Connector method to retrieve the repository details inside the Iterator mediator. The following Connector method gives the repository details for the specified page number.
       
<github.listOrganizationRepositories configKey="GH">
<org>wso2</org>
<page>{$ctx:pageNum}</page>
</github.listOrganizationRepositories>
Here I used Local Entry called “GH” to store GitHub Init operation and then it used in proxy as the configKey.

You need to create a local entry with inline XML as shown below. You can use [5] to create local entry.
       
<github.init xmlns="http://ws.apache.org/ns/synapse">
<accessToken>xxxxxxxxxxxxxxxxxx</accessToken>
<apiUrl>https://api.github.com</apiUrl>
<mediaType>application/json</mediaType>
</github.init>

You can create an access token using your Git Hub account [3].




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