In Oracle APEX we have a feature to call Web API which gives data in JSON format. Along with the native features we can use JavaScript also to call a Web API in APEX.
Here, I will demonstrate a small example how to build the code for the same.
Step 1: We create a static type region and two page items, let's say P5_URL (Type: Text Field) and P5_RESPONSE (Type: Textarea) . One for giving the Web API and second is to get the response.
Step 2: Write the below JavaScript code in page property "Function and Global Variable Declaration"
function CALL_TO_WEBSERVICE()
{
var urlvariable;
var ItemJSON;
var v_url = apex.item("P5_URL").getValue();
URL = v_url ;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = callbackFunction(xmlhttp);
xmlhttp.open("GET", URL, false);
xmlhttp.onreadystatechange = callbackFunction(xmlhttp);
xmlhttp.send(ItemJSON);
$x("P5_RESPONSE").value = xmlhttp.responseText;
}
function callbackFunction(xmlhttp)
{
// alert(xmlhttp.responseXML);
}
The XMLHttpRequest object can be used to exchange data with a web server.
To send a request to a server, you can use the open() and send() methods of the XMLHttpRequest object.
xmlhttp.onreadystatechange defines a function to be called when the readyState property changes
xmlhttp.responseText, returns the response data as a string
Step 3: Create button "Call" & set the action property under Behavior as "Defined by Dynamic Action"
Step 4: Create a dynamic action on "Call" button as "Click" & set the True Action as "Execute JavaScript Code" and call the function written under JavaScript property at page level.
Step 5: Run the application. Put any Web API in item "P5_URL" and click the "Call" button.
Ex: Here I used a github public Web API https://api.github.com/users/oracle/repos
In the "response" item you can see the reply from the server.
Thanks for reading !!