wffweb - Java Developers Guide

Custom Server Method

The aim of custom server method is to declare a custom method in the server which can be called from the client using JavaScript.

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browserPage.addServerMethod(methodName, serverMethod);

addServerMethod of BrowserPage can be used to register a custom server method. The custom server method can be called from JavaScript code. See the below sample

ServerMethod serverMethod = event -> {
    WffBMObject wffBMObject = event.data();
    //will print 'some value'
    System.out.println(wffBMObject.get("somekeyFromClient").getValue());
    //prints the type of value
    System.out.println(wffBMObject.get("somekeyFromClient").getValueType());

    String serverMethodName = event.serverMethodName();

    //will print someUniqueMethodName
    System.out.println(serverMethodName);

    // used to send data to the client
    WffBMObject bmObject = new WffBMObject();
    bmObject.put("someKey", BMValueType.STRING,
            "こんにちは Web Firm Framework");
    bmObject.put("testFun", BMValueType.FUNCTION, "function(arg) {alert(arg);}");

    return bmObject;
};

browserPage.addServerMethod("someUniqueMethodName", serverMethod);

Invoke the server method from JavaScript, see the code

var arguments = {
	'somekeyFromClient' : 'some value',
	'numb' : 55555,
	'bool' : true,
	'anObj' : {
		'key' : 'val'
	},
	'funcArray' : function() {console.log('m function');},
	'numberArray' : [ 5, 55, 555, 55, 5555 ]
};

var callbackFunction = function(obj) {

    console.log('callback obj ', obj);

    for (key in obj) {
	    console.log('key is ' + key, obj[key]);
    }

    obj.testFun('check out browser console to see values received from server');
};

wffAsync.serverMethod('someUniqueMethodName', arguments).invoke(callbackFunction);

The first argument passed in wffAsync.serverMethod is the name of the method to be called.

The second argument arguments passed in wffAsync.serverMethod will be received as a wffBMObject in data() property of event in the invoke method (which is the method name in ServerMethod class). The JavaScript object arguments can also contain Int8Array value type to pass binary data, which will be received in wffBMObject as a value type of BMValueType.BM_BYTE_ARRAY i.e. the value is a class type of WffBMByteArray which contains bytes.

The callbackFunction function will be called for the result of invoke server method. The argument obj in callbackFunction is conventional JavaScript object of bmObject returned by invoke method in the server.

The server method can also send binary data using WffBMByteArray . Check out BMValueType enum to know the supported data types of value to send from server to client and vice versa.

In the above JavaScript code, arguments , callbackFunction and obj are optional arguments.