How to call a objective c code from javascript in cocoa

Question

Right now my javascript looks like this :

 testStackData.addOrUpdateHeader("username", "vikas test", 1);
 testStackData.addOrUpdateHeader("testHeader", testStackData.priorResults.responseBody.cars[0].name, 1);
 testStackData.addOrUpdateVariable("carNameTest", "variable updated from pre script", 1);
 testStackData.stepError.haveError = false;
 return testStackData

Now I need to create an Objective-C function addOrUpdateHeader or addOrUpdateVariable as mentioned in javascript.

But I am confused as how to call these functions.

possible duplicate of [How to call an Objective-C method from Javascript in a Cocoa/WebKit app?](http://stackoverflow.com/questions/92471/how-to-call-an-objective-c-method-from-javascript-in-a-cocoa-webkit-app) — legoscia, Apr 02 '15 at 10:48
They are using webview to achieve this but my requirement doesnot allow me to use webview. I was looking something using Javascriptcore — Jas_meet, Apr 02 '15 at 12:26

Jas_meet · Accepted Answer · 2017-06-30T06:38:17.583

I finally got my javascript code running my application with the help of Javascript core framework.

I created json string with my javascript functions embedded in the string itself. As javascript is lose in its definitions, it allowed the calling and execution of the functions effectively.

Moving on to the code, I created separate function for addOrUpdateHeader addOrUpdateVariable

The functions read as follows :

"addOrUpdateHeader" : 



   function(headerName, headerValue, trackHistory){
        if(this.projectServers.projectServerDefaultHeaders.length>0) {
        var index ;
        var isHeaderNameExists = false;
        for(var h =0; h<this.projectServers.projectServerDefaultHeaders.length;h++) {
        if(this.projectServers.projectServerDefaultHeaders[h].headerName === headerName) {
        index=h;
        isHeaderNameExists = true;
        break;
        } }
        if(isHeaderNameExists) {
       this.projectServers.projectServerDefaultHeaders[index].headerValue = headerValue;
        }
        else {
        this.projectServers.projectServerDefaultHeaders.push({
        headerName : headerName,
        headerValue : headerValue,
        projectServerDefaultHeaderId : '',
        trackHistory : trackHistory
        });
        } } },
        "addOrUpdateVariable" : function(variableName, variableValue){
        if(this.projectServers.projectServerDefaultVariables.length>0) {
        var index ;
        var isVariableNameExists = false;
        for(var v =0; v<this.projectServers.projectServerDefaultVariables.length;v++) {
        if(this.projectServers.projectServerDefaultVariables[v].variableName === variableName) {
        index=v;
        isVariableNameExists = true;
        break;
        } }
        if(isVariableNameExists) {
 this.projectServers.projectServerDefaultVariables[index].variableValue = variableValue;
        }
        else {
        this.projectServers.projectServerDefaultVariables.push({
        variableName : variableName,
        variableValue : variableValue,
        projectServerDefaultVariableId : ''
        });
        }}
        }

and then used javascript core framework's JSContext to do the required functionality with the help of following code

JSContext *context = [[JSContext alloc] init];
    context.exceptionHandler = ^(JSContext *context, JSValue *exception) {
        NSLog(@"[%@:%@:%@] %@\n%@", exception[@"sourceURL"], exception[@"line"], exception[@"column"], exception, [exception[@"stack"] toObject]);
    };
    [context evaluateScript:testStackData];
    NSString * jsCode = [NSString stringWithFormat:@"var prescript = function (testStackData) {%@}",script];
    [context evaluateScript:jsCode];
    JSValue * ret = [context evaluateScript:@"prescript(testStackData);"];

here testStackData is my json string

How to call a objective c code from javascript in cocoa

1 Answers1