Returning Array from Python to Javascript

Question

I was trying to return an array of data from python function to Javascript. I am using eel python module. The python function returns a string with ease, but when I tried to return an array object, it returns nothing to javascript.

Here is the python function:

@eel.expose

def get_list_data(column_name):
    tree = ET.parse('resources.xml')
    root = tree.getroot()

    column_list_data = []

    for child in root.findall('column'):
        if child.get('name') == column_name:
            for grandchild in child:
                column_list_data.append(grandchild.text)
    return(column_list_data)

And here is the javascript function.

function getListData(){
    let retData = eel.get_list_data("Response")();
    console.log(retData);
}

getListData();

Here is the console log shows.

Promise
__proto__: Promise
[[PromiseStatus]]: "resolved"
[[PromiseValue]]: Array(0)

It seems like it's returning a promise. Try adding async before calling in JS or use Promise.resolve(...) or new Promise() syntax. There are many ways to resolve a promise in JS (stackoverflow.com/questions/26711243/…) — VPaul
– VPaul, Commented Apr 8, 2020 at 13:43
Only declaring the function as asynchroneously like async function getListData() won't do the job. You'll have to use await on the asynchroneous promise which then makes your function asynchroneous as well and therefore requires the async declaration: let retData = await eel.get_list_data("Response")();. — Leo
– Leo, Commented Apr 8, 2020 at 13:57

Leo · Accepted Answer · 2020-04-08 13:50:49Z

1

That is, because retData seems to be a Promise. Please consider reading the following (MDN Promise) for a deeper understanding of promises in javascript.

The promise is executed asynchronously. The code below the "then-callback" is executed in case that the promise has been resolved successfully. To give you something to start with:

function getListData(){
    let retData = eel.get_list_data("Response")()
       .then(retData => {
           console.log(retData);
       })
       .catch(e => console.log(e));
}

answered Apr 8, 2020 at 13:50

Leo

1,77719 silver badges38 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Returning Array from Python to Javascript

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related