Hello how to iterate on objects in Select.edit.data.js

Question

Hello,

          I am using formio select component in my angular 8 project. But i am using Data Source Type as URL in Data Tab and in Data Source URL i have given the json path(project.json). Also i have used custom select component to read keys from json in Data Tab. i have used the following  custom select component to read the keys from json file. i have used the following code in Select.edit.data.js

 

{

type: 'select',

input: true,

multiple: true,

label: 'Json Keys',

key: 'jsonKey',

placeholder: 'Select your json key you want to show',

clearOnHide: true,

tooltip: '',

weight: 12,

refreshOn: 'data.url',

clearOnRefresh: true,

dataSrc: 'url',

data: {

url: 'project.json'

},

conditional: {

json: {

'===': [{

var: 'data.dataSrc'

}, 'url']

}

},

template: '<span>{{ Object.keys(item) }}</span>'

},

 

Also i have project.json which contains following data

 

 

 

[

{

"projectid": 100,

"surveytitle": "Parth Infotech Survey",

"surveydescription": "Health Checkup",

"date": "03/30/2020",

"country": "India",

"latitude": "",

"longitude": "",

"survey expiry date": ""

},

{

"projectid": 101,

"surveytitle": "PnAutomation Survey",

"surveydescription": "Health Checkup",

"date": "03/30/2020",

"country": "US",

"latitude": "",

"longitude": "",

"survey expiry date": ""

},

{

"projectid": 103,

"surveytitle": "Parth Survey",

"surveydescription": "Health Checkup",

"date": "03/30/2020",

"country": "China",

"latitude": "",

"longitude": "",

"survey expiry date": ""

}

]

 

 

But i want to bind the unique keys from project.json. So how can i iterate on array of item objects in template. i have used the template field to get the keys from json but not working properly. i have changed in select.edit.data.js

like 

template: '<span>{{ Object.keys(item) }}</span>'

 

 

pleae provide the solution for me to get unique keys from json and bind to custom select component.