Author: John Au-Yeung

Sometimes, we want to make a JSON call to an URL with JavaScript.

In this article, we’ll look at how to make a JSON call to an URL with JavaScript.

How to make a JSON call to an URL with JavaScript?

To make a JSON call to an URL with JavaScript, we use fetch.

For instance, we write

const getJSON = async (url) => {
  const response = await fetch(url);
  return response.json();
};

const data = await getJSON("https://yesno.wtf/api");
console.log(data);

to define the getJSON function.

In it, we call fetch with url to make a get request to url.

Then we get the response from the returned promise with await.

We get the JSON response body by calling json.

Then we call getJSON and get the response body with await.

Conclusion

To make a JSON call to an URL with JavaScript, we use fetch.

Sometimes, we want to set full calendar to a specific start date when it’s initialized for the 1st time with JavaScript.

In this article, we’ll look at how to set full calendar to a specific start date when it’s initialized for the 1st time with JavaScript.

How to set full calendar to a specific start date when it’s initialized for the 1st time with JavaScript?

To set full calendar to a specific start date when it’s initialized for the 1st time with JavaScript, we call fullcalendar with an object with the initial date.

For instance, we write

$("#calendar").fullCalendar({
  year: 2022,
  month: 4,
  date: 25,
});

to select the calendar element and then call fullCalendar with an object with the initial year, month, and date values.

Conclusion

To set full calendar to a specific start date when it’s initialized for the 1st time with JavaScript, we call fullcalendar with an object with the initial date.

Sometimes, we want to create a hidden field in JavaScript.

In this article, we’ll look at how to create a hidden field in JavaScript.

How to create a hidden field in JavaScript?

To create a hidden field in JavaScript, we call createElement.

For instance, we write

const input = document.createElement("input");
input.setAttribute("type", "hidden");
input.setAttribute("name", "name");
input.setAttribute("value", "value");

document.body.appendChild(input);

to create an input with createElement.

Then we call setAttribute to set the type, name, and value attribute values of the input.

We set the type attribute to 'hidden' to make it hidden

Next we call appendChild to append the input to the body element as its last child.

Conclusion

To create a hidden field in JavaScript, we call createElement.

Sometimes, we want to fill a JavaScript object literal with many static key/value pairs efficiently.

In this article, we’ll look at how to fill a JavaScript object literal with many static key/value pairs efficiently.

How to fill a JavaScript object literal with many static key/value pairs efficiently?

To fill a JavaScript object literal with many static key/value pairs efficiently, we create a map.

For instance, we write

const map = new Map([
  ["key1", "value1"],
  ["key2", "value2"],
]);
const value = map.get("key1");

to call the Map constructor with an array of key-value pair arrays to create a map.

Then we get the value by the get with 'key1'.

Conclusion

To fill a JavaScript object literal with many static key/value pairs efficiently, we create a map.

Sometimes, we want to open generated PDF using jspdf in new window with JavaScript.

In this article, we’ll look at how to open generated PDF using jspdf in new window with JavaScript.

How to open generated PDF using jspdf in new window with JavaScript?

To open generated PDF using jspdf in new window with JavaScript, we call the doc.output method.

For instance, we write

doc.output('dataurlnewwindow');

to open the PDF doc in a new window.

We can also write

const string = doc.output("datauristring");
const x = window.open();
x.document.open();
x.document.location = string;

to call output with 'datauristring' to return the base64 string URL version of the PDF.

Then we call window.open to open a new window.

And then we call document.open to open the document.

Finally we set document.location to the URL string to show the PDF.

Conclusion

To open generated PDF using jspdf in new window with JavaScript, we call the doc.output method.