Usage
nebula.fetch(url, headers, type).then(function(data){...})
Parameters
url
(Required) (String) The endpoint URL for the data to be fetched
Default: None
headers
(Optional) (Object) Optional fetch headers
Default: None
type
(Optional) (String) The expected data type for processing (json or text)
Default: json
data
(Required) (Mixed) The fetched data response
Default: None
Parameter Notes
If no headers are needed, you can pass the type as the second parameter.
Examples
Simple JSON fetch
nebula.fetch('https://example.com/data.json').then(function(json){
console.log('here is the fetched json:', json);
});
A text fetch with no-cache headers
nebula.fetch('https://example.com/data.txt', {
cache: 'no-cache'
}, 'text').then(function(data){
console.log('here is the fetched text data:', data);
});
Fetching text data without passing a headers object
nebula.fetch('https://example.com/data.txt', 'text').then(function(data){
console.log('here is the fetched text data:', data);
});
Catch errors
nebula.fetch('https://example.com/data.json').then(function(json){
console.log('here is the fetched json:', json);
}).catch(function(error) {
console.log('Fetch error:', error);
});
Demo
Check the Network, Console, and/or Performance tabs in DevTools to see demo results.
Additional Notes
For more complicated patterns, you may want to use the Fetch API directly, but this Nebula function simplifies the traditional fetch() pattern significantly for simple tasks.
This Nebula fetch function will also automatically monitor performance using marks and measures. So when running tests in the Performance tab of DevTools or using WebPageTest (for example), you’ll see each of the individual fetch timings appear in the associated track. This allows for scrutinizing which endpoints may be slowing down the website.
Source File
Located in /assets/js/modules/utilities.js on line 296.
No Hooks
This function does not have any filters or actions available. Request one?nebula.fetch = async function(url = false, headers = {}, type = 'json') {
if ( !url ){
nebula.help('nebula.fetch() requires a URL to retrieve.', '/functions/fetch/');
return false;
}
if ( typeof headers !== 'object' ){ //If the type is passed as the second parameter
type = headers;
headers = {};
}
const fetchLabel = nebula.sanitize(url);
window.performance.mark('(Nebula) Fetch Start ' + fetchLabel);
await nebula.yield();
//Create a new promise to handle fetch
let fetchPromise = new Promise(async function(resolve, reject){
try {
let response = await fetch(url, headers);
if ( !response.ok ){
throw new Error('Network response was not ok: ' + response.statusText);
}
let data;
if ( type === 'json' ){
data = await response.json();
} else {
data = await response.text();
}
window.performance.mark('(Nebula) Fetch End ' + fetchLabel);
window.performance.measure('(Nebula) Fetch ' + url, '(Nebula) Fetch Start ' + fetchLabel, '(Nebula) Fetch End ' + fetchLabel);
resolve(data);
} catch(error){
reject(error);
}
});
return fetchPromise;
};
Override
To override or disable this JavaScript function, simply redeclare it with the exact same function name. Remember: Some functionality is conditionally loaded via dynamic imports, so if your function is not overriding properly, try listening for a DOM event (described below).
For non-module import functions:
nebula.fetch = function(url, headers, type, data){
//Write your own code here, leave it blank, or return false.
}
For dynamically imported module function overrides:
jQuery(window).on('load', function(){
nebula.fetch = function(url, headers, type, data){
//Write your own code here, leave it blank, or return false.
}
});
Custom Nebula DOM events do also exist, so you could also try the following if the Window Load listener does not work:
jQuery(document).on('nebula_module_loaded', function(module){
//Note that the module variable is also available to know which module specifically was imported
if ( typeof nebula.fetch === 'function' ){
nebula.fetch = function(url, headers, type, data){
//Write your own code here, leave it blank, or return false.
}
}
});