I have this simple function which loads scripts into the current DOM:
function loadscripts ( async ) {
if( async === undefined ) {
async = false;
}
var scripts = [];
var _scripts = ['jquery.min.js', 'bootstrap.min.js', 'plugins.js', 'main.js'];
for(var s in _scripts) {
scripts[s] = document.createElement('script');
scripts[s].type = 'text/javascript';
scripts[s].src = _scripts[s];
scripts[s].async = async;
document.getElementsByTagName('head').appendChild( scripts[s] );
}
}
They are loaded fine and without no errors. I know there are event handlers when loading scripts programmatically:
- onreadystatechange, and
- onload, etc
Now I would like to wish to do the following:
- Load first script from the array, and when the event handlers are COMPLETE load the next one, and so on (recursively).
Sorry, I have not provided the onreadystatechange and onload events in my function.
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Answer
I would do this that way :
LoadScripts();
function LoadScripts(async)
{
if( async === undefined ) {
async = false;
}
var scripts = [];
var _scripts = ['jquery.min.js', 'bootstrap.min.js', 'plugins.js', 'main.js'];
if(async){
LoadScriptsAsync(_scripts, scripts)
}else{
LoadScriptsSync(_scripts,scripts)
}
}
// what you are looking for :
function LoadScriptsSync (_scripts, scripts) {
var x = 0;
var loopArray = function(_scripts, scripts) {
// call itself
loadScript(_scripts[x], scripts[x], function(){
// set x to next item
x++;
// any more items in array?
if(x < _scripts.length) {
loopArray(_scripts, scripts);
}
});
}
loopArray(_scripts, scripts);
}
// async load as in your code
function LoadScriptsAsync (_scripts, scripts){
for(var i = 0;i < _scripts.length;i++) {
loadScript(_scripts[i], scripts[i], function(){});
}
}
// load script function with callback to handle synchronicity
function loadScript( src, script, callback ){
script = document.createElement('script');
script.onerror = function() {
// handling error when loading script
alert('Error to handle')
}
script.onload = function(){
console.log(src + ' loaded ')
callback();
}
script.src = src;
document.getElementsByTagName('head')[0].appendChild(script);
}