/**
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* Loads a JavaScript file from the given URL and executes it.
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*
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* @param {string} url Address of the .js file to load
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* @param {function} callback Method to invoke when the script
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* has loaded and executed
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*/
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export const loadScript = ( url, callback ) => {
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const script = document.createElement( 'script' );
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script.type = 'text/javascript';
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script.async = false;
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script.defer = false;
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script.src = url;
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if( typeof callback === 'function' ) {
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// Success callback
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script.onload = script.onreadystatechange = event => {
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if( event.type === 'load' || /loaded|complete/.test( script.readyState ) ) {
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// Kill event listeners
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script.onload = script.onreadystatechange = script.onerror = null;
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callback();
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}
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};
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// Error callback
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script.onerror = err => {
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// Kill event listeners
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script.onload = script.onreadystatechange = script.onerror = null;
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callback( new Error( 'Failed loading script: ' + script.src + '\n' + err ) );
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};
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}
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// Append the script at the end of <head>
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const head = document.querySelector( 'head' );
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head.insertBefore( script, head.lastChild );
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}
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