Tested this code, and it outputs the correct image with the desired tab selected. It wasn't so straightforward because of the underlying structure of the page. Hopefully you can use this as a bit of a learning exercise in processing the DOM.
// utility function to send mouseclick event to an element
function mouseclick( element ) {
// create a mouse click event
var event = document.createEvent( 'MouseEvents' );
event.initMouseEvent( 'click', true, true, window, 1, 0, 0 );
// send click to element
element.dispatchEvent( event );
}
// final function called, output screenshot, exit
function after_clicked( page ) {
console.log( "+after_clicked()" );
page.render( "after_click.png" );
console.log( "Done" );
phantom.exit( 0 );
}
// middle function, click on desired tab
function click_div( page ) {
console.log( "+click_div()" );
var clicked = page.evaluate(
function ( mouseclick_fn ) {
// want the div with class "submenu"
var div = document.querySelector( "div.submenu" );
if ( ! div ) {
return false;
}
// want all the list elements in the div
var li_array = div.querySelectorAll( "li" );
if ( ! li_array ) {
return false;
}
// we want the 2nd list element
var li2 = li_array[1];
if ( ! li2 ) {
return false;
}
// want the anchor inside the 2nd list element
var anchor = li2.querySelector( "a" );
if ( ! anchor ) {
return false;
}
// must focus on anchor to trigger underlying javascript on page
anchor.focus();
// want the div within this anchor, so we can click on the div
var element = anchor.querySelector( "div" );
if ( ! element ) {
return false;
}
// click on this inner div
mouseclick_fn( element );
return true;
}, mouseclick
);
if ( ! clicked ) {
console.log( "Failed to find desired element" );
phantom.exit( 1 );
return;
}
console.log( "- clicked, waiting 5 seconds" );
window.setTimeout(
function () {
after_clicked( page );
},
5000
);
}
// first function, create page, load page
function main() {
console.log( "+main()" );
var page = require('webpage').create();
page.open(
"http://sa.ttu.edu.tw/bin/home.php",
function (status) {
if ( status !== 'success' ) {
console.log( "Failed" );
phantom.exit( 1 );
return;
}
console.log( "- page loaded, waiting 2 seconds..." );
window.setTimeout(
function () {
click_div( page );
},
2000
);
}
);
}
main();