javascript - How to execute a content script every time a page loads? -

i'm writing chrome extension provides content script page on github (i.e. url matching https://github.com/*).

i'm trying log console each time page on github loads, so:

window.onload = function() {   console.log("load"); }; 

this listener function executed first time github page loaded, if user navigates other pages on github there (by clicking on links or through other means), doesn't fire. why? :(

steps reproduce:

1. open repository's page on github (example). should see message logged console.
2. click on link on page. when new page loaded, no message logged. :(

how solve this?

it seems github uses ajax (along history.pushstate) load parts of site, onload fire when page loads, not when content loaded via ajax.

since github uses pushstate change url when ajax content done loading, can detect when happens, , execute code. there isn't native event right fires when pushstate used, there's little hack:

(function(history){     var pushstate = history.pushstate;     history.pushstate = function(state) {         if (typeof history.onpushstate == "function") {             history.onpushstate({state: state});         }         return pushstate.apply(history, arguments);     } })(window.history); 

so, run that, , then, instead of window.onload, can do:

history.onpushstate = function () {     console.log("load"); }; 

not of github page's load way (ajax + pushstate), you'd have use both, window.onload , history.onpushstate.

also, should use window.addeventlistener('load', fn); instead of window.onload, since don't know if github's code overwriting window.onload.