In order to access the web-pages DOM you'll need to programmatically inject some code into it (using chrome.tabs.executeScript()
).
That said, although it is possible to grab the DOM as a string, pass it back to your popup, load it into a new element and look for what ever you want, this is a really bad approach (for various reasons).
The best option (in terms of efficiency and accuracy) is to do the processing in web-page itself and then pass just the results back to the popup. Note that in order to be able to inject code into a web-page, you have to include the corresponding host match pattern in your permissions
property in manifest.
What I describe above can be achieved like this:
editorMarket.js
var refresherID = 0;
var currentID = 0;
$(document).ready(function(){
$('.start-button').click(function(){
oldGroupedHTML = null;
oldIndividualHTML = null;
chrome.tabs.query({ active: true }, function(tabs) {
if (tabs.length === 0) {
return;
}
currentID = tabs[0].id;
refresherID = setInterval(function() {
chrome.tabs.reload(currentID, { bypassCache: true }, function() {
chrome.tabs.executeScript(currentID, {
file: 'content.js',
runAt: 'document_idle',
allFrames: false
}, function(results) {
if (chrome.runtime.lastError) {
alert('ERROR:\n' + chrome.runtime.lastError.message);
return;
} else if (results.length === 0) {
alert('ERROR: No results !');
return;
}
var nIndyJobs = results[0].nIndyJobs;
var nGroupJobs = results[0].nGroupJobs;
$('.lt').text('Indy: ' + nIndyJobs + '; '
+ 'Grouped: ' + nGroupJobs);
});
});
}, 5000);
});
});
$('.stop-button').click(function(){
clearInterval(refresherID);
});
});
content.js:
(function() {
function getNumberOfIndividualJobs() {...}
function getNumberOfGroupedJobs() {...}
function comparator(grouped, individual) {
var IndyJobs = getNumberOfIndividualJobs();
var GroupJobs = getNumberOfGroupedJobs();
nIndyJobs = IndyJobs[1];
nGroupJobs = GroupJobs[1];
console.log(GroupJobs);
return {
nIndyJobs: nIndyJobs,
nGroupJobs: nGroupJobs
};
}
var currentGroupedHTML = $(".grouped_jobs").html();
var currentIndividualHTML = $(".individual_jobs").html();
var result = comparator(currentGroupedHTML, currentIndividualHTML);
return result;
})();