chrome扩展-将消息从内容脚本发送到后台页面，然后再发送回内容脚本？

Question

I have no idea if this is the most efficient way of doing what I'm trying to do, if isn't by all means tell me.

I'm building a chrome extension that is supposed to loop through each word on the page, and then compare it to a list of 12,000 elements in an array. I managed to make it work on the content script page, but to my dismay, it takes about 7 seconds to load my content script because of all the looping that is taking place. This isn't ideal, obviously. So I had the idea of sending all the p tags to the background page, where it then compares the p words to the array, and once it figures out which match, it sends a message back to the content script with a smaller array of just the words that are located both in the p tags and in my array.

Now my question is, is this possible? Will it reduce the load time? Is this efficient?

One final question: My manifest is using a background page in the form of html but if I wanted to also use a background script Google doesn't allow that, so can I place my background script in the background page html file and will it load that script?

Answer 1

For your first question, yes it is possible to do this. It will execute your heavy treatment in an the background (and hidden) page. The page with the content script will not freeze this way.

You can do it like this :

In your background script :

function heavyStuff(request, sender, sendResponse)
{

    ...
    doSomeThing(request)
    doOtherThing()
    ...

    sendResponse(youreSmallerArray)
}

chrome.runtime.onMessage.addListener(heavyStuff)

And in your content script :

function manageResponse(smallerArray)
{
    ...
    doWhatYouWant(smallerArray)
    ...
}

arrayOfP = $("p")
chrome.runtime.sendMessage(arrayOfP, manageResponse)

So it will do what you want, but are you sure of what you're doing? Perhaps your algorithm have to be improved?

For more information about Chrome's message system, you can read the documentation .

Especially if you have to send lot of messages, look for the long-lived connections section.

---

For the second question, you can replace in the manifest the background page attribute by that :

"background":
{
    "scripts":
    [
        "background.js",
        "otherScript.js",
        ....
        "theLastScript.js"
    ]
}

Chrome will create automaticaly a background page with this scripts included (in the same order).

PS : The next time you post on this site, please ask only one question at a time ;-)