Firefox plugin for eBay - change listing structure

[emax4]

Hello. I've been a member for 20 years and want to get back into programming. One thing that irked me was that when viewing listings, the option to display items with the shipping cost calculated in is no longer available (I know it hasn't been around for years). What I'd like to do is make a Firefox plugin so that it can take a page of listings, but simply scale them down if the shipping cost is too high.

For example there may be a 6 ounce computer part that costs $10, but the seller charges $50 for shipping. That's an impossible shipping charge. I'd like to take the page of listings the user searched for, apply the plug-in so that the user can enter a maximum shipping charge (based on the origin and weight of item), then have it re-display the same listings minus the items that fall outside the maximum shipping charge.

I was reading that Firefox uses JavaScript and XML for its plug-ins, so can this be done? I don't want to invest in reading only to find out it's not permitted.

[berserkerplanet]

First I'll ask why just using the eBay "Price+Shipping: lowest first" or "Price+Shipping: highest first" sort filters doesn't work to attain that goal?

I assume you are planning to basically "scrape" through a loaded search page with a JS routine, grab the price and shipping amount, do some math based on those and previously user entered max limits, and remove results that exceed it (or remove them on the fly)

If not, I think you would have to do it through the eBay APIs, set up a developer account, access keys, etc, and probably not worth it.

I do something somewhat similar in JavaScript in the SellerSnubber script running in Firefox via GreaseMonkeythat filters out search results for undesirable sellers blacklisted in an array in the script (no nice user interface). https://berserkerplanet.altervista.org/code/scripts/SellerSnubber_v0.15.user.js


As far as a Firefox extension goes, Mozilla/Firefox no longer allows the old JS/XUL approach, is using a new framework called
WebExtensions, and requires all extensions be signed, which means setting up a developer account (and possible vetting?).

addons.mozilla.org no longer accepts legacy extensions, so you would have to host and distribute yourself (good luck getting anyone here to use it), and legacy would only work for Firefox versions below 57 which few use.

https://developer.mozilla.org/en-US/Add-ons/WebExtensions
https://wiki.mozilla.org/WebExtensions/FAQ
https://developer.mozilla.org/en-US/docs/Archive/Add-ons/Add-on_SDK/Guides/XUL_Migration_Guide


Hope that helps.