I am trying to build a simple chrome extension so that when a form on a webpage in a specific website is populated and the user presses Submit then the data in the form is captured and then some of that data is injected into another form running on a different website.
I have no access to edit the code for either of the forms so a chrome extension seems to be the best way to do this from what I have read.
I would like to know if this is possible and how to go about it
It is possible using Content Scripts, a Background Page, and/or Chrome.storage
You will need Content Scripts on both websites that have the forms. Use the Manifest File correctly to set up which websites to attach which Content Scripts to.
The first Content Script (the one reading the form being filled and submitted) will have to take the values of each form input, triggered by the submit button.
Then you will need to use Message Passing to send a message (containing all the form data) from that Content Script to your Background Page. The data can be held temporarily or saved into chrome.storage by the Background Page.
Then the second form's Content Script also uses Message Passing to request the data from Background Page, which is delivered from temporary holding or retrieved from chrome.storage then sent.
And finally the second Content Script modifies its website's form to fill in the values.
Related
I'm currently developing an extension that comes in different parts:
- background script (Chrome background.js
- content script (Chrome content-script.js)
- popup script (popup.js and loaded from the iFrame)
- iframe.html (iframe to be loaded when user activate the extension)
It works great except that I lose all the settings/context (used in the popup script to display info in the iframe) when the user change of page or reload the page in the tab.
Technically I want to isolate the extension per tab (each tab can have its own config) but when a user navigate in a same tab the context should be kept.
Question is: what is the best way to achieve that?
I'm thinking about persisting all the context in the content script and reload it when the event chrome.tabs.onUpdated is fired. Is it the right approach?
I recommend you to read about chrome.storage. You can store data there, both background and content script have access to it.
And probably you will need chrome.runtime.sendMessage and chrome.runtime.onMessage to have conversation between background and content. Each time content script runs in a tab it can request background whether this tab have some existing data or not.
I'm writing a Google Chrome Extension, and I need a way of saving the contents of the current page, whether it's an HTML page or a PDF page.
For HTML, I can use chrome.pageCapture.saveAsMHTML, however, this does not work if the current page is a PDF document. I've been searching for a way to dump the PDF from Chrome's PDFViewer, but I've found absolutely no information on it.
The one requirement I have is that I can't issue a second request, as the PDF is the response from a form submission, and a second request would re-submit the form causing duplicate data. This system is out of my control, so I can't change the behavior.
I want to log text on any webpage (using content-script to handle selection) into a database that is popup's resource in order to collect text in one place.
what i am trying
I create a database in popup page and try to manage it from content-script though popup is not active (not opened) by using chrome messaging but cannot make the popup receives any message from content-script.
I'm not sure about using messaging to solve this problem.
Is there any better solution?
A content script cannot send a message to an invisible popup, because the popup's context is inactive (closed) when it's hidden.
There are several solutions to your problem.
Option 1: No message passing, use storage events
If your "database" is in fact a simple key-value store, switch to the chrome.storage API. This API is available to the Content script and the popup, and comes with an event to notify you of value changes.
Example:
// Get notified of changes (in the popup?)
chrome.storage.onChanged.addListener(function(changes, areaName) {
// Do whatever you want with the changes.
});
// Initialization of the popup (print initial information?)
chrome.storage.local.get({keyName: 'defaultValue'}, function(items) {
// Do something with items.keyName
});
// Content script, storage (remember document title?)
chrome.storage.local.set({keyName: document.title});
Option 2: Pass messages to the background/event page
The popup and the background / event page share the same process. Any database tied to the popup is also available to the background page, and vice versa. A high-level overview of this method:
Content script sends a message to the background page.
The background page stores the value in the database
If the popup is open, update the popup's view.
If the popup is opened (so it was closed before), it should read the database (either directly, or by reading data from the background page using chrome.runtime.getBackgroundPage) and handle the results.
I've provided the code corresponding to this flow in this answer.
I am making an extension for chrome. It fetches data from webpages and emails it via local email client. I have a toolbar button which user has to click to invoke the script.
My script works for a few selected urls. I want my toolbar button to change icon based on whether the url is among our list or not. For example for site1 it should be redicon.png and for site2 it should be blueicon.png. I can change button icon using chrome.browserAction.setIcon. But the problem is that this API does not work in content script. It works fine in the background.js file but not in content.js. Kindly tell me how to achieve this.
I know using pageAction instead would do the trick but my client requirement is that the toolbar icon should change rather than appear and disappear.
What you need to read about is message passing. You are right, content scripts have limited chrome API. However, you can contact background page from content script and tell it to execute anything from chrome API for you. First, you need to create a listener on a background page that will be waiting for messages and then send a message from a content script.
I've read the message passing page repeatedly and tried multiple variations of it and I'm assuming I'm making a small mistake.
What I'm trying to do: I want to grab the background color of a page with a content script and then send that information to my popup (not a background page; I don't know if that matters) and then allow the popup to (simple example) write that variable in the popup.
Content scripts run in the same process as the webpage (the "tab" process). Popups run in the same process as the background page (the "extension" process).
It sounds like you want the popup to send a request to the content script using chrome.tabs.sendRequest. The content script should be listening for requests using chrome.extension.onRequest.
Or, you might do it the other way around: the content script sends the request to the extension using chrome.extension.sendRequest and the popup listens for requests using chrome.extension.onRequest. When you send a request from a tab to the extension, any page in the extension process (popups or background) can listen for that request.
See the message passing tutorial which includes examples that you can copy and paste.