Writing content to a new empty tab in Chrome extensions - google-chrome-extension

I am trying to open a new empty tab and add some HTML (or anything else) to it.
I am successful in opening a new empty tab, but not in adding anything to it.
Here is the code in file "background.js":
chrome.tabs.create({url:"about:blank"}, function(tab){chrome.tabs.executeScript(tab.id, {code: "document.write('Some HTML tags')"});
});
Usually, you open a new tab to an existing URL, and you ask for permission in the manifest file, e.g.
"permissions" : ["tabs","http://*/*","https://*/*"]
but I am not sure what permissions to ask for an empty tab, if any.

You can use a javascript: URL to write your content. For example:
chrome.tabs.create({url:'javascript:document.write("<h1>Hello, World!</h1>")'});

Related

chrome extension new tab override but does not focus on input element [duplicate]

With Chrome 27, it seems that extensions that override Chrome's New Tab Page can't take focus away from Chrome's Omnibox like they used to in previous versions of Chrome.
Is there a new way to focus an input box in a New Tab Page, or has this functionality been disabled completely? :(
To test this, create an extension folder with three files:
1. manifest.json:
{
"name": "Focus Test",
"version": "0",
"minimum_chrome_version": "27",
"chrome_url_overrides": {
"newtab": "newTab.html"
},
"manifest_version": 2
}
2. focus.js:
document.getElementById('foo').focus();
3. newTab.html:
<html>
<body>
<input id="foo" type="text" />
<script type="text/javascript" src="focus.js"></script>
</body>
</html>
Then, when you load the extension and open a new tab, the input field does not get focused on the new tab page.
I have also tried adding the autofocus attribute to the input field, but no luck either. The extension's new tab page can't take focus away from Chrome's Omnibox.
Any ideas? Is this a bug or a new "feature"?
ManifestV3 update
This answer is adapted from https://stackoverflow.com/a/11348302/1754517.
This has been tested with both Manifest V2 and V3.
Tested in Google Chrome 99.0.4844.51 64-bit (Windows 10).
Replace the content of focus.js with:
if (location.search !== "?x") {
location.search = "?x";
throw new Error; // load everything on the next page;
// stop execution on this page
}
Add the autofocus attribute to the <input>.
Go to the Extensions page in Chrome and click the Load unpacked button. Choose the folder of your extension.
Open your new tab page. You might see a modal dialogue reading Change back to Google?. Click Keep it to keep your custom new tab page.
Inline Javascript - Manifest V2 only
If you're inlining the Javascript in the HTML file, then you'll need to take some extra steps:
After adding your inline Javascript to your HTML file, open DevTools (F12 key) and observe the error output in the Console. Example output you should see:
Refused to execute inline script because it violates the following Content Security Policy directive: "script-src 'self' blob: filesystem:".
Either the 'unsafe-inline' keyword, a hash ('sha256-MK0Gypb4mkZTI11eCOtWT+mGYcJNpN5zccvhfeaRb6E='), or a nonce ('nonce-...') is required to enable inline execution.
Select & copy this hash.
Add a line to manifest.json to allow the JS to run, pasting in the hash you just copied between the single-quotes. E.g.:
"content_security_policy": "script-src 'self' 'sha256-MK0Gypb4mkZTI11eCOtWT+mGYcJNpN5zccvhfeaRb6E='"
Go to the Extensions page again. Remove the extension, then re-add it using the Load unpacked button.
Open your new tab page. Your extension should now autofocus on the <input>.
Note inlining only works with Manifest V2; Manifest V3 returns a failure message when attempting to load the extension (even with a properly formed "content_security_policy" object in manifest.json, to replace the Manifest V2 "content_security_policy" string):
Failed to load extension
File C:\path\to\extension
Error 'content_security_policy.extension_pages': Insecure CSP value "'sha256-...'" in directive 'script-src'.
Could not load manifest.
As per the Chrome Extension Documentation,
Don't rely on the page having the keyboard focus.
The address bar always gets the focus first when the user creates a new tab.
See reference here: Override Pages
Here's the solution for Manifest v3
chrome.tabs.onCreated.addListener((tab) => {
if (tab.pendingUrl === 'chrome://newtab/') {
chrome.tabs.remove(tab.id)
chrome.tabs.create({
url: '/index.html',
})
}
})
I saw a pretty old blog which updates the new tab conditionally. However, simply updating the tab does not steal the focus. I had to close the pending tab and open a new one.
Cons: An ugly chrome-extension://akfdobdepdedlohhjdalbeadhkbelajj/index.html in the URL bar.
I have a cheap work around that allows stealing focus from address bar focus. It's not for everyone. I do actually do use this because I want to control a new tab focus just that bad in my own custom new tab solution:
<script>
alert('Use enter key to cancel this alert and then I will control your focus');
document.getElementById('...AckerAppleIsCrafty...').focus()
</script>
USE CASE: I built my own HTML chrome custom tab that has a search input that custom searches my history and bookmarks the way I like it too.
Cash me focusing outside how bout dat?

How can one debug the Chrome extension "options" page using the new OptionsV2 method?

https://developer.chrome.com/extensions/optionsV2 tells me that I should be using options_ui in my manifest, rather than options_page, and recommends I start upgrading immediately.
However, I can't find any way to actually debug the script run by my options page when I use options_ui—the Options popup is in an tag, and the developer tools don't show me the source, or even the HTML content.
For now, I just comment out options_ui and let options_page take effect when I need to debug. I'm guessing that setting "options_ui": {"open_in_tab": true,...} would have the same effect, but it would be really nice to figure out how to actually debug the script when it's running the new way.
Auspex,
Teepeemm's comment is correct.
Other way, you can launch your options page from other tab using its full URL
like,
chrome-extension://{your extension id here}/{your options page path here, from the extension root}
e.g. say my extension id aaabbbcccdddeeefffggg, and say, my options page is located (from extension root) at app/html/options.html; then i can load up below URL in a new tab ---
chrome-extension://aaabbbcccdddeeefffggg/app/html/options.html
Now here, in this tab; you can do your regular debugging around HTML and javascript.
I hope this suffices your debugging requirement for 'new options UI' for chrome.
Teepeemm's comment is correct.
It's as simple as right-clicking inside the options page modal and selecting "Inspect element" - it will open the correct Dev Tools.

ExecuteScript in a random tab that is not part of the chrome extension send result back to background javascript

I would like to check the html of an element of a
chrome.tabs.executeScript(tab_id,{code: 'sendRequestToBackground(document.getElementById('important_val').innerHTML); '},
function(){
});
I want to be able to get this value from my background script, I saw a lot of examples with chrome.extension.sendRequest and chrome.extension.onRequest.addListener because all the examples is for working from the extension popup.html to background script and vice-versa.
But I open a brand new tab, change the URL, and I want to get a value of a field that (which btw is generated via Javascript) belongs to this random tab.
Is it possible to do that?
Thanks!
If you want to inject your code to a random tab, do this:
Be sure to have permissions to "tabs" and "<all_urls>" in your manifest.json
Get all tabs using chrome.tabs.query
Pick random tab using Math.random()
Inject the code using chrome.tabs.executeScript
In the incjected code call chrome.extension.sendRequest
On the background page receive the message using chrome.extension.onRequest

Override downloading a file type with Chrome Extensions

I'm trying to build a chrome extension that overrides a download of a file and displays it in the browser. For example if you click on a link to a '.csv' file I'd like it to render in the browser instead of downloading it.
Chrome already does it for PDF's types and the Xml Tree extension also does exactly that for xml files.
So it should be possible, just not sure how to go about catching that event?
An implementation along the lines indicated by in the previous answers and specifically designed for CSV files can be found in this extension of mine on github:
https://github.com/rgrp/chrome-csv-viewer
Furthermore, with the new(ish) chrome webrequest API a direct approach is also now possible along the following lines:
Listen to onBeforeRequest (this has to be in a background script - see background.js)
Check if this is a CSV file (mimetype or file extension)
If so cancel the request and then display the data using xhr
A working version of this can be found in a branch of that extension: https://github.com/rgrp/chrome-csv-viewer/tree/4-webrequest-intercept
You could always look at the XML Tree code :).
If you only need to work with links, and not opening files from the address bar or File > Open, you could build a content script that adds a click event listener to every link.
In the event listener function:
Add e.preventDefault() in the first line to prevent the browser 'following' the link.
Using the link href value, get the data with XMLHttpRequest.
In the XMLHttpRequest callback, open a new tab and render content accordingly.
Obviously, in many ways, this is not a great solution:
you want 'normal' links to be handled as usual by the browser
how can you tell if a text file contains comma-separated values (for example) except by looking at the file extension which, of course, may not be reliable?
Are you specifically thinking of .csv files -- and/or other specific types of content?

Can I link to an HTML file in my project from a UIWebView?

If I load a string containing HTML into a UIWebView, and that string contains objects (hyperlinks) that are relative to that string, i.e. , where there is some object with id "something," then the link works - click on it and the web view jumps to the referenced object.
What I want is to get navigation to a different file in my project, in other words as though the path to the different file were a URL.
I have found that if the href IS a URL, such as href="http://www.amazon.com", then the link works.
If I put the name of a file, OR the [NSBundle mainBundle] pathForResource: ] of that name, in the href, then the link does not work.
Is there some way I can generate the equivalent of a URL pointing to an HTML file that is in the project, so that an can link to that HTML file?
I found a solution at this link:
How to use Javascript to communicate with Objective-c code?
Essentially, the solution is to implement the UIWebViewDelegate protocol's shouldStartLoadWithRequest method, and "trap" a particular value of scheme. So my links, instead of saying something like:
<a href="http://someplace.location">
are like:
<a href="mylink://#filename.ext">
By catching attempts to load anything with scheme "mylink," I can use:
[[request URL] fragment]
within shouldStartLoadWithRequest, and get the filename.ext. I then release my previous UIWebView, load in the contents of the specified file, and make that the contents of a new UIWebView. The effect is that the links work with normal appearance, even though they are being implemented with my code. I return NO because I don't want the usual loading to take place. If the scheme is NOT mylink, I can return YES to allow normal operation.
Regrettably, I still have no way to jump TO a fragment within a web view. In linking to a real URL, you can say something like "www.foo.org#page50" and jump straight to wherever an object on the new page has an id of "page50." With my method, I can only go to the top of the page.
This is also not going to give me a "go-back" function unless I record the filenames and implement it myself.

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