Chrome extension: load different content scripts

Question

I want to load a different content script depending on the page and tab that is currently selected. Right now, I have three content scripts. I want to use two of them for one page and the third one for another page.

Belonging to page 1:

content_script.js load_content_script.js

Belonging to page2:

newtab_content_script.js

right now my manifest looks like this

{
  "name": "A plugin for AdData express. Generate an instant excel document from the brands you check mark.",
  "version": "1.0",
  "background_page": "background.html",
  "permissions": [
    "cookies",
    "tabs", 
    "http://*/*", "https://", "*", "http://*/*", "https://*/*",
    "http://www.addataexpress.com", "http://www.addataexpress.com/*"
  ],
  "content_scripts": [
    {
      "matches": ["<all_urls>","http://*/*","https://*/*"],
      "js": ["load_content_script.js", "content_script.js", "newtab_content_script.js", "jquery.min.js", "json.js"]
    }
  ],
  "browser_action": {
      "name": "AdData Express Plugin",
      "default_icon": "icon.png",
      "js": "jquery.min.js",
      "popup": "popup.html"
  }
}

how would I structure this in the manifest or elsewhere?

Solution 1

Just in the interest of completeness, the way you'd do this from the manifest is to have as many matches blocks under "content_scripts" as needed:

"content_scripts": [
  {
    "matches": ["http://www.google.com/*"],
    "css": ["mygooglestyles.css"],
    "js": ["jquery.js", "mygooglescript.js"]
  },
  {
    "matches": ["http://www.yahoo.com/*"],
    "css": ["myyahoostyles.css"],
    "js": ["jquery.js", "myyahooscript.js"]
  }
],

Solution 2

Rather than using content scripts that are bound to URL expressions specified in the manifest, you should use executeScript, which lets you programmatically decide when to inject a JS snippet or file:

// background.js
chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
  // there are other status stages you may prefer to inject after
  if (changeInfo.status === "complete") {
    const url = new URL(tab.url);
    if (url.hostname === "www.stackoverflow.com") {
    
      // this is the line which injects the script
      chrome.tabs.executeScript(tabId, {file: "content_script.js"});
    }
  }
});

Make sure to add tabs permission to manifest.json:

{
  // ...settings omitted...
  "permissions": [
    "tabs",  // add me
  ]
}

Solution 3

you should use Programmatic injection

chrome.tabs.executeScript(null, {file: "content_script.js"});