InjectionService: A TypeScript repository from PenguiniVogel

InjectionService

Provide ways to inject scripts or css with extensions on manifest V3

Setup

The InjectionServiceLib should be put first as document_start content script.

{
    "js": [
        "InjectionServiceLib.js"
    ],
    "matches": [ "..." ],
    "run_at": "document_start"
}

Any content script that requires the InjectionServiceLib should come immediately after.

Code Injection

Example:

InjectionServiceLib.injectCode(`console.log('Hi!')`);
// OR ---
InjectionServiceLib.injectCode(`console.log('Hi!')`, 'head');

// You can also choose to append to <body> instead
InjectionServiceLib.injectCode(`console.log('Hi!')`, 'body');

CSS Injection

CSS always gets appended to the <head> element.
Example:

InjectionServiceLib.injectCSS('e.isl { color: #00f; }');

Settings

encode_content: boolean
true by default, in the case you have code that contains template strings, or other special formatting (html/xml), this setting should be kept enabled.
You can set this before any injectCode or injectCSS call, but that only applies if the onReady has completed, e.g. document_end, before that the state applies to all injections.

InjectionServiceLib.encode_content = true | false;

append_on_document: boolean
This setting only applies to injectCode and injectCSS, this basically tells the InjectionServiceLib if the injection anchor needs to be appended on the document.
Default is false, only change this if you are having issues with code injection.

InjectionServiceLib.append_on_document = false | true;

onReady

The onReady function provides a way to know when the InjectionServiceLib can inject scripts. You can also choose to execute or run your own actions at this time. The callback / event gets triggered almost immediately after the base document (e.g. <head> and <body>) are available.

InjectionServiceLib.onReady(function() { /*magic code*/ });

Alternatively you can also listen to the event EVENT_ISL_READY directly.
Note: This only fires once when the page is loaded initially, you are better off adding your event handler to onReady that executes even after the page was loaded.

window.addEventListener('EVENT_ISL_READY', function() { /*magic code*/ });

PenguiniVogel/InjectionService