Accessing a local directory from a Chrome App

Question

I am working on a Chrome extension called Chrome Snippets that will allow you to inject snippets of JavaScript from files but I am having trouble accessing local directories on the user's computer. Anyone have an idea of how to accomplish this?

manifest.json:

{
    "name": "Chrome Snippets",
    "description": "Run JavaScript on the DOM of any web page from a library of recipes stored on your computer.",
    "author":  "Adam Fisher",
    "version": "1.0",
    "manifest_version": 2,
    "default_locale": "en",
    "permissions": [ "tabs", "webNavigation", "*://*/*", {"fileSystem": ["write", "retainEntries", "directory"]} ],
    "app": {
        "background": {
            "scripts": ["js/background.js"],
            "persistent":  false
        }
    },
    "icons": { 
        "16":  "img/icon16.png",
        "48":  "img/icon48.png",
        "128": "img/icon128.png"
    },
    "options_page": "html/options.html",
    "homepage_url": "http://adamfisher.me"
}

background.js:

/*
** file: js/background.js
** description: Main functionality of the extension. Checks if a file exists
**              for the given host name and loads it.
*/


chrome.webNavigation.onCompleted.addListener(function (details) {

    var recipesDirectory = localStorage['Chrome_Snippets_Recipes_Directory'];
    var host = "/^(?:ht|f)tps?:\/\/([^/]+)/".exec(details.url); // Get the host part of the URL.

    chrome.tabs.executeScript(details.tabId, {
        file: ''
    });
});

Errors when attempting to load plugin.

Pawel Uchida-Psztyc · Answer 1 · 2015-01-12T21:34:01.210

0

Replace "app" in the manifest.json file with "background":

"background": {
  "scripts": ["js/background.js"],
  "persistent": false
},

Reference: https://developer.chrome.com/extensions/event_pages

The "app" entry is reserved for Chrome Apps which have different set of API's and permissions.

================================================

Edit

Forgot about what you really asking for.

Chrome extensions can't access user's filesystem. This API is only available for Chrome Apps. So if you need to do it as an extension you can't save files on local file system.

edited Jan 12 '15 at 21:34

answered Jan 12 '15 at 21:28

Pawel Uchida-Psztyc

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New error: 'fileSystem' is only allowed for packaged apps, but this is a extension. I suppose packaged app is the way to go. How can I make it a packaged app and do a read from a directory? https://github.com/adamfisher/Chrome-Snippets – Adam Jan 12 '15 at 21:38
1

Chrome Apps does not support content scripts API since it is not working in context of the browser. It is an app and does not know what the user do with a webpage. You can still achieve your goal using web filesystem. User can "upload" files in options page (for example) and this files will be accessible for your extension. You can treat is as a regular file but they will be kept in sandboxed filesystem. – Pawel Uchida-Psztyc Jan 12 '15 at 21:44

score 0 · Accepted Answer · answered Jan 12 '15 at 21:43

You CAN'T make what you want in a single app/extension, that's what Paweł tries to tell you.

Compare Apps APIs and Extensions APIs

Apps can't use tabs (and in general can't interact with normal browser content), extensions can't use fileSystem (and in general can't access system resources).

You need to rethink your strategy OR use both an extension and an app that talk to each other.

Accessing a local directory from a Chrome App

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