I want to develop an offline chrome application.
As in offline app SQL is not available , so what API can serve the following purpose.
=>Large Storage
=>Efficient method to set and get values
=>Fast
=>Secured (user cannot temper the data)
Confused between IndexDB and File System API
I have knowledge of web languages and how online apps can store data on server. But don't know much about how to save data offline.
It all depends on your needs.
The Chrome apps have couple of limitations. Because they must to be very fast some web API's are disabled. You can't use localStorage and webSql for example.
However in apps you have different set of storage options:
chrome.storage.local - equivalent for localStorage but asynchronous. you can also save/read many objects at once
chrome.storage.sync - same as above but data are shared between different app instances (on other browser's profiles or machines)
web filesystem API - well known web filesystem API that can keep any kind of file in protected, browser storage. User's do not have direct access to this files, only the app have
extension to the above: chrome.syncFileSystem - it works similar to the above but files saved using this API are synced between app's instances (e.g. different machines) using Google Drive as a back-end. However user's can't see synced files in Drive UI because they are hidden.
chrome.fileSystem API - another extension to the web filesystem API and it gives you access to the user's sandboxed local filesystem. You can read from and write to selected by the user locations.
IndexedDB - quoting the docs: IndexedDB is an API for client-side storage of significant amounts of structured data, which also enables high performance searches of this data using indexes.
other custom solutions saving data on some server and syncing changes in all instances
You can choose one of above. As I can see you'll probably want to use IndexedDB API. It is not SQL and it is different approach to saving data. If you never use it before try some sample app first. However it's fast, efficient and combining with unlimitedStorage permission also can set large amount of data.
I also suggesting you to read Offline First page in Chrome Apps documentation where are examples of solutions for making an app offline.
Related
We are developing application that needs write access to restricted data types. And looks like Google has stopped taking new request for whitelisting apps.
https://developers.google.com/fit/android/data-types#restricted_data_types
Note: Google has temporarily stopped taking new requests to write to restricted data types. We are updating our policy and process for reviewing requests and will update this documentation again when we resume.
Does anyone from Google have any idea when they will resume it?
Also: Is there a way to implement/write restricted data in development environment or debug build without whitelisting, and whitelist app before going to production?
There is no timeline yet for when this will be available.
(Source: I work on Google Fit)
So, I am working on a project(building a chrome extension) that requires data to be stored on the local machine of the user. The size of data is quite large hence I thought of using IndexDB for this purpose.
My Question is whether is it possible to connect a chrome extension with IndexDB and query the database at the same time??
If Yes, Then how can I integrate them. In which file(popup.js or background.js or any other file) should I include the source code for creating the database.
I want the code for creating the database to run only once. After that I only want to update or delete data only.
If No, then is there any other way to achieve this?? The data is large hence I cannot store data in local storage.
Any paper, online material, advice or method from chrome developers or any other valid site would be helpful. Any example would help me alot.
Thankyou.
You can store tons of data in any HTML5 storage (including IndexedDB or localStorage) and chrome.storage.local with "unlimitedStorage" permission.
HTML5 data is stored per URL origin and each extension has its own one that looks like chrome-extension://id where id is a 32-character string that is the extension's id. In Firefox the origin looks like moz-extension://id.
Extension's own HTML5 storage:
can be accessed in any extension page (popup, options, background) just like you would do it in a web page, there are no differences.
cannot be accessed in a content script as it runs in a web page and thus can only access HTML5 storage of the web page's URL origin.
chrome.storage.local can be accessed in any extension page and in a content script.
No need for special event to create/upgrade your IndexedDB storage - it'll happen automatically if needed - simply open it as shown in the documentation whenever you need to access it and your onupgradeneeded callback will be invoked in case there was no DB or it was outdated.
Use a wrapper library for IndexedDB that provides a simplified syntax. Some are listed in the documentation, but you can probably find better ones yourself.
We currently use Jive Cloud N which can use the Rest API and allows the use of Custom Apps. Our UI devs have created an app which uses a JS GET to pull data from a JSON file for our "Birthdays and Anniversaries" tile.
At the moment, the JSON file is hosted on our UI dev's Google Cloud Apps account, but we wish to host it internally so we don't have to keep contacting them for changes.
I uploaded the file to our OneDrive for Business storage and created a public URL with full read permissions but the Jive platform is throwing an error trying to load the custom app.
The error is that the file
has been blocked by CORS policy: No "Access-Control-Allow-Origin"
header is present
Our dev said that to get it working on his Google Cloud App storage, he had to specify the allow-control-allow-origin field in the server's server app.yaml file. I don't know what this is and if there is an equivalent for ODfB/SharePoint.
To get to my question: How can I host this JSON file on ODfB or even somewhere on our Azure tenancy so that it can be used? Or am I better off trying to setup a Google Cloud App storage location and replicate our dev's setup? FYI - I'd prefer the former because we're using M$ for a number of cloud hosted services already.
Thanks in advance
To get to my question: How can I host this JSON file on ODfB or even somewhere on our Azure tenancy so that it can be used?
FYI - I'd prefer the former because we're using M$ for a number of cloud hosted services already.
Per my understanding, you could leverage Azure Blob Storage to store your JSON file, and you could use Microsoft Azure Storage Explorer to easily manage/share your files.
Moreover, You could manage anonymous read access to your containers and blobs, refer to this tutorial for more details. Also, you could leverage SAS to grant limited access to your storage account for other clients, you could follow this tutorial for getting started with SAS.
For a simple way, you could create your storage account and leverage Microsoft Azure Storage Explorer to manage/share your file as follows:
For cross domain accessing, you need to configure CORS Setting:
For sharing your file(blob), you could Set Container Public Access Level or leverage SAS to grant limited access to your file for other clients as follows:
Right click your container, select "Set Public Access Level":
Sample file for share: https://brucechen.blob.core.windows.net/brucechen/index.json
Also, you could right click your JSON file, click "Get Shared Access Signature":
Sample file for share: https://brucechen.blob.core.windows.net/brucechen/index.json?st=2017-02-28T08%3A04%3A00Z&se=2017-09-01T08%3A04%3A00Z&sp=r&sv=2015-12-11&sr=b&sig=rVkorHeNOd4j2YhkmmxZ6DfXVLf1FoN2smY6mNRIoWs%3D
I'm making a small Chrome extension and would like to keep its data online.
I need a free and very small(<1MB per user) cloud hosting provider that has painless authentication.
Ideally, I'd just like a Google API that does localStorage, but in the cloud and different for each username.
FYI there is a new extension API to asynchronously store things like user settings, and optionally sync them across the user's other devices.
https://developer.chrome.com/extensions/storage.html
For example:
chrome.storage.sync.set({name:'Bob'}, function() {
console.log('Name saved');
});
// Later on...
chrome.storage.sync.get('name', function(r) {
console.log('Name retrieved: ' + r['name']);
});
Using sync will sync this across devices, using local will not.
Why can't you use Google App Engine? The API is pretty easy to use. Or use other Google services tied to each individual user such as Google Docs. That is how Google Chrome Sync stores bookmarks that are synchronized in your browser through Docs.
Concerning localStorage, localStorage is a key value storage API for JavaScript (Client Side). If you want to store your extension's localStorage externally online, you can iterate your storage keys/values and store them through contacting some external (whatever API you use) service. And retrieve them every time your extension starts (in background.html page).
Why would you do that though? Google Chrome Sync, synchronizes all those information by default.
I started reading Google Chrome's documentation, and liked it's approach of using HTML and Javascript to create extensions. Reading this tutorial about Local Storage made me think about a lot of different uses.
I want to develop an extension to help me with corporate systems. It's very specific, and it's only going to be used inside a company.
This extension would do some activities to this corporate system, using javascript DOM, with just one click on Google's Chrome toolbar. To work with just one click, the extension needs to store a password in Chrome: so if you restart your system, you don't need to enter it again.
How do I do that? Persist a password in a Google Chrome extension to login to another system? I don't want to store it in "plain text", I would like to at least use some kind of encryption (maybe a Google Chrome API with this resource).
Is it possible? How do I persist this data with Google Chrome's extensions structure (best way)?
You could encrypt and store a user’s password with localStorage (or the Web SQL Database API). But not very securely. Anyone who gained access to the user’s computer could retrieve the ciphertext, pluck the encryption algorithm out of your extension source, and determine the plaintext password.
If feasible, here are a couple more bulletproof solutions:
Piggyback on the user logging into a web interface. For an example, see the Google Mail Checker.
Connect to the services through OAuth (or a similar authorization scheme). For an example, see the Google Wave Notifier.