I am unable to persist indexedDB when I re-install the chrome app which is using it. While I'm able to persist data using the sync file system across re-installations.
Should I use the storage API to push the indexedDB data in an array and store it in a file?
Is there a "C language" like way in JS(while making chrome app) to save data using structs and file access? Something like data structures using JS.
Am I going all wrong? And the solution to this problem is rather simple and obvious.
All what you get for app is the app sandbox and resources also using in the app sandbox. Chrome delete the sandbox and it resources after app was removed. And it's true behavior then you create a sandbox.
You need any back-end/server-side storage to store use data and sync it then user reinstall the app.
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I'm developing an Ionic-Angular mobile application that involves tracking user progress. While I'm familiar with how to read from locally defined JSON files (and render that data), I've been unable to find any solutions online to write/append to local JSON files.
Until I'm able to utilize something like Google Firebase, I'd like to be able to just store this data by writing to local JSON.
Is there any way I can do this or is a database the only solution?
I'm assuming this is a web application. There is no way you can access the file system of the user to persist the data.
Other options
Index DB (save the information locally to the user at the browser level). User can go to the mobile device settings and clear it if required.
Use a mock api if this is only during the local development purpose (Use json-server and watch the database json file. You can update the database json file and it will reflect)
If you are building a hybrid application using ionic, then use one of the cordova plugins available here.
Use an actual backend service which persists it in the database.
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.
I have been developing a chrome extension and now I want to create version 2 with database support. For this I am going to use Firebase.
I need to create a file in my extension where I add the details about the firebase connection, api key and url etc..
After reading this question: Where does Chrome store extensions?
I went to look for mine. and boom there it was. I could open the files for the extensions and see the details I added about my firebase connection.
However, I am unsure as to whether I could see it because I am the developer and its on my machine. I do not like the idea of having my access keys available nor url.
Not that I think anyone would sabotage it, but I would hate to be billed for over usage of my requests etc..
My chrome app needs to save a file with human-readable or standard format such as SQLite (It should be readable outside Chrome).
Is there any API suitable for this purpose?
Some files with .localstorage extension (SQLite format) are in Chrome\User Data\Default\Local Storage folder. Is it possible to create such files by the app?
Edited: The app should not ask user for extra permission.
Thanks for your consideration.
chrome.fileSystem API is what you need.
You will need to ask the user at least once where to save the file, but then you can retain the entry to write again to the same file/folder.
There is no way around asking the user to "escape the sandbox".
You'll want to use the Quota Management API. This is per-origin storage, and you request specific amounts of quota.
It sounds like you also want your users to open the files directly? There's an HTML5 filesystem explorer Chrome app that you can use. It'll show you the files, and you can figure things out from their URLs (e.g. I'm currently using filesystem:http://localhost:8000/temporary/bar for a local experiment).
Or are you looking for something more user friendly? I think you have to use file save in that case, the same way Google Drive does.
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.