I'm using sqflite to create my SQL database and save the data I receive from the RESTful API locally. I get the image link from the API but I have no idea how to store it. should I heard I can use BLOB (Uint8List) and cached_network_image. which of these two (or another way!) would u suggest and how to do it exactly?
I tried to save the Image link as String, but it did not satisfy my needs because I need to load my images once and load them locally next times.
Last time I searched on this topic, storing the image as a file on the device and as a string with the filename in the db was the proposed solution
Related
I have a flutter application that is meant for collecting data on road usage, and I would like to carry out analysis after collection of data.
I've saved the file and I am able to read the file via readAsString and writeAsString to
'data/user/0/com.example.flutter_example_app/app_flutter/fault_report.txt'
How can I access the data quickly and easily without having to integrate too much stuff [For instance, opening an API and writing to cloud and etc]?
The app is supposed to be just a collection method and all analysis will be carried out afterward.
It depends on how ofter you would like to retrieve your data. If you only want to get the data once in a while, you can use File Explorer, Bluetooth file sharing, Cloud Drive or etc. to retrieve your data. But if you want to retrieve data more often, making some simple api will not take too much time.
I am building an app like google's keep (notes taking app) using flutter. I can add notes but when I close the app, it resets to initial state. How can I save these notes so when I come back to app, I can read my previously added notes.
When you're saving in a list for example, and render, you're doing that on UI state which is temporary. If you want to store data to last even after the UI got refreshed, you have to use a database that will hold the data until you delete it.
If you just want to store some tiny data, for example light/dark mode preferences or login/logout sessions, you can use shared_preferences. For larger data, I used sqflite to store data in SQL database in system as a file which will be cleared after the app is memory-cleared or deleted. If you want to store the data in cloud, you can use firebase for that.
You have two options:
1) Save locally on device using database. Below are the db solutions.
Moor
Floor
2) Save on the server, you can use Firebase Cloud Firestore.
I have a document in Cloud firestore to which I listen for updates. It has 2 fields, it has a field description and a field for a picture. The picture is approximately 0.2 mb and description is a few words. I wanted to know what would happen if I made changes to the description in the document, I wanted to know if addSnapshotListener actually downloads a fresh new copy of the document or just the field that has been changed.
I indeed see, by looking at how much data is being downloaded in Xcode, a new fresh copy of the document is downloaded.
This is not efficient at all, since the picture field is rarely changed, only the description might change in my application.
Is there a way to optimize this?
Is there a way to optimize this?
Yes! Don't do that.
Firestore (and the realtime database) is not intended to store images or large datasets per field.
You should explore Storage and keep a reference (url) to the item stored in storage in your Firebase.
Cloud Storage is built for app developers who need to store and serve
user-generated content, such as photos or videos.
By leveraging storage if you need to update or change a field in Firestore, you're only working with a small amount of data instead of an entire image worth.
To answer the question; if you read a document from Firebase, it does read the Document and it's child data.
Here's a link to the Storage Docs which shows how to capture a reference to the item uploaded to storage.
https://firebase.google.com/docs/storage/ios/upload-files
If you want to automatically sync the images to all clients and have them available offline, just put them in a separate document.
// Store your small, frequently changing text here:
db.collection('users').doc(userId).set({email: vince#example.com})
// Store your image here:
db.collection('user_profile_pic').doc(userId).set({data: <imagedata>})
I developed an application for Android with Ionic2 framework. I used Local storage functions to handle data.
Now, I want to replace local storage by database with some API calls.
And before switching to my API, I wish to extract the application data in order to no lost them.
Q1: That why, I wonder where is the path for the local storage data? In other words, where can I find the file with my stored data?
Q2: If retrieving my data isn't possible. I was wondering: If I modify the application with a extract function, when I reinstall it, will it delete my data or leave it as it is? (and so extract my data easily)
Thanks for your help!
I hope I gave enough information.
Local storage doc: https://ionicframework.com/docs/building/storage/
Which use localForage: https://github.com/localForage/localForage
I am developing an iPhone app which retrieves information via NSUrlRequest and displays through UIWebView.
I want to hold initial data (such as HTML pages, images) as a cache so that users of my app can access to data without network costs at the first time.
Then, if data on my web server are updated, I would download them and update the cache.
For performance issues, I think it is better to store data on file system than on core data.
Yet, I think it's not possible to release a new app writing data on disk.
So, I am about to store initial data(or initial cache) at Core Data, and when users launch my app for the first time, I would copy the data to disk (like /Library folder).
Is it, do you think, a good approach?
Or,...hmm, can I access to Core Data using NSUrlRequest?
One more question,
I might access to file system using NSURL, which is the same as to data on the Web. (right?)
My app would compare version of the cache with version of data on my web server, and if it's old, retrieve new data.
and my app will access only to file system.
All data are actually HTML pages including script, and images. And, I want to cache them.
could you suggest a better design?
Thank you.
Is it, do you think, a good approach? Or,...hmm, can I access to Core Data using NSUrlRequest?
No.
One more question, I might access to file system using NSURL, which is the same as to data on the Web. (right?) My app would compare version of the cache with version of data on my web server, and if it's old, retrieve new data. and my app will access only to file system. All data are actually HTML pages including script, and images. And, I want to cache them.
Yes.
But you could also be more clever. And by "more clever" I mean "Matt Gallagher." Take a look at his very interesting approach in Substituting local data for remote UIWebView requests.