When I pass pdf URL value to this its getting error with the built-in keyword "path" and it seems to be null?
loadPdf(String pdfPath) async {
setState(() => _isLoading = true);
var fileName = pdfPath.split('/').last;
var localFileUrl = (await Directory(CacheManager.getInstance().appDocumentDir.path +'/'+"realpro"+"/").create(recursive: true)).path +fileName;
if (await CacheManager.getInstance().checkFileExist(localFileUrl)) {
document = await PDFDocument.fromAsset(localFileUrl);
print(document);
setState(() {
_isLoading = false;
});
} else {
document = await PDFDocument.fromURL(pdfPath);
print(document);
setState(() {
_isLoading = false;
});
}
}
The getter 'path' was called on null.
The error means that the object for which you are writing object.path is null. You can use ?. operator like this: object?.something which is equivalent to:
object!=null ? object.something : null
Related
How can i fix this and make it not deprecated
import 'package:purchases_flutter/purchases_flutter.dart';
class PurchaseApi{
static const _apiKey = '';
static Future init() async{
await Purchases.setDebugLogsEnabled(true);
await Purchases.setup(_apiKey);
}
static Future<List<Offering>> fetchOffers() async {
try{
final offerings = await Purchases.getOfferings();
final current = offerings.current;
return current == null ? [] : [current];
} on PlatformException catch (e) {
return [];
}
}
}
I already changed the firt on to await Purchases.setLogLevel(true as LogLevel); But when i change the setup one i get an error. The error is The method 'PurchasesConfiguration' isn't defined for the type 'Purchases'. I already tried to import'package:purchases_flutter/models/purchases_configuration.dart';
When you hover over the deprecated setup method, you have a hint.
You need to replace this:
await Purchases.setup(_apiKey);
to this:
PurchasesConfiguration(_apiKey);
I'm new on the Flutter & working on the integration of POS printing machine in flutter & using the pos_printer_manager package.
It shows an error in the catch part of this package i.e.
type 'Future<bool?>' is not a subtype of type 'FutureOr<bool>' in type cast
& pointing out in this code
/// [writeBytes] let you write raw list int data into socket
#override
Future<ConnectionResponse> writeBytes(List<int> data,
{bool isDisconnect: true}) async {
try {
if (!isConnected) {
await connect();
}
if (Platform.isAndroid || Platform.isIOS) {
if ((await (bluetooth.isConnected as FutureOr<bool>))) {
Uint8List message = Uint8List.fromList(data);
PosPrinterManager.logger.warning("message.length ${message.length}");
await bluetooth.writeBytes(message);
if (isDisconnect) {
await disconnect();
}
return ConnectionResponse.success;
}
return ConnectionResponse.printerNotConnected;
}
// else if (Platform.isIOS) {
// // var services = (await fbdevice.discoverServices());
// // var service = services.firstWhere((e) => e.isPrimary);
// // var charactor =
// // service.characteristics.firstWhere((e) => e.properties.write);
// // await charactor?.write(data, withoutResponse: true);
// return ConnectionResponse.success;
// }
return ConnectionResponse.unsupport;
} catch (e) {
print("Error : $e");
return ConnectionResponse.unknown;
}
}
This is due to bluetooth.isConnected as FutureOr<bool>.
So any big difference between Future<bool?> & FutureOr<bool> ?
Basically I faced type casting error in the package & I need a solution to handle this on the package side & how to manage the optional.
Based on your findings typecast is not required, it requires a null check
change this it to
if (Platform.isAndroid || Platform.isIOS) {
bool? isConnected = await bluetooth.isConnected;
if (isConnected != null && isConnected!) {
Uint8List message = Uint8List.fromList(data);
PosPrinterManager.logger.warning("message.length ${message.length}");
await bluetooth.writeBytes(message);
if (isDisconnect) {
await disconnect();
}
return ConnectionResponse.success;
}
return ConnectionResponse.printerNotConnected;
}
Resolved it by a simple check:
bool? btConnected = await bluetooth.isConnected ?? false;
I am new in flutter.And i have a question.I have method checkIsExistByString to check if i have a data before to insert date in sqflite.I expect true or false.
class DbManager {
Future<bool> checkIsExistByString(String title) async {
await openDb();
var result = await _database
.rawQuery('SELECT $Title FROM $tableName WHERE $Title = ?', [title]);
return Future<bool>.value(result.isEmpty ? true : false);
}
}
When i try to use checkIsExistByString i expect bool, but i have Instance of 'Future
void _submit() async {
print(dbmanager.checkIsExistByString('Title'));//print -- Instance of 'Future<bool>',but i expect true
...
}
you need to put await.
print(await dbmanager.checkIsExistByString('Title'));
also there is no need to convert bool into Future<bool>.
return result.isEmpty ? true : false;
Use await keyword as below :
print(await dbmanager.checkIsExistByString('Title'));
Hi I'm trying to get a Future to be used as a normal boolean, how do I use this function as the determiner for a normal boolean without it giving me an incorrect type error?
Future<bool> checkIfOnAnyChats() async {
FirebaseUser user = await _auth.currentUser();
final QuerySnapshot result = await _firestore
.collection('chats')
.where('members', arrayContains: _username)
.getDocuments();
final List<DocumentSnapshot> documents = result.documents;
if(documents.length > 0) {
return Future<bool>.value(true);
}else{
return Future<bool>.value(false);
}
}
How do I apply it to a normal type boolean and not get this error? Thanks.
you don't need to convert bool into future, as you are in async method it will return future only.
you can get that value in initstate, you can not get value outside any method.
bool _isInChat;
#override
void initState() {
super.initState();
CheckIfOnAnyChats().then((value){
SetState((){
_isInChat = value;
});
});
}
i have a cloud function where i pass an array of numbers and compare those numbers with collection in the firestore . And if the numbers are present than return an array with those numbers. But before comparing those numbers the function return empty value in the promise.
I've tried using async await but the execution sequence remained same.
//sort contact list
export const addMessage= functions.https.onCall(async (data:any, context) => {
const col=admin.firestore().collection("joshua");
var match:[]
match=data.list
var perm1=new Array()
res11.push("454675556")
console.log("above resolve")
for(let val in match){
var inter=await Promise.all([getValues(col,val)])
console.log("inside resolve"+inter)
}
perm1.push("23432")
console.log("just before resolve")
return new Promise((res,rej)=>{
res(perm1)
})
});
//the async function which is suppose to process on every iteration
function getValues(col1:any,val1:any)
{
return new Promise(async(res,rej)=>{
var query= await col1.where('Listed','array-contains',val1)
var value=await query.get()
res(value)
})
.catch(err=>{
console.log(err)
})
}
i want the sequence to be asynchronous where the return value from getValues is waited upon and inside getValues result of query.get is waited upon.
so that at last return only be sent when all process is finished.
I think this is what you are looking for
export const addMessage= functions.https.onCall(async (data:any, context) => {
const col = admin.firestore().collection("joshua");
var match:[]
match = data.list
var perm1 = []
// res11.push("454675556") // ? undefined
for(let val in match){
var inter = await getValues(col,val)
console.log("inside resolve" + inter)
}
perm1.push("23432") // ??
// console.log("just before resolve")
return Promise.resolve(perm1)
});
const getValues = async (col1:any, val1:any) => {
const query = col1.where('Listed','array-contains', val1)
var value = await query.get().then(getAllDocs)
return value
}
const getAllDocs = function(data: any) {
const temp: Array<any> = []
data.forEach(function (doc: any) {
temp.push(doc.data())
})
return temp
}