Adam Rose

Adam Rose

1600489043

3 Ways To Handle Errors in RxJs

This post is about handling errors in RxJs. We’ll dive into when and how you’d handle them using the following three Operators that RxJs provides:

  • catchError
  • retry
  • retryWhen

Without further delay, lets jump right in.

Note: _You can find all of the code examples in this Git repository

What happens when an error occurs

As we covered in the last post, an Observable emits a stream of values. While emitting values, an error might occur and be emitted. The Observer should be able to handle any errors that get emitted.

But once the Observable emits an error the stream will be terminated and no further items will be emitted. If the stream is terminated the application would need some way to handle that or it’ll crash.

One of the core principles in Reactive Programming is that the application should be resilient. Meaning, we should be able to handle errors before they reach the Observer. Because, if the error function is invoked on the Observer it means the stream is terminated.

It’s too late.

So, is there a way to intercept the error before it gets to the Observer and do something about it in a way that the stream won’t be terminated? Or, even if the stream is terminated, is there a way to switch over to one that’s available?

You guessed it. The catchError(), retry() and retryWhen() Operators allow us to handle errors in different ways and depending on your use case you can use one or a combination of these Operators.

Lets look at each one in detail.

#web-development #programming #javascript #rxjs #developer

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3 Ways To Handle Errors in RxJs

A Wrapper for Sembast and SQFlite to Enable Easy

FHIR_DB

This is really just a wrapper around Sembast_SQFLite - so all of the heavy lifting was done by Alex Tekartik. I highly recommend that if you have any questions about working with this package that you take a look at Sembast. He's also just a super nice guy, and even answered a question for me when I was deciding which sembast version to use. As usual, ResoCoder also has a good tutorial.

I have an interest in low-resource settings and thus a specific reason to be able to store data offline. To encourage this use, there are a number of other packages I have created based around the data format FHIR. FHIR® is the registered trademark of HL7 and is used with the permission of HL7. Use of the FHIR trademark does not constitute endorsement of this product by HL7.

Using the Db

So, while not absolutely necessary, I highly recommend that you use some sort of interface class. This adds the benefit of more easily handling errors, plus if you change to a different database in the future, you don't have to change the rest of your app, just the interface.

I've used something like this in my projects:

class IFhirDb {
  IFhirDb();
  final ResourceDao resourceDao = ResourceDao();

  Future<Either<DbFailure, Resource>> save(Resource resource) async {
    Resource resultResource;
    try {
      resultResource = await resourceDao.save(resource);
    } catch (error) {
      return left(DbFailure.unableToSave(error: error.toString()));
    }
    return right(resultResource);
  }

  Future<Either<DbFailure, List<Resource>>> returnListOfSingleResourceType(
      String resourceType) async {
    List<Resource> resultList;
    try {
      resultList =
          await resourceDao.getAllSortedById(resourceType: resourceType);
    } catch (error) {
      return left(DbFailure.unableToObtainList(error: error.toString()));
    }
    return right(resultList);
  }

  Future<Either<DbFailure, List<Resource>>> searchFunction(
      String resourceType, String searchString, String reference) async {
    List<Resource> resultList;
    try {
      resultList =
          await resourceDao.searchFor(resourceType, searchString, reference);
    } catch (error) {
      return left(DbFailure.unableToObtainList(error: error.toString()));
    }
    return right(resultList);
  }
}

I like this because in case there's an i/o error or something, it won't crash your app. Then, you can call this interface in your app like the following:

final patient = Patient(
    resourceType: 'Patient',
    name: [HumanName(text: 'New Patient Name')],
    birthDate: Date(DateTime.now()),
);

final saveResult = await IFhirDb().save(patient);

This will save your newly created patient to the locally embedded database.

IMPORTANT: this database will expect that all previously created resources have an id. When you save a resource, it will check to see if that resource type has already been stored. (Each resource type is saved in it's own store in the database). It will then check if there is an ID. If there's no ID, it will create a new one for that resource (along with metadata on version number and creation time). It will save it, and return the resource. If it already has an ID, it will copy the the old version of the resource into a _history store. It will then update the metadata of the new resource and save that version into the appropriate store for that resource. If, for instance, we have a previously created patient:

{
    "resourceType": "Patient",
    "id": "fhirfli-294057507-6811107",
    "meta": {
        "versionId": "1",
        "lastUpdated": "2020-10-16T19:41:28.054369Z"
    },
    "name": [
        {
            "given": ["New"],
            "family": "Patient"
        }
    ],
    "birthDate": "2020-10-16"
}

And we update the last name to 'Provider'. The above version of the patient will be kept in _history, while in the 'Patient' store in the db, we will have the updated version:

{
    "resourceType": "Patient",
    "id": "fhirfli-294057507-6811107",
    "meta": {
        "versionId": "2",
        "lastUpdated": "2020-10-16T19:45:07.316698Z"
    },
    "name": [
        {
            "given": ["New"],
            "family": "Provider"
        }
    ],
    "birthDate": "2020-10-16"
}

This way we can keep track of all previous version of all resources (which is obviously important in medicine).

For most of the interactions (saving, deleting, etc), they work the way you'd expect. The only difference is search. Because Sembast is NoSQL, we can search on any of the fields in a resource. If in our interface class, we have the following function:

  Future<Either<DbFailure, List<Resource>>> searchFunction(
      String resourceType, String searchString, String reference) async {
    List<Resource> resultList;
    try {
      resultList =
          await resourceDao.searchFor(resourceType, searchString, reference);
    } catch (error) {
      return left(DbFailure.unableToObtainList(error: error.toString()));
    }
    return right(resultList);
  }

You can search for all immunizations of a certain patient:

searchFunction(
        'Immunization', 'patient.reference', 'Patient/$patientId');

This function will search through all entries in the 'Immunization' store. It will look at all 'patient.reference' fields, and return any that match 'Patient/$patientId'.

The last thing I'll mention is that this is a password protected db, using AES-256 encryption (although it can also use Salsa20). Anytime you use the db, you have the option of using a password for encryption/decryption. Remember, if you setup the database using encryption, you will only be able to access it using that same password. When you're ready to change the password, you will need to call the update password function. If we again assume we created a change password method in our interface, it might look something like this:

class IFhirDb {
  IFhirDb();
  final ResourceDao resourceDao = ResourceDao();
  ...
    Future<Either<DbFailure, Unit>> updatePassword(String oldPassword, String newPassword) async {
    try {
      await resourceDao.updatePw(oldPassword, newPassword);
    } catch (error) {
      return left(DbFailure.unableToUpdatePassword(error: error.toString()));
    }
    return right(Unit);
  }

You don't have to use a password, and in that case, it will save the db file as plain text. If you want to add a password later, it will encrypt it at that time.

General Store

After using this for a while in an app, I've realized that it needs to be able to store data apart from just FHIR resources, at least on occasion. For this, I've added a second class for all versions of the database called GeneralDao. This is similar to the ResourceDao, but fewer options. So, in order to save something, it would look like this:

await GeneralDao().save('password', {'new':'map'});
await GeneralDao().save('password', {'new':'map'}, 'key');

The difference between these two options is that the first one will generate a key for the map being stored, while the second will store the map using the key provided. Both will return the key after successfully storing the map.

Other functions available include:

// deletes everything in the general store
await GeneralDao().deleteAllGeneral('password'); 

// delete specific entry
await GeneralDao().delete('password','key'); 

// returns map with that key
await GeneralDao().find('password', 'key'); 

FHIR® is a registered trademark of Health Level Seven International (HL7) and its use does not constitute an endorsement of products by HL7®

Use this package as a library

Depend on it

Run this command:

With Flutter:

 $ flutter pub add fhir_db

This will add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):

dependencies:
  fhir_db: ^0.4.3

Alternatively, your editor might support or flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:fhir_db/dstu2.dart';
import 'package:fhir_db/dstu2/fhir_db.dart';
import 'package:fhir_db/dstu2/general_dao.dart';
import 'package:fhir_db/dstu2/resource_dao.dart';
import 'package:fhir_db/encrypt/aes.dart';
import 'package:fhir_db/encrypt/salsa.dart';
import 'package:fhir_db/r4.dart';
import 'package:fhir_db/r4/fhir_db.dart';
import 'package:fhir_db/r4/general_dao.dart';
import 'package:fhir_db/r4/resource_dao.dart';
import 'package:fhir_db/r5.dart';
import 'package:fhir_db/r5/fhir_db.dart';
import 'package:fhir_db/r5/general_dao.dart';
import 'package:fhir_db/r5/resource_dao.dart';
import 'package:fhir_db/stu3.dart';
import 'package:fhir_db/stu3/fhir_db.dart';
import 'package:fhir_db/stu3/general_dao.dart';
import 'package:fhir_db/stu3/resource_dao.dart'; 

example/lib/main.dart

import 'package:fhir/r4.dart';
import 'package:fhir_db/r4.dart';
import 'package:flutter/material.dart';
import 'package:test/test.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  final resourceDao = ResourceDao();

  // await resourceDao.updatePw('newPw', null);
  await resourceDao.deleteAllResources(null);

  group('Playing with passwords', () {
    test('Playing with Passwords', () async {
      final patient = Patient(id: Id('1'));

      final saved = await resourceDao.save(null, patient);

      await resourceDao.updatePw(null, 'newPw');
      final search1 = await resourceDao.find('newPw',
          resourceType: R4ResourceType.Patient, id: Id('1'));
      expect(saved, search1[0]);

      await resourceDao.updatePw('newPw', 'newerPw');
      final search2 = await resourceDao.find('newerPw',
          resourceType: R4ResourceType.Patient, id: Id('1'));
      expect(saved, search2[0]);

      await resourceDao.updatePw('newerPw', null);
      final search3 = await resourceDao.find(null,
          resourceType: R4ResourceType.Patient, id: Id('1'));
      expect(saved, search3[0]);

      await resourceDao.deleteAllResources(null);
    });
  });

  final id = Id('12345');
  group('Saving Things:', () {
    test('Save Patient', () async {
      final humanName = HumanName(family: 'Atreides', given: ['Duke']);
      final patient = Patient(id: id, name: [humanName]);
      final saved = await resourceDao.save(null, patient);

      expect(saved.id, id);

      expect((saved as Patient).name?[0], humanName);
    });

    test('Save Organization', () async {
      final organization = Organization(id: id, name: 'FhirFli');
      final saved = await resourceDao.save(null, organization);

      expect(saved.id, id);

      expect((saved as Organization).name, 'FhirFli');
    });

    test('Save Observation1', () async {
      final observation1 = Observation(
        id: Id('obs1'),
        code: CodeableConcept(text: 'Observation #1'),
        effectiveDateTime: FhirDateTime(DateTime(1981, 09, 18)),
      );
      final saved = await resourceDao.save(null, observation1);

      expect(saved.id, Id('obs1'));

      expect((saved as Observation).code.text, 'Observation #1');
    });

    test('Save Observation1 Again', () async {
      final observation1 = Observation(
          id: Id('obs1'),
          code: CodeableConcept(text: 'Observation #1 - Updated'));
      final saved = await resourceDao.save(null, observation1);

      expect(saved.id, Id('obs1'));

      expect((saved as Observation).code.text, 'Observation #1 - Updated');

      expect(saved.meta?.versionId, Id('2'));
    });

    test('Save Observation2', () async {
      final observation2 = Observation(
        id: Id('obs2'),
        code: CodeableConcept(text: 'Observation #2'),
        effectiveDateTime: FhirDateTime(DateTime(1981, 09, 18)),
      );
      final saved = await resourceDao.save(null, observation2);

      expect(saved.id, Id('obs2'));

      expect((saved as Observation).code.text, 'Observation #2');
    });

    test('Save Observation3', () async {
      final observation3 = Observation(
        id: Id('obs3'),
        code: CodeableConcept(text: 'Observation #3'),
        effectiveDateTime: FhirDateTime(DateTime(1981, 09, 18)),
      );
      final saved = await resourceDao.save(null, observation3);

      expect(saved.id, Id('obs3'));

      expect((saved as Observation).code.text, 'Observation #3');
    });
  });

  group('Finding Things:', () {
    test('Find 1st Patient', () async {
      final search = await resourceDao.find(null,
          resourceType: R4ResourceType.Patient, id: id);
      final humanName = HumanName(family: 'Atreides', given: ['Duke']);

      expect(search.length, 1);

      expect((search[0] as Patient).name?[0], humanName);
    });

    test('Find 3rd Observation', () async {
      final search = await resourceDao.find(null,
          resourceType: R4ResourceType.Observation, id: Id('obs3'));

      expect(search.length, 1);

      expect(search[0].id, Id('obs3'));

      expect((search[0] as Observation).code.text, 'Observation #3');
    });

    test('Find All Observations', () async {
      final search = await resourceDao.getResourceType(
        null,
        resourceTypes: [R4ResourceType.Observation],
      );

      expect(search.length, 3);

      final idList = [];
      for (final obs in search) {
        idList.add(obs.id.toString());
      }

      expect(idList.contains('obs1'), true);

      expect(idList.contains('obs2'), true);

      expect(idList.contains('obs3'), true);
    });

    test('Find All (non-historical) Resources', () async {
      final search = await resourceDao.getAll(null);

      expect(search.length, 5);
      final patList = search.toList();
      final orgList = search.toList();
      final obsList = search.toList();
      patList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Patient);
      orgList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Organization);
      obsList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Observation);

      expect(patList.length, 1);

      expect(orgList.length, 1);

      expect(obsList.length, 3);
    });
  });

  group('Deleting Things:', () {
    test('Delete 2nd Observation', () async {
      await resourceDao.delete(
          null, null, R4ResourceType.Observation, Id('obs2'), null, null);

      final search = await resourceDao.getResourceType(
        null,
        resourceTypes: [R4ResourceType.Observation],
      );

      expect(search.length, 2);

      final idList = [];
      for (final obs in search) {
        idList.add(obs.id.toString());
      }

      expect(idList.contains('obs1'), true);

      expect(idList.contains('obs2'), false);

      expect(idList.contains('obs3'), true);
    });

    test('Delete All Observations', () async {
      await resourceDao.deleteSingleType(null,
          resourceType: R4ResourceType.Observation);

      final search = await resourceDao.getAll(null);

      expect(search.length, 2);

      final patList = search.toList();
      final orgList = search.toList();
      patList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Patient);
      orgList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Organization);

      expect(patList.length, 1);

      expect(patList.length, 1);
    });

    test('Delete All Resources', () async {
      await resourceDao.deleteAllResources(null);

      final search = await resourceDao.getAll(null);

      expect(search.length, 0);
    });
  });

  group('Password - Saving Things:', () {
    test('Save Patient', () async {
      await resourceDao.updatePw(null, 'newPw');
      final humanName = HumanName(family: 'Atreides', given: ['Duke']);
      final patient = Patient(id: id, name: [humanName]);
      final saved = await resourceDao.save('newPw', patient);

      expect(saved.id, id);

      expect((saved as Patient).name?[0], humanName);
    });

    test('Save Organization', () async {
      final organization = Organization(id: id, name: 'FhirFli');
      final saved = await resourceDao.save('newPw', organization);

      expect(saved.id, id);

      expect((saved as Organization).name, 'FhirFli');
    });

    test('Save Observation1', () async {
      final observation1 = Observation(
        id: Id('obs1'),
        code: CodeableConcept(text: 'Observation #1'),
        effectiveDateTime: FhirDateTime(DateTime(1981, 09, 18)),
      );
      final saved = await resourceDao.save('newPw', observation1);

      expect(saved.id, Id('obs1'));

      expect((saved as Observation).code.text, 'Observation #1');
    });

    test('Save Observation1 Again', () async {
      final observation1 = Observation(
          id: Id('obs1'),
          code: CodeableConcept(text: 'Observation #1 - Updated'));
      final saved = await resourceDao.save('newPw', observation1);

      expect(saved.id, Id('obs1'));

      expect((saved as Observation).code.text, 'Observation #1 - Updated');

      expect(saved.meta?.versionId, Id('2'));
    });

    test('Save Observation2', () async {
      final observation2 = Observation(
        id: Id('obs2'),
        code: CodeableConcept(text: 'Observation #2'),
        effectiveDateTime: FhirDateTime(DateTime(1981, 09, 18)),
      );
      final saved = await resourceDao.save('newPw', observation2);

      expect(saved.id, Id('obs2'));

      expect((saved as Observation).code.text, 'Observation #2');
    });

    test('Save Observation3', () async {
      final observation3 = Observation(
        id: Id('obs3'),
        code: CodeableConcept(text: 'Observation #3'),
        effectiveDateTime: FhirDateTime(DateTime(1981, 09, 18)),
      );
      final saved = await resourceDao.save('newPw', observation3);

      expect(saved.id, Id('obs3'));

      expect((saved as Observation).code.text, 'Observation #3');
    });
  });

  group('Password - Finding Things:', () {
    test('Find 1st Patient', () async {
      final search = await resourceDao.find('newPw',
          resourceType: R4ResourceType.Patient, id: id);
      final humanName = HumanName(family: 'Atreides', given: ['Duke']);

      expect(search.length, 1);

      expect((search[0] as Patient).name?[0], humanName);
    });

    test('Find 3rd Observation', () async {
      final search = await resourceDao.find('newPw',
          resourceType: R4ResourceType.Observation, id: Id('obs3'));

      expect(search.length, 1);

      expect(search[0].id, Id('obs3'));

      expect((search[0] as Observation).code.text, 'Observation #3');
    });

    test('Find All Observations', () async {
      final search = await resourceDao.getResourceType(
        'newPw',
        resourceTypes: [R4ResourceType.Observation],
      );

      expect(search.length, 3);

      final idList = [];
      for (final obs in search) {
        idList.add(obs.id.toString());
      }

      expect(idList.contains('obs1'), true);

      expect(idList.contains('obs2'), true);

      expect(idList.contains('obs3'), true);
    });

    test('Find All (non-historical) Resources', () async {
      final search = await resourceDao.getAll('newPw');

      expect(search.length, 5);
      final patList = search.toList();
      final orgList = search.toList();
      final obsList = search.toList();
      patList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Patient);
      orgList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Organization);
      obsList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Observation);

      expect(patList.length, 1);

      expect(orgList.length, 1);

      expect(obsList.length, 3);
    });
  });

  group('Password - Deleting Things:', () {
    test('Delete 2nd Observation', () async {
      await resourceDao.delete(
          'newPw', null, R4ResourceType.Observation, Id('obs2'), null, null);

      final search = await resourceDao.getResourceType(
        'newPw',
        resourceTypes: [R4ResourceType.Observation],
      );

      expect(search.length, 2);

      final idList = [];
      for (final obs in search) {
        idList.add(obs.id.toString());
      }

      expect(idList.contains('obs1'), true);

      expect(idList.contains('obs2'), false);

      expect(idList.contains('obs3'), true);
    });

    test('Delete All Observations', () async {
      await resourceDao.deleteSingleType('newPw',
          resourceType: R4ResourceType.Observation);

      final search = await resourceDao.getAll('newPw');

      expect(search.length, 2);

      final patList = search.toList();
      final orgList = search.toList();
      patList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Patient);
      orgList.retainWhere(
          (resource) => resource.resourceType == R4ResourceType.Organization);

      expect(patList.length, 1);

      expect(patList.length, 1);
    });

    test('Delete All Resources', () async {
      await resourceDao.deleteAllResources('newPw');

      final search = await resourceDao.getAll('newPw');

      expect(search.length, 0);

      await resourceDao.updatePw('newPw', null);
    });
  });
} 

Download Details:

Author: MayJuun

Source Code: https://github.com/MayJuun/fhir/tree/main/fhir_db

#sqflite  #dart  #flutter 

Let Developers Just Need to Grasp only One Button Component

 From then on, developers only need to master one Button component, which is enough.

Support corners, borders, icons, special effects, loading mode, high-quality Neumorphism style.

Author:Newton(coorchice.cb@alibaba-inc.com)

✨ Features

Rich corner effect

Exquisite border decoration

Gradient effect

Flexible icon support

Intimate Loading mode

Cool interaction Special effects

More sense of space Shadow

High-quality Neumorphism style

🛠 Guide

⚙️ Parameters

🔩 Basic parameters

ParamTypeNecessaryDefaultdesc
onPressedVoidCallbacktruenullClick callback. If null, FButton will enter an unavailable state
onPressedDownVoidCallbackfalsenullCallback when pressed
onPressedUpVoidCallbackfalsenullCallback when lifted
onPressedCancelVoidCallbackfalsenullCallback when cancel is pressed
heightdoublefalsenullheight
widthdoublefalsenullwidth
styleTextStylefalsenulltext style
disableStyleTextStylefalsenullUnavailable text style
alignmentAlignmentfalsenullalignment
textStringfalsenullbutton text
colorColorfalsenullButton color
disabledColorColorfalsenullColor when FButton is unavailable
paddingEdgeInsetsGeometryfalsenullFButton internal spacing
cornerFCornerfalsenullConfigure corners of Widget
cornerStyleFCornerStylefalseFCornerStyle.roundConfigure the corner style of Widget. round-rounded corners, bevel-beveled
strokeColorColorfalseColors.blackBorder color
strokeWidthdoublefalse0Border width. The border will appear when strokeWidth > 0
gradientGradientfalsenullConfigure gradient colors. Will override the color
activeMaskColorColorColors.transparentThe color of the mask when pressed
surfaceStyleFSurfacefalseFSurface.FlatSurface style. Default [FSurface.Flat]. See [FSurface] for details

💫 Effect parameters

ParamTypeNecessaryDefaultdesc
clickEffectboolfalsefalseWhether to enable click effects
hoverColorColorfalsenullFButton color when hovering
onHoverValueChangedfalsenullCallback when the mouse enters/exits the component range
highlightColorColorfalsenullThe color of the FButton when touched. effect:true required

🔳 Shadow parameters

ParamTypeNecessaryDefaultdesc
shadowColorColorfalseColors.greyShadow color
shadowOffsetOffsetfalseOffset.zeroShadow offset
shadowBlurdoublefalse1.0Shadow blur degree, the larger the value, the larger the shadow range

🖼 Icon & Loading parameters

ParamTypeNecessaryDefaultdesc
imageWidgetfalsenullAn icon can be configured for FButton
imageMargindoublefalse6.0Spacing between icon and text
imageAlignmentImageAlignmentfalseImageAlignment.leftRelative position of icon and text
loadingboolfalsefalseWhether to enter the Loading state
loadingWidgetWidgetfalsenullLoading widget in loading state. Will override the default Loading effect
clickLoadingboolfalsefalseWhether to enter Loading state after clicking FButton
loadingColorColorfalsenullLoading colors
loadingStrokeWidthdoublefalse4.0Loading width
hideTextOnLoadingboolfalsefalseWhether to hide text in the loading state
loadingTextStringfalsenullLoading text
loadingSizedoublefalse12Loading size

🍭 Neumorphism Style

ParamTypeNecessaryDefaultdesc
isSupportNeumorphismboolfalsefalseWhether to support the Neumorphism style. Open this item [highlightColor] will be invalid
lightOrientationFLightOrientationfalseFLightOrientation.LeftTopValid when [isSupportNeumorphism] is true. The direction of the light source is divided into four directions: upper left, lower left, upper right, and lower right. Used to control the illumination direction of the light source, which will affect the highlight direction and shadow direction
highlightShadowColorColorfalsenullAfter the Neumorphism style is turned on, the bright shadow color

📺 Demo

🔩 Basic Demo

// FButton #1
FButton(
  height: 40,
  alignment: Alignment.center,
  text: "FButton #1",
  style: TextStyle(color: Colors.white),
  color: Color(0xffffab91),
  onPressed: () {},
)

// FButton #2
FButton(
  padding: const EdgeInsets.fromLTRB(12, 8, 12, 8),
  text: "FButton #2",
  style: TextStyle(color: Colors.white),
  color: Color(0xffffab91),
  corner: FCorner.all(6.0),
)

// FButton #3
FButton(
  padding: const EdgeInsets.fromLTRB(12, 8, 12, 8),
  text: "FButton #3",
  style: TextStyle(color: Colors.white),
  disableStyle: TextStyle(color: Colors.black38),
  color: Color(0xffF8AD36),

  /// set disable Color
  disabledColor: Colors.grey[300],
  corner: FCorner.all(6.0),
)

By simply configuring text andonPressed, you can construct an available FButton.

If onPressed is not set, FButton will be automatically recognized as not unavailable. At this time, ** FButton ** will have a default unavailable status style.

You can also freely configure the style of FButton when it is not available via the disabledXXX attribute.

🎈 Corner & Stroke

// #1
FButton(
  width: 130,
  text: "FButton #1",
  style: TextStyle(color: Colors.white),
  color: Color(0xffFF7043),
  onPressed: () {},
  clickEffect: true,
  
  /// 配置边角大小
  ///
  /// set corner size
  corner: FCorner.all(25),
),

// #2
FButton(
  width: 130,
  text: "FButton #2",
  style: TextStyle(color: Colors.white),
  color: Color(0xffFFA726),
  onPressed: () {},
  clickEffect: true,
  corner: FCorner(
    leftBottomCorner: 40,
    leftTopCorner: 6,
    rightTopCorner: 40,
    rightBottomCorner: 6,
  ),
),

// #3
FButton(
  width: 130,
  text: "FButton #3",
  style: TextStyle(color: Colors.white),
  color: Color(0xffFFc900),
  onPressed: () {},
  clickEffect: true,
  corner: FCorner(leftTopCorner: 10),
  
  /// 设置边角风格
  ///
  /// set corner style
  cornerStyle: FCornerStyle.bevel,
  strokeWidth: 0.5,
  strokeColor: Color(0xffF9A825),
),

// #4
FButton(
  width: 130,
  padding: EdgeInsets.fromLTRB(6, 16, 30, 16),
  text: "FButton #4",
  style: TextStyle(color: Colors.white),
  color: Color(0xff00B0FF),
  onPressed: () {},
  clickEffect: true,
  corner: FCorner(
      rightTopCorner: 25,
      rightBottomCorner: 25),
  cornerStyle: FCornerStyle.bevel,
  strokeWidth: 0.5,
  strokeColor: Color(0xff000000),
),

You can add rounded corners to FButton via the corner property. You can even control each fillet individually。

By default, the corners of FButton are rounded. By setting cornerStyle: FCornerStyle.bevel, you can get a bevel effect.

FButton supports control borders, provided that strokeWidth> 0 can get the effect 🥳.

🌈 Gradient


FButton(
  width: 100,
  height: 60,
  text: "#1",
  style: TextStyle(color: Colors.white),
  color: Color(0xffFFc900),
  
  /// 配置渐变色
  ///
  /// set gradient
  gradient: LinearGradient(colors: [
    Color(0xff00B0FF),
    Color(0xffFFc900),
  ]),
  onPressed: () {},
  clickEffect: true,
  corner: FCorner.all(8),
)

Through the gradient attribute, you can build FButton with gradient colors. You can freely build many types of gradient colors.

🍭 Icon

FButton(
  width: 88,
  height: 38,
  padding: EdgeInsets.all(0),
  text: "Back",
  style: TextStyle(color: Colors.white),
  color: Color(0xffffc900),
  onPressed: () {
    toast(context, "Back!");
  },
  clickEffect: true,
  corner: FCorner(
    leftTopCorner: 25,
    leftBottomCorner: 25,),
  
  /// 配置图标
  /// 
  /// set icon
  image: Icon(
    Icons.arrow_back_ios,
    color: Colors.white,
    size: 12,
  ),

  /// 配置图标与文字的间距
  ///
  /// Configure the spacing between icon and text
  imageMargin: 8,
),

FButton(
  onPressed: () {},
  image: Icon(
    Icons.print,
    color: Colors.grey,
  ),
  imageMargin: 8,

  /// 配置图标与文字相对位置
  ///
  /// Configure the relative position of icons and text
  imageAlignment: ImageAlignment.top,
  text: "Print",
  style: TextStyle(color: textColor),
  color: Colors.transparent,
),

The image property can set an image for FButton and you can adjust the position of the image relative to the text, throughimageAlignment.

If the button does not need a background, just set color: Colors.transparent.

🔥 Effect


FButton(
  width: 200,
  text: "Try Me!",
  style: TextStyle(color: textColor),
  color: Color(0xffffc900),
  onPressed: () {},
  clickEffect: true,
  corner: FCorner.all(9),
  
  /// 配置按下时颜色
  ///
  /// set pressed color
  highlightColor: Color(0xffE65100).withOpacity(0.20),
  
  /// 配置 hover 状态时颜色
  ///
  /// set hover color
  hoverColor: Colors.redAccent.withOpacity(0.16),
),

The highlight color of FButton can be configured through the highlightColor property。

hoverColor can configure the color when the mouse moves to the range of FButton, which will be used during Web development.

🔆 Loading

FButton(
  text: "Click top loading",
  style: TextStyle(color: textColor),
  color: Color(0xffffc900),
  ...

  /// 配置 loading 大小
  /// 
  /// set loading size
  loadingSize: 15,

  /// 配置 loading 与文本的间距
  ///
  // Configure the spacing between loading and text
  imageMargin: 6,
  
  /// 配置 loading 的宽
  ///
  /// set loading width
  loadingStrokeWidth: 2,

  /// 是否支持点击自动开始 loading
  /// 
  /// Whether to support automatic loading by clicking
  clickLoading: true,

  /// 配置 loading 的颜色
  ///
  /// set loading color
  loadingColor: Colors.white,

  /// 配置 loading 状态时的文本
  /// 
  /// set loading text
  loadingText: "Loading...",

  /// 配置 loading 与文本的相对位置
  ///
  /// Configure the relative position of loading and text
  imageAlignment: ImageAlignment.top,
),

// #2
FButton(
  width: 170,
  height: 70,
  text: "Click to loading",
  style: TextStyle(color: textColor),
  color: Color(0xffffc900),
  onPressed: () { },
  ...
  imageMargin: 8,
  loadingSize: 15,
  loadingStrokeWidth: 2,
  clickLoading: true,
  loadingColor: Colors.white,
  loadingText: "Loading...",

  /// loading 时隐藏文本
  ///
  /// Hide text when loading
  hideTextOnLoading: true,
)


FButton(
  width: 170,
  height: 70,
  alignment: Alignment.center,
  text: "Click to loading",
  style: TextStyle(color: Colors.white),
  color: Color(0xff90caf9),
  ...
  imageMargin: 8,
  clickLoading: true,
  hideTextOnLoading: true,

  /// 配置自定义 loading 样式
  ///
  /// Configure custom loading style
  loadingWidget: CupertinoActivityIndicator(),
),

Through the loading attribute, you can configure Loading effects for ** FButton **.

When FButton is in Loading state, FButton will enter an unavailable state, onPress will no longer be triggered, and unavailable styles will also be applied.

At the same time loadingText will overwritetext if it is not null.

The click start Loading effect can be achieved through the clickLoading attribute.

The position of loading will be affected by theimageAlignment attribute.

When hideTextOnLoading: true, if FButton is inloading state, its text will be hidden.

Through loadingWidget, developers can set completely customized loading styles.

Shadow


FButton(
  width: 200,
  text: "Shadow",
  textColor: Colors.white,
  color: Color(0xffffc900),
  onPressed: () {},
  clickEffect: true,
  corner: FCorner.all(28),
  
  /// 配置阴影颜色
  ///
  /// set shadow color
  shadowColor: Colors.black87,

  /// 设置组件高斯与阴影形状卷积的标准偏差。
  /// 
  /// Sets the standard deviation of the component's Gaussian convolution with the shadow shape.
  shadowBlur: _shadowBlur,
),

FButton allows you to configure the color, size, and position of the shadow.

🍭 Neumorphism Style

FButton(

  /// 开启 Neumorphism 支持
  ///
  /// Turn on Neumorphism support
  isSupportNeumorphism: true,

  /// 配置光源方向
  ///
  /// Configure light source direction
  lightOrientation: lightOrientation,

  /// 配置亮部阴影
  ///
  /// Configure highlight shadow
  highlightShadowColor: Colors.white,

  /// 配置暗部阴影
  ///
  /// Configure dark shadows
  shadowColor: mainShadowColor,
  strokeColor: mainBackgroundColor,
  strokeWidth: 3.0,
  width: 190,
  height: 60,
  text: "FWidget",
  style: TextStyle(
      color: mainTextTitleColor, fontSize: neumorphismSize_2_2),
  alignment: Alignment.center,
  color: mainBackgroundColor,
  ...
)

FButton brings an incredible, ultra-high texture Neumorphism style to developers.

Developers only need to configure the isSupportNeumorphism parameter to enable and disable the Neumorphism style.

If you want to adjust the style of Neumorphism, you can make subtle adjustments through several attributes related to Shadow, among which:

shadowColor: configure the shadow of the shadow

highlightShadowColor: configure highlight shadow

FButton also provides lightOrientation parameters, and even allows developers to adjust the care angle, and has obtained different Neumorphism effects.

😃 How to use?

Add dependencies in the project pubspec.yaml file:

🌐 pub dependency

dependencies:
  fbutton: ^<version number>

⚠️ Attention,please go to [pub] (https://pub.dev/packages/fbutton) to get the latest version number of FButton

🖥 git dependencies

dependencies:
  fbutton:
    git:
      url: 'git@github.com:Fliggy-Mobile/fbutton.git'
      ref: '<Branch number or tag number>'

Use this package as a library

Depend on it

Run this command:

With Flutter:

 $ flutter pub add fbutton_nullsafety

This will add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):

dependencies:
  fbutton_nullsafety: ^5.0.0

Alternatively, your editor might support or flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:fbutton_nullsafety/fbutton_nullsafety.dart';

Download Details:

Author: Fliggy-Mobile

Source Code: https://github.com/Fliggy-Mobile/fbutton

#button  #flutter 

Ethen Ellen

1619519725

Immediate $olution to Fix AOL Blerk Error Code 5 with easy instructions

This is image title

AOL Email is one of the leading web email services. It has a number of features who access easily at any place. Through this, you can easily share messages, documents or files, etc.AOL Blerk Error is not a big issue. It is a temporary error and it occurs when there is an issue in loading messages from the AOL server. If your mind is stuck, How to Resolve or Fix AOL Blerk Error Code 5? Here, In this article, we mentioned troubleshooting steps to fix AOL Blerk Error Code 5.

What are the causes of AOL Blerk Error Code 5?

AOL mail usually presents an AOL Blerk Error 5 after the AOL connection details have been entered. meaning. Your password and your username. This error is usually found in words! Or 'BLERK! Error 5 Authentication problem, 'Your sign-in has been received.

Some of the reasons for the error are as follows:
• Internet browser configuration problem

• Saved erroneous bookmark addresses

• browser cache or cookie

• An AOL Desktop Gold technical error.
How to Fix AOL Mail Blerk Error 5 in a Simple Way

This type of error is mostly due to your browser settings or the use of outdated, obsolete software. Users should remember that the steps to solve problems vary, depending on the browser you are using. Here are the steps to fix the mistake, check your browser and follow the steps.

Internet Explorer: Make sure you use the most recent web browser version. Open a new window and follow the “Tools> Web Options> Security> Internet Zone” thread. Activate ‘Safeguard Mode’ and follow the steps to include AOL Mail in the list of assured websites. Start the browser again to save changes and run Internet Explorer without additional information.
Firefox Mozilla: Open a new Firefox window and press Menu. To start the browser in safe mode, disable the add-on and choose the option to restart Firefox. You can see two options in the dialog box. Use the “Start in Safe Mode” option to disable all themes and extensions. The browser also turns off the hardware speed and resets the toolbar. You should be able to execute AOL mail when this happens.

Google Chrome: Update to the latest version of Chrome. Open the browser and go to the Advanced Options section. Go to ‘Security and Privacy’ and close the appropriate add-ons. Once the browsing history is deleted, the password, cookies saved and the cache will be cleared. Restart your system and try to log in to your AOL account with a new window.

Safari: Some pop-up windows block AOL mail when it comes to Safari and causes authentication issues. To fix the error, use Safari Security Preferences to enable the pop-up window and disable the security warning.

If you see, even when you change the required browser settings, the black error will not disappear, you can consult a skilled professional and see all the AOL email customer support numbers.

Get Connect to Fix Blerk Error Even After Clearing Cache & Cookies?
Somehow you can contact AOL technical support directly and get immediate help if you still get the error. Call +1(888)857-5157 to receive assistance from the AOL technical support team.

Source: https://email-expert247.blogspot.com/2021/04/immediate-olution-to-fix-aol-blerk.html “How to Resolve or Fix AOL Blerk Error Code 5”)**? Here, In this article, we mentioned troubleshooting steps to fix AOL Blerk Error Code 5.

What are the causes of AOL Blerk Error Code 5?

AOL mail usually presents an AOL Blerk Error 5 after the AOL connection details have been entered. meaning. Your password and your username. This error is usually found in words! Or 'BLERK! Error 5 Authentication problem, 'Your sign-in has been received.

Some of the reasons for the error are as follows:
• Internet browser configuration problem

• Saved erroneous bookmark addresses

• browser cache or cookie

• An AOL Desktop Gold technical error.
How to Fix AOL Mail Blerk Error 5 in a Simple Way

This type of error is mostly due to your browser settings or the use of outdated, obsolete software. Users should remember that the steps to solve problems vary, depending on the browser you are using. Here are the steps to fix the mistake, check your browser and follow the steps.

  1. Internet Explorer: Make sure you use the most recent web browser version. Open a new window and follow the “Tools> Web Options> Security> Internet Zone” thread. Activate ‘Safeguard Mode’ and follow the steps to include AOL Mail in the list of assured websites. Start the browser again to save changes and run Internet Explorer without additional information.

  2. Firefox Mozilla: Open a new Firefox window and press Menu. To start the browser in safe mode, disable the add-on and choose the option to restart Firefox. You can see two options in the dialog box. Use the “Start in Safe Mode” option to disable all themes and extensions. The browser also turns off the hardware speed and resets the toolbar. You should be able to execute AOL mail when this happens.

  3. Google Chrome: Update to the latest version of Chrome. Open the browser and go to the Advanced Options section. Go to ‘Security and Privacy’ and close the appropriate add-ons. Once the browsing history is deleted, the password, cookies saved and the cache will be cleared. Restart your system and try to log in to your AOL account with a new window.

  4. Safari: Some pop-up windows block AOL mail when it comes to Safari and causes authentication issues. To fix the error, use Safari Security Preferences to enable the pop-up window and disable the security warning.

If you see, even when you change the required browser settings, the black error will not disappear, you can consult a skilled professional and see all the AOL email customer support numbers.

Get Connect to Fix Blerk Error Even After Clearing Cache & Cookies?

Somehow you can contact AOL technical support directly and get immediate help if you still get the error. Call +1(888)857-5157 to receive assistance from the AOL technical support team.

Source: https://email-expert247.blogspot.com/2021/04/immediate-olution-to-fix-aol-blerk.html

#aol blerk error code 5 #aol blerk error 5 #aol mail blerk error code 5 #aol mail blerk error 5 #aol error code 5 #aol error 5

John Kartan

John Kartan

1620157351

QuickBooks Error 3371 Status Code 11118 | Top 6 Solutions to Fix

QuickBooks has always been the first choice of thousands of mid-sized enterprises and solopreneurs when it comes to accounting and financing software. With the help of QuickBooks, businesses can handle all of their regular accounting activities, like managing income and expenses, tracking mileage, generating financial reports, submitting and printing tax forms, payroll, etc.
However, despite the impeccable feature that QuickBooks provides its users with, there are uncountable errors and bugs that many users often face while working with QuickBooks. With this post, we are going to discuss about QuickBooks error 3371 status code 11118 that usually happens when users try to open or activate QuickBooks Desktop applications on their computers.
While activating QuickBooks, the error code abruptly pops up on the screen with an error message, stating, “QuickBooks could not load the license data. This may be caused by missing or damaged files.” Generally, such an error gets triggered when the Microsoft MSXML component, which helps QuickBooks retrieve the license information in the QBregistration.dat file, is unregistered.

Need troubleshooting assistance to get rid of QuickBooks error 3371 status code 11118? If yes, feel free to reach our QuickBooks experts at (844-888-4666) and get the error resolved immediately.

What causes QuickBooks error 3371 could not initialize license properties?

Apart from the unregistered Microsoft MSXML component, there are several other reasons that can trigger QuickBooks error 3371 could not initialize license properties, such as:

  • The QB.registration.dat file, which contains all the license information, is damaged or corrupted.
  • Due to outdated Windows operating system.
  • Any QuickBooks program file is damaged or corrupted.

What should you do to rectify QuickBooks error 3371 status code 11118?

Solution 1) Manually register Microsoft MSXML DLL files

For the 32-Bit Windows operating system:

  • Open the Run command window by pressing Windows + R keys on the keyboard.
  • Type “cmd” in the Run command dialog box and then press the Enter key to open Command Prompt.
  • Now, you need to type regsvr32 MSXML6.dll in the command prompt window and then press the Enter key.

For the 64-Bit Windows operating system:

  • At first, press Windows + R keys simultaneously to open the Run command window.
  • In the Open: field, you need to type “cmd” and then click on the OK button.
  • At the C: prompt, type cd\windows\syswow64.
  • Thereafter, you need to enter regsvr32 MSXML6.dll and then press the Enter key.

Solution 2) Remove the Entitlement file and re-register QuickBooks Desktop

  • Open the Windows File Explorer by pressing Windows + E keys simultaneously on the keyboard.
  • Navigate to the following path: C:\ProgramData\Intuit\Entitlement Client\v8.
  • In the v8 folder, search for the file named EntitlementDataStore.ecml, and right-click it.
  • Choose the Delete option and then hit the Yes button to confirm.
  • Open the QuickBooks application and re-register it using the license & product information.

Solution 3) Get the Windows updated to the latest release

  • Select the Windows Start menu, type “settings” in the search column, and then open Settings.
  • Click on the Update & Security option.
  • Select the Windows Update tab from the left panel.
  • At last, click the Check for Updates option to download and install the Windows update.

Solution 4) Run the 3371 Error Fix tool to resolve QuickBooks license, validation, and registration errors.

  • Download the latest version of the QuickBooks Tool Hub (1.4.0.0) from Intuit’s official website.
  • Select the downloaded file (QuickBooksToolHub.exe) and follow the instructions you see on the computer screen.
  • Give your consent to terms and conditions to finish installing the QuickBooks Tool Hub.
  • Open the QB Tool Hub by double-clicking its icon.
  • Select the Installation Issues tab and then choose the 3371 Error Fix option.
  • Hit the OK button.

Solution 5) Repair the QuickBooks Desktop program for Windows

  • Select the Windows Start menu, type “Control Panel” in the search column, and then open Control Panel.
  • In the control panel, choose the Programs and Features option.
  • From the list of installed programs, select QuickBooks and then choose the Repair option.
  • Hit the Next button.
  • Once QuickBooks repairing is done, click on the Finish button.

Conclusion:

Even after following all the troubleshooting steps mentioned in the post, if you can’t resolve QuickBooks error 3371 status code 11118, then there is a great possibility that the Windows Firewall or any third-party security application is blocking necessary QuickBooks installation files. We suggest you restore any blocked QuickBooks file from security applications and make exceptions for QuickBooks programs to prevent them from being scanned. You can also reach our QuickBooks professionals at (844-888-4666) for troubleshooting assistance and get the error resolved immediately.

#error 3371 could not initialize license properties #fatal error: quickbooks has encountered a problem on startup #how to fix quickbooks error 3371 #i have received the on start up [error 3371 #quickbooks 2016 & win 7 error 3371 #quickbooks error 3371

Adam Rose

Adam Rose

1600489043

3 Ways To Handle Errors in RxJs

This post is about handling errors in RxJs. We’ll dive into when and how you’d handle them using the following three Operators that RxJs provides:

  • catchError
  • retry
  • retryWhen

Without further delay, lets jump right in.

Note: _You can find all of the code examples in this Git repository

What happens when an error occurs

As we covered in the last post, an Observable emits a stream of values. While emitting values, an error might occur and be emitted. The Observer should be able to handle any errors that get emitted.

But once the Observable emits an error the stream will be terminated and no further items will be emitted. If the stream is terminated the application would need some way to handle that or it’ll crash.

One of the core principles in Reactive Programming is that the application should be resilient. Meaning, we should be able to handle errors before they reach the Observer. Because, if the error function is invoked on the Observer it means the stream is terminated.

It’s too late.

So, is there a way to intercept the error before it gets to the Observer and do something about it in a way that the stream won’t be terminated? Or, even if the stream is terminated, is there a way to switch over to one that’s available?

You guessed it. The catchError(), retry() and retryWhen() Operators allow us to handle errors in different ways and depending on your use case you can use one or a combination of these Operators.

Lets look at each one in detail.

#web-development #programming #javascript #rxjs #developer