I'm learning flutter by making an app following some youtube tutorials. I'm trying to make a listview of search results. I'm able to query and get data from node backend but there's this error while mapping the json to model.
The data I'm getting from api is like this:
{id: <uuid>,
userEmail: <email_string>,
profile: [{profileName: <profile_name_string>,
profileImage: <image_url_string>,
profileBio: <profile_bio_string>}]
}
With the new model class I made following an answer here I'm able to get profile model separately but when i try to get account model with all profiles I'm getting the error:type 'List<dynamic>' is not a subtype of type 'List<ProfileModel>?'. The model class is:
class AccountModel {
String userId;
String userEmail;
String? userPassword;
final List<ProfileModel>? profile;
AccountModel({
required this.userId,
required this.userEmail,
this.userPassword,
this.profile,
});
factory AccountModel.fromJson({required Map<String, dynamic> map}) {
return AccountModel(
userId: map['id'],
userEmail: map['userEmail'],
userPassword: map['userPassword'],
profile: map['profile']
.map((profileJson) => ProfileModel.fromJson(profileJson))
.toList(),
);
}
}
class ProfileModel {
String profileName;
String profileImage;
String? profileBio;
ProfileModel({
required this.profileName,
required this.profileImage,
this.profileBio,
});
factory ProfileModel.fromJson(profileJson, {Map<String, dynamic>? map}) {
if (map != null) {
return ProfileModel(
profileName: map['profileName'],
profileImage: map['profileImage'] ?? "default",
profileBio: map['profileBio'],
);
} else {
return ProfileModel(
profileName: profileJson['profileName'],
profileImage: profileJson['profileImage'] ?? "default",
profileBio: profileJson['profileBio'],
);
}
}
}
How to make the list work?
You can use List.from() in this case.
profile: map['profile'] != null
? List<ProfileModel>.from(
map['profile']?.map((p) => ProfileModel.fromJson(p)))
: null)
We are using fromMap here on ProfileModel, you can simplify just separation while both are same on ProfileModel.
More about List and List.from.
When you declared the list here as
final List<ProfileModel>? profile;
It expects the list to have only ProfileModels as ListItem even though with "?". The way to solve it is either declared a list without generic ProfileModel :
final List? profile;
Or to typecast the item you're pushing as ProfileModel.
2. profile: map['profile'] .map((profileJson) => ProfileModel.fromJson(profileJson) as ProfileModel) .toList(),
I don't know the output structures and such so try to experiment with typecasting if the above code doesn't work. May be typecasting after toList() method as List can work too.
Related
I am looking to create a query-builder for my Amplify Datastore.
The function should process an an array of conditions, that need to be applied to the query and return the according Predicate.
This is easily done, if there is only one filter, but I would like to be able to process any amount of filters.
My goal is to be able to write the queries like so:
Datastore.query(Post, *queryBuilder(filters)*)
Where I can pass an array of filters with a filter looking like this:
filter = {
connector: 'or' |
property: rating
predicate: 'gt'
value: 4
}
and the query builder returns the Predicate in the below mentioned format.
I have tried to chain and return multiple functions in the query builder, but I was not able to figure out a pattern for how to create the correct predicate function.
For reference, this is how queries are built according to the docs: https://docs.amplify.aws/lib/datastore/data-access/q/platform/js#predicates
const posts = await DataStore.query(Post, c => c.rating("gt", 4));
and for multiple conditions:
const posts = await DataStore.query(Post, c =>
c.rating("gt", 4).status("eq", PostStatus.PUBLISHED)
);
Let's say we have the model:
type Post #model{
id: ID!
category: String
city: String
content: String
}
And we want to query & filter by city and category by a dynamic amount of variables. Then we can make a function as such on our script:
const fetchData = async props => {
/*
More configurable wrapper for Datastore.query calls
#param props: {model: Model, criteria: [{fieldId, predicate, value}]}.
*/
try {
let criteria;
if (props.criteria && typeof props.criteria === 'object') {
criteria = c => {
props.criteria.forEach(item => {
const predicate = item.predicate || 'eq';
c[item.fieldId](predicate, item.value);
});
return c;
};
} else {
criteria = props.criteria;
}
return await DataStore.query(props.model, criteria);
} catch (e) {
throw new Error(e);
}
}
So now if we want to execute this we can pass the parameters:
// where Post = models.Post
const myResult = fetchData({model: Post, criteria: [
{ fieldId: 'category',
predicate: 'eq',
value: 'news'
},
{
fieldId: 'city',
predicate: 'eq',
value: 'SomeCityName'
}]
})
Unfortunately I do not know of a way to also query linked relationships as you would using a direct graphQL api query while using DataStore and this method I presented only uses implicit AND between criteria.
I don't know if this has changed since you asked the question but, based on the documents, it looks like multiple conditions have an implicit and, but you can explicitly chain them with or/and/not:
const posts = await DataStore.query(Post, c => c.or(
c => c.rating("gt", 4).status("eq", PostStatus.PUBLISHED)
));
I have a model that uses reactive forms and keeps giving me the error of regex.test is not a function.
The model is the following:
import { date, email, maxDate, maxLength, minDate, minLength, pattern, prop, required } from "#rxweb/reactive-form-validators";
export class UserInfo {
#required()
public firstName: string;
#required()
public lastName: string;
#pattern({expression: {pattern: /(^\+?[\d\W-/]{4,16}$)/ } })
#minLength({value: 4})
public phoneNumber: string;
}
And the error
ERROR TypeError: regex.test is not a function
at Function.isValid (reactive-form-validators.js:719)
at reactive-form-validators.js:3418
at forms.js:1155
at Array.map (<anonymous>)
at _executeValidators (forms.js:1151)
at RxFormControl.validator (forms.js:1096)
at RxFormControl._runValidator (forms.js:3438)
at RxFormControl.updateValueAndValidity (forms.js:3399)
at new FormControl (forms.js:3843)
at new RxFormControl (reactive-form-validators.js:2017)
happens when on the component I'm doing on the ngOnInit():
this.baseForm = this.formBuilder.formGroup(this.user) as RxFormGroup;
What is even stranger is that it only happens when I actually have data on the phoneNumber. If my phoneNumber is empty it works perfectly.
I even tested the following:
this.user.phoneNumber = "";
this.baseForm = this.formBuilder.formGroup(this.user) as RxFormGroup;
And this works. What is even stranger to me is that I did a small example on stackblitz and there it also works without any problem even with data.
It is working in my machine, please check the below image :
If you have sample not working example of pattern then please share the same
I've find out a solution and it was the following:
this.baseForm = this.formBuilder.formGroup(this.user) as RxFormGroup;
(this.baseForm .controls.phoneNumber as FormControl)
.addValidators(
[TextValidator.regexMatchValidator(new RegExp(/(^\+?[\d\W-/]{4,16}$)/), "error message")]);
basically add a validator after the form initialization
I would like to add a list from my flutter test app to my Google Firestore.
This is my method, which adds all the data:
void postToFireStore(
{String mediaUrl, String location, String description}) {
var reference = Firestore.instance.collection('insta_posts');
reference.add({
"marked_friends": [chipstuete.toString()],
"username": currentUserModel.username,
"location": location,
"likes": {},
"mediaUrl": mediaUrl,
"description": description,
"ownerId": googleSignIn.currentUser.id,
"timestamp": new DateTime.now().toString(),
}).then((DocumentReference doc) {
String docId = doc.documentID;
reference.document(docId).updateData({"postId": docId});
});
}
Everything is working fine, expect the list "marked_friends"...
The list "chipstuete" has multiple strings:
[Martin Seubert, Lena Hessler, Vivien Jones]
But my Firestore looks like that:
At the moment the whole list is stored in marked_friends[0]...
What do I need to change, that every entry of my list "chipstuete" is stored in a seperate field of my array "marked_friends" in Firestore?
Best regards!
You have to add a method in your AppProfile class that serializes it to a List.
So in your AppProfile class:
class AppProfile {
... // Whatever fields/methods you have
// Add this method
List<String> getFriendList() {
// Somehow implement it so it returns a List<String> based on your fields
return ['name1','name2','name3'];
}
}
Then you can do
"marked_friends": chipstuete.getFriendList(),
I have the solution.
Like SwiftingDuster said, I needed a new method which serializes it to a List:
List<String> toList() {
chipstuete.forEach((item) {
newtuete.add(item.toString());
});
return newtuete.toList();
}
After that I just call toList() in my postToFirestore() Method and add "marked_friends": newtuete. Thats it!
I'm just diving in to Ember. I'm looking for a way to pass a plain array of vanilla objects into a collection/controller and have them type cast to the correct model.
Here's the simple collection view:
{{#collection id="prods" contentBinding="Vix.prodsController" tagName="ul"}}
{{content.title}}
{{/collection}}
Here's the model:
Vix.Prod = Ember.Object.extend({
id: null,
title: null
});
And the controller:
Vix.prodsController = Ember.ArrayController.create({
content: []
});
Then let's get some JSON-formatted data from the server. In this example I'll just hard-code it:
var prods = [{id:"yermom1", title:"yermom 1"}, {id:"yermom2", title:"yermom 2"}]
Vix.prodsController.set('content', prods);
So far so good. I get my simple list of li elements displaying the titles as I'd expect. But when I want to update the title of one of the objects, using:
Vix.prodsController.objectAt(0).set('title', 'new title')
It complains because the object has no set method-- it has not been properly cast to my Vix.Prod Ember Object.
Using this alternative:
Vix.prodsController.pushObjects(prods);
Produces the same result. It's only if I explicitly create new model instances that I get the get/set goodness:
var prods = [Vix.Prod.create({id:"yermom1", title:"yermom 1"}), {Vix.Prod.create(id:"yermom2", title:"yermom 2"})]
Is there a way to automatically type cast those vanilla objects to my Vix.Prod Ember Object? If not, am I the only one that really wants something like that? In Backbone one can set the model property on a collection. I suppose I can create a setter on my Controller to do something similar- just wondering if there is something built-in that I'm missing. Thanks!
No magic. I'd suggest do a loop wrapping the model.
var prods = [{id:"yermom1", title:"yermom 1"}, {id:"yermom2", title:"yermom 2"}];
for (var i = 0; i < prods.length; i++) {
prods[i] = Vix.Prod.create(prods[i]);
}
If I use ember as much as I hope to, I'm going to want a shortcut. So here's what I've done for now. I created a base Collection class that I use to create my Collections/Controllers:
Vix.Collection = Ember.ArrayController.extend({
model: null,
pushObject: function(obj) {
if (this.get('model') && obj.__proto__.constructor !== this.get('model')) {
obj = this.get('model').create(obj);
}
return this._super(obj);
},
pushObjects: function(objs) {
if (this.get('model')) {
objs = this._typecastArray(objs)
}
return this._super(objs);
},
set: function(prop, val) {
if (prop === 'content' && this.get('model')) {
val = this._typecastArray(val);
}
return this._super(prop, val);
},
_typecastArray: function(objs) {
var typecasted = [];
objs.forEach(function(obj){
if (obj.__proto__.constructor !== this.get('model')) {
obj = this.get('model').create(obj);
}
typecasted.push(obj);
}, this);
return typecasted;
}
})
Now when I call pushObject, pushObjects, or .set('collection', data), if the collection instance has a defined model property and the objects being added to the collection aren't already of that type, they'll be cast. Been working good so far, but I welcome any feedback.
You should have a look at ember-data: https://github.com/emberjs/data
It seems to fit your needs...
As of today, it's not yet production ready (as stated in the readme), but is quickly converging toward maturity, thanks to an active development.
We have read a document from firebase using Python.
doc_ref = db.collection(u'collection_name').document(collection_abc)
doc_fetched = doc_ref.get()
if (doc_fetched.exists):
if (doc_fetched.get('doc_field')):
We get the following error
KeyError("'doc_field' is not contained in the data")
How do we check if doc_field exists in doc_fetched? This document might have some fields populated, and some not populated at the time of read (by design).
We also tried the following with the same error.
if (doc_fetched.get('doc_field') != null):
As you can see from the API documentation for DocumentSnapshot, there is a method to_dict() that provides the contents of a document as a dictionary. You can then deal with it just like any other dictionary: Check if a given key already exists in a dictionary
To solve this, you can simply check the DocumentSnapshot object for nullity like this:
var doc_ref = db.collection('collection_name').doc(collection_abc);
var getDoc = doc_ref.get()
.then(doc => {
if (!doc.exists) {
console.log('No such document!');
} else {
if(doc.get('yourPropertyName') != null) {
console.log('Document data:', doc.data());
} else {
console.log('yourPropertyName does not exist!');
}
}
})
.catch(err => {
console.log('Error getting document', err);
});
Or you can use to_dict() method as in the #Doug Stevenson answer