I am trying to remove part of an object in firebase. This is what it looks like in the database:
this is within a specific user id inside a 'users' collection.
The way I am currently trying to delete it:
removeUserLikedProperty(property_id: string) {
console.log(property_id)
return fromPromise(this.usersCollection.doc(`${this._auth.currentUserId}/test/${property_id}`).delete());
}
this is within my service. Then I have this in my ts file:
removeUserLikedProperty(property_id: string) {
this._user.removeUserLikedProperty(property_id);
console.log(property_id)
}
and then finally call this on click in my html:
<button class="button button-previous" (click)="removeUserLikedProperty(property?.property_id)">unlike</button>
From everything that I have read, this is my understanding of how to delete a member of a field. By accessing the users collection, getting user id, then going into 'test' and then removing the specific id. Anyone have any further knowledge on this? May syntax may be completely off!
You're mixing documents and fields. Please Read the documentation about data model
Either way, from the image what I understand you're trying to achieve is to delete a field in a nested object.
You need to know two things: how to delete a field in a document and how to access a field in a nested object
The following should work:
removeUserLikedProperty(property_id: string) {
console.log(property_id);
return fromPromise(this.usersCollection.doc(`${this._auth.currentUserId}`).update({
[`test.${property_id}`]: firebase.firestore.FieldValue.delete()
})
);
}
Related
Good day!
I have the data structure on the diagram below in a PostrgreSQL database. Backend is NestJS with TypeORM. I have to read the data, modify some props of the entities on the frontend, then write the same structure back in the DB as a new version, essentially, copying the entire stucture into new rows of the same table. Some of the 1st level child entities reference the same 2nd level child. This creates the following behaviour.
When I read the data into a JS object, I get it like this:
{questionGroup(id1): {
question(id1): {
answerGroup(id1): {
answerOption(id1)
answerOption(id2)
}
}
question(id2): {
answerGroup1(id1): {
answerOption(id1)
answerOption(id2)
}
question(id3): {
answerGroup(id2): {
answerOption(id3)
answerOption(id4)
}
}
}
When I manually incremented their ID to keep the same structure, after writing back to the DB, some data didn't get written when using TypeORM's .save( ) method with the top level entity questionGroup.
When I deleted their ID to let the system sort it out, all the answerGroups and answerOptions got written back as many times as they were referenced by a question. I'm really lost on how to handle this kind of data structure's versioning, open to solutions. Thank you in advance!
First look:
Create tables for all yours unique fields, they are contains only ID. But the main table is the nastiest field answerOption.
Create regular tables:
questionGroup
question
answerGroup
answerOption
Create main table:
answerOption: {
questionGroup: id,
question: id,
answerGroup: id,
answerOption: id,
}
Better solution is use manyToOne and OneToMany options for TypeORM
Ive looked related posts and couldn't quite find what I was looking for.
So I am build a backend rest api and I have certain tests I am collecting data on. The tests have their own models, and these models are associated with collections (obviously).
So I have a separate controller for each model. Now I have a "job" controller which queries data from each separate test. Now I have a separate script where I store these model objects in an JSON object. I am wondering how I can access these models properly (I am close but cant quite assign properly). Here is the block:
const testMappings = {
'aprobe':aprobe,
'status':status,
//'rxserial':rxserial,
}
Now when I try assignment as follows, where testMappings is the imported script variable:
const testMappings = activeTests.testMappings;
console.log(testMappings['aprobe']);
I get the following output:
Model {aprobe}
I would like to access the actual aprobe object. Also if anyone knows a better way of dynamically assigning these (instead of having bunch of if statements ie if(name == 'aprobe').... do something), it would be much appreciated.
You are probably looking for something like below :
const name = 'aprobe';
Object.keys(testMappings).indexOf(name) > -1 ? testMappings[name] : null
the above should give you: Model {aprobe}
So basically if the key exists in your object then you'd like to fetch the value of that key which would give you your model dynamically.
I am new to firebase and am struggling a little bit.
Currently, I am trying to update an array within a user, within a document. However, I cannot match the user to current user using the unique ID, as each users unique ID is their username, and it may have changed since creation.
I figured the best way to match the documents user to the current user would be to use a .where().get() and then use an "update()" to update the array.
Now, this is where I am getting stuck. In the firebase documents, their example of using .update is attached to a .doc
var washingtonRef = db.collection("cities").doc("DC");
//Atomically add a new region to the "regions" array field.
washingtonRef.update({
regions: firebase.firestore.FieldValue.arrayUnion("greater_virginia")
});
However, as I am using a .where, I assume I have to use references and snapshots. But, I am not quite sure how references work in this scenario and, with that, how to update properly.
Here is the code I have after a while of messing round, but no matter my variations i cannot figure it out. (essentially, I want to add a new project (in this case called "new project" to the users array of postedProjects.)
db.collection('users').where('user_id', '==', this.userInfo.user_id)
.get()
.then(function(querySnapshot) {
querySnapshot.forEach(function(doc) {
doc.data().update({
postedProjects: firebase.firestore.FieldValue.arrayUnion("new project")
})
})
})
This gives me an error of ".update() is not a function".
Is anyone able to help me with my solution to show me how references should properly be used in this scenario?
You're almost there. You can't update the data of DocumentSnapshot though, since that is the in-memory representation of the document data. Instead you need to get the DocumentReference and call update on that.
doc.ref.update({
postedProjects: firebase.firestore.FieldValue.arrayUnion("new project")
})
You need a DocumentReference in order to update() a document. Nothing else will work.
In your code, doc is a QueryDocumentSnapshot type object. If you want the DocumentReference object that refers to the document from that snapshot, use its ref property.
doc.ref.update({
postedProjects: firebase.firestore.FieldValue.arrayUnion("new project")
})
I'm trying to detect when ever an object changes. The object is connected to a large form. Whenever a user changes the input I would like it to have save/cancel buttons popup at the bottom of the page.
My idea was to just make a copy of the object and do *ngIf="object !== object_copy" and if they hit cancel set the data equal to the copied object. I don't know if this the proper way to do it since I will be using it twice as many variables for a small task, but I've only used angular for a short time. I can't get this method to work however because when ever I make a type copy the object losses it's type.
Can someone help me with this or figure out a better way to do this?
If you are using a Form, then you could take advantage of Angular's form control, which will tell you anytime a form and any of its values have been altered in any way. Then, you could do something as simple as:
form.dirty
or even specific fields. There are tons of things you can do with reactive and template forms from Angular.
https://angular.io/guide/forms
You have to subscribe an event to handle the change event:
constructor(private formBuilder: FormBuilder) {
this.myForm = formBuilder.group({
name: 'Jose Anibal Rodriguez',
age: 23
})
this.myForm.valueChanges.subscribe(data => {
console.log('Form changes', data);
})
}
It should works.
ReactiveForm supports the dirty property. You can use 'myForm.dirty' to check the dirty status of the form.
Otherwise, you can set the initial value of the form to an object property using the getRawValue() method
this.initailFormValue = this.myForm.getRawValue();
Then just subscribe the form changes using
myForm.valueChanges.subscribe((value) => {
this.updatedFormValue = this.myForm.getRawValue();
},
(err) => {
//
}
);
Now you have the initial and current form values. You can compare and do the remaining.
I have just started with Angular 4 and I need to develop a CRUD grid, where the user can add, edit or delete rows.
During my research I found this article where it shows how to create the grid and also the actions: Angular 4 Grid with CRUD operations.
Looking at his code, what called my attention was the way he is using the ng-template to toggle between edit/view mode.
<tr *ngFor="let emp of EMPLOYEES;let i=idx">
<ng-template [ngTemplateOutlet]="loadTemplate(emp)" [ngOutletContext]="{ $implicit: emp, idx: i }"></ng-template>
</tr>
On the article he uses template driven forms to edit the row. However, I was trying to change to reactive forms.
In my attempt to do that, I tried to replace the [(ngModel)] to formControlName and I got some errors. My first attempt I tried to add the [formGroup] at the beginning of the template html inside form element. But when I tried to run and edit the row, I got the following error:
Error: formControlName must be used with a parent formGroup directive. You'll want to add a formGroup directive and pass it an existing FormGroup instance (you can create one in your class).
When I tried to move the [formGroup] inside the ng-template it works, however I was not able to bind the value to the fields and I had to set the values in the loadTemplate function:
loadTemplate(emp: Employee) {
if (this.selemp && this.selemp.id === emp.id) {
this.rForm.setValue({
id: emp.id,
name: emp.name
});
return this.editTemplate;
} else {
return this.readOnlyTemplate;
}
}
This works and show the values inside the fields in a read only mode :(
Here is the Plunker of what I have got so far.
How can I make a reactive form work with ng-template and how to set values to edit the entries?
Any help is appreciated! Thanks
Actually your form is not readonly, you are just constantly overwriting the input you are entering. Since you are having a method call in template (which is usually not a good idea), loadTemplate gets called whenever changes happen, which in it's turn means that
this.rForm.setValue({
id: emp.id,
name: emp.name
});
gets called over and over whenever you try and type anything. We can overcome this with instead setting the form values when you click to edit. Here we also store the index so that we can use it to set the modified values in the correct place in array, utilizing the index could perhaps be done in a smarter way, but this is a quick solution to achieve what we want.
editEmployee(emp: Employee) {
this.index = this.EMPLOYEES.indexOf(emp)
this.selemp = emp;
this.rForm.setValue({
id: emp.id,
name: emp.name
});
}
so when we click save, we use that index...
saveEmp(formValues) {
this.EMPLOYEES[this.index] = formValues;
this.selemp = null;
this.rForm.setValue({
id: '',
name: ''
});
}
Your plunker: https://plnkr.co/edit/6QyPmqsbUd6gzi2RhgPp?p=preview
BUT notice...
I would suggest you perhaps rethink this idea, having the method loadTemplate in template, will cause this method to fire way too much. You can see in the plunker, where we console log fired! whenever it is fired, so it is a lot! Depending on the case, this can cause serious performance issues, so keep that in mind :)
PS. Made some other changes to code for adding a new employee to work properly (not relevant to question)