Multi-path update

[expleosoftware]

Hi

Is there a way to perform multi-path update (like described here: https://firebase.googleblog.com/2015/09/introducing-multi-location-updates-and_86.html) using angularfire2 ?

[davideast]

It works the same way :)

The .update() operator will work the same way as the .update() method on a reference. It really just calls set anyways.

constructor(af: AngularFire) {
  var updatedUserData = {};
  updatedUserData["user/posts/" + newPostKey] = true;
  updatedUserData["posts/" + newPostKey] = {
    title: "New Post",
    content: "Here is my new post!"
  };
  af.database.object('path').update(updatedUserData);
}

[zefrench]

Thanks David. You save my time !!

[mikeybyker]

@davideast
Is the multi-path update working as expected? I figured it wasn't - it is not updating, it is setting - but I just saw your comment:

"It really just calls set anyways."

So maybe that is the intention with multi-path? To me the name implies it should be an update rather than a set operation...

eg. if I start off with firebase data of:
test/objectA: {a:1, b:2, c: 3, d: 4, e:5}
test/objectB: {w:1, x:2, y: 3, z: 4}

  constructor(af: AngularFire) {
    let update = {};
    update['test/objectA'] = {a:10, e:50};
    update['test/objectB'] = {x:20};
    af.database.object('').update(update);
  }

Then I end up with:
test/objectA: {a:10, e:50}
test/objectB: {x:20}

rather than the expected (if it was an update)
test/objectA: {a:10, b:2, c: 3, d: 4, e:50}
test/objectB: {w:1, x:20, y: 3, z: 4}

[robodair]

@mikeybyker @davideast I'm experiencing the same thing. Perhaps Firebase 3 doesn't support this?

When I run this and actually allow the write in my database rules

        // Create an object representing our complete changes
        let databaseUpdate = {
            // Add the company change to the update
            companies: company,          // company object is defined elsewhere
            users: {}
        };

        // Build the user object
        let userCompanies = {};
        userCompanies[companyKey] = employeeKey;

        let user = {
            companies: userCompanies
        };

        // Add the user object to the database tree at the user id's location
        databaseUpdate.users[this.auth.auth.uid] = user;

        return this.af.database.object('').update(databaseUpdate);

It just replaces the whole database

[expleosoftware]

Works for me.
@robodair - Did you try to do it from the root ('/')?
return this.af.database.object('/').update(databaseUpdate);

[robodair]

I thought I'd tried everything - thanks @expleosoftware! I don't know how I missed that.

[mikeybyker]

@robodair for me, using update still doesn't work as I had in my example:

  constructor(af: AngularFire) {
    let update = {};
    update['test/objectA'] = {a:10, e:50};
    update['test/objectB'] = {x:20};
    af.database.object('').update(update);
  }

That does a set operation - or at least, overwrites the entire object. Any values in the fb database (eg. objectA.b, objectA.c, objectA.d) not specified in the update object are deleted. Which is a shame - lost a lot of data finding that out!

However, a way round it, and maybe how it is meant to work here, is to go further down the path, so to speak:

  constructor(af: AngularFire) {
    let update = {};
    update['test/objectA/a'] = 10;
    update['test/objectA/e'] = 50;
    update['test/objectB/x'] = 20;
    af.database.object('').update(update);
  }

So update['test/objectA/a'] = 10 rather than update['test/objectA'] = {a:10};
That way, the other values remain intact. Perhaps not quite what your issue was, but maybe helpful to someone trying to update this way.

[mikeybyker]

...although if you look at how firebase themselves say it should work it doesn't appear to be working the same way...

Using the pre-existing atomic update support, we can change the user's age and add a city without updating their name

    {
      "user": {
        "name": "Samantha",
        "age": 25
      }
    }

    var userRef = ref.child("user");
    var newUserData = {
      "age": 30,
      "city": "Provo, UT"
    };
    ref.child("user").update(newUserData);

So, still not sure if an angularfire bug or not...Maybe @davideast could say?

[robodair]

@mikeybyker

try

  constructor(af: AngularFire) {
    let update = {};
    update['test/objectA'] = {a:10, e:50};
    update['test/objectB'] = {x:20};
    af.database.object('/').update(update);
  }

the / in

af.database.object('/').update(update);

is what made it work for me

[mikeybyker]

@robodair
Cheers - I did try that, and still no go - it still sets the data rather than updates it.

Normal (single) updates work fine - i.e.

this.af.database.object('test/objectA').update({ a: 99 });

Updates 'a' and leaves b,c,d,e alone.

Have a look: https://mikeybyker.github.io/multi-location-updates/
Or maybe download: https://github.com/mikeybyker/multi-location-updates

[robodair]

@mikeybyker you're right. This is hella confusing. It just so happens that for my application there's nothing that exists at said locations so I didn't notice.

Thanks for the test repo, I made a fork and submitted a pull request with explanations.

Basically update() performs a set() on every immediate child of the update object, no more. Reading the docs after this realisation it all seems clear. Before however, it wasn't. Very confusing.

[mikeybyker]

No problem :-) Yep, a bit confusing is right!

[mikeybyker]

@wceolin - it does perform a set() yup. To me it would be a bug, and it doesn't fit with what firebase have said about how it should work (see quote & link above) - but the description used by @davideast at the top of this issue ("It really just calls set anyways.") sounds like they don't think it is... Which doesn't help much - sorry!

[davideast]

@wceolin @mikeybyker

It performs an update at the first level, but everything below is treated as a set. To get the effects of an update you'll have to go to the deepest level of the path.

Rather than:

let update = {};
update['test/objectA'] = {a:10, e:50};
update['test/objectB'] = {x:20};

Do this:

let update = {};
update['test/objectA/a'] = 10;
update['test/objectB/x'] = 20;

By specifying deep path level it will only do an update for a and x.

[robodair]

My guess is that it would be too expensive of an operation on the firebase
end if you were updating a big tree.
On Wed., 16 Nov. 2016 at 06:25, Will Ceolin notifications@github.com
wrote:

@davideast https://github.com/davideast is there a technical limitation
for updating the first level only and not the whole tree? Or is it just a
design choice?

—
You are receiving this because you were mentioned.
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[rubenheymans]

how do you do this in angularfire2 4.0?

[Unkn0wn0x]

I hope my solution could be useful for someone:

/** define first path */
var updateUserPath = '/users/' + firebase.auth().currentUser.uid + '/';
/** some data which should be updated via a multi-path update to the first defined path */
var updateUser = {
    'username': 'John Doe',
    'firstname': 'John',
    'lastname': 'Doe',
};

/** define second path */
var updateUserGroupPath = '/groups/' + firebase.auth().currentUser.uid + '/';
/** some data which should be updated via a multi-path update to the second defined path */
var updateUserGroup = {
    'group': 'Firebase',
    'description': 'The awesome firebase group!'
};

/** create new object for storing the multi-path updates */
var updateData = {};

/** loop through the object updateUser and push for each property a new property into updateData with the defined path including the key of the updateUser */
for (var key in updateUser) {
    updateData[updateUserPath + key] = updateUser[key];
};

/** same here for the updateUserGroup */
for (var key in updateUserGroup) {
    updateData[updateUserGroupPath + key] = updateUserGroup[key];
}

/**
 * this console.log() will show a object like this:
 * {
 * "/users/1234567890/username": "John Doe",
 * "/users/1234567890/firstname": "John",
 * "/users/1234567890/lastname": "Doe",
 * "/groups/1234567890/group": "Firebase",
 * "/groups/1234567890/description": "The awesome firebase group!"
 * }
 */
console.log(updateData);

/** update your data without touching anything else */
firebase.database().ref().update(updateData);

It works fine for me.

[paean99]

Here is a video about this feature on the Firebase youtube channel:
Data consistency with Multi-path updates - The Firebase Database For SQL Developers #7

This post gives a little more explanations:
Client-side fan-out for data consistency

[MohitKS5]

If I give a type to document reference, then running update on it with multi-path gives type error. Any idea how to solve that?

export interface Personal{
  tel: number
}
export interface LocalUser{
  personal: Personal
}
public userRef = (id: string): AngularFirestoreDocument<LocalUser> => this.afs.doc(`users/${id}`);
this.usrRef.update({"personal/tel": 237486238746})

this gives ERRORArgument of type '{ "personal/tel": any; }' is not assignable to parameter of type 'Partial<LocalUser>'.