Delete a document from firebase - firebase

I'm building an app that contains pet adoption offers. Each pet document has an ID that's generated by DateTime.now() + the user ID to make it unique, anyway, I'm trying to write a deleting method within the Slidable widget to delete the adoption offer.
The problem is that I'm unable to reach the document ID to delete it.
Is there a way to delete a document without getting the ID?
This is the Firebase database
Here is my current code
Future getOffersList() async {
List<PetTile> tiles = [];
List<Slidable> slidables = [];
var data = await FirebaseFirestore.instance
.collection('pets')
.where('owner',
isEqualTo: FirebaseAuth.instance.currentUser!.uid.toString())
.get();
_petsList = List.from(data.docs.map((doc) => Pet.fromSnapshot(doc)));
for (var pet in _petsList) {
tiles.add(PetTile(pet: pet));
}
for (var tile in tiles) {
slidables.add(
Slidable(
child: tile,
endActionPane: ActionPane(
motion: const DrawerMotion(),
children: [
SlidableAction(
onPressed: (value) async {
var ref = FirebaseFirestore.instance
.collection('pets')
.where('id', isEqualTo: tile.pet.id)
.get();
// Deleting...
},
backgroundColor: Color(0xFFFE4A49),
foregroundColor: Colors.white,
icon: Icons.delete,
label: 'Delete',
),
],
),
),
);
}
}

You can get the id of the document by doing the following steps:
Add await infront when you're accessing the conditioned data from firebase collection.. in your case in front of FirebaseFirestore.instance
*This will return a QuerySnapshot rather than a Future instance of the same.
You need to get the doc and the id of that doc.. write:
final id= ref.docs[0].id
*Using first index(0) because i am assuming that only one pet id matches with other pet id.
since you have the id now.. you can perform the delete function

Related

Updating element ordering in Firestore(NoSQL) of an ordered collection (Flutter-Firestore)

As the title suggests, I have a stream that delivers through a StreamBuilder an AsyncSnapshot<List>, a list of elements. The elements then are built in a ReorderableListView.builder in order to rearrange them through drag & drop.
Widget - View
body: Column(children: [
StreamBuilder(
initialData: controller.listOfProjectTasks,
stream: controller.retrieveTasksOfProject(),
builder: (BuildContext context,
AsyncSnapshot<List<Task>> dataSnapshot) {
return Expanded(
child: GetBuilder<BacklogController>(
init: Get.find<BacklogController>(),
builder: (value) {
if (dataSnapshot.hasData) {
return ReorderableListView.builder(
onReorder: (int oldIndex, int newIndex) {
if (oldIndex < newIndex) {
newIndex -= 1;
}
final Task? taskToOrder =
dataSnapshot.data?.removeAt(oldIndex);
dataSnapshot.data?.insert(newIndex, taskToOrder!);
controller.saveNewTaskPositions(dataSnapshot.data);
},
itemCount: dataSnapshot.data!.length,
itemBuilder: (context, int index) {
GlobalKey globalKey = GlobalKey();
return Draggable(
feedback: Container(
width: 10,
),
child: TaskTile(
dataSnapshot.data![index]),
key: globalKey,
);
});
} else {
return const Center(
child: CircularProgressIndicator(),
);
}
}));
})
]),
View model Stream generator
yield* Stream.periodic(const Duration(seconds: 5), (_) {
return backlogRepository.retrieveTasks(projectId);
}).asyncMap((value) async => await value);
Problem I: I need to save the Task ordering and I face 2 challenges, on one side whenever the Builder delivers the list and I reorder it, the stream yields the same data again with the previous order, and the ListView gets built with the previous order.
Problem II: the list ordering would need to be preserved on App restart
Possible hack: I'm using the Flutter Firestore combo so I have a document-oriented DB, no Autoincrement on IDs like in relational db's. The solution that I came up with is trivial and essentially I add a new field to the Task element named "order".
Sample Task Document Model, should be a toJson method in Model class
Future<void> addNewTask(String projectId, String createdProjectName,
String startDate, String endDate) async {
firestore.collection('task').add({
'name': createdProjectName,
'startDate': startDate,
'endDate': endDate,
'teamId': '',
'projectId': projectId,
'epicId': '',
'order': 1,
'teamMemberId': '',
'position': null
});
}
Now problem is that the List is preserving a Scrum Backlog, for scalability issues I'm assuming that it could hold 1000 Tasks related to 1 Project.
With 1 rearrangement of Tasks I could on worst case assume 999 Firestore calls to just update each Task document field "order", and it's only on 1 Project on Firestore.
Is there a better way to act on this problem?
Possible changes that I see are on:
How Task documents are stored -> how to address the order persistence
How the field "order" of each Task document can be updated through the Firestore call on the Repository
Any suggestions?

How to get document ID for a specific document?

I would like to get the document id of a specific document when I put its name in a function.
Here is my function:
void _getId(town) {
var data = FirebaseFirestore.instance
.collection('towns')
.where('town_name', isEqualTo: town)
.snapshots();
print(data.id);}
Here is my button:
ElevatedButton(
onPressed: () => _getId(_townChosen), child: Text('Get ID')),
The value _townChosen is a string which corresponds to the field town_name in the database. In the complete program, I get the value from a dropdown button, this part works well.
Here is the database
All documents have an town_name field.
I need the id of the chosen town and send it in others widgets to use its subcollection. Please can you help me to get the id?
First, create a variable called townid, and change your function to async, and use a stateful widget to update it, and use get instead of snapshots:
String townId = 'Get ID';
void _getId(town) async {
var data = await FirebaseFirestore.instance
.collection('towns')
.where('town_name', isEqualTo: town)
.get();
setState(() {
townId = data.docs[0].id; //because the query returns a list of docs, even if the result is 1 document. You need to access it using index[0].
});
print(townId);
}
In your button:
ElevatedButton(onPressed: () => _getId(_townChosen), child: Text(townId)),

Return new document id and use it again with one button

I am making a chat page in part of my application. There is a field in the document that recording members, user id and timestamp. Also in the same document, there is a sub-collection that recording messages.
There is FloatingActionButton that opens a form to write title and text. My problem starts after here.
These codes are for onPress within the form.
onPressed: () async {
if (_sohbetFormu.currentState.validate()) {
var docId;
var refOne = FirebaseFirestore.instance
.collection("conversations");
await refOne.add({
"displayMessage": _textControllerTitle.text,
"members": _currentUid,
}).then((value) => docId = FieldPath.documentId);
_textControllerTitle.text = "";
var refTwo = FirebaseFirestore.instance
.collection("conversations/$docId/messages");
await refTwo.add({
"senderId": _currentUid,
"message": _textControllerText.text,
"timeStamp": DateTime.now(),
});
_textControllerText.text = "";
Navigator.pop(context);
}
},
First Problem: I cant use same document Id for sub-collection and information field. I tried to use FieldPath.documentId but it didn't work. FieldPath.documentId didn't return any id.
Second Problem You see "members" in codes. It should be array and record members. But it's String at the moment. How can i change it to array?
I solved problems.
At first one: I changed FieldPath.documentId to
.then((value) => docId = value.id);
At second one: I changed "message": _textControllerText.text, to
"members": FieldValue.arrayUnion(["$_currentUid"]),
I didn't delete the post just because it might work for others

Firestore replicating a SQL Join for noSQL and Flutter

I realise there is many questions in regards to replicating joins with NoSql document databases such as FireStore, however i'm unable to find a thorough solution utilising Dart/Flutter with FireStore.
I have done some research i feel that in the following example i would be looking for a 'many to many' relationship (please correct me if this is wrong) as there may be a future need to look at all profiles as well as all connections.
In firebase, i have two root level collections (profile & connection):
profile
> documentKey(Auto Generated)
> name = "John Smith"
> uid = "xyc4567"
> documentKey(Auto Generated)
> name = "Jane Doe"
> uid = "abc1234"
> documentKey(Auto Generated)
> name = "Kate Dee"
> uid = "efg8910"
connection
> documentKey(Auto Generated)
> type = "friend"
> profileuid = "abc1234"
> uid = "xyc4567"
> documentKey(Auto Generated)
> type = "family"
> profileuid = "abc1234"
> uid = "efg8910"
For this example the 'connection' documents have been created hypothetically for the user John Smith (uid: xyc4567) when he connected to Jane Doe (uid: abc1234) and Kate Dee (uid: efg8910).
Here is the relational SQL i'm looking to replicate to show a list of profiles which John Smith has connected with:
Select * FROM profile, connection
WHERE profile.uid = connection.profileuid
AND profile.uid = "xyc4567"
In flutter my flutter app i have a fireStore query starting point:
stream: Firestore.instance.collection('profile')
.where('uid', isEqualTo: "xyc4567").snapshots(),
Obviously it only returns from one collection. How do i join the collections in a many to many relationship?
Unfortunately, there is no JOIN clause in Cloud Firestore nor in others NoSQL databases. In Firestore queries are shallow. This means that they only get items from the collection that the query is run against. There is no way to get documents from two top-level collection in a single query. Firestore doesn't support queries across different collections in one go. A single query may only use properties of documents in a single collection.
So the most simple solution I can think of is to query the database to get the uid of a user from the profile collection. Once you have that id, make another database call (inside the callback), and get the corresponding data that you need from the connection collection using the following query:
stream: Firestore.instance.collection('connection').where('uid', isEqualTo: "xyc4567").snapshots(),
Another solution would be to create a subcollection named connection under each user and add all connection objects beneath it. This practice is called denormalization and is a common practice when it comes to Firebase. If you are new to NoQSL databases, I recommend you see this video, Denormalization is normal with the Firebase Database for a better understanding. It is for Firebase realtime database but same rules apply to Cloud Firestore.
Also, when you are duplicating data, there is one thing that need to keep in mind. In the same way you are adding data, you need to maintain it. With other words, if you want to update/detele an item, you need to do it in every place that it exists.
Suppose, you want to use a Stream that depends on some Future objcets.
Stories
Document ID (Auto Generated) //Suppose, "zddgaXmdadfHs"
> name = "The Lion & the Warthog"
> coverImage = "https://...."
> author = "Furqan Uddin Fahad"
> publisDate = 123836249234
Favorites
Document ID (Auto Generated)
> storyDocID = "zddgaXmdadfHs" //Document ID of a story
> userId = "adZXkdfnhoa" //Document ID of a user
Sql equivalent query should look like this
SELECT * FROM Favorites AS f, Stories AS s
WHERE f.storyDocID = s.DocumentID
AND f.userId = user.userId
And Firestore query like this
final _storeInstance = Firestore.instance;
Stream <List<Favorite>> getFavorites() async* {
final user = await _getUser(); //_getUser() Returns Future<User>
yield* _storeInstance
.collection('Favorites')
.where('userId', isEqualTo: user.userId)
.snapshots()
.asyncMap((snapshot) async {
final list = snapshot.documents.map((doc) async {
final story = await _getStory(doc['storyDocID']);
return Favorite.from(doc, story); //Favorite.from(DocumentSnapshot doc, Story story) returns an instance of Favorite
}).toList(); //List<Future<Favorite>>
return await Future.wait(list); //Converts List<Future<Favorite>> to Future<List<Favorite>>
});
}
Future<Story> _getStory(String storyDocID) async {
final docRef = _storeInstance
.collection('Stories')
.document(storyDocID);
final document = await docRef.get();
final story = Story.from(document);
return story;
}
I did some like this to join results from two colections objects and categories.
i did two StreamBuilders to show in a list, in the first one i got the categories and put in a map, then i query the objects and get the category object from the map using the categoryID:
StreamBuilder<QuerySnapshot>(
stream: Firestore.instance
.collection('categoryPath')
.snapshots(),
builder: (BuildContext context,
AsyncSnapshot<QuerySnapshot> categorySnapshot) {
//get data from categories
if (!categorySnapshot.hasData) {
return const Text('Loading...');
}
//put all categories in a map
Map<String, Category> categories = Map();
categorySnapshot.data.documents.forEach((c) {
categories[c.documentID] =
Category.fromJson(c.documentID, c.data);
});
//then from objects
return StreamBuilder<QuerySnapshot>(
stream: Firestore.instance
.collection('objectsPath')
.where('day', isGreaterThanOrEqualTo: _initialDate)
.where('day', isLessThanOrEqualTo: _finalDate)
.snapshots(),
builder: (BuildContext context,
AsyncSnapshot<QuerySnapshot> objectsSnapshot) {
if (!objectsSnapshot.hasData)
return const Text('Loading...');
final int count =
objectsSnapshot.data.documents.length;
return Expanded(
child: Container(
child: Card(
elevation: 3,
child: ListView.builder(
padding: EdgeInsets.only(top: 0),
itemCount: count,
itemBuilder: (_, int index) {
final DocumentSnapshot document =
objectsSnapshot.data.documents[index];
Object object = Object.fromJson(
document.documentID, document.data);
return Column(
children: <Widget>[
Card(
margin: EdgeInsets.only(
left: 0, right: 0, bottom: 1),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(
Radius.circular(0)),
),
elevation: 1,
child: ListTile(
onTap: () {},
title: Text(object.description,
style: TextStyle(fontSize: 20)),
//here is the magic, i get the category name using the map
of the categories and the category id from the object
subtitle: Text(
categories[object.categoryId] !=
null
? categories[
object.categoryId]
.name
: 'Uncategorized',
style: TextStyle(
color: Theme.of(context)
.primaryColor),
),
),
),
],
);
}),
),
),
);
I'm not sure if is what you want or is clear but i hope it help you.
I think denominational should not be preferred because to maintain the it you have to make extra writes to firestore
instead jorge vieira is correct since you are allowed to make double reads as compare to the writes
so its better to read twice instead of writing writing data twice and its also very impractical to remember every demoralized thing in a large project

Google Firestore: Query on substring of a property value (text search)

I am looking to add a simple search field, would like to use something like
collectionRef.where('name', 'contains', 'searchTerm')
I tried using where('name', '==', '%searchTerm%'), but it didn't return anything.
I agree with #Kuba's answer, But still, it needs to add a small change to work perfectly for search by prefix. here what worked for me
For searching records starting with name queryText
collectionRef
.where('name', '>=', queryText)
.where('name', '<=', queryText+ '\uf8ff')
The character \uf8ff used in the query is a very high code point in the Unicode range (it is a Private Usage Area [PUA] code). Because it is after most regular characters in Unicode, the query matches all values that start with queryText.
Full-Text Search, Relevant Search, and Trigram Search!
UPDATE - 2/17/21 - I created several new Full Text Search Options.
See Code.Build for details.
Also, side note, dgraph now has websockets for realtime... wow, never saw that coming, what a treat! Cloud Dgraph - Amazing!
--Original Post--
A few notes here:
1.) \uf8ff works the same way as ~
2.) You can use a where clause or start end clauses:
ref.orderBy('title').startAt(term).endAt(term + '~');
is exactly the same as
ref.where('title', '>=', term).where('title', '<=', term + '~');
3.) No, it does not work if you reverse startAt() and endAt() in every combination, however, you can achieve the same result by creating a second search field that is reversed, and combining the results.
Example: First you have to save a reversed version of the field when the field is created. Something like this:
// collection
const postRef = db.collection('posts')
async function searchTitle(term) {
// reverse term
const termR = term.split("").reverse().join("");
// define queries
const titles = postRef.orderBy('title').startAt(term).endAt(term + '~').get();
const titlesR = postRef.orderBy('titleRev').startAt(termR).endAt(termR + '~').get();
// get queries
const [titleSnap, titlesRSnap] = await Promise.all([
titles,
titlesR
]);
return (titleSnap.docs).concat(titlesRSnap.docs);
}
With this, you can search the last letters of a string field and the first, just not random middle letters or groups of letters. This is closer to the desired result. However, this won't really help us when we want random middle letters or words. Also, remember to save everything lowercase, or a lowercase copy for searching, so case won't be an issue.
4.) If you have only a few words, Ken Tan's Method will do everything you want, or at least after you modify it slightly. However, with only a paragraph of text, you will exponentially create more than 1MB of data, which is bigger than firestore's document size limit (I know, I tested it).
5.) If you could combine array-contains (or some form of arrays) with the \uf8ff trick, you might could have a viable search that does not reach the limits. I tried every combination, even with maps, and a no go. Anyone figures this out, post it here.
6.) If you must get away from ALGOLIA and ELASTIC SEARCH, and I don't blame you at all, you could always use mySQL, postSQL, or neo4Js on Google Cloud. They are all 3 easy to set up, and they have free tiers. You would have one cloud function to save the data onCreate() and another onCall() function to search the data. Simple...ish. Why not just switch to mySQL then? The real-time data of course! When someone writes DGraph with websocks for real-time data, count me in!
Algolia and ElasticSearch were built to be search-only dbs, so there is nothing as quick... but you pay for it. Google, why do you lead us away from Google, and don't you follow MongoDB noSQL and allow searches?
There's no such operator, allowed ones are ==, <, <=, >, >=.
You can filter by prefixes only, for example for everything that starts between bar and foo you can use
collectionRef
.where('name', '>=', 'bar')
.where('name', '<=', 'foo')
You can use external service like Algolia or ElasticSearch for that.
While Kuba's answer is true as far as restrictions go, you can partially emulate this with a set-like structure:
{
'terms': {
'reebok': true,
'mens': true,
'tennis': true,
'racket': true
}
}
Now you can query with
collectionRef.where('terms.tennis', '==', true)
This works because Firestore will automatically create an index for every field. Unfortunately this doesn't work directly for compound queries because Firestore doesn't automatically create composite indexes.
You can still work around this by storing combinations of words but this gets ugly fast.
You're still probably better off with an outboard full text search.
While Firebase does not explicitly support searching for a term within a string,
Firebase does (now) support the following which will solve for your case and many others:
As of August 2018 they support array-contains query. See: https://firebase.googleblog.com/2018/08/better-arrays-in-cloud-firestore.html
You can now set all of your key terms into an array as a field then query for all documents that have an array that contains 'X'. You can use logical AND to make further comparisons for additional queries. (This is because firebase does not currently natively support compound queries for multiple array-contains queries so 'AND' sorting queries will have to be done on client end)
Using arrays in this style will allow them to be optimized for concurrent writes which is nice! Haven't tested that it supports batch requests (docs don't say) but I'd wager it does since its an official solution.
Usage:
collection("collectionPath").
where("searchTermsArray", "array-contains", "term").get()
Per the Firestore docs, Cloud Firestore doesn't support native indexing or search for text fields in documents. Additionally, downloading an entire collection to search for fields client-side isn't practical.
Third-party search solutions like Algolia and Elastic Search are recommended.
I'm sure Firebase will come out with "string-contains" soon to capture any index[i] startAt in the string...
But
I’ve researched the webs and found this solution thought of by someone else
set up your data like this
state = { title: "Knitting" };
// ...
const c = this.state.title.toLowerCase();
var array = [];
for (let i = 1; i < c.length + 1; i++) {
array.push(c.substring(0, i));
}
firebase
.firestore()
.collection("clubs")
.doc(documentId)
.update({
title: this.state.title,
titleAsArray: array
});
query like this
firebase.firestore()
.collection("clubs")
.where(
"titleAsArray",
"array-contains",
this.state.userQuery.toLowerCase()
)
As of today (18-Aug-2020), there are basically 3 different workarounds, which were suggested by the experts, as answers to the question.
I have tried them all. I thought it might be useful to document my experience with each one of them.
Method-A: Using: (dbField ">=" searchString) & (dbField "<=" searchString + "\uf8ff")
Suggested by #Kuba & #Ankit Prajapati
.where("dbField1", ">=", searchString)
.where("dbField1", "<=", searchString + "\uf8ff");
A.1 Firestore queries can only perform range filters (>, <, >=, <=) on a single field. Queries with range filters on multiple fields are not supported. By using this method, you can't have a range operator in any other field on the db, e.g. a date field.
A.2. This method does NOT work for searching in multiple fields at the same time. For example, you can't check if a search string is in any of the fileds (name, notes & address).
Method-B: Using a MAP of search strings with "true" for each entry in the map, & using the "==" operator in the queries
Suggested by #Gil Gilbert
document1 = {
'searchKeywordsMap': {
'Jam': true,
'Butter': true,
'Muhamed': true,
'Green District': true,
'Muhamed, Green District': true,
}
}
.where(`searchKeywordsMap.${searchString}`, "==", true);
B.1 Obviously, this method requires extra processing every time data is saved to the db, and more importantly, requires extra space to store the map of search strings.
B.2 If a Firestore query has a single condition like the one above, no index needs to be created beforehand. This solution would work just fine in this case.
B.3 However, if the query has another condition, e.g. (status === "active",) it seems that an index is required for each "search string" the user enters. In other words, if a user searches for "Jam" and another user searches for "Butter", an index should be created beforehand for the string "Jam", and another one for "Butter", etc. Unless you can predict all possible users' search strings, this does NOT work - in case of the query has other conditions!
.where(searchKeywordsMap["Jam"], "==", true); // requires an index on searchKeywordsMap["Jam"]
.where("status", "==", "active");
**Method-C: Using an ARRAY of search strings, & the "array-contains" operator
Suggested by #Albert Renshaw & demonstrated by #Nick Carducci
document1 = {
'searchKeywordsArray': [
'Jam',
'Butter',
'Muhamed',
'Green District',
'Muhamed, Green District',
]
}
.where("searchKeywordsArray", "array-contains", searchString);
C.1 Similar to Method-B, this method requires extra processing every time data is saved to the db, and more importantly, requires extra space to store the array of search strings.
C.2 Firestore queries can include at most one "array-contains" or "array-contains-any" clause in a compound query.
General Limitations:
None of these solutions seems to support searching for partial strings. For example, if a db field contains "1 Peter St, Green District", you can't search for the string "strict."
It is almost impossible to cover all possible combinations of expected search strings. For example, if a db field contains "1 Mohamed St, Green District", you may NOT be able to search for the string "Green Mohamed", which is a string having the words in a different order than the order used in the DB field.
There is no one solution that fits all. Each workaround has its limitations. I hope the information above can help you during the selection process between these workarounds.
For a list of Firestore query conditions, please check out the documentation https://firebase.google.com/docs/firestore/query-data/queries.
I have not tried https://fireblog.io/blog/post/firestore-full-text-search, which is suggested by #Jonathan.
Late answer but for anyone who's still looking for an answer, Let's say we have a collection of users and in each document of the collection we have a "username" field, so if want to find a document where the username starts with "al" we can do something like
FirebaseFirestore.getInstance()
.collection("users")
.whereGreaterThanOrEqualTo("username", "al")
I used trigram just like Jonathan said it.
trigrams are groups of 3 letters stored in a database to help with searching. so if I have data of users and I let' say I want to query 'trum' for donald trump I have to store it this way
and I just to recall this way
onPressed: () {
//LET SAY YOU TYPE FOR 'tru' for trump
List<String> search = ['tru', 'rum'];
Future<QuerySnapshot> inst = FirebaseFirestore.instance
.collection("users")
.where('trigram', arrayContainsAny: search)
.get();
print('result=');
inst.then((value) {
for (var i in value.docs) {
print(i.data()['name']);
}
});
that will get correct result no matter what
EDIT 05/2021:
Google Firebase now has an extension to implement Search with Algolia. Algolia is a full text search platform that has an extensive list of features. You are required to have a "Blaze" plan on Firebase and there are fees associated with Algolia queries, but this would be my recommended approach for production applications. If you prefer a free basic search, see my original answer below.
https://firebase.google.com/products/extensions/firestore-algolia-search
https://www.algolia.com
ORIGINAL ANSWER:
The selected answer only works for exact searches and is not natural user search behavior (searching for "apple" in "Joe ate an apple today" would not work).
I think Dan Fein's answer above should be ranked higher. If the String data you're searching through is short, you can save all substrings of the string in an array in your Document and then search through the array with Firebase's array_contains query. Firebase Documents are limited to 1 MiB (1,048,576 bytes) (Firebase Quotas and Limits) , which is about 1 million characters saved in a document (I think 1 character ~= 1 byte). Storing the substrings is fine as long as your document isn't close to 1 million mark.
Example to search user names:
Step 1: Add the following String extension to your project. This lets you easily break up a string into substrings. (I found this here).
extension String {
var length: Int {
return count
}
subscript (i: Int) -> String {
return self[i ..< i + 1]
}
func substring(fromIndex: Int) -> String {
return self[min(fromIndex, length) ..< length]
}
func substring(toIndex: Int) -> String {
return self[0 ..< max(0, toIndex)]
}
subscript (r: Range<Int>) -> String {
let range = Range(uncheckedBounds: (lower: max(0, min(length, r.lowerBound)),
upper: min(length, max(0, r.upperBound))))
let start = index(startIndex, offsetBy: range.lowerBound)
let end = index(start, offsetBy: range.upperBound - range.lowerBound)
return String(self[start ..< end])
}
Step 2: When you store a user's name, also store the result of this function as an array in the same Document. This creates all variations of the original text and stores them in an array. For example, the text input "Apple" would creates the following array: ["a", "p", "p", "l", "e", "ap", "pp", "pl", "le", "app", "ppl", "ple", "appl", "pple", "apple"], which should encompass all search criteria a user might enter. You can leave maximumStringSize as nil if you want all results, however, if there is long text, I would recommend capping it before the document size gets too big - somewhere around 15 works fine for me (most people don't search long phrases anyway).
func createSubstringArray(forText text: String, maximumStringSize: Int?) -> [String] {
var substringArray = [String]()
var characterCounter = 1
let textLowercased = text.lowercased()
let characterCount = text.count
for _ in 0...characterCount {
for x in 0...characterCount {
let lastCharacter = x + characterCounter
if lastCharacter <= characterCount {
let substring = textLowercased[x..<lastCharacter]
substringArray.append(substring)
}
}
characterCounter += 1
if let max = maximumStringSize, characterCounter > max {
break
}
}
print(substringArray)
return substringArray
}
Step 3: You can use Firebase's array_contains function!
[yourDatabasePath].whereField([savedSubstringArray], arrayContains: searchText).getDocuments....
I just had this problem and came up with a pretty simple solution.
String search = "ca";
Firestore.instance.collection("categories").orderBy("name").where("name",isGreaterThanOrEqualTo: search).where("name",isLessThanOrEqualTo: search+"z")
The isGreaterThanOrEqualTo lets us filter out the beginning of our search and by adding a "z" to the end of the isLessThanOrEqualTo we cap our search to not roll over to the next documents.
I actually think the best solution to do this within Firestore is to put all substrings in an array, and just do an array_contains query. This allows you to do substring matching. A bit overkill to store all substrings but if your search terms are short it's very very reasonable.
If you don't want to use a third-party service like Algolia, Firebase Cloud Functions are a great alternative. You can create a function that can receive an input parameter, process through the records server-side and then return the ones that match your criteria.
This worked for me perfectly but might cause performance issues.
Do this when querying firestore:
Future<QuerySnapshot> searchResults = collectionRef
.where('property', isGreaterThanOrEqualTo: searchQuery.toUpperCase())
.getDocuments();
Do this in your FutureBuilder:
return FutureBuilder(
future: searchResults,
builder: (context, snapshot) {
List<Model> searchResults = [];
snapshot.data.documents.forEach((doc) {
Model model = Model.fromDocumet(doc);
if (searchQuery.isNotEmpty &&
!model.property.toLowerCase().contains(searchQuery.toLowerCase())) {
return;
}
searchResults.add(model);
})
};
Following code snippet takes input from user and acquires data starting with the typed one.
Sample Data:
Under Firebase Collection 'Users'
user1: {name: 'Ali', age: 28},
user2: {name: 'Khan', age: 30},
user3: {name: 'Hassan', age: 26},
user4: {name: 'Adil', age: 32}
TextInput: A
Result:
{name: 'Ali', age: 28},
{name: 'Adil', age: 32}
let timer;
// method called onChangeText from TextInput
const textInputSearch = (text) => {
const inputStart = text.trim();
let lastLetterCode = inputStart.charCodeAt(inputStart.length-1);
lastLetterCode++;
const newLastLetter = String.fromCharCode(lastLetterCode);
const inputEnd = inputStart.slice(0,inputStart.length-1) + lastLetterCode;
clearTimeout(timer);
timer = setTimeout(() => {
firestore().collection('Users')
.where('name', '>=', inputStart)
.where('name', '<', inputEnd)
.limit(10)
.get()
.then(querySnapshot => {
const users = [];
querySnapshot.forEach(doc => {
users.push(doc.data());
})
setUsers(users); // Setting Respective State
});
}, 1000);
};
2021 Update
Took a few things from other answers. This one includes:
Multi word search using split (acts as OR)
Multi key search using flat
A bit limited on case-sensitivity, you can solve this by storing duplicate properties in uppercase. Ex: query.toUpperCase() user.last_name_upper
// query: searchable terms as string
let users = await searchResults("Bob Dylan", 'users');
async function searchResults(query = null, collection = 'users', keys = ['last_name', 'first_name', 'email']) {
let querySnapshot = { docs : [] };
try {
if (query) {
let search = async (query)=> {
let queryWords = query.trim().split(' ');
return queryWords.map((queryWord) => keys.map(async (key) =>
await firebase
.firestore()
.collection(collection)
.where(key, '>=', queryWord)
.where(key, '<=', queryWord + '\uf8ff')
.get())).flat();
}
let results = await search(query);
await (await Promise.all(results)).forEach((search) => {
querySnapshot.docs = querySnapshot.docs.concat(search.docs);
});
} else {
// No query
querySnapshot = await firebase
.firestore()
.collection(collection)
// Pagination (optional)
// .orderBy(sortField, sortOrder)
// .startAfter(startAfter)
// .limit(perPage)
.get();
}
} catch(err) {
console.log(err)
}
// Appends id and creates clean Array
const items = [];
querySnapshot.docs.forEach(doc => {
let item = doc.data();
item.id = doc.id;
items.push(item);
});
// Filters duplicates
return items.filter((v, i, a) => a.findIndex(t => (t.id === v.id)) === i);
}
Note: the number of Firebase calls is equivalent to the number of words in the query string * the number of keys you're searching on.
Same as #nicksarno but with a more polished code that doesn't need any extension:
Step 1
func getSubstrings(from string: String, maximumSubstringLenght: Int = .max) -> [Substring] {
let string = string.lowercased()
let stringLength = string.count
let stringStartIndex = string.startIndex
var substrings: [Substring] = []
for lowBound in 0..<stringLength {
for upBound in lowBound..<min(stringLength, lowBound+maximumSubstringLenght) {
let lowIndex = string.index(stringStartIndex, offsetBy: lowBound)
let upIndex = string.index(stringStartIndex, offsetBy: upBound)
substrings.append(string[lowIndex...upIndex])
}
}
return substrings
}
Step 2
let name = "Lorenzo"
ref.setData(["name": name, "nameSubstrings": getSubstrings(from: name)])
Step 3
Firestore.firestore().collection("Users")
.whereField("nameSubstrings", arrayContains: searchText)
.getDocuments...
With Firestore you can implement a full text search but it will still cost more reads than it would have otherwise, and also you'll need to enter and index the data in a particular way, So in this approach you can use firebase cloud functions to tokenise and then hash your input text while choosing a linear hash function h(x) that satisfies the following - if x < y < z then h(x) < h (y) < h(z). For tokenisation you can choose some lightweight NLP Libraries in order to keep the cold start time of your function low that can strip unnecessary words from your sentence. Then you can run a query with less than and greater than operator in Firestore.
While storing your data also, you'll have to make sure that you hash the text before storing it, and store the plain text also as if you change the plain text the hashed value will also change.
Typesense service provide substring search for Firebase Cloud Firestore database.
https://typesense.org/docs/guide/firebase-full-text-search.html
Following is the relevant codes of typesense integration for my project.
lib/utils/typesense.dart
import 'dart:convert';
import 'package:flutter_instagram_clone/model/PostModel.dart';
import 'package:http/http.dart' as http;
class Typesense {
static String baseUrl = 'http://typesense_server_ip:port/';
static String apiKey = 'xxxxxxxx'; // your Typesense API key
static String resource = 'collections/postData/documents/search';
static Future<List<PostModel>> search(String searchKey, int page, {int contentType=-1}) async {
if (searchKey.isEmpty) return [];
List<PostModel> _results = [];
var header = {'X-TYPESENSE-API-KEY': apiKey};
String strSearchKey4Url = searchKey.replaceFirst('#', '%23').replaceAll(' ', '%20');
String url = baseUrl +
resource +
'?q=${strSearchKey4Url}&query_by=postText&page=$page&sort_by=millisecondsTimestamp:desc&num_typos=0';
if(contentType==0)
{
url += "&filter_by=isSelling:false";
} else if(contentType == 1)
{
url += "&filter_by=isSelling:true";
}
var response = await http.get(Uri.parse(url), headers: header);
var data = json.decode(response.body);
for (var item in data['hits']) {
PostModel _post = PostModel.fromTypeSenseJson(item['document']);
if (searchKey.contains('#')) {
if (_post.postText.toLowerCase().contains(searchKey.toLowerCase()))
_results.add(_post);
} else {
_results.add(_post);
}
}
print(_results.length);
return _results;
}
static Future<List<PostModel>> getHubPosts(String searchKey, int page,
{List<String>? authors, bool? isSelling}) async {
List<PostModel> _results = [];
var header = {'X-TYPESENSE-API-KEY': apiKey};
String filter = "";
if (authors != null || isSelling != null) {
filter += "&filter_by=";
if (isSelling != null) {
filter += "isSelling:$isSelling";
if (authors != null && authors.isNotEmpty) {
filter += "&&";
}
}
if (authors != null && authors.isNotEmpty) {
filter += "authorID:$authors";
}
}
String url = baseUrl +
resource +
'?q=${searchKey.replaceFirst('#', '%23')}&query_by=postText&page=$page&sort_by=millisecondsTimestamp:desc&num_typos=0$filter';
var response = await http.get(Uri.parse(url), headers: header);
var data = json.decode(response.body);
for (var item in data['hits']) {
PostModel _post = PostModel.fromTypeSenseJson(item['document']);
_results.add(_post);
}
print(_results.length);
return _results;
}
}
lib/services/hubDetailsService.dart
import 'package:flutter/material.dart';
import 'package:flutter_instagram_clone/model/PostModel.dart';
import 'package:flutter_instagram_clone/utils/typesense.dart';
class HubDetailsService with ChangeNotifier {
String searchKey = '';
List<String>? authors;
bool? isSelling;
int nContentType=-1;
bool isLoading = false;
List<PostModel> hubResults = [];
int _page = 1;
bool isMore = true;
bool noResult = false;
Future initSearch() async {
isLoading = true;
isMore = true;
noResult = false;
hubResults = [];
_page = 1;
List<PostModel> _results = await Typesense.search(searchKey, _page, contentType: nContentType);
for(var item in _results) {
hubResults.add(item);
}
isLoading = false;
if(_results.length < 10) isMore = false;
if(_results.isEmpty) noResult = true;
notifyListeners();
}
Future nextPage() async {
if(!isMore) return;
_page++;
List<PostModel> _results = await Typesense.search(searchKey, _page);
hubResults.addAll(_results);
if(_results.isEmpty) {
isMore = false;
}
notifyListeners();
}
Future refreshPage() async {
isLoading = true;
notifyListeners();
await initSearch();
isLoading = false;
notifyListeners();
}
Future search(String _searchKey) async {
isLoading = true;
notifyListeners();
searchKey = _searchKey;
await initSearch();
isLoading = false;
notifyListeners();
}
}
lib/ui/hub/hubDetailsScreen.dart
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_instagram_clone/constants.dart';
import 'package:flutter_instagram_clone/main.dart';
import 'package:flutter_instagram_clone/model/MessageData.dart';
import 'package:flutter_instagram_clone/model/SocialReactionModel.dart';
import 'package:flutter_instagram_clone/model/User.dart';
import 'package:flutter_instagram_clone/model/hubModel.dart';
import 'package:flutter_instagram_clone/services/FirebaseHelper.dart';
import 'package:flutter_instagram_clone/services/HubService.dart';
import 'package:flutter_instagram_clone/services/helper.dart';
import 'package:flutter_instagram_clone/services/hubDetailsService.dart';
import 'package:flutter_instagram_clone/ui/fullScreenImageViewer/FullScreenImageViewer.dart';
import 'package:flutter_instagram_clone/ui/home/HomeScreen.dart';
import 'package:flutter_instagram_clone/ui/hub/editHubScreen.dart';
import 'package:provider/provider.dart';
import 'package:smooth_page_indicator/smooth_page_indicator.dart';
class HubDetailsScreen extends StatefulWidget {
final HubModel hub;
HubDetailsScreen(this.hub);
#override
_HubDetailsScreenState createState() => _HubDetailsScreenState();
}
class _HubDetailsScreenState extends State<HubDetailsScreen> {
late HubDetailsService _service;
List<SocialReactionModel?> _reactionsList = [];
final fireStoreUtils = FireStoreUtils();
late Future<List<SocialReactionModel>> _myReactions;
final scrollController = ScrollController();
bool _isSubLoading = false;
#override
void initState() {
// TODO: implement initState
super.initState();
_service = Provider.of<HubDetailsService>(context, listen: false);
print(_service.isLoading);
init();
}
init() async {
_service.searchKey = "";
if(widget.hub.contentWords.length>0)
{
for(var item in widget.hub.contentWords) {
_service.searchKey += item + " ";
}
}
switch(widget.hub.contentType) {
case 'All':
break;
case 'Marketplace':
_service.isSelling = true;
_service.nContentType = 1;
break;
case 'Post Only':
_service.isSelling = false;
_service.nContentType = 0;
break;
case 'Keywords':
break;
}
for(var item in widget.hub.exceptWords) {
if(item == 'Marketplace') {
_service.isSelling = _service.isSelling != null?true:false;
} else {
_service.searchKey += "-" + item + "";
}
}
if(widget.hub.fromUserType == 'Followers') {
List<User> _followers = await fireStoreUtils.getFollowers(MyAppState.currentUser!.userID);
_service.authors = [];
for(var item in _followers)
_service.authors!.add(item.userID);
}
if(widget.hub.fromUserType == 'Selected') {
_service.authors = widget.hub.fromUserIds;
}
_service.initSearch();
_myReactions = fireStoreUtils.getMyReactions()
..then((value) {
_reactionsList.addAll(value);
});
scrollController.addListener(pagination);
}
void pagination(){
if(scrollController.position.pixels ==
scrollController.position.maxScrollExtent) {
_service.nextPage();
}
}
#override
Widget build(BuildContext context) {
Provider.of<HubDetailsService>(context);
PageController _controller = PageController(
initialPage: 0,
);
return Scaffold(
backgroundColor: Colors.white,
body: RefreshIndicator(
onRefresh: () async {
_service.refreshPage();
},
child: CustomScrollView(
controller: scrollController,
slivers: [
SliverAppBar(
centerTitle: false,
expandedHeight: MediaQuery.of(context).size.height * 0.25,
pinned: true,
backgroundColor: Colors.white,
title: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
InkWell(
onTap: (){
Navigator.pop(context);
},
child: Container(
width: 35, height: 35,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(20)
),
child: Center(
child: Icon(Icons.arrow_back),
),
),
),
if(widget.hub.user.userID == MyAppState.currentUser!.userID)
InkWell(
onTap: () async {
var _hub = await push(context, EditHubScreen(widget.hub));
if(_hub != null) {
Navigator.pop(context, true);
}
},
child: Container(
width: 35, height: 35,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(20)
),
child: Center(
child: Icon(Icons.edit, color: Colors.black, size: 20,),
),
),
),
],
),
automaticallyImplyLeading: false,
flexibleSpace: FlexibleSpaceBar(
collapseMode: CollapseMode.pin,
background: Container(color: Colors.grey,
child: Stack(
children: [
PageView.builder(
controller: _controller,
itemCount: widget.hub.medias.length,
itemBuilder: (context, index) {
Url postMedia = widget.hub.medias[index];
return GestureDetector(
onTap: () => push(
context,
FullScreenImageViewer(
imageUrl: postMedia.url)),
child: displayPostImage(postMedia.url));
}),
if (widget.hub.medias.length > 1)
Padding(
padding: const EdgeInsets.only(bottom: 30.0),
child: Align(
alignment: Alignment.bottomCenter,
child: SmoothPageIndicator(
controller: _controller,
count: widget.hub.medias.length,
effect: ScrollingDotsEffect(
dotWidth: 6,
dotHeight: 6,
dotColor: isDarkMode(context)
? Colors.white54
: Colors.black54,
activeDotColor: Color(COLOR_PRIMARY)),
),
),
),
],
),
)
),
),
_service.isLoading?
SliverFillRemaining(
child: Center(
child: CircularProgressIndicator(),
),
):
SliverList(
delegate: SliverChildListDelegate([
if(widget.hub.userId != MyAppState.currentUser!.userID)
_isSubLoading?
Center(
child: Padding(
padding: EdgeInsets.all(5),
child: CircularProgressIndicator(),
),
):
Padding(
padding: EdgeInsets.symmetric(horizontal: 5),
child: widget.hub.shareUserIds.contains(MyAppState.currentUser!.userID)?
ElevatedButton(
onPressed: () async {
setState(() {
_isSubLoading = true;
});
await Provider.of<HubService>(context, listen: false).unsubscribe(widget.hub);
setState(() {
_isSubLoading = false;
widget.hub.shareUserIds.remove(MyAppState.currentUser!.userID);
});
},
style: ElevatedButton.styleFrom(
primary: Colors.red
),
child: Text(
"Unsubscribe",
),
):
ElevatedButton(
onPressed: () async {
setState(() {
_isSubLoading = true;
});
await Provider.of<HubService>(context, listen: false).subscribe(widget.hub);
setState(() {
_isSubLoading = false;
widget.hub.shareUserIds.add(MyAppState.currentUser!.userID);
});
},
style: ElevatedButton.styleFrom(
primary: Colors.green
),
child: Text(
"Subscribe",
),
),
),
Padding(
padding: EdgeInsets.all(15,),
child: Text(
widget.hub.name,
style: TextStyle(
color: Colors.black,
fontSize: 18,
fontWeight: FontWeight.bold
),
),
),
..._service.hubResults.map((e) {
if(e.isAuction && (e.auctionEnded || DateTime.now().isAfter(e.auctionEndTime??DateTime.now()))) {
return Container();
}
return PostWidget(post: e);
}).toList(),
if(_service.noResult)
Padding(
padding: EdgeInsets.all(20),
child: Text(
'No results for this hub',
style: TextStyle(
fontSize: 18,
fontWeight: FontWeight.bold
),
),
),
if(_service.isMore)
Center(
child: Container(
padding: EdgeInsets.all(5),
child: CircularProgressIndicator(),
),
)
]),
)
],
),
)
);
}
}
You can try using 2 lambdas and S3. These resources are very cheap and you will only be charged once the app has extreme usage ( if the business model is good then high usage -> higher income).
The first lambda will be used to push a text-document mapping to an S3 json file.
the second lambda will basically be your search api, you will use it to query the JSON in s3 and return the results.
The drawback will probably be the latency from s3 to lambda.
I use this with Vue js
query(collection(db,'collection'),where("name",">=",'searchTerm'),where("name","<=","~"))
I also couldn't manage to create a search function to Firebase using the suggestions and Firebase tools so I created my own "field-string contains search-string(substring) check", using the .contains() Kotlin function:
firestoreDB.collection("products")
.get().addOnCompleteListener { task->
if (task.isSuccessful){
val document = task.result
if (!document.isEmpty) {
if (document != null) {
for (documents in document) {
var name = documents.getString("name")
var type = documents.getString("type")
if (name != null && type != null) {
if (name.contains(text, ignoreCase = true) || type.contains(text, ignoreCase = true)) {
// do whatever you want with the document
} else {
showNoProductsMsg()
}
}
}
}
binding.progressBarSearch.visibility = View.INVISIBLE
} else {
showNoProductsMsg()
}
} else{
showNoProductsMsg()
}
}
First, you get ALL the documents in the collection you want, then you filter them using:
for (documents in document) {
var name = documents.getString("name")
var type = documents.getString("type")
if (name != null && type != null) {
if (name.contains(text, ignoreCase = true) || type.contains(text, ignoreCase = true)) {
//do whatever you want with this document
} else {
showNoProductsMsg()
}
}
}
In my case, I filtered them all by the name of the product and its type, then I used the boolean name.contains(string, ignoreCase = true) OR type.contains(string, ignoreCase = true, string is the text I got in the search bar of my app and I recommend you to use ignoreCase = true. With this setence being true, you can do whatever you want with the document.
I guess this is the best workaround since Firestore only supports number and exacts strings queries, so if your code didn't work doing this:
collection.whereGreaterThanOrEqualTo("name", querySearch)
collection.whereLessThanOrEqualTo("name", querySearch)
You're welcome :) because what I did works!
Firebase suggests Algolia or ElasticSearch for Full-Text search, but a cheaper alternative might be MongoDB. The cheapest cluster (approx US$10/mth) allows you to index for full-text.
We can use the back-tick to print out the value of a string. This should work:
where('name', '==', `${searchTerm}`)

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