CODEWITHSUNDEEP
javascriptgoogle-cloud-firestoredialogflow-es-fulfillment
jako4689
jako4689

Reputation: 3

Dialogflow to firestore inline editor javascript: sorting and filtering on different parameters of collection

I have a database in Google cloud firestore with a collection of documents that each includes the following parameters: country, headline, URL, date.

I need to return two separate things depending on the input in Dialogflow. The first thing is the headlines of the 3 latest news and the second thing is the headlines of the 3 latest news in France. I am to do it in Dialogflows inline editor, which is javascript, but it doesn't seem entirely the same as javascript e.g. in Node.

I have already solved the first problem with the following code:

function TopNews_Global(agent) {
      agent.add('Here are the latest Global news');

      let documents = db.orderBy('Date', 'desc').limit(3);      
    return documents.get()
      .then(snapshot => {
    snapshot.forEach(doc => {
          agent.add('-' + doc.data().Headline + '.');
          agent.add('Link:(' + doc.data().URL + ')');
        });
        return Promise.resolve('Read complete');
      }).catch(() => {
        agent.add('Error reading entry from the Firestore database.');
      });
  }

Where db is my collection in firebase. The following code is my solution to the second thing I want to return, and this is where I am stuck. It is not possible to filter and order over two different fields as I do. But there MUST be a way around this - it's a pretty simple thing I wanna do.

https://firebase.google.com/docs/firestore/manage-data/export-import

function TopNews_France(agent) {
      agent.add('Here are the latest French news');

      let documents = db.orderBy('Date', 'desc').where('Country', '==', 'France').limit(3);       
    return documents.get()
      .then(snapshot => {
    snapshot.forEach(doc => {
          agent.add('-' + doc.data().Headline + '.');
          agent.add('Link:(' + doc.data().URL + ')');

        });
        return Promise.resolve('Read complete');
      }).catch(() => {
        agent.add('Error reading entry from the Firestore database.');
      });
  }

Upvotes: 0

Views: 105

Answers (1)

robsiemb
robsiemb

Reputation: 6354

Assuming that as you state, db is a collection object, your query is a valid one for Firestore.

db.orderBy('Date', 'desc').where('Country', '==', 'France').limit(3);

Firestore does allow queries across multiple fields, assuming that the only orderBy or range queries are on the same field. Thus, your query is valid (one orderBy and one non-range where on different fields).

You didn't mention what error you are getting, but I suspect it is this (nominally visible in a Javascript console):

The query requires an index. You can create it here: (url)

That is because this is a query which requires a composite index -- it sorts on one field and filters on another.

Thus, to fix this, you just need to create the index. In an ideal case, you can just click on the URL in that error message and be brought to the exact point in the Firebase console to create the exact index you need. If for some reason you need to create it manually, you can also do that through the console. After it completes building, your query should work.

In this case, you will need to create an index for whatever collection db is pointing at, with the fields Date (in descending order) and Country (in either descending or ascending order -- the equality won't care), and with collection scope.

Upvotes: 1

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