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Daniel Rivas
Asked: 2022-04-03 12:22:15 +0800 CST 2022-04-03 12:22:15 +0800 CST

Call data from a Firebase Database to Validate

  • 772

I have a simple HTML form where there are 3 text type inputs, one called "Day" another called "Month and another "Year (Year)" , and this same one in a variable called "Date" does the following:

var fecha = dia + '/' + mes + '/' + anio

And the result would be something like: 26/05/2021, I need to validate that when someone enters this date and a time again (Ejemplo: 08:30 pm), an error type

"This appointment already exists, please check for an available one"

The code I am testing is:

else if (fecha == db.collection("citas_registradas").fecha && hora == db.collection("citas_registradas").hora) {
        alert('Esta cita ya existe, por favor, verifique una disponible.');

fechais the name of my field in my firebase database, and " citas_registradas" my table, does anyone know how I can do that validation? , I would be very grateful.

javascript

2 Answers

  1. Suppose the "time" is entered by the user in a fourth input. And that in the object we save the date and time entered fecha_inputin its property .fecha_input.datefecha_input.hora

    In the database we save all that data in an object called fechawithin a document Firebaseas follows:

    let fecha = {
  date: fecha_input.date,
  hora: fecha_input.hora    
}

    The next time a user registers an appointment again, what needs to be done now is to validate if that data already exists in the database.

    To do that validation, you could do a query .get()and use the condition .where().

    For example:

    let fechaExiste
 
db.collection("citas_registradas").where("fecha.date", "==", 
fecha_input.date).where("fecha.hora", "==", fecha_input.hora)
.get()
.then((querySnapshot) => {
    querySnapshot.forEach((doc) => {
        fechaExiste = doc.data()
    });
})
.catch((error) => {
    console.log("Error getting documents: ", error);
});

    In this example we would be accessing the data in the collection citas_registradasand looking for all the documents whose value fecha.dateand fecha.horaare equal to the date and time that they just entered in the inputs, which in this case would be in the object called fecha_input.

    The result of that query will be stored in the object fechaExiste.

    Then we do a validation with a if:

    if (fechaExiste) {
    alert('Esta cita ya existe, por favor, verifique una disponible.');
}

    In this way, if there is data found in the object, we fechaExistecommunicate the message to the user.

    In this documentation there is more information about this type of queries to Firebase:

    Get multiple documents from a collection

    • 1
  2. Best Answer

    According to the response of my friend Desarrollos-Web-Urquiza, I modified his response to adapt it, it is not necessary to use a constructor or an object or anything like that, so the code that worked for me would be the following:

    db.collection("citas_registradas").where("fecha", "==", fecha).where("hora", "==", hora).get().then((querySnapshot) => {
            querySnapshot.forEach((doc) => {
                // doc.data() is never undefined for query doc snapshots
                console.log(doc.id, " => ", doc.data());
                fechaValidacion = fecha;
                horaValidacion = hora;
                }
            });
        })
        .catch((error) => {
            console.log("Error getting documents: ", error);
        });
    if (fecha == fechaValidacion && hora == horaValidacion) {
        Swal.fire("Oops!", "Esa cita ya está llena, por favor, busque las citas libres y agende una.", "error");
    }

    Substituting Swal.fire for Alert, since Swal.Fire is a CDN to make alerts more visual, attached link: https://sweetalert2.github.io/

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