Firebase: permission_denied -- cannot access newData.child() - firebase

Question

This is the structure of my data
{
"projects" : {
"proj1" : {
"-JccS4StrTnJdTficR-u" : {
"name" : "consultation",
"status" : false
},
"-Jd6JlJUfyyZ2U0NTQEs" : {
"name" : "Words",
"status" : false
}
},
"proj2" : {
"-JccS6nwYHRrxvjZtCkt" : {
"name" : "Rework",
"status" : false
},
"-Jd6Jqa7-EPJuWxbtJAV" : {
"name" : "Review",
"status" : false
}
},
"proj3" : {
"-JccSJ5lEBQEg3XCbG-u" : {
"name" : "translation",
"status" : false
}
}
}
}
Here are my rules
{
"rules": {
".read": true,
"projects": {
"proj1": {
".write": "auth != null"
},
"proj2": {
".write": true
},
"proj3": {
".write": true,
".validate": "newData.child('name').isString()
&& newData.child('name').val().length < 10"
}
}
}
}
When I created the database, there was no rule. Now, I've created the rules. I want the length of the name to be less than 10 characters.
When I run the code, I'm getting the following error: FIREBASE WARNING: set at /projects/proj3/-Jd4n6XditTHLWKVmhC6 failed: permission_denied
I can't exactly tell why it's not working. I've also tried just this portion newData.child('name').isString(), but I'm still getting the same error.
Here is the code that push data to FireBase
function saveToFB(taskName, proj) {
// this will save data to Firebase
var project=projTasks.child(proj);
project.push({
name: taskName,
status: false
});
};

Answer 1

Looking at the structure of your data, as well as your rules, it looks like there is a missing level of data between "proj1"/"proj2"/"proj3" and the object that has name and status attributes.
Specifically, the .validate rules you have configured is checking the length of the name attribute for "proj3", not the new element added to the list there.
To get around this, try increasing the depth of the security rules definitions, and make use of the $wildcard functionality, where any security rules key prefixed with $ is treated as a wildcard with a name that you can reuse.
{
"rules": {
".read": true,
"projects": {
"proj1": {
".write": "auth != null"
},
"proj2": {
".write": true
},
"proj3": {
".write": true,
"$someChildElementHere": {
".validate": "newData.child('name').isString()
&& newData.child('name').val().length < 10"
}
}
}
}
}