IOS 10.3.1 cordova based App crashes when trying to write to IndexedDB - ios

Question

I'm developing a cordova-based multi-platform web-app using sapui5 framework v1.44 and indexedDB for storing data.The app was working fine untill last ios update, 10.3.1, now it crashes when trying to write to indexedDB. I'm using put method for updating data and i did a clean install of the app. The code frame where i try to write to indexedDB is this:
writeToIDB: function (objStoreName, result, success, error) {
//Asynchronous function
var defer = Q.defer();
var res = [];
if (!!result && Array.isArray(result)) {
res = result;
} else if (!!result && result.hasOwnProperty("results") && Array.isArray(result.results)) {
res = result.results;
} else if (!!result && typeof result === 'object') {
res.push(result);
}
if (res.length >= 0) {
if (window.myDB) {
if (!window.myDB.objectStoreNames.contains(objStoreName)) {
console.log("ObjectStore for " + objStoreName + " doesn't exist");
if (error) {
error("ko")
} else {
defer.reject("ko");
}
} else {
var oTransaction = window.myDB.transaction([objStoreName], "readwrite");
var oDataStore = oTransaction.objectStore(objStoreName);
oTransaction.oncomplete = function (event) {
console.log("Transaction completed: database modification for " + objStoreName + " finished.");
if (success) {
success();
} else {
defer.resolve("ok");
}
};
oTransaction.onerror = function (event) {
console.log("Transaction for " + objStoreName + " not opened due to error. Check for duplicate items or missing properties!");
console.log(event.target.error);
if (error) {
error("ko")
} else {
defer.reject("ko");
}
};
var oRecord = {};
for (var i = 0; i < res.length; i++) {
oRecord = res[i];
oDataStore.put(oRecord);
}
}
} else {
this.createIDB().then(
function (resCreate) {
console.log("DB Created successfully");
if (!window.myDB.objectStoreNames.contains(objStoreName)) {
console.log("ObjectStore for " + objStoreName + " doesn't exist");
if (error) {
error("ko")
} else {
defer.reject("ko");
}
} else {
var oTransaction = window.myDB.transaction([objStoreName], "readwrite");
var oDataStore = oTransaction.objectStore(objStoreName);
oTransaction.oncomplete = function (event) {
console.log("Transaction completed: database modification for " + objStoreName + " finished.");
if (success) {
success();
} else {
defer.resolve("ok");
}
};
oTransaction.onerror = function (event) {
console.log("Transaction for " + objStoreName + " not opened due to error. Check for duplicate items or missing properties!");
console.log(event.target.error);
if (error) {
error("ko")
} else {
defer.reject("ko");
}
};
var oRecord = {};
for (var i = 0; i < res.length; i++) {
oRecord = res[i];
oDataStore.put(oRecord);
}
}
}.bind(this),
function (err) {
console.log("DB Creation failed");
if (error) {
error("ko")
} else {
defer.reject("ko");
}
}.bind(this)
);
}
} else {
if (error) {
error("ko")
} else {
defer.reject("ko");
}
}
if (typeof success === 'undefined' && typeof error === 'undefined') {
return defer.promise;
}
},
P.S.I have omitted parts of the code.
This was working fine with the previous version of ios, i think i had installed the 10.2.1, now it simply crashes after calling the put method. I tried upgrading now ios to the beta of 10.3.2 but the result is the same. Anyone else noticed this or have any idea of how to resolve this problem?
Thanks
K
UPDATE
I've found the issue: the complex dataTypes. Since IndexedDB supports saving and retrieving complex dataTypes, i had some properties which were arrays or objects that i used to save in some of my ObjectStores. This is definitely a big problem for me because the only workaround i can think for this is to stingify the complex fields but since i work with a lot of data this would create a big performance issue. I hope the ios developer team will find a solution for this soon enough

Answer 1

Are you sure every key in the res[] array is a valid key? There is a closed bug here:
https://bugs.webkit.org/show_bug.cgi?id=170000
It looks if you pass in an invalid key it will cause webkit to crash.
This fix for this will likely be contained in the next public release of iOS.
To determine what a valid key is see this section of the W3.org spec:
3.1.3 Keys
In order to efficiently retrieve records stored in an indexed database, each record is organized according to its key. A value is said to be a valid key if it is one of the following ECMAScript [ECMA-262] types: Number primitive value, String primitive value, Date object, or Array object. An Array is only a valid key if every item in the array is defined and is a valid key (i.e. sparse arrays can not be valid keys) and if the Array doesn't directly or indirectly contain itself. Any non-numeric properties on an Array are ignored, and thus do not affect whether the Array is a valid key. If the value is of type Number, it is only a valid key if it is not NaN. If the value is of type Date it is only a valid key if its [[PrimitiveValue]] internal property, as defined by [ECMA-262], is not NaN. Conforming user agents must support all valid keys as keys.
This was taken from here:
https://www.w3.org/TR/IndexedDB/#key-construct

Answer 2

Not sure if it's the same issue, but I had a crash on iOS 10.3 that I didnt get in any other browser. Using Dexie wrapper for indexedDB, I did a get all records from table search:
db.table.toArray(function (results) {
// process...
})
and got flames from Xcode to what looked like a threading issue in WebKit so I just added setTimeout( ... ,1) and that hacked around the problem for me.