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add prototype to show we can prevent the txn from being aborted on error

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Bruno Windels 2021-09-21 20:58:16 +02:00
parent 07c6bf7055
commit 2d2521cd9a
1 changed files with 100 additions and 0 deletions
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prototypes/idb-continue-on-constrainterror.html Normal file
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<script type="text/javascript">
class IDBError extends Error {
constructor(errorEvent) {
const request = errorEvent.target;
const {error} = request;
super(error.message);
this.name = error.name;
this.errorEvent = errorEvent;
}
preventAbort() {
this.errorEvent.preventDefault();
}
}
class AbortError extends Error {
get name() { return "AbortError"; }
}
function reqAsPromise(req) {
return new Promise(function (resolve, reject) {
req.onsuccess = function(e) {
resolve(e.target.result);
};
req.onerror = function(e) {
reject(new IDBError(e));
};
});
}
function txnAsPromise(txn) {
return new Promise((resolve, reject) => {
txn.addEventListener("complete", () => resolve());
txn.addEventListener("abort", event => {
reject(new AbortError());
});
});
}
function Storage(databaseName) {
this._databaseName = databaseName;
this._database = null;
}
Storage.prototype = {
open: function() {
const req = window.indexedDB.open(this._databaseName);
const self = this;
req.onupgradeneeded = function(ev) {
const db = ev.target.result;
const oldVersion = ev.oldVersion;
self._createStores(db, oldVersion);
};
return reqAsPromise(req).then(function() {
self._database = req.result;
});
},
readWriteTxn: function(storeName) {
return this._database.transaction([storeName], "readwrite");
},
readTxn: function(storeName) {
return this._database.transaction([storeName], "readonly");
},
_createStores: function(db) {
db.createObjectStore("foos", {keyPath: "id"});
}
};
async function main() {
const storage = new Storage("idb-continue-on-constrainterror");
await storage.open();
const txn1 = storage.readWriteTxn("foos");
const store = txn1.objectStore("foos");
await reqAsPromise(store.clear());
console.log("first foo read back", await reqAsPromise(store.get(5)));
await reqAsPromise(store.add({id: 5, name: "Mr Foo"}));
try {
await reqAsPromise(store.add({id: 5, name: "bar"}));
} catch (err) {
console.log("we did get an error", err.name);
err.preventAbort();
}
await txnAsPromise(txn1);
const txn2 = storage.readTxn("foos");
const store2 = txn2.objectStore("foos");
console.log("got name from second txn", await reqAsPromise(store2.get(5)));
}
main().catch(err => console.error(err));
</script>
</body>
</html>