本文整理匯總了TypeScript中@jupyterlab/coreutils.StateDB.fetch方法的典型用法代碼示例。如果您正苦於以下問題：TypeScript StateDB.fetch方法的具體用法？TypeScript StateDB.fetch怎麽用？TypeScript StateDB.fetch使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類@jupyterlab/coreutils.StateDB的用法示例。
在下文中一共展示了StateDB.fetch方法的5個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的TypeScript代碼示例。
示例1: it
it('should allow an overwrite data transformation', async () => {
const transform = new PromiseDelegate<StateDB.DataTransform>();
const db = new StateDB({
namespace: 'test',
transform: transform.promise
});
const prepopulate = new StateDB({ namespace: 'test' });
const key = 'foo';
const correct = 'bar';
const incorrect = 'baz';
const transformation: StateDB.DataTransform = {
type: 'overwrite',
contents: { [key]: correct }
};
// By sharing a namespace, the two databases will share data.
await prepopulate.save(key, incorrect);
let value = await prepopulate.fetch(key);
expect(value).to.equal(incorrect);
transform.resolve(transformation);
await transform.promise;
value = await db.fetch(key);
expect(value).to.equal(correct);
await db.clear();
});示例2: it
it('should resolve a nonexistent key fetch with undefined', done => {
let { localStorage } = window;
let db = new StateDB({ namespace: 'test-namespace' });
let key = 'foo:bar';
expect(localStorage.length).to.be(0);
db.fetch(key)
.then(fetched => { expect(fetched).to.be(undefined); })
.then(done)
.catch(done);
});示例3: StateDB
activate: (app: JupyterLab) => {
const state = new StateDB({ namespace: app.info.namespace });
const version = app.info.version;
const key = 'statedb:version';
const fetch = state.fetch(key);
const save = () => state.save(key, { version });
const reset = () => state.clear().then(save);
const check = (value: JSONObject) => {
let old = value && value['version'];
if (!old || old !== version) {
const previous = old || 'unknown';
console.log(`Upgraded: ${previous} to ${version}; Resetting DB.`);
return reset();
}
};
app.commands.addCommand(CommandIDs.clearStateDB, {
label: 'Clear Application Restore State',
execute: () => state.clear()
});
return fetch.then(check, reset).then(() => state);
}