IndexedDB getAll in non-Firefox browsers

Question

I am aware that IDBObjectStore.getAll is not part of the IndexedDB standard and that it might never be. But it is implemented in FireFox, and it makes your code prettier if you do have to retrieve a lot of objects from the database.

Would it be possible to make some kind of polyfill or something to allow getAll to work in other browsers that support IndexedDB? The actual functionality of getAll is simple, but I don't know how to deal with the asynchronous nature of IndexedDB in the context of replicating its precise syntax in non-Firefox browsers.

Answer 1

I made a GitHub repo for a shim to support getAll in other browsers, which seems to work well enough in Chrome. The code is repeated below for posterity:

(function () {
    "use strict";

    var Event, getAll, IDBIndex, IDBObjectStore, IDBRequest;

    IDBObjectStore = window.IDBObjectStore || window.webkitIDBObjectStore || window.mozIDBObjectStore || window.msIDBObjectStore;
    IDBIndex = window.IDBIndex || window.webkitIDBIndex || window.mozIDBIndex || window.msIDBIndex;

    if (typeof IDBObjectStore.prototype.getAll !== "undefined" && typeof IDBIndex.prototype.getAll !== "undefined") {
        return;
    }

    // https://github.com/axemclion/IndexedDBShim/blob/gh-pages/src/IDBRequest.js
    IDBRequest = function () {
        this.onsuccess = null;
        this.readyState = "pending";
    };
    // https://github.com/axemclion/IndexedDBShim/blob/gh-pages/src/Event.js
    Event = function (type, debug) {
        return {
            "type": type,
            debug: debug,
            bubbles: false,
            cancelable: false,
            eventPhase: 0,
            timeStamp: new Date()
        };
    };

    getAll = function (key) {
        var request, result;

        key = typeof key !== "undefined" ? key : null;

        request = new IDBRequest();
        result = [];

        // this is either an IDBObjectStore or an IDBIndex, depending on the context.
        this.openCursor(key).onsuccess = function (event) {
            var cursor, e, target;

            cursor = event.target.result;
            if (cursor) {
                result.push(cursor.value);
                cursor.continue();
            } else {
                if (typeof request.onsuccess === "function") {
                    e = new Event("success");
                    e.target = {
                        readyState: "done",
                        result: result
                    };
                    request.onsuccess(e);
                }
            }
        };

        return request;
    };

    if (typeof IDBObjectStore.prototype.getAll === "undefined") {
        IDBObjectStore.prototype.getAll = getAll;
    }
    if (typeof IDBIndex.prototype.getAll === "undefined") {
        IDBIndex.prototype.getAll = getAll;
    }
}());