I am using SQL.js for SQLite in my chrome app , I am loading external db file to perform query , now i want to save my changes to local storage to make it persistent , it is already define here-
https://github.com/kripken/sql.js/wiki/Persisting-a-Modified-Database
i am using the same way as defined in the article-
function toBinString (arr) {
var uarr = new Uint8Array(arr);
var strings = [], chunksize = 0xffff;
// There is a maximum stack size. We cannot call String.fromCharCode with as many arguments as we want
for (var i=0; i*chunksize < uarr.length; i++){
strings.push(String.fromCharCode.apply(null, uarr.subarray(i*chunksize, (i+1)*chunksize)));
}
return strings.join('');
}
function toBinArray (str) {
var l = str.length,
arr = new Uint8Array(l);
for (var i=0; i<l; i++) arr[i] = str.charCodeAt(i);
return arr;
}
save data to storage -
var data =toBinString(db.export());
chrome.storage.local.set({"localDB":data});
and to get data from storage-
chrome.storage.local.get('localDB', function(res) {
var data = toBinArray(res.localDB);
//sample example usage
db = new SQL.Database(data);
var result = db.exec("SELECT * FROM user");
});
Now when i make a query , i am getting this error -
Error: file is encrypted or is not a database
is there any differnces for storing values in chrome.storage and localStorage ? because its working fine using localStorage, find the working example here-
http://kripken.github.io/sql.js/examples/persistent.html
as document sugggested here -
https://developer.chrome.com/apps/storage
we don't need to use stringify and parse in chrome.storage API unlike localStorage, we can directly saves object and array.
when i try to save result return from db.export without any conversion, i am getting this error-
Cannot serialize value to JSON
So please help me guys what will be the approach to save db export in chrome's storage, is there anything i am doing wrong?
Related
I am trying to read data from a firebase real time database and store it in a list to use in my flutter app.
As seen in the code below, I start by creating a reference to the database. I also create some global variables, where "itemName" stores the name of the item in the database, "itemID" stores the id of each item in the database and "itemNames" is a list of all the item names in the database.
The "activate listeners" method listens to the database, and returns any values if they are changed. Each item ID starts with a J, and continues onto J1, J2, J3 etc. Hence I am using a for loop to access all the item IDs.
The issue I am having is that the itemNames are successfully being stored in the itemNames list, and can be see when I print the list within the for loop (The first print line).
However, when I try print the list value OUTSIDE the for loop, it prints an empty list for loop (second print line).
So in other words, the list is not retaining the elements added to it during the for loop.
Any help would be much appreciated!
final DatabaseReference _dbRef = FirebaseDatabase.instance.ref();
late StreamSubscription _dailySpecialStream;
//Stores the description of each menu item in the DB
String itemName = "";
String itemID = "";
List<String> itemNames = [];
//"Listens for any changes being made to the DB, and updates our app in real time"
void _activateListeners() {
for (int i = 0; i <= 10; i++) {
itemID = "J$i";
_dailySpecialStream =
_dbRef.child("menuItem/$itemID/itemName").onValue.listen((event) {
itemName = event.snapshot.value.toString();
itemNames.addAll([itemName]);
print(itemNames);
});
}
print(itemNames);
}
That is the expected behavior. Data is loaded from Firebase (and most modern cloud APIs) asynchronously, and while that is happening your main code continues to run.
You can most easily see this by placing some print statements:
print('before starting to load data');
for (int i = 0; i <= 10; i++) {
itemID = "J$i";
_dailySpecialStream =
_dbRef.child("menuItem/$itemID/itemName").onValue.listen((event) {
print('loaded data: %i');
});
}
print('after starting to load data');
If you run this, you'll see something like:
before starting to load data
after starting to load data
loaded data: 0
loaded data: 1
loaded data: 2
loaded data: 3
...
So as you can see the after print statement that is lowest in your code, actually printed before any of the data was loaded. This is probably not what you expected, but explains perfectly why the print statement you had outside the loop doesn't print the data: it hasn't been loaded yet!
The solution for this type of problem is always the same: you have to make sure the code that requires the data is inside the callback, or it is called from there, or it is otherwise synchronized.
A simple way to do the latter is by using get() instead of onValue, and then use await on the Future that is returns:
print('before starting to load data');
for (int i = 0; i <= 10; i++) {
itemID = "J$i";
_dailySpecial = await _dbRef.child("menuItem/$itemID/itemName").get();
print('loaded data %i: ${_dailySpecial.value}');
}
print('after starting to load data');
Now with this, the print statements will be in the order you expected.
Where can I find code and instruction on how to allow users to upload files with Google Form without login?
I searched all over here and couldn't find any information.
https://developers.google.com/apps-script/reference
Thanks in advance.
The user will be uploading the files to your drive. So, google needs to verify the user. If there is no verification, someone can fill your drive in no time.
It is for your safety to know who has uploaded, so, login is must.
There's a workaround, I'm in a hurry to write the code now, but if you're interested let me know and I'll edit later.
Basically, you set up a web app with apps script, then you setup a custom HTML form, you'll have to manually collect the file, convert is to base64 then json, then when you catch it in apps script you reverse the process and save it wherever you want in your drive.
Since the user will be executing the script as you, there's no verification required
/*
These functions basically go through a file array and reads the files first as binary string (in second function), then converts the files to base64 string (func 1) before stringifying the files (after putting their base64 content into an object with other metadata attached; mime, name e.t.c);
You pass this stringified object into the body part of fetch(request,{body:"stringified object goes here"})
see next code block for how to read in apps script and save the files to google drive
N.B. The body data will be available under doPost(e){e.postData.contents}
*/
async function bundleFilesForUpload(){
let filesDataObj = [];
let copy = {fileInfo:{"ogname":"","meme":""},fileData:""};
for(let i = 0 ; i < counters.localVar.counters.filesForUploadArr.length ; i++){
let tempObj = JSON.parse(JSON.stringify(copy));
let file = counters.localVar.counters.filesForUploadArr[i];
tempObj.fileInfo.ogname = file.name;
tempObj.fileInfo.meme = file.type;
tempObj.fileData = await readFile(file).then((file)=>{
file = btoa(file);
return file;
}).then((file)=>{
return file;
})
filesDataObj.push(tempObj);
}
return filesDataObj;
}
async function readFile (file){
const toBinaryString = file => new Promise((resolve, reject) => {
const reader = new FileReader();
reader.readAsBinaryString(file);
reader.onload = () => resolve(reader.result);
reader.onerror = error => reject(error);
});
let parsedFile = null;
parsedFile = await toBinaryString(file);
return parsedFile;
}
/*From doPost downward, we read the file Array convert the base64 to blob and make a file in google drive using the blob and metadata we have, you may also see some sheet code, I'm using sheet as db for this */
//in buit function doPost in Code.gs
doPost(e){
const myDataObj = JSON.parse(e.postData.contents);
mainFileFunc(myDataObj.params[0].dataObj.images);
//the actual object structure might look different from yours, console log around
}
function mainFileFunc(fileArr) {
let myArrObj = [{"madeit":"toFileF"}];
let copy = JSON.parse(JSON.stringify(myArrObj[0]));
//sheet.getRange("A1").setValue(JSON.stringify(fileArr.length));
for(let i=0 ; i < fileArr.length ; i++){
myArrObj.push(copy);
let blob = doFileStuff(fileArr[i].data,fileArr[i].info[0].mime,fileArr[i].id);
myArrObj[i] = uploadFileOne(blob,fileArr[i].id);
myArrObj[i].mime = fileArr[i].info[0].mime;
myArrObj[i].realName = fileArr[i].name;
// sheet.getRange("A"+(i+1)).setValue(myArrObj[i].name);
// sheet.getRange("B"+(i+1)).setValue(myArrObj[i].url);
// sheet.getRange("C"+(i+1)).setValue(myArrObj[i].mime);
// sheet.getRange("D"+(i+1)).setValue(myArrObj[i].size);
}
return myArrObj;
}
function doFileStuff(filedata,filetype,filename){
var data = Utilities.base64Decode(filedata, Utilities.Charset.UTF_8);
var blob = Utilities.newBlob(data,filetype,filename);
return blob;
}
function uploadFileOne(data,filename) {
let myObj = {}
myObj["name"] = "";
myObj["realName"] = "Story_Picture";
myObj["url"] = "";
myObj["mime"] = "";
myObj["size"] = "";
myObj["thumb"] = "nonety";
var folders = DriveApp.getFoldersByName("LadhaWeb");
while (folders.hasNext()) {
var folder = folders.next();
folder.createFile(data);
}
var files = DriveApp.getFilesByName(filename);
while (files.hasNext()) {
var file = files.next();
myObj.name = file.getName();
myObj.url = file.getUrl();
myObj.mime = file.getMimeType();
myObj.size = file.getSize();
}
return myObj;
}
You can view the full frontend code for this project here and the backend here.
Hope this helps someone.
I have figured out how to run a Google App Script project/function on a form submit using the information at https://developers.google.com/apps-script/guides/triggers/events#form-submit_4.
Once I have e I can call e.response to get a FormResponse object and then call getItemResponses() to get an array of all of the responses.
Without iterating through the array and checking each one, is there a way to find the ItemResponse for a specific question?
I see getResponseForItem(item) but it looks like I have to somehow create an Item first?
Can I some how use e.source to get the Form object and then find the Item by question, without iterating through all of them, so I could get the Item object I can use with getResponseForItem(item)?
This is the code I use to pull the current set of answers into a object, so the most current response for the question Your Name becomes form.yourName which I found to be the easiest way to find responses by question:
function objectifyForm() {
//Makes the form info into an object
var myform = FormApp.getActiveForm();
var formResponses = myform.getResponses()
var currentResponse = formResponses[formResponses.length-1];
var responseArray = currentResponse.getItemResponses()
var form = {};
form.user = currentResponse.getRespondentEmail(); //requires collect email addresses to be turned on or is undefined.
form.timestamp = currentResponse.getTimestamp();
form.formName = myform.getTitle();
for (var i = 0; i < responseArray.length; i++){
var response = responseArray[i].getResponse();
var item = responseArray[i].getItem().getTitle();
var item = camelize(item);
form[item] = response;
}
return form;
}
function camelize(str) {
str = str.replace(/[\.,-\/#!$%\^&\*;:{}=\-_`~()#\+\?><\[\]\+]/g, '')
return str.replace(/(?:^\w|[A-Z]|\b\w|\s+)/g, function(match, index) {
if (+match === 0) return ""; // or if (/\s+/.test(match)) for white spaces
return index == 0 ? match.toLowerCase() : match.toUpperCase();
});
}
//Use with installable trigger
function onSubmittedForm() {
var form = objectifyForm();
Logger.log(form);
//Put Code here
}
A couple of important things.
If you change the question on the form, you will need to update your
code
Non required questions may or may not have answers, so check if answer exists before you use it
I only use installable triggers, so I know it works with those. Not sure about with simple triggers
You can see the form object by opening the logs, which is useful for finding the object names
I am working on GeoSpatial project which I am using MongoDB as database and Meteor for creating my app. I have used mapReduce in my query. in order to visualize the result of query I put Google map API in the meteor. To make long story short, I want to get some location as an Input from meteor app and when I click on the button, see the result in Google Map API (which is placed in Meteor app.
Now my problem is that I cannot pass the variables (the ones that I got from textbox) from client function to server side in meteor.
Here is some part of my code in client side (here I have passed text1 and text2 as an argument in call function):
var text2 = document.getElementById("coords2").value;
var text1 = document.getElementById("coords1").value;
Meteor.call("doMapReducePointQuery", text1, text2, function(error, result){
if(error){
console.error(error)
}
else{
console.log("It works!");
}....// continued
and here is the part of the code in server side:
if (Meteor.isServer) {
Meteor.methods({
'doMapReducePointQuery': function(txt1,txt2) {
pxx=parseInt(txt1);
pyy=parseInt(txt2);
console.log(pxx); **// here I can see the pxx and pyy**
console.log(pyy);
var mapFn = function () { **// in this function I cannot get the pxx and pyy**
var px = -83.215; // here I just manually set the number, here where i want to get value from the text box and set it to px and py
var py = 41.53;
var key= this._id;
var value={
id:this._id,
type: this.type,
};
if (this.geometry.minlon <= px && px <= this.geometry.maxlon && this.geometry.minlat <= py && py <= this.geometry.maxlat) {
emit(key, value);
}
};
var reduceFn = function (key, value) { ....... // continued
As I mentioned in comments within the code, I can pass txt1 and txt2 to the doMapReducePointQuery method but the I cannot access then access the coordinates within my mapReduce mapFn function. I need to use txt1 (px) and txt2 (py) values in mapFn.
I did some research about how to make a variable, global in meteor, some of the people used "scope", but they did not mentioned how.
I would be really appreciated if somebody help me!
I am uploading files using the following code:
using (var s = File.OpenRead(#"C:\2gbDataTest.zip"))
{
var t = Task.Run<ObjectId>(() =>
{
return fs.UploadFromStreamAsync("2gbDataTest.zip", s);
});
return t.Result;
}
//works for the files below 2gb
var t1 = fs.DownloadAsBytesAsync(id);
Task.WaitAll(t1);
var bytes = t1.Result;
I am getting error
I am new to MongoDb and C#, can any one please show me how to download files greater than 2GB in size?
You are hitting the limit in terms of the size a byte array (kept in memory) download can be, so your only choice is to use a Stream instead like you are doing when you upload, something like (with a valid destination):
IGridFSBucket fs;
ObjectId id;
FileStream destination;
await fs.DownloadToStreamAsync(id, destination);
//Just writing complete code for others, This will work ;
//Thanks to "Adam Comerford"
var fs = new GridFSBucket(database);
using (var newFs = new FileStream(filePathToDownload, FileMode.Create))
{
//id is file objectId
var t1 = fs.DownloadToStreamAsync(id, newFs);
Task.WaitAll(t1);
newFs.Flush();
newFs.Close();
}