So this is my code
_image1 = File(pickedImage.path);
List<int> imageBytes = _image1.readAsBytesSync();
String base64Image = base64.encode(imageBytes);
_shcpImg = base64Image;
But when I print the string _shcpImg, it just prints a part of the string, because when I copy and paste that base64 into an online converter, it only shows a really tiny piece of the image. So the thing is that the string is not showing completely or somehow the base64 encoder is not working well.
Any suggestions?
From the comments, since you are using VsCode and you can't print the full string (long string)
You can use log from dart: developer,
if the string is REALLY LONG, There is a workaround to fix this, the idea is to divide your long string into small pieces (in the example, 800 length for each piece) using RegExp and then iterate into the result and print each piece.
void printWrapped(String text) {
final pattern = new RegExp('.{1,800}'); // 800 is the size of each chunk
pattern.allMatches(text).forEach((match) => print(match.group(0)));
}
Related
Basically I'm trying to convert a base64 jpeg image to normal image in flutter using
Image.memory(base64Decode(stringBase64))
the image initially used to be jp/2 format which isn't supported by flutter so i converted the jp/2 base64 string to bitmap in java and then to base64 string jpeg to be able to decode it in flutter using this code :
public static String encodeToBase64(Bitmap image)
{
Bitmap immagex=image;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
immagex.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] b = baos.toByteArray();
String imageEncoded = Base64.encodeToString(b, Base64.DEFAULT);
return imageEncoded;
}
how ever when i try to decode this base64 string in flutter i'm getting this error
Invalid character (at character 77)
/9j/4AAQSkZJRgABAQAAAQABAAD/4gIoSUNDX1BST0ZJTEUAAQEAAAIYAAAAAAIQAABtbnRyUkdC
which is pointing to the last C in the given line.
i don't seem understand where does the issue come from since i can convert my base64 string to image online but in flutter it throws that exception every time
thank you very much #Jamesdlin for the solution that was given in the comments
The issue was due to whitespace in the base64 string , solved by using
base64.decode(photoBase64.replaceAll(RegExp(r'\s'), '')),
If your URI contains data after the comma as it is defined by RFC-2397. Dart's Uri class is based on RFC-3986, so you can't use it.
Split the string by a comma and take the last part of it:
String uri = 'data:image/gif;base64,...';
Uint8List _bytes = base64.decode(uri.split(',').last);
REFERENCE: https://stackoverflow.com/a/59015116/12382178
For interaction with an API, I need to pass the course code in <string><space><number> format. For example, MCTE 2333, CCUB 3621, BTE 1021.
Yes, the text part can be 3 or 4 letters.
Most users enter the code without the space, eg: MCTE2333. But that causes error to the API. So how can I add a space between string and numbers so that it follows the correct format.
You can achieve the desired behaviour by using regular expressions:
void main() {
String a = "MCTE2333";
String aStr = a.replaceAll(RegExp(r'[^0-9]'), ''); //extract the number
String bStr = a.replaceAll(RegExp(r'[^A-Za-z]'), ''); //extract the character
print("$bStr $aStr"); //MCTE 2333
}
Note: This will produce the same result, regardless of how many whitespaces your user enters between the characters and numbers.
Try this.You have to give two texfields. One is for name i.e; MCTE and one is for numbers i.e; 1021. (for this textfield you have to change keyboard type only number).
After that you can join those string with space between them and send to your DB.
It's just like hack but it will work.
Scrolling down the course codes list, I noticed some unusual formatting.
Example: TQB 1001E, TQB 1001E etc. (With extra letter at the end)
So, this special format doesn't work with #Jahidul Islam's answer. However, inspired by his answer, I manage to come up with this logic:
var code = "TQB2001M";
var i = course.indexOf(RegExp(r'[^A-Za-z]')); // get the index
var j = course.substring(0, i); // extract the first half
var k = course.substring(i).trim(); // extract the others
var formatted = '$j $k'.toUpperCase(); // combine & capitalize
print(formatted); // TQB 1011M
Works with other formats too. Check out the DartPad here.
Here is the entire logic you need (also works for multiple whitespaces!):
void main() {
String courseCode= "MMM 111";
String parsedCourseCode = "";
if (courseCode.contains(" ")) {
final ensureSingleWhitespace = RegExp(r"(?! )\s+| \s+");
parsedCourseCode = courseCode.split(ensureSingleWhitespace).join(" ");
} else {
final r1 = RegExp(r'[0-9]', caseSensitive: false);
final r2 = RegExp(r'[a-z]', caseSensitive: false);
final letters = courseCode.split(r1);
final numbers = courseCode.split(r2);
parsedCourseCode = "${letters[0].trim()} ${numbers.last}";
}
print(parsedCourseCode);
}
Play around with the input value (courseCode) to test it - also use dart pad if you want. You just have to add this logic to your input value, before submitting / handling the input form of your user :)
How to display Unicode Smiley from json response dynamically in flutter. It's display properly when i declare string as a static but from dynamic response it's not display smiley properly.
Static Declaration: (Working)
child: Text("\ud83d\ude0e\ud83d\ude0eThis is just test notification..\ud83d\ude0e\ud83d\ude0e\ud83d\udcaf\ud83d\ude4c")
Dynamic Response:
"message":"\\ud83d\\ude4c Be Safe at your home \\ud83c\\udfe0",
When i'm parse and pass this response to Text then it's consider Unicode as a String and display as a string instead of Smiley Code is below to display text with smiley:
child: Text(_listData[index].message.toString().replaceAll("\\\\", "\\"))
Already go through this: Question but it's only working when single unicode not working with multiple unicode.
Anyone worked with text along with unicode caracter display dynamically then please let me know.
Another alternate Good Solution I would give to unescape characters is this:
1st ->
String s = "\\ud83d\\ude0e Be Safe at your home \\ud83c\\ude0e";
String q = s.replaceAll("\\\\", "\\");
This would print and wont be able to escape characters:
\ud83d\ud83d Be Safe at your home \ud83c\ud83d
and above would be the output.
So what one can do is either unescape them while parsing or use:
String convertStringToUnicode(String content) {
String regex = "\\u";
int offset = content.indexOf(regex) + regex.length;
while(offset > 1){
int limit = offset + 4;
String str = content.substring(offset, limit);
// print(str);
if(str!=null && str.isNotEmpty){
String uni = String.fromCharCode(int.parse(str,radix:16));
content = content.replaceFirst(regex+str,uni);
// print(content);
}
offset = content.indexOf(regex) + regex.length;
// print(offset);
}
return content;
}
This will replace and convert all the literals into unicode characters and result and output of emoji:
String k = convertStringToUnicode(q);
print(k);
😎 Be Safe at your home 🈎
That is above would be the output.
Note: above answer given would just work as good but this is just when you want to have an unescape function and don't need to use third-party libraries.
You can extend this using switch cases with multiple unescape solutions.
Issue resolved by using below code snippet.
Client client = Client();
final response = await client.get(Uri.parse('YOUR_API_URL'));
if (response.statusCode == 200) {
// If the server did return a 200 OK response,
// then parse the JSON.
final extractedData = json.decode(response.body.replaceAll("\\\\", "\\"));
}
Here we need to replace double backslash to single backslash and then decode JSON respone before set into Text like this we can display multiple unicode like this:
final extractedData = json.decode(response.body.replaceAll("\\",
"\"));
Hope this answer help to other
I have this Flutter bit of code here, which is a large String. It would be different every time, but the format would stay the same since it's a template:
"William\nWilliam description here...\n$^170^ usd" + Uuid().v4()
I want to extract the 170 part, and then convert it to interger, so I can remove it from list of ints. I have tried a lot of code, but it isn't working for a few reasons, one is I can't extract the actual number from the String between the ^ and ^, and then I can't convert it to interger. Here's the try function (incomplete).
deleteSumItem(item) {
final regEx = RegExp(r'\^\d+(?:\^\d+)?'); //not sure if this is right regex for the String template
final priceValueMatch = regEx.firstMatch(item); //this doesn't return the particular number extracted
_totalPrice.remove(priceValueMatch); //i get error here that it isn't a int
_counter = _counter - priceValueMatch; //then remove it from interger as int
}
The function would take that String ("William\nWilliam description here...\n$^170^ usd" + Uuid().v4()) template (the number would be different between the ^ ^, but the template is same), then convert it to interger and remove from list as int.
Try the following:
void main() {
RegExp regExp = RegExp(r'\^(\d+)\^');
String input = r"William\nWilliam description here...\n$^170^ usd";
String match = regExp.firstMatch(input).group(1);
print(match); // 170
int number = int.parse(match);
print(number); // 170
}
I have changed the RegExp so it does correctly capture the number in its own capture group. It looked like you got a little confused in the process of creating the RegExp but it could also be I am missing some details about the problem.
I am parsing a local JSON file that has words containing rarely used special characters in Icelandic.
When displaying the characters I get mixed up symbols but not the characters, for some others I just get a square instead of a symbol.
I am using this type of encoding "\u00c3"
Update: Example of the characters I am using: þ, æ, ý, ð
Q: What is the best way to display those kind of characters and avoid any chance of display failures?
Update #2:
How I am parsing:
Future<Null> getAll() async{
var response = await
DefaultAssetBundle.of(context).loadString('assets/json/dictionary.json');
var decodedData = json.decode(response);
setState(() {
for(Map word in decodedData){
mWordsList.add(Words.fromJson(word));
}
});
}
The class:
class Words{
final int id;
final String wordEn, wordIsl;
Words({this.id, this.wordEn, this.wordIsl});
factory Words.fromJson(Map<String, dynamic> json){
return new Words(
id: json['wordId'],
wordEn: json['englishWord'],
wordIsl: json['icelandicWord']
);
}
}
JSON Model:
{
"wordId": 47,
"englishWord": "Age",
//Here's a String that has two special characters
"icelandicWord": "\u00c3\u00a6vi"
}
I had similar issues with accented characters. They were not displayed as expected.
This worked for me
final codeUnits = source.codeUnits;
return Utf8Decoder().convert(codeUnits);
The problem is that your JSON is stored locally.
Let's say you have
Map<String, String> jsonObject = {"info": "Æ æ æ Ö ö ö"};
So to show your text correctly you have to encode and decode back your JSON with utf-8.
I understand that's serialization and deserialization are costly operations, but's it's a workaround for locally stored JSON objects that contains UTF-8 texts.
import 'dart:convert';
jsonDecode(jsonEncode(jsonObject))["info"]
If you get that JSON from server, then it's much more simpler, for example in dio package you can chose contentType params that's is "application/json; charset=utf-8" by default.