Import mongo_dart package stops text from displaying - mongodb

Question

The following code works just fine...simply displaying some JSON in an unordered list:
import 'dart:html';
import 'dart:convert';
main() {
// Db db = new Db("mongodb://127.0.0.1/mongo_dart-showjson");
querySelector("#sample_text_id")
..onClick.listen(showJSON);
}
void reverseText(MouseEvent event) {
var text = querySelector("#sample_text_id").text;
var buffer = new StringBuffer();
for (int i = text.length - 1; i >= 0; i--) {
buffer.write(text[i]);
}
querySelector("#sample_text_id").text = buffer.toString();
}
void showJSON(MouseEvent event) {
var path = 'hcps.json';
var hcpDisplay = querySelector('#json_length_id');
HttpRequest.getString(path).then((String fileContents) {
List<String> hcpList = JSON.decode(fileContents);
for (int i = 0; i < hcpList.length; i++) {
hcpDisplay.children.add(new LIElement()..text = hcpList[i].toString());
}
});
}
However, when I add an import statement for mongo-dart, the JSON is not displayed, though I do not receive an error:
import 'dart:html';
import 'dart:convert';
import 'package:mongo_dart/mongo_dart.dart';
main() {
Db db = new Db("mongodb://127.0.0.1/mongo_dart-showjson");
querySelector("#sample_text_id")
..onClick.listen(showJSON);
}
...
The mongo_dart package has been added to pubspec.yaml as a dependency.
Does anyone have an idea as to why importing the mongo_dart package would cause the json text not to display, though there is no error? Thank you in advance.

Answer 1

As stated in package readme
mongo-dart is a server-side driver library for MongoDb implemented in
pure Dart
.
It cannot work at client side. Main reason for that - browsers do not have real sockets to connect to databases like mongodb, mysql, postgress and so on. You may look at some database with a RESTful API like CouchDB. Or you should use some middleware - for example objectory.

Answer 2

You could try
import 'package:mongo_dart/mongo_dart.dart' as mdb;
main() {
mdb.Db db = new mdb.Db("mongodb://127.0.0.1/mongo_dart-showjson");
to see if there is a conflict
You could also add a try/catch block
try {
mdb.Db db = new mdb.Db("mongodb://127.0.0.1/mongo_dart-showjson");
} catch(e) {
print(e)
}
sometimes exceptions are swallowed due to the use of zones (might not help here though) but I think it's worth a try.
It is possible that the package cache directory is corrupted.
You could try
pub cache repair