What's the new syntax for the following please? :
Map mAcctData = JSON.parse(sResponse); // sResponse is Json String
parse (and stringify) has been moved to a top-level function.
import 'dart:json' as JSON; // note the JSON name
main() {
var text = // some text...
var map = JSON.parse(text); // using the JSON name
}
or
import 'dart:json'; // note, no JSON name
main() {
var text = // some text...
var map = parse(text); // calling parse as a top-level function.
}
Related
How can I get a List object in "result"? I tried with toList() method on "request" object, but I can't solve this.
import 'dart:io';
import 'dart:convert';
void main() async {
var request = await HttpClient().getUrl(Uri.parse('https://jsonplaceholder.typicode.com/posts')); // produces a request object
var response = await request.close(); // sends the request
// transforms and prints the response
var result;
await for (var contents in response.transform(Utf8Decoder())) {
result =contents;
}
print(result);
}
Thanks,
Daniel
Firstly, response.transform return multiple parts of result, you need to get all by joining them together:
var result = new StringBuffer();
await for (var contents in response.transform(Utf8Decoder())) {
result.write(contents);
}
Secondly, you result is just a "text" (in json format), not an "object" as you expect, you need to decode it:
List<dynamic> myList = jsonDecode(result.toString());
print(myList);
Simply the following
List elements = json.decode(response.body);
i have a function called foo which is listening to the stdout, what i want is to return some string which i got from stdout. here is my function;
dynamic foo(process) {
return (
process.stdout.transform(UTF8.decoder).listen((data) {
String s = data.toString();
// print(s);
if (s.contains("received event of")) {
var s1 = s.split(":");
print("${s1[1]}");
return s1[1];
}
}));
}
I want to return s1 to the calling function
here a callback function do the trick
foo(process, callback) {
process.stdout.transform(UTF8.decoder).listen((data) {
String s = data.toString();
if (s.contains("received event of")) {
String message = s.split(":")[1];
callback(message);
}
});
}
and here i am calling the method and printing the data which i get get from stream.
foo(process,(data){print(data);})
This should do what you want
Future<String> dynamic foo(process) {
return process.stdout.transform(UTF8.decoder).map((data) {
String s = data.toString();
// print(s);
if (s.contains("received event of")) {
var s1 = s.split(":");
print("${s1[1]}");
return s1[1];
} else {
return null;
}
}).where((val) => val != null).first;
}
Your custom code either returns a valid value or null.
I changed listen to map to be able to use additional stream methods.
where filters invalid values (null) and returns the first non-null value.
The caller of the foo method needs to handle the returned Future (using for example async/await) to get the value when it becomes available.
Use it like
bar() async {
...
var input = await foo(proc);
print(input);
}
I think that everybody wants this:
import 'dart:io';
import 'dart:convert';
// Using system encoding:
var outputStr = await process.stdout.transform(systemEncoding.decoder).join();
// Using UTF-8 encoding:
var outputStr = await process.stdout.transform(utf8.decoder).join();
I have an SIU S12 message that does not contain a PV2 segment. However, when I get the parsed message from NHAPI, the parent group for PV2, the SIU_S12_PATIENT group, return 1 for currentReps ("PV2"), which means the PV2 is present.
var parser = new NHapi.Base.Parser.PipeParser();
var parsedMessage = parser.Parse(message) as NHapi.Model.V231.Message.SIU_S12;
var patientGroup=parsedMessage.GetPATIENT(0);
// This call should not create the segment if it does not exist
int pv2Count=patientGroup.currentReps("PV2");
//pv2Count is 1 here despite no PV2 segment exists in the message
//also Both GetAll("PV2") and SegmentFinder say the PV2 segment is present
//DG1RepetitionsUsed is also 1 despite no DG1 segment is present in the message
I am trying to avoid writing code to evaluate every field in the segment. PV2 is just an example - there are a lot more segments that could be missing from the message source.
I am using NHAPI v 2.4, the latest version.
Update: following Tyson's suggestion I come up with this method；
var parser = new NHapi.Base.Parser.PipeParser();
var parsedMessage = parser.Parse(message) as NHapi.Model.V231.Message.SIU_S12;
var encodingChars = new NHapi.Base.Parser.EncodingCharacters('|', null);
var patientGroup = parsedMessage.GetPATIENT(0);
var dg1 = (NHapi.Model.V231.Segment.DG1) (patientGroup.GetStructure("DG1"));
string encodedDg1 = NHapi.Base.Parser.PipeParser.Encode(dg1, encodingChars);
bool dg1Exists = string.Compare(encodedDg1,
"DG1", StringComparison.InvariantCultureIgnoreCase)==0;
easiest thing that I have found to do is to determine if a segment is in a message is to search the actual string of the message for the segment name plus a pipe. So, for example
if(message.Contains("PV2|"))
{
//do something neat
}
From my experience, it is either that, or examining every sub-field under the segment to see if there is a value.
EDIT
I found another way to check that might work a little better. The PipeParser class has a couple of static methods on it that takes in ISegment, IGroup, and IType objects that will return a string representation of the object NHapi reference.
Sample code:
string validTestMessages =
"MSH|^~\\&|ADT1|MCM|LABADT|MCM|198808181126|SECURITY|ADT^A01|MSG00001|P|2.6\r" +
"EVN|A01-|198808181123\r" +
"PID|||PID1234^5^M11^HBOC^CPI^HV||JONES^WILLIAM^A^III||19610615000000|M||2106-3|1200 N ELM STREET^^GREENSBORO^NC^27401-1020|GL||||S||S|123456789|9-87654^NC\r" +
"PV1|1|I|||||TEST^TEST^TEST||||||||||||||||||||||||||||||||||||||||||||\r";
var encodingChars = new EncodingCharacters('|', null);
PipeParser parser = new PipeParser();
var message = parser.Parse(validTestMessages);
PV1 pv1 = (PV1)message.GetStructure("PV1");
var doctor = pv1.GetAttendingDoctor(0);
string encodedMessage = PipeParser.Encode(pv1, encodingChars);
Console.WriteLine(encodedMessage);
encodedMessage = PipeParser.Encode(doctor, encodingChars);
Console.WriteLine(encodedMessage);
Output:
PV1|1|I|||||TEST^TEST^TEST
TEST^TEST^TEST
if there is no segment or the item is empty, then the PiperParser will return an empty string.
You can read segment line by line to a file and add in hl7 Record object and check segment exist or not.
package com.sachan.ranvijay#gmail.com.hl7.msg;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import org.nule.lighthl7lib.hl7.Hl7Record;
import org.nule.lighthl7lib.hl7.Hl7Segment;
import com.stpl.hl7.dto.HL7PatientInfoDTO;
/**
* This class will parse the hl7 message. it can accept message file in the format of java.io.file
* as well as String. Its Uses org.nule.lighthl7lib.hl7.Hl7Record
* as a main component.
* #author Ranvijay.Singh
*
*/
public class PrepareHL7Message {
StringBuilder hl7Msg = new StringBuilder();
Hl7Record record = null;
public PrepareHL7Message(File file) throws Exception {
BufferedReader reader = new BufferedReader(
new FileReader(file));
String str = reader.readLine();
while (str != null) {
hl7Msg.append(str).append("\r");
str = reader.readLine();
}
reader.close();
try{
record = new Hl7Record(hl7Msg.toString());
}catch (Exception e) {
throw e;
}
}
public PrepareHL7Message(String msg) throws Exception {
try{
record = new Hl7Record(msg);
}catch (Exception e) {
throw e;
}
}
private HL7PatientInfoDTO getPatientOrderingPhysician(HL7PatientInfoDTO padto) {
Hl7Segment seg = record.getSegment("PV1");
if(seg!=null)
padto.setOrderingPhysician(seg.field(7).toString());
return padto;
}
}
//DTO.............
package com.sachan.ranvijay#gmail.com.hl7.dto;
public class HL7PatientInfoDTO {
/**
* maped with PV1-7
*/
private String orderingPhysician;
/**
* #return the orderingPhysician
*/
public String getOrderingPhysician() {
return orderingPhysician;
}
/**
* #param orderingPhysician the orderingPhysician to set
*/
public void setOrderingPhysician(String orderingPhysician) {
this.orderingPhysician = orderingPhysician;
}
}
So i have this code:
import 'dart:html';
import 'dart:json';
class BaseModel {
Map values;
String _url;
// another basic properties
// constructor defined here
fetch() {
var el = document.query('#container');
HttpRequest.getString(_url).then(
(result) {
values = new Map.from(parse(result));
el.innerHtml = values['name'];
return result;
})
}
}
void main() {
BaseModel bm = new BaseModel(url: /path/to/test.json);
bm.fetch();
}
And i have a json data like this:
{
"name" : "Andrew",
"age" : 20
}
I expect to see "Andrew" on the DOM, but i see nothing. If i change the
el.innerHtml = "SOME_TEXT"
then i can see the "SOME_TEXT" text displayed.
Can you guys help me?
What do you see in the JavaScript console if you print the name?
What happens if you add an error handler?
Something along the following lines:
HttpRequest.getString(_url)
.then((result) {
values = new Map.from(parse(result));
print(values['name']);
el.innerHtml = values['name'];
return result;
})
.catchError((e) => print(e));
Like the question at Dynamic class method invocation in PHP I want to do this in Dart.
var = "name";
page.${var} = value;
page.save();
Is that possible?
There are several things you can achieve with Mirrors.
Here's an example how to set values of classes and how to call methods dynamically:
import 'dart:mirrors';
class Page {
var name;
method() {
print('called!');
}
}
void main() {
var page = new Page();
var im = reflect(page);
// Set values.
im.setField("name", "some value").then((temp) => print(page.name));
// Call methods.
im.invoke("method", []);
}
In case you wonder, im is an InstanceMirror, which basically reflects the page instance.
There is also another question: Is there a way to dynamically call a method or set an instance variable in a class in Dart?
You can use Dart Mirror API to do such thing. Mirror API is not fully implemented now but here's how it could work :
import 'dart:mirrors';
class Page {
String name;
}
main() {
final page = new Page();
var value = "value";
InstanceMirror im = reflect(page);
im.setField("name", value).then((_){
print(page.name); // display "value"
});
}
You can use Serializable
For example:
import 'package:serializable/serializable.dart';
#serializable
class Page extends _$PageSerializable {
String name;
}
main() {
final page = new Page();
var attribute = "name";
var value = "value";
page["name"] = value;
page[attribute] = value;
print("page.name: ${page['name']}");
}