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Zuko edited this page Jan 21, 2026 · 1 revision

NetworkManager - Qt Network Integration

QNetworkAccessManager wrapper với disk cache và feature flag integration

Overview

NetworkManager cung cấp:

  • QNetworkAccessManager instance
  • Disk cache (50MB)
  • Feature flag integration (PSA_ENABLE_NETWORK)
  • UI thread only (Qt limitation)

API Reference

Access

from core import QtAppContext

ctx = QtAppContext.globalInstance()

# Check feature enabled
if ctx.isFeatureEnabled('network'):
    network = ctx.network  # QNetworkAccessManager | None

QNetworkAccessManager

from PySide6.QtNetwork import QNetworkRequest
from PySide6.QtCore import QUrl

request = QNetworkRequest(QUrl('https://api.example.com'))
reply = network.get(request)
reply.finished.connect(lambda: handleResponse(reply))

Usage Examples

Basic GET Request

from core import QtAppContext
from PySide6.QtNetwork import QNetworkRequest
from PySide6.QtCore import QUrl

ctx = QtAppContext.globalInstance()

if ctx.isFeatureEnabled('network'):
    network = ctx.network
    
    request = QNetworkRequest(QUrl('https://api.example.com/data'))
    reply = network.get(request)
    reply.finished.connect(lambda: onReplyFinished(reply))

def onReplyFinished(reply):
    if reply.error() == QNetworkReply.NoError:
        data = reply.readAll()
        print(data.data().decode('utf-8'))
    else:
        print(f'Error: {reply.errorString()}')
    reply.deleteLater()

POST Request

from PySide6.QtNetwork import QNetworkRequest
from PySide6.QtCore import QUrl, QByteArray

network = ctx.network
request = QNetworkRequest(QUrl('https://api.example.com/users'))
request.setHeader(QNetworkRequest.ContentTypeHeader, 'application/json')

data = QByteArray(b'{"name": "John", "email": "john@example.com"}')
reply = network.post(request, data)
reply.finished.connect(lambda: onPostFinished(reply))

UI Thread vs Background Thread

✅ UI Thread (NetworkManager)

# In controller/handler (UI thread)
class MyHandler(BaseCtlHandler):
    def onLoadDataClicked(self):
        ctx = QtAppContext.globalInstance()
        network = ctx.network
        
        request = QNetworkRequest(QUrl('https://api.example.com'))
        reply = network.get(request)
        reply.finished.connect(self.onDataLoaded)

❌ Background Thread (Use requests)

# In task (background thread)
import requests

class DataFetchTask(AbstractTask):
    def handle(self):
        # Don't use NetworkManager here!
        # Use requests library instead
        response = requests.get('https://api.example.com')
        data = response.json()

Feature Flag

Enable/Disable

# .env file
PSA_ENABLE_NETWORK=true   # Enable NetworkManager
PSA_ENABLE_NETWORK=false  # Disable NetworkManager

Check Before Use

ctx = QtAppContext.globalInstance()

if ctx.isFeatureEnabled('network'):
    # Use NetworkManager
    network = ctx.network
else:
    # Fallback to requests
    import requests
    response = requests.get('https://api.example.com')

Disk Cache

Location: {CACHE_DIR}/network_cache
Size: 50MB
Auto-managed: Qt handles cache eviction

Best Practices

✅ DO

# Check feature flag
if ctx.isFeatureEnabled('network'):
    network = ctx.network

# Use in UI thread only
class MyHandler(BaseCtlHandler):
    def onButtonClicked(self):
        network = ctx.network
        # Make request...

# Delete replies
def onFinished(reply):
    # Process reply...
    reply.deleteLater()  # Don't forget!

❌ DON'T

# Don't use in background threads
class MyTask(AbstractTask):
    def handle(self):
        network = ctx.network  # Wrong! Use requests

# Don't forget to delete replies
def onFinished(reply):
    data = reply.readAll()
    # Missing: reply.deleteLater()  # Memory leak!

# Don't assume network enabled
network = ctx.network  # May be None!

Related Documentation

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