MQL4 WebRequest POST Json to Django API using Django rest framework, getting \x00 at the end of body

External question — Stack Overflow Stack Exchange Author: GuiDrn Original post: https://stackoverflow.com/questions/71149477 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. I am using Django only for few weeks so there might be some mistakes. I have an API using Django rest framework, which seems to work well. Using postman every thing is ok I send data using WebRequest in Mql4 to the api string data = "{ ... }“; char post_data[]; post_data = StringToCharArray(data, post_data, WHOLE_ARRAY); int r = WebRequest("POST", "http://127.0.0.1/api/symbol/","Content-Type: application/json",5000, data,res_data, res_headers); The data given to WebRequest is fine but the function add \x00 at the end of body. Here is my post data when it arrive to Django rest framework {'Content-Length': '982', 'Content-Type': 'application/json', 'Accept': 'image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*', 'Host': '127.0.0.1', 'Accept-Language': 'fr,en', 'Accept-Charset': '*,utf-8', 'Connection': 'Keep-Alive', 'Proxy-Connection': 'Keep-Alive', 'Pragma': 'no-cache', 'Cache-Control': 'no-cache', 'User-Agent': 'MetaTrader 4 Terminal/4.1353 (Windows NT 6.1; x86)'} b'{"name": "GOLDs","date_market": "2022-02-01T00:00:00.000000Z","period": "M1","open_price": 1797.64,"close_price": 1870.91,"low_price": 1788.33,"high_price": 1879.12,"bollinger_band":[{"period":"M1","moving_average_period":20,"standard_deviation":1.5,"high":1936.06829,"low":1717.61271,"moving_average":1826.8405},{"period":"M1","moving_average_period":20,"standard_deviation":2,"high":1972.47755,"low":1681.20345,"moving_average":1826.8405},{"period":"M1","moving_average_period":20,"standard_deviation":2.5,"high":2008.88681,"low":1644.79419,"moving_average":1826.8405}],"moving_average":[{"period":"M1","moving_average_period":50,"type": "0","value":1569.6854},{"period":"M1","moving_average_period":100,"type": "0","value":1399.8002},{"period":"M1","moving_average_period":200,"type": "0","value":1245.38985}],"MACD_zerolag":[{"period":"M1","fast_EMA_period":12,"slow_EMA_period":26,"signal_EMA_period":9,"histogram_value":-0.01794,"signal_value":0.09465,"MACD_value":0.07671}]}\x00' so I get the following error : POST /api/symbol/ - 400 {'Content-Type': 'application/json', 'Vary': 'Accept', 'Allow': 'GET, POST, HEAD, OPTIONS'} b'{"detail":"JSON parse error - Extra data: line 1 column 982 (char 981)"}' if a send the same data removing the \x00 with Postman every thing goes well. Is there a misconfiguration client side with mql4 ? Or can I remove the received data to remove this \x00 ? Here is my models.py from django.db import models, transaction M1 = 'M1' M5 = 'M5' M15 = 'M15' M30 = 'M30' H1 = 'H1' H4 = 'H4' DAILY = 'DAILY' WEEKLY = 'WEEKLY' MONTHLY = 'MONTHLY' PERIOD_CHOICES = ( (M1, 'Une minute'), (M5, 'Cinq minutes'), (M15, 'Quinze minutes'), (M30, 'Trente minutes'), (H1, 'Une heure'), (H4, 'Quatre heures'), (DAILY, 'Journalier'), (WEEKLY, 'Hebdomadaire'), (MONTHLY, 'Mensuel'), ) class BollingerBand(models.Model): period = models.CharField(max_length=30, choices=PERIOD_CHOICES, verbose_name='Période') moving_average_period = models.CharField(max_length=8) standard_deviation = models.DecimalField(max_digits=6, decimal_places=2) symbol = models.ForeignKey('API.Symbol', on_delete=models.CASCADE, related_name='bollinger_band', default=1) high = models.DecimalField(max_digits=12, decimal_places=6) low = models.DecimalField(max_digits=12, decimal_places=6) moving_average = models.DecimalField(max_digits=12, decimal_places=6) class MovingAverage(models.Model): period = models.CharField(max_length=30, choices=PERIOD_CHOICES, verbose_name='Période') moving_average_period = models.CharField(max_length=8) type = models.TextField(max_length=30) symbol = models.ForeignKey('API.Symbol', on_delete=models.CASCADE, related_name='moving_average', default=1) value = models.DecimalField(max_digits=12, decimal_places=6) class MACDZR(models.Model): period = models.CharField(max_length=30, choices=PERIOD_CHOICES, verbose_name='Période') fast_EMA_period = models.CharField(max_length=4) slow_EMA_period = models.CharField(max_length=4) signal_EMA_period = models.CharField(max_length=4) symbol = models.ForeignKey('API.Symbol', on_delete=models.CASCADE, related_name='MACD_zerolag', default=1) histogram_value = models.DecimalField(max_digits=12, decimal_places=6) signal_value = models.DecimalField(max_digits=12, decimal_places=6) MACD_value = models.DecimalField(max_digits=12, decimal_places=6) class Symbol(models.Model): name = models.CharField(max_length=30, default='undefined') date_created = models.DateTimeField(auto_now_add=True) date_updated = models.DateTimeField(auto_now=True) date_market = models.DateTimeField() period = models.CharField(max_length=30, choices=PERIOD_CHOICES, verbose_name='Période') open_price = models.DecimalField(max_digits=12, decimal_places=6) close_price = models.DecimalField(max_digits=12, decimal_places=6) high_price = models.DecimalField(max_digits=12, decimal_places=6) low_price = models.DecimalField(max_digits=12, decimal_places=6) class Meta: constraints = [ models.UniqueConstraint( fields=['name', 'date_market', 'period'], name='unique_symbol' ) ] def __str__(self): return self.name Serializers.py from rest_framework import serializers from API.models import Symbol, BollingerBand, MACDZR, MovingAverage class BollingerBandSerializer(serializers.ModelSerializer): class Meta: model = BollingerBand fields = ['period', 'moving_average_period', 'standard_deviation', 'symbol', 'high', 'low', 'moving_average'] class MovingAverageSerializer(serializers.ModelSerializer): class Meta: model = MovingAverage fields = ['period', 'moving_average_period', 'type', 'symbol', 'value'] class MACDZRSerializer(serializers.ModelSerializer): class Meta: model = MACDZR fields = ['period', 'fast_EMA_period', 'slow_EMA_period', 'signal_EMA_period', 'symbol', 'histogram_value', 'signal_value', 'MACD_value'] class SymbolSerializer(serializers.ModelSerializer): bollinger_band = BollingerBandSerializer(many=True) moving_average = MovingAverageSerializer(many=True) MACD_zerolag = MACDZRSerializer(many=True) class Meta: model = Symbol fields = ['id', 'name', 'date_created', 'date_updated', 'date_market', 'period', 'open_price', 'close_price', 'high_price', 'low_price', 'bollinger_band', 'moving_average', 'MACD_zerolag' ] def create(self, validated_data): bollinger_bands_data = validated_data.pop('bollinger_band') moving_averages_data = validated_data.pop('moving_average') MACDs_zerolag_data = validated_data.pop('MACD_zerolag') symbol = Symbol.objects.create(**validated_data) for bollinger_band_data in bollinger_bands_data: BollingerBand.objects.create(symbol=symbol, **bollinger_band_data) for MACD_zerolag_data in MACDs_zerolag_data: MACDZR.objects.create(symbol=symbol, **MACD_zerolag_data) for moving_average_data in moving_averages_data: MovingAverage.objects.create(symbol=symbol, **moving_average_data) return symbol and settings.py """ Django settings for trading_project project. Generated by 'django-admin startproject' using Django 4.0.2. For more information on this file, see https://docs.djangoproject.com/en/4.0/topics/settings/ For the full list of settings and their values, see https://docs.djangoproject.com/en/4.0/ref/settings/ """ from pathlib import Path import os # Build paths inside the project like this: BASE_DIR / 'subdir'. BASE_DIR = Path(__file__).resolve().parent.parent # Quick-start development settings - unsuitable for production # See https://docs.djangoproject.com/en/4.0/howto/deployment/checklist/ # SECURITY WARNING: keep the secret key used in production secret! SECRET_KEY = 'django-insecure-)6f&ci7@)t96(k^7am%66@%e%(88a%u00+3h5a13s461#q7dqm' # SECURITY WARNING: don't run with debug turned on in production! DEBUG = True ALLOWED_HOSTS = [ '0.0.0.0', '127.0.0.1', ] # Application definition INSTALLED_APPS = [ 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', #'django.contrib.sites', 'rest_framework', 'authentication', 'API', ] MIDDLEWARE = [ 'django.middleware.security.SecurityMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware', 'django.middleware.clickjacking.XFrameOptionsMiddleware', 'request_logging.middleware.LoggingMiddleware', ] ROOT_URLCONF = 'trading_project.urls' TEMPLATES = [ { 'BACKEND': 'django.template.backends.django.DjangoTemplates', 'DIRS': [ os.path.join(BASE_DIR, 'templates/'), ], 'APP_DIRS': True, 'OPTIONS': { 'context_processors': [ 'django.template.context_processors.debug', 'django.template.context_processors.request', 'django.contrib.auth.context_processors.auth', 'django.contrib.messages.context_processors.messages', ], }, }, ] WSGI_APPLICATION = 'trading_project.wsgi.application' # Database # https://docs.djangoproject.com/en/4.0/ref/settings/#databases DATABASES = { 'default': { 'ENGINE': 'django.db.backends.postgresql_psycopg2', 'NAME': 'trading_project', 'USER': 'admin', 'PASSWORD': 'testpassword', 'HOST': 'localhost', 'PORT': '5432', } } # Password validation # https://docs.djangoproject.com/en/4.0/ref/settings/#auth-password-validators AUTH_PASSWORD_VALIDATORS = [ { 'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator', }, { 'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator', }, { 'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator', }, { 'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator', }, ] # Internationalization # https://docs.djangoproject.com/en/4.0/topics/i18n/ LANGUAGE_CODE = 'fr-fr' TIME_ZONE = 'UTC' USE_I18N = True USE_TZ = True # Static files (CSS, JavaScript, Images) # https://docs.djangoproject.com/en/4.0/howto/static-files/ STATIC_URL = 'static/' STATIC_ROOT = os.path.join(BASE_DIR, 'static/') # Default primary key field type # https://docs.djangoproject.com/en/4.0/ref/settings/#default-auto-field DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField' AUTH_USER_MODEL = 'authentication.User' LOGIN_URL = 'login' LOGIN_REDIRECT_URL = 'home' LOGOUT_URL = 'logout' LOGOUT_REDIRECT_URL = 'login' LOGGING = { 'version': 1, 'disable_existing_loggers': False, 'handlers': { 'console': { 'class': 'logging.StreamHandler', }, }, 'loggers': { 'django.request': { 'handlers': ['console'], 'level': 'DEBUG', # change debug level as appropiate 'propagate': False, }, }, } if anyone have a simple solution for that Thanks

External answer — Stack Overflow Stack Exchange Author: GuiDrn Original post: https://stackoverflow.com/a/71154520 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. I find my solution, when I converted my data string to post_Data object the length was not WHOLE_ARRAY, but StringLen. StringToCharArray(data, post_data,0, StringLen(data));