public static async Task <HttpResponseMessage> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "{datasetname}")] HttpRequest req,
string datasetname,
ILogger log, ExecutionContext context)
{
var baseconfig = new ConfigurationBuilder()
.SetBasePath(context.FunctionAppDirectory)
.AddJsonFile("local.settings.json", optional: true, reloadOnChange: true)
.AddEnvironmentVariables()
.Build();
var configOptions = new ConfigurationOptions();
baseconfig.Bind("AzureTableSchema", configOptions);
if (configOptions.Environment == null || configOptions.Environment == "")
{
configOptions.Environment = baseconfig["ASPNETCORE_ENVIRONMENT"];
}
if (configOptions.ConnectionString == null || configOptions.ConnectionString == "")
{
log.LogError($"ConnectionString is not specified");
return(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("{ 'error': 'service misconfiguration' }")
});
}
Configuration configuration = new Configuration(configOptions);
string datasetconfigStr = null;
try
{
datasetconfigStr = await configuration.GetConfigurationAsync(datasetname);
} catch (Exception e)
{
log.LogError(e, $"Unable to query config string with key '{datasetname}'");
return(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("{ 'error': 'dataset not found' }")
});
}
if (datasetconfigStr == null)
{
log.LogError($"Unable to find config string with key '{datasetname}'");
return(new HttpResponseMessage(HttpStatusCode.NotFound)
{
Content = new StringContent("{ 'error': 'dataset not found' }")
});
}
AzureTableSchema schema = null;
try
{
schema = JsonConvert.DeserializeObject <AzureTableSchema>(datasetconfigStr, new JsonSerializerSettings {
NullValueHandling = NullValueHandling.Include
});
} catch (Exception e)
{
log.LogError(e, $"Unable to deserialize config string with key '{datasetname}'");
return(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("{ 'error': 'service misconfiguration' }")
});
}
// starting with result.
var result = new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new PushStreamContent(async(outputStream, httpContext, transportContext) =>
{
// Add query parameters passby
// https://benjii.me/2017/04/parse-modify-query-strings-asp-net-core/
var uri = new Uri(schema.SourceUrl);
var baseUri = uri.GetComponents(UriComponents.Scheme | UriComponents.Host | UriComponents.Port | UriComponents.Path, UriFormat.UriEscaped);
var query = QueryHelpers.ParseQuery(uri.Query);
var qb = new QueryBuilder();
foreach (var item in query)
{
qb.Add(item.Key, item.Value.AsEnumerable());
}
List <string> allowedParameters = new List <string>()
{
"$filter", "$orderby", "$select", "$skip", "$top"
};
foreach (var item in req.Query)
{
if (allowedParameters.Contains(item.Key) && !query.ContainsKey(item.Key)) // do not allow to overwrite existing values
{
qb.Add(item.Key, item.Value.AsEnumerable());
}
}
var targetUrl = baseUri + qb.ToQueryString();
//HttpRequestMessage r = new HttpRequestMessage(HttpMethod.Get, schema.SourceUrl);
HttpRequestMessage r = new HttpRequestMessage(HttpMethod.Get, targetUrl);
r.Headers.Add("Accept", "application / json; odata = nometadata");
// TODO: Add request query string parameters to request
var response = await httpClient.SendAsync(r);
var serializer = new JsonSerializer();
//var ss = new StringBuilder();
bool inValueArray = false;
string lastPropertyName = "";
using (var sr = new StreamReader(await response.Content.ReadAsStreamAsync(), new UTF8Encoding(), false))
using (var jsonTextReader = new JsonTextReader(sr))
using (JsonWriter writer = new JsonTextWriter(new StreamWriter(outputStream, new UTF8Encoding(), 512, false)))
{
while (jsonTextReader.Read())
{
if (!inValueArray)
{
if (jsonTextReader.TokenType == JsonToken.PropertyName)
{
lastPropertyName = jsonTextReader.Value.ToString();
}
else if (jsonTextReader.TokenType == JsonToken.StartArray && lastPropertyName == "value")
{
inValueArray = true;
// write object beginning and such..
await writer.WriteStartObjectAsync();
await writer.WritePropertyNameAsync("value");
await writer.WriteStartArrayAsync();
}
}
else
{
if (jsonTextReader.TokenType == JsonToken.StartObject) // read entire object
{
JObject obj = JObject.Load(jsonTextReader);
// add missing columns
if (schema.AddMissing)
{
foreach (var item in schema.Columns)
{
if (!obj.ContainsKey(item.Key))
{
obj.Add(item.Key, item.Value.Default);
}
}
}
// remove unspecified columns
if (schema.RemoveUnspecified)
{
var props = obj.Properties().Select(a => a.Name).ToList();
foreach (var item in props)
{
if (!schema.Columns.ContainsKey(item))
{
obj.Remove(item);
}
}
}
var objstr = JsonConvert.SerializeObject(obj,
new JsonSerializerSettings()
{
NullValueHandling = NullValueHandling.Include,
Formatting = Formatting.None
}
);
log.LogInformation(objstr);
await writer.WriteRawValueAsync(objstr);
await writer.FlushAsync();
}
else if (jsonTextReader.TokenType == JsonToken.EndArray)
{
await writer.WriteEndArrayAsync();
await writer.WriteEndObjectAsync();
inValueArray = false;
}
}
}
}
outputStream.Close();
}),
};
result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = $"{datasetname}.json"
};
return(result);
}
public static async Task <HttpResponseMessage> RunSchema(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "{datasetname}/schema")] HttpRequest req,
string datasetname,
ILogger log, ExecutionContext context)
{
var baseconfig = new ConfigurationBuilder()
.SetBasePath(context.FunctionAppDirectory)
.AddJsonFile("local.settings.json", optional: true, reloadOnChange: true)
.AddEnvironmentVariables()
.Build();
var configOptions = new ConfigurationOptions();
baseconfig.Bind("AzureTableSchema", configOptions);
if (configOptions.Environment == null || configOptions.Environment == "")
{
configOptions.Environment = baseconfig["ASPNETCORE_ENVIRONMENT"];
}
if (configOptions.ConnectionString == null || configOptions.ConnectionString == "")
{
log.LogError($"ConnectionString is not specified");
return(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("{ 'error': 'service misconfiguration' }")
});
}
Configuration configuration = new Configuration(configOptions);
string datasetconfigStr = null;
try
{
datasetconfigStr = await configuration.GetConfigurationAsync(datasetname);
}
catch (Exception e)
{
log.LogError(e, $"Unable to query config string with key '{datasetname}'");
return(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("{ 'error': 'dataset not found' }")
});
}
if (datasetconfigStr == null)
{
log.LogError($"Unable to find config string with key '{datasetname}'");
return(new HttpResponseMessage(HttpStatusCode.NotFound)
{
Content = new StringContent("{ 'error': 'dataset not found' }")
});
}
AzureTableSchema schema = null;
try
{
schema = JsonConvert.DeserializeObject <AzureTableSchema>(datasetconfigStr, new JsonSerializerSettings {
NullValueHandling = NullValueHandling.Include
});
}
catch (Exception e)
{
log.LogError(e, $"Unable to deserialize config string with key '{datasetname}'");
return(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("{ 'error': 'service misconfiguration' }")
});
}
return(new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new StringContent(JsonConvert.SerializeObject(schema.Columns, new JsonSerializerSettings {
NullValueHandling = NullValueHandling.Include
}))
});
}