/// <summary>
/// Extracts lo/la from a json object
/// </summary>
/// <param name="jObj"></param>
/// <param name="lo"></param>
/// <param name="la"></param>
/// <returns></returns>
protected static bool TryExtractLoLaFromJsonObject(JObject jObj, out object lo, out object la)
{
lo = null;
la = null;
var jProps = jObj.Properties();
var loProp = jProps.FirstOrDefault(p => FlatLonProps.Contains(p.Name.ToLower()));
if (loProp != null)
{
lo = loProp.Value;
}
var laProp = jProps.FirstOrDefault(p => FlatLatProps.Contains(p.Name.ToLower()));
if (laProp != null)
{
la = laProp.Value;
}
if (lo == null && la == null)
{
var locationProp = jProps.FirstOrDefault(p => FlatGeoLocationProps.Contains(p.Name.ToLower()));
if (locationProp != null)
{
if (locationProp.Value is JArray array && array.Count == 2)
{
lo = array.First.Value <double>();
la = array.Last.Value <double>();
}
else
{
TryExtractLoLaFromJsonObject((JObject)locationProp.Value, out lo, out la);
}
}
}
/// <summary>
/// Processes a flat json file; file has got to have numeric lon / longitude & lat / latitude properties; coords are assumed to be in lon/lat
/// </summary>
/// <param name="dbCtx"></param>
/// <param name="path"></param>
/// <param name="dsc"></param>
/// <returns></returns>
public static async Task <DataStore> ProcessJson(DbContext dbCtx, string path, DataSourceCredentials dsc)
{
//assuming a single zip can only be present in a directory, as uploading data for a single layer
//if there is a zip archive, need to extract it
ExtractZip(path);
//test for required shp format files presence...
var file = Directory.GetFiles(path, "*.json").FirstOrDefault();
if (string.IsNullOrEmpty(file))
{
throw MapHive.Core.DataModel.Validation.Utils.GenerateValidationFailedException("JSON", "no_json_file",
"JSON file has not been found");
}
var fName = Path.GetFileNameWithoutExtension(file);
var output = GetDataStore(fName, "json", dsc);
var json = JsonConvert.DeserializeObject(File.ReadAllText(file));
if (json.GetType() != typeof(JArray))
{
throw MapHive.Core.DataModel.Validation.Utils.GenerateValidationFailedException("JSON", "not_array",
"JSON file has not been deserialized to array");
}
var data = new List <Dictionary <string, object> >(((JArray)json).Count);
foreach (JObject jRec in (JArray)json)
{
var rec = new Dictionary <string, object>();
foreach (var jProp in jRec.Properties())
{
var propName = jProp.Name.ToLower();
//basically looking at a flat json file, BUT allowing convenience parsing for some nested properties
if (FlatLonProps.Contains(propName))
{
rec.Add("lo", GetValueFromJsonProperty(jProp.Value));
}
else if (FlatLatProps.Contains(propName))
{
rec.Add("la", GetValueFromJsonProperty(jProp.Value));
}
else if (FlatGeoLocationProps.Contains(propName))
{
if (TryExtractLoLaFromJsonObject((JObject)jProp.Value, out var lo, out var la))
{
rec.Add("lo", lo);
rec.Add("la", la);
}
;
}
else if (FlatGeomProps.Contains(propName))
{
rec.Add("wkt", GetValueFromJsonProperty(jProp.Value));
}
else
{
rec.Add(jProp.Name, GetValueFromJsonProperty(jProp.Value));
}
}
if (rec.ContainsKey("lo") && rec.ContainsKey("la") || rec.ContainsKey("wkt"))
{
data.Add(rec);
}
}
//work out a data model - this is json, so can be totally unpredictable
foreach (var rec in data)
{
foreach (var fProp in rec)
{
//ignore lon/lat, this will be turned into a point
//testing for lon/lat only as data is already normalized
if (fProp.Key == "lo" || fProp.Key == "la" || fProp.Key == "wkt")
{
continue;
}
if (output.DataSource.Columns.Any(c => c.Name == GetSafeDbObjectName(fProp.Key)))
{
continue;
}
if (!CheckIfObjectSafe(fProp.Key))
{
throw MapHive.Core.DataModel.Validation.Utils.GenerateValidationFailedException("ColName", "bad_col_name",
"Column name contains forbidden words");
}
var colType = SystemTypeToColumnDataType(fProp.Value.GetType());
if (colType != ColumnDataType.Unknown)
{
output.DataSource.Columns.Add(new Column
{
Type = colType,
Name = GetSafeDbObjectName(fProp.Key),
FriendlyName = fProp.Key
});
}
}
}
//create object straight away, so when something goes wrong with import, etc. there is a chance for a cleanup bot
//to pick it up and cleanup the orphaned data when necessary
await output.CreateAsync(dbCtx);
return(await ProcessFlatData(dbCtx, output, data));
}