For a quick start in using the custom data source API (our custom communication protocol), we have prepared a sample .NET Core server that implements it. The sample .NET Core server allows loading data from CSV, JSON, as well as from several databases.
The sample .NET Core server implements version 2.8.5 of the custom data source API.
To get our sample project, download it as ZIP or clone it with the following commands:
git clone https://github.com/flexmonster/api-data-source
cd api-data-source
The sample .NET Core server is in the server-dotnetcore/ folder. Raw data is stored in JSON and CSV formats in the server-dotnetcore/data/ folder.
The sample .NET Core server can be configured in the appsettings.json file, which contains the following properties:
{
DataSources: DataSourceConfigObject[],
DataStorageOptions: DataStorageOptionsObject
}
| Property/Type | Description |
|---|---|
| DataSources DataSourceConfigObject[] | Configures the data sources. |
| DataStorageOptions DataStorageOptionsObject | optional Configures the options for data storage. |
This object allows configuring a data source. It has the following properties:
{
Type: string,
DatabaseType: string,
ConnectionString: string,
Indexes: object
}
| Property/Type | Description |
|---|---|
| Type String | The type of the data source: "json", "csv", or "database". |
| DatabaseType String | optional The type of the database: "mysql", "mssql", "postgresql", or "oracle". Only for the "database" data source type. |
| ConnectionString String | optional A connection string for the database. Only for the "database" data source type. |
| Indexes Object | Contains a list of datasets. Each dataset is represented by a "key": "value" pair, where "key" is the dataset name, and "value" is an IndexObject. |
This object describes a specific dataset. It has the following properties:
{
Path: string,
Query: string,
Delimiter: string
}
This object allows configuring options for data storage. It has the following properties:
{
DataRefreshTime: number
}
The sample .NET Core server configurations vary depending on the data source type: JSON, CSV, or database.
The sample .NET Core server supports only a specific JSON format – an array of objects, where each object is an unordered set of "key": "value" pairs. Here is an example:
[
{
"Color" : "green",
"Country" : "Canada",
"State" : "Ontario",
"City" : "Toronto",
"Price" : 174,
"Quantity" : 22
},
...
]
To connect to a JSON data source with the sample .NET Core server, specify the Type and Indexes properties in the appsettings.json file. For example:
"DataSources": [
{
"Type": "json",
"Indexes": {
"index_json": {
"Path": "./data/data.json"
}
}
}
],
"index_json" is a dataset identifier. It will be used to configure the data source on the client side. Additional indexes can be specified like this:
{
"Type": "json",
"Indexes": {
"index_json": {
"Path": "./data/data.json"
},
"another_index_json": {
"Path": "./data/another_data.json"
}
}
}
To start the sample .NET Core Server, refer to the Run the sample .NET Core server guide.
To see how the connection with the sample .NET Core server is configured in the component, refer to the Configure the report section.
To connect to a CSV data source with the sample .NET Core server, specify the Type and Indexes properties in the appsettings.json file. For example:
"DataSources": [
{
"Type": "csv",
"Indexes": {
"index_csv": {
"Path": "./data/data.csv"
}
}
}
],
"index_csv" is a dataset identifier. It will be used to configure the data source on the client side. Additional indexes can be specified like this:
{
"Type": "csv",
"Indexes": {
"index_csv": {
"Path": "./data/data.csv"
},
"another_index_csv": {
"Path": "./data/another_data.csv"
}
}
}
If CSV fields are not separated by "," but by another character, the Delimiter parameter should be specified:
"index_csv": {
"Path": "./data/data.csv",
"Delimiter": ";"
}
To start the sample .NET Core Server, refer to the Run the sample .NET Core server guide.
To see how the connection with the sample .NET Core server is configured in the component, refer to the Configure the report section.
The sample .NET Core server supports MySQL, Microsoft SQL Server, PostgreSQL, Oracle, and Microsoft Azure SQL databases.
To connect to a database with the sample .NET Core server, specify the Type, DatabaseType, ConnectionString, and Indexes properties in the appsettings.json file. For example:
{
"DataSources": [
{
"Type": "database",
"DatabaseType": "mysql"
"ConnectionString":
"Server=localhost;Port=3306;Uid=root;Pwd=password;Database=database_name",
"Indexes": {
"index_database": {
"Query": "SELECT * FROM tablename"
}
}
}
]
}
"index_database" is a dataset identifier. It will be used to configure the data source on the client side.
ConnectionString is a connection string for the database. Here are some example connection strings for each supported database type:
"Server=localhost;Port=3306;Uid=;Pwd=;Database= ""Server=(localdb)\\MSSQLLocalDB;Uid=;Pwd=;Database= ""Server=localhost;Port=5432;Uid=;Pwd=;Database= ""Data Source=ORCL;User Id=;Password=;"Server=tcp:myserver.database.windows.net,1433;Database= ;User ID=;Password=;Trusted_Connection=False;Encrypt=True; (to connect to Microsoft Azure SQL, set the "DatabaseType" to "mssql")To start the sample .NET Core Server, refer to the Run the sample .NET Core server guide.
To see how the connection with the sample .NET Core server is configured in the component, refer to the Configure the report section.
To start the server, run the following commands in a console:
cd server-dotnetcore
dotnet restore
dotnet run
All requests from Flexmonster Pivot Table are handled by the http://localhost:3400/api/cube endpoint.
As soon as you start the sample .NET Core server, it automatically preloads the data specified in the Indexes property. Thus, when Flexmonster Pivot requests the data, the server responds with the already preloaded data.
Note The preloaded data is kept in the server’s RAM, so the number of indexes you can specify is limited by the amount of RAM available to the server.
On the client side, the report should be configured as follows:
new Flexmonster({
container: "pivotContainer",
componentFolder: "node_modules/flexmonster/",
report: {
dataSource: {
type: "api",
url: "http://localhost:3400/api/cube",
index: "index_json"
}
}
});
Note The index must match the name of the index defined when configuring the data source (e.g., "index_json").
When Flexmonster Pivot requests data, the sample .NET Core server sends a response and then caches it. If the component sends the same request again, the server responds with the data from its cache.
The server’s cache has a limit. When the cache does not have enough space for a new response, the .NET Core server deletes one of the previously cached responses.
The server clears the cache when restarted.
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