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  1. API reference
  2. Welcome
    1. Component overview
    2. Quick start
    3. System requirements
    4. Troubleshooting
    5. Managing license keys
    6. Migrating from WebDataRocks to Flexmonster
  3. Connecting to Data Source
    1. JSON
      1. Connecting to JSON
      2. Connecting to JSON using Flexmonster Data Server
      3. Data types in JSON
    2. CSV
      1. Connecting to CSV
      2. Connecting to CSV using Flexmonster Data Server
      3. Data types in CSV
    3. Database
      1. Connecting to SQL databases
      2. Connecting to a MySQL database
      3. Connecting to a Microsoft SQL Server database
      4. Connecting to a PostgreSQL database
      5. Connecting to an Oracle database
      6. Connecting to other databases
    4. Flexmonster Data Server
      1. Getting started with Flexmonster Data Server
      2. Installation guide
      3. Configurations reference
      4. Data sources guide
      5. Security and authorization guide
      6. The Data Server as a DLL
        1. Getting started with the Data Server as a DLL
        2. Referring the Data Server as a DLL
        3. Implementing the API controller
        4. Implementing the server filter
        5. Implementing the custom parser
        6. DLL configurations reference
        7. The controller's methods for request handling
    5. MongoDB
      1. Introduction to Flexmonster MongoDB Connector
      2. Getting started with the MongoDB Connector
      3. Embedding the MongoDB Connector into the server
    6. Microsoft Analysis Services
      1. Connecting to Microsoft Analysis Services
      2. Getting started with the Accelerator
      3. Installing the Accelerator as a Windows service
      4. Referring the Accelerator as a DLL
      5. Configuring the authentication process
      6. Configuring a secure HTTPS connection
      7. Troubleshooting
    7. Custom data source API
      1. Introduction to the custom data source API
      2. A quick overview of a sample Node.js server
      3. A quick overview of a sample .NET Core server
      4. Implementing the custom data source API server
      5. Implementing filters
      6. Supporting more aggregation functions
      7. Returning data for the drill-through view
    8. Elasticsearch
      1. Connecting to Elasticsearch
      2. Configuring the mapping
    9. Pentaho Mondrian
      1. Connecting to Pentaho Mondrian
      2. Getting started with the Accelerator
      3. Configuring Mondrian roles
      4. Configuring username/password protection
      5. Configuring a secure HTTPS connection
      6. Troubleshooting
  4. Security
    1. Security in Flexmonster
    2. Security aspects of connecting to an OLAP cube
      1. Ways of connecting to an OLAP cube
      2. The data transfer process
      3. Data security
      4. Data access management
  5. Configuring report
    1. What is a report
    2. Data source
    3. Slice
    4. Options
    5. Mapping
    6. Number formatting
    7. Conditional formatting
    8. Set the report for the component
    9. Get the report from the component
    10. Date and time formatting
    11. Configuring global options
    12. Export and print
    13. Calculated values
    14. Custom sorting
  6. Integration with frameworks
    1. Available tutorials
    2. Integration with Angular
    3. Integration with React
    4. Integration with Vue
    5. Integration with Python
      1. Integration with Django
      2. Integration with Jupyter Notebook
    6. Integration with React Native
    7. Integration with AngularJS (v1.x)
    8. Integration with TypeScript
    9. Integration with R Shiny
    10. Integration with jQuery
    11. Integration with Ionic
    12. Integration with Electron.js
    13. Integration with Webpack
    14. Integration with RequireJS
  7. Charts
    1. Available tutorials
    2. Flexmonster Pivot Charts
    3. Integration with Highcharts
    4. Integration with Google Charts
    5. Integration with FusionCharts
    6. Integration with any charting library
  8. Customizing
    1. Customizing the Toolbar
    2. Customizing appearance
    3. Customizing the context menu
    4. Customizing the grid
    5. Localizing the component
  9. Updating to the latest version
    1. Updating to the latest version
    2. Release notes
    3. Migration guide from 2.7 to 2.8
    4. Migration guide from 2.6 to 2.7
    5. Migration guide from 2.5 to 2.6
    6. Migration guide from 2.4 to 2.5
    7. Migration guide from 2.3 to 2.4
    8. Migration guide from 2.2 to 2.3
    9. Documentation for older versions
Table of contents

Connecting to CSV using Flexmonster Data Server

In the previous article, we described how to connect the pivot table to the CSV data source. To gain even better performance while working with CSV datasets, use Flexmonster Data Server – a special server developed by Flexmonster. This server communicates with the client using the custom data source API – our custom communication protocol allowing you to retrieve already aggregated data from a server to Flexmonster Pivot.

Flexmonster Data Server has the following advantages:

  • Reduced browser’s memory usage. Since loading, processing, filtering, and aggregating of the data is made on the server side, Flexmonster Pivot gets the data in a ready-to-show format. Thus, the data is visualized faster, and the browser’s resources are used more efficiently.
  • Larger datasets. Despite Flexmonster Pivot can connect to a CSV file directly, the size of a file is limited by the browser’s capability (on average, up to 100 MB). With Flexmonster Data Server, it is possible to visualize datasets up to 1GB.
  • Built-in security configurations. Flexmonster Data Server is provided with convenient tools for data access security management.
  • Cross-platform solution. The Data Server is available for popular operating systems: Windows, Ubuntu/Linux, and macOS.

Get Flexmonster Data Server on a special download page. You can also find a detailed step-by-step guide on how to install the Data Server there. 

Flexmonster Data Server can be configured in the flexmonster-config.json file. To learn more about all the available configurations, see the configurations reference. To set configurations needed for the CSV data source, follow these steps:

  1. Set up an empty component in your HTML page. If Flexmonster is not yet embedded – return to Quick start. Your code should look similar to the following example:
    <div id="pivotContainer">The component will appear here</div>
    <script src="flexmonster/flexmonster.js"></script>
        var pivot = new Flexmonster({
            container: "pivotContainer",
            toolbar: true,
            licenseKey: "XXXX-XXXX-XXXX-XXXX-XXXX"
  2. The previous step demonstrated how to set up Flexmonster Pivot. Now it’s time to configure Flexmonster Data Server. Set the "Type" property in flexmonster-config.json to "csv". It should be done as follows:
    "DataSources": [
            "Type": "csv"
  3. Create an index for the file with your data. "Path" is the path to the file. For example:
    "DataSources": [
          "Type": "csv",
            "Indexes": {
              "index_csv": {
                  "Path": "./data/data.csv"

    In a similar way, more indexes can be specified:
    "Indexes": {
    "index_csv": {
        "Path": "./data/data.csv"
       "another_index_csv": {
           "Path": "./data/another_data.csv"
    Note: "index_csv" and "another_index_csv" are dataset identifiers. They will be used to configure the data source on the client side.
  4. (optional) If СSV fields are separated by anything other than ",", the "Delimiter" parameter should be specified:
    "Indexes": {
    "index_csv": {
    "Path": "./data/data.csv",
    "Delimiter": ";"
  5. (optional) If decimal parts of numbers in the data are separated by anything other than ".", the "DecimalSeparator" parameter should be specified:
    "Indexes": {
       "index_csv": {
           "Path": "./data/data.csv",
           "Delimiter": ";",
          "DecimalSeparator": ","
  6. On the client side, the report should be configured as follows:
    <div id="pivotContainer">The component will appear here</div>
    <script src="flexmonster/flexmonster.js"></script>
        var pivot = new Flexmonster({
            container: "pivotContainer",
            toolbar: true,
            report: {
               dataSource: {
                type: "api",
                   url: "http://localhost:9500",
             index: "index-csv"

            licenseKey: "XXXX-XXXX-XXXX-XXXX-XXXX"
    Note 1: index must match the name of the index defined in step 2 (e.g., "index_csv").
    Note 2: when Flexmonster Pivot requests the data, Flexmonster Data Server server sends the response and then caches it. In case the component sends the same request once again, the server responds with the data from its cache. The cache is cleared only when the server is restarted, though the cache has a memory limit: when the limit is reached, and the new response can’t be cached, Flexmonster Data Server server deletes one of the previously cached responses from the cache.
  7. Start Flexmonster Data Server by running the following command in the console:

    on Windows


    on macOS and Ubuntu/Linux


As soon as you start Flexmonster Data Server, it automatically preloads the data specified in the "Indexes" property. Thus, when Flexmonster Pivot requests the data, the server responds with already preloaded data.

Note that 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.

What’s next?

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