This article explains connecting a Page or an RDL report to a JSON data source.

Connect to a JSON Data Source

1. In the designer, go to the Report Explorer, right-click the Data Sources node and select the Add Data Source option or click the Add button and then select the Data Source option.
2. In the Report Data Source dialog that appears, select the General page and enter the name of the data source in the Name field. By default, the data source name is set to DataSource1. This name appears as a child node to the Data Sources node in the Report Explorer.
3. Under the Type field, select Json Provider.
   
4. In the Content tab, set the type of Json data to 'External file or URL'.
5. Click the dropdown next to the Select or type the file name or URL field and select the <Browse...> option to specify the json file path, or enter the URL. For example, connect to the 'https://demodata.grapecity.com/northwind/odata/v1/Orders' data source.
   
   The Connection String tab displays the generated connection string as shown below:
   
       jsondoc=https://demodata.grapecity.com/northwind/odata/v1/Orders

   For more information, see the Configuration Properties for JSON Data Source section.
6. Verify the generated connection string by clicking the Validate DataSource icon .
7. Click OK to save the changes and close the Report Data Source dialog.

Configuration Settings for JSON Data Source

The JSON Data Provider provides the following configuration settings under the Connection section in the Report Data Source dialog.

The Content tab describes the type of JSON data you want to use for connecting to a data source. The options available for specifying the JSON data are as follows:

• External file or URL: Enter the path or URL of an external JSON data file or select the file from the drop-down which displays the JSON files available in the same folder as the report. The connection string generated using this option starts with the keyword jsondoc.
• Embedded: Enter the path of the JSON data file to embed in the report. You can enter the data manually or edit the data in the selected JSON file. The connection string generated using this option starts with the keyword jsondata.
• Expression: Enter an expression to bind to the JSON data at runtime.

The Schema tab describes the options available for specifying the JSON schema in ActiveReports.

• Auto: This is the default option that auto-generates the JSON schema.
• External file or URL: Enter the path or URL of an external JSON schema file or select the file from the drop-down which displays the JSON files available in your system. The connection string generated using this option starts with the keyword schemadoc.
• Embedded: Enter the path of the JSON schema file to embed in the report. You can enter the schema manually or edit the schema in the selected JSON file. The connection string generated using this option starts with the keyword schemadata.
  For generating JSON schema, use the JSON schema generator available at https://jsonschema.net. 

The JSON schema describes the structure of the JSON data. In ActiveReports, the JSON data provider uses the JSON schema to obtain fields. For more information on JSON schema, please see https://json-schema.org/understanding-json-schema/.
JSON data provider does not support the following schema keywords, such as:

• type: Indicates the type of JSON schema element. See here for more information on the type keyword.
• properties: Indicates the properties collection for JSON schema elements with the object type. See here for more information on properties keyword.
• items: Indicates the definition of items for JSON schema elements with array type. Only single values are supported.
  For example, "items" : [ {...}, {...}, {...} ] is not supported because it contains multiple values. See here for more information on items keyword.
• definitions: Indicates the independent definitions which can be used by other JSON schema elements using $ref keyword. See here for more information on definitions keyword.
• $ref: Indicates the reference to a definition for JSON schema elements with the object type. Only "definitions" ({ $ref : #/definitions/... }) references are supported.

The Connection String tab displays the JSON connection string based on the defined configuration settings in the Content and Schema tab.

• If you choose the External file or URL option, the connection string will be as follows -
  jsondoc=C:\customers.json
  or
  jsondoc=https://demodata.grapecity.com/northwind/odata/v1/Orders
  
• If you choose the Embedded option, the connection string will be generated as follows -

  Connection String	Copy Code
  jsondata={"Customers":[{"Id":"ALFKI", "CompanyName":"Alfreds Futterkiste", "Country":"Germany"}, {"Id":"ANATR", "CompanyName":"Ana Trujillo Emparedados y helados", "Country":"Mexico"}], "ResponseStatus":{}}

• If you choose the Expression option, the connection string will start with an "equals to" as shown -
         

  Connection String	Copy Code
  ="jsondata={ 'Name': 'Name'};schemadata={ '$schema': 'http://json-schema.org/draft-04/schema#', 'definitions': {}, 'id': 'http://example.com/example.json', 'properties': { 'Name': { 'id': '/properties/Name', 'type': 'string' } }, 'type': 'object'}"

  Caution: If you include an expression in the connection string, use single quotes (') in jsondoc or jsondata and schemadoc or schemadata instead of the double quotes (") .

  For example, the following connection string is invalid:

  Connection String (invalid)	Copy Code
  ="jsondata={ "Name": "Name"};schemadata={ "$schema": "http://json-schema.org/draft-04/schema#", "definitions": {}, "id": "http://example.com/example.json", "properties": { "Name": { "id": "/properties/Name", "type": "string" } }, "type": "object"}"

Build Connection String

It is possible to configure the JSON data source connection string by using the Edit button in the Connection String tab of the Report Data Source - General dialog. This allows fetching a JSON from an external URL using the specified method (GET, POST) and other request options. The Edit button opens the Configure JSON Data Source dialog where you can create a JSON connection string with parameters such as data path, method (GET, POST), headers, and body.

To connect to a external URL containing JSON data, some settings are required to be configured as elaborated.

Data Path:

The URL or the endpoint of the request consists of service root URI, resource path, and query options. The fields from json provided in the data source's endpoint are extracted depending on the dataset’s settings. A URL with IP address (eg. http://10.64.2.17:51980/admin) or with a machine name (eg. http://in-esxi-w10v17:8080/) is also valid.

HTTP Headers:

Contains additional info related to the request or the response, for eg, provide expected content type necessary for establishing connection with endpoint which must return json. For example, providing credentials to login to a service/URI to retrieve data. Collection editor to add header/value pair for headers is available. This parameter has to be set to send the request body in JSON format.

Example of Header,Value pairs:

• Content-Type, application-json (to send the request body in JSON format)

• Accept, application-json (to read the response in the desired format)

HTTP Method:

Request method can be GET (included in URL) or POST (included in 'body').

• GET requests data from a specified resource. GET method examples are provided in Sample connection strings and dataset queries section.
• POST requests allow defining a body as an expression to obtain data. 
  

Request Body (POST):

Text area, applicable only in case of POST HTTP request.

You should provide a valid combination of configuration settings for the successful processing of the connection string with the POST method. If a combination of a valid URL, a valid header name, a valid header value, and a valid body is provided, then the connection string can be saved and validated. Only in this case, it is possible to create a dataset based on this data source.

If an invalid URL, an invalid header name or header value, invalid body, or a combination of these settings is entered, error message is displayed while validating the connection string.         

Request Body:

Body for the POST request method. The text area is enabled only when the HTTP Method is set to POST.

Sample connection strings and dataset queries

1. Simple

jsondoc=https://demodata.grapecity.com/northwind/api/v1/Categories

$.[*]

To convert the format of data in the requested URI to JSON, use either $format query or Http Header as shown in the following connection strings:

• $format query:

jsondoc=https://services.odata.org/v3/northwind/northwind.svc/Invoices?$format=json

•  Http Header:

headers={"Accept":"application/json"};jsondoc=https://services.odata.org/v3/northwind/northwind.svc/Invoices

$.value[*]

2. Using Parameters to query specific fields

headers={"Accept":"application/json"};jsondoc=https://services.odata.org/v3/northwind/northwind.svc/Invoices?$select=ShipName,ShipRegion

$.value[*]

3. Using Parameters to filter database fields

headers={"Accept":"application/json"};jsondoc=https://services.odata.org/v3/northwind/northwind.svc/Invoices?$filter=ShipName eq 'Alfreds%20Futterkiste'

$.value[*]