Parameterization of the Connections

Parameterization of the Connections

Almost all Connection parameters can be configured using {tokens}. Just enter the {variable name} into any field. The system will replace the {token} on the value of the global variable with the same name.

Below is an example:

Parameterization of the Database Connections

By default, Etlworks Integrator opens all databases connections that are referenced in the flow before the flow execution starts. It closes all connections and coordinates distributed transactions when the flow stops, successfully or with an error. 

It works perfectly well but creates a problem when the database connection is parametrized using {tokens}. When the flow starts the values of the tokens (global variables) are not available yet so the flow fails before it even starts executing the transformations.

Read how to configure the database connection so it can work with {tokens}.

URL with parameters (dynamic URL)

Step 1. Create a Connection to the Web Service using a tokenized URL:

URL example: https://my.api.com/metrics/?apiKey=111-222-333&periodStart={period_start}&periodEnd={period_end}

Notice the tokens {period_start} and {period_end}. Make sure that the token names are unique for each endpoint.

Step 2. Create a Flow that pulls data from the web service, where the source (FROM) Connection is the Connection created in Step 1.

Step 3. Create a JavaScript Flow, which will be used to set tokens.

Below is an example of the JavaScript code:

importPackage(com.toolsverse.config);
importPackage(java.util);

// getting properties
var props = SystemConfig.instance().getProperties();

// getting instance of the Calendar
var cal = Calendar.getInstance();

// calculating today
var now = new java.util.Date(cal.getTimeInMillis());

// calculating 50 days ago
cal.add(Calendar.DATE, -50);
var then = new java.util.Date(cal.getTimeInMillis());

// setting tokens
props.put("period_start", Utils.date2Str(then, "yyyy-MM-dd"));
props.put("period_end", Utils.date2Str(now, "yyyy-MM-dd"));

Step 4. Create a nested Flow which includes the Flows created in Step 2 and Step 3.