The parsing possibilities of the Template-Based extractor are not limited to simple templates. It also allows the user to define complex structures like nested templates where a template element can contain other template elements as children. These children can be defined using the element tag.

To understand how we can define nested templates, let's take an example where we want to extract "int" from an input source followed by a “quotedString” separated by a comma. The structure is delimited by “{“ and “}”. Let's take the input source as {7891, "hello"} that matches the following template definition:

<template name="myTwoElementSequence" startingRegex="{" endingRegex="}" childrenSeparatorRegex="," childrenOrderMatter="true">
   <element name="myFirstElement" extractFomat="int"/>
   <element name="mySecondAndLastElement" extractFomat="quotedString"/>
 </template>

The above example introduces following properties of the “template” element to be defined when creating a template consisting of children elements:

There is also a possibility of searching a text for multiple occurrences of the same child element. In case we want to search for multiple integer values, so we can either define a child element for each occurrence of integer value or we can set the “occurs” property of the element tag defined for the integer value. The property defines how many occurrences of the child element must exist. The value of this property can be set either to a single integer value or to a range of integer values.

For example, we want to extract a sequence of integer values whose count ranges from 3 to 7 separated by comma, and enclosed within “{ }” from the following input:

{12 , 34} {65, 87, 34} {1, 34, 267,123} {123} {1, 23, 45, 67, 89, 12, 23}

The template for the above example can be defined as following:

<template name="myIntegerSequence" startingRegex="{" endingRegex="}" childrenSeparatorRegex="," childrenOrderMatter="true">
  <element name="myResult" extractFormat="int" occurs="3-7"/>
</template>

Following drop down section displays the output:

Click here to see the output

Lastly, let's consider an example which implements all the properties explained above to define a nested template structure for extracting relevant ticket information from a mail containing text about the customer support tickets:

Following drop down section displays the text input source:

Click here to see the input

The following nested XML template defines the structure of a customer support ticket and can be used to extract the customer support ticket information from the above input source:

<template name="CustomerTicketInfo" childrenSeparatorRegex=",">
<element name="customer_name" startingRegex="customerName" extractFormat="quotedString" />
<element name="customer_id" startingRegex="customerId" extractFormat="int" />
<element name="ticket_id" startingRegex="ticketId" extractFormat="int" />
<element name="ticket_subject" startingRegex="ticketSubject" extractFormat="quotedString" />
<element name="ticket_content" startingRegex="ticketContent" extractFormat="quotedString"/>
</template>

You can observe the use of the name, extractFormat, startingRegex and childSeparatorRegex properties in the above defined template.

Following image shows the parsed result in JSON string format after applying the template: