Using Expression Language

The web services virtual appliance-based connector supports expression language in URLs, Header values, and in the Body section.

The following objects can support expression language when you use them with placeholders:

  • Response

  • Plan

  • Application

Writing Expression Language

To use expressions in a web services configuration, wrap them with _#.

Placeholders can be used within an expression. For example:

_#$response.data$.length()_#

One or more placeholders can be used with an expression. For example:

_#$application.city$.concat($application.city2$)_#

Expressions can also be written without any placeholder. For example:

_#'hello'.concat('world')_#

To represent a value in the URL, Header values, and Body sections, you can also use multiple expressions. For example:

"Address" : "_#$application.city$.concat($application.city2$)_# lane name, street name, _#$application.city2$.concat($application.city$)_#"

You can configure consecutive expressions. For example:

_#$application.city$.concat($application.city2$)_#_#$application.city2$.concat($application.city$)_#

To provide a string or literal value, enter it within single quotes ('). For example:

_#'hello'.concat('world')_#

Supported Operations

The connector supports using expression language for the following operations:

No.

String operations (Examples)

1

concat

2

length

3

toUpperCase

4

toLowerCase

5

replace

6

substring

The connector supports six relational operators.

Note
[SPACE] has no impact within the expression for relational operations.

No.

Relational operators

1

>

2

<

3

==

4

!=

5

>=

6

<=

The connector supports five arithmetic operators.

Note
[SPACE] has no impact within the expression for arithmetic operations.

No.

Arithmetic operators

1

+

2

-

3

/

4

*

5

% (Modulus)

The connector supports three logical operators.

Note
[SPACE] has no impact within the expression for logical operations.

No.

Logical operators

1

&&

2

||

3

!

Support for Expression Language in URLs

The web services connector supports expression language in URLs. To use expressions in a URL, wrap them with _#.

The following objects can support expression language when you use them with placeholders:

  • Response

  • Plan

  • Application

For example:

https://domain.com/2/team/members/list/_#$response.data$.length()_#

/2/team/members/list/_#'hello'.concat('world')_#

/2/team/members/list/_# 5 >= 4_#

Support for Expression Language in the Header Values

The web services connector supports expression language in the Header. To use expressions in the Header, wrap them with _#.

The following objects can support expression language when you use them with placeholders:

  • Response

  • Plan

  • Application

For example, the following example displays sample key value pairs:

Count - _#2+2_#

Service-Name - _#$application.serviceName$.concat('service')_#

Support for Expression Language in the Body

The web services connector supports expression language in the Body. To use expressions in the Body, wrap them with _#.

The following objects can support expression language when you use them with placeholders:

  • Response

  • Plan

  • Application

The following example is of a JSON request using expression language in the Body/Payload:

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{
    "type": "$plan.type$",
    "id": "$plan.nativeIdentity$",
    "name": "_#'hello'.concat('world')_#"
    "size": _#$response.data$.length()_#,
    "isActive" : _# 2 >= 2 _#  
    "externalid": "12345"
}

Do not provide QUOTES outside the expression for values like Boolean and numbers. For example:

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{
    "size": _#$response.data$.length()_#,
    "isActive" : _# 2 >= 2 _#  
    "count" : _#'Hello'.length()_#
}

The following is an example of an XML request using expression language in the Body/Payload:

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<worker>
    <fname>_#'hello'.concat('world')_#</fname>
    <lname>$plan.lname$</lname>
    <size>_#$response.data$.length()_#</wid>
    <description> permanent worker</description>
</worker>