Other Functions

Function

Description

Result Type

Backend Support

Frontend Support

and(Boolean condition1 [, Boolean condition2, ...])

Returns true if all provided conditions are true.

Boolean

Yes

No

case(Object defaultResult, Boolean condition1, Object result1 [, Boolean condition2, Object result2, ...])

Returns result1 if condition1 is true, else returns result2 if condition2 is true, and so on. If none of the provided conditions is true, returns defaultResult.

Object

Yes

No

catch(Object normalResult [, Object errorResult])

This function tries to evaluate the normalResult argument and returns it if evaluation was successful. However, if any error occurred during evaluation of normalResult the behaviour differs:

• If errorResult is not specified, the text of normalResult evaluation error is returned

• If errorResult is specified, it's returned instead

Object

Yes

Yes

dataBlock(Object value[, String charset[, String name]])

Constructs a new DataBlock from the string value using the provided charset (or default charset if charset is not specified). If human-readable name is specified, adds it to the data block.

DataBlock

Yes

No

evaluate(String expression [, String defaultContext [, DataTable defaultTable [, Integer defaultRow]]])

Evaluates its string argument as an Iotellect expression and returns the result. Uses custom defaultContext, defaultTable and defaultRow if provided.

Object

Yes

Yes

fail(Boolean condition, String message[, Object result])

Terminates expression evaluation with the provided error message if the condition is true. If the condition is false, returns the provided result or null.

Object

Yes

No

fetchDataBlock(DataBlock data)

Fills input value with the encoded bytes of the DataBlock fetched from the database.

DataBlock

Yes

Yes

if(Boolean condition, Object resultIfTrue, Object resultIfFalse)

Returns resultIfTrue if condition is true, else returns resultIfFalse.

Object

Yes

No

ld(String variable)

Returns value of local environmental variable named variable. This variable can be only defined by calling st() function. External (non-local) environmental variables will not be returned, they should be referred via {env/variable}.

Object

Yes

Yes

login()

Returns login name of a current user (e.g. john@company.com).

In contrast to user() function, this function returns a username that was used during external authentication (e.g. via LDAP or Active Directory).

If external authentication was not used, this function returns value of a local Iotellect Server user, i.e. works similar to user() function.

String

Yes

Yes

or(Boolean condition1 [, Boolean condition2, ...])

Returns true if any of the provided conditions is true.

Boolean

Yes

No

script(String name, Object parameter1, Object parameter2, ...)

Calls a widget script called name and passes several parameters to it. Returns script output object.

Object

Yes

Yes

This function is available only inside widget binding expressions.

sleep(Integer milliseconds)

Causes the thread processing this expression to pause execution for the specified number of milliseconds.

Null

Yes

Yes

st(String variable, Object value)

Defines or updates local environmental variable named variable by setting it to value. Also, returns value.

This function is useful for reusing certain parts of expression to optimize evaluation performance and make it more compact.

Example: st('var', {a} *  {b} * {c} * {d} * {e}) > 50 ? ld('var') : -1

This expression returns multiplication of fields a, b, c, d and e if it's larger than 50 and -1 otherwise. However, the multiplication is calculated just once and stored inside local environmental variable called var.

Object

Yes

Yes

trace(Object value [, String message])

Logs the value accompanied by the message as a system event to enable expression debugging. Returns the unchanged value.

Object

Yes

Yes

user()

Returns name of a current Iotellect Server user (e.g. admin or john), i.e. user account whose permissions are used during the expression evaluation.

In contrast to login() function, this function returns a name of a local user account, not a login name that was used during external authentication (e.g. via LDAP or Active Directory).

String

Yes

Yes

xpath(String xml, String query [, Boolean table])

Takes an XML document as an input and evaluates an XPath query over it. The query may be evaluated to a String (this is a default behaviour) or Data Table (if table parameter is true). Tabular mode should be used if the query evaluates to a node set, not just a single node's text content or attribute value.

A table returned in tabular mode has three fields:

• Name. Name of a node.

• Context. Text node content.

• Children. Table of children nodes of a node. Has the same format.

Object

Yes

Yes