Call function

Anatomy

<call func="var" var="var" var_params="var" var_this="var">
    ixml
</call>

Description: CALL breaks out of the current control flow and continues with the execution of a function. It then returns to its original control flow. Arguments may be passed to local variables as parameters on switch of context.

A function can be coded so that it may call itself recursively. This technique allows direct implementation of functions defined by mathematical induction and recursive divide and conquer algorithms.

Attention:

CALL will throw an error for an undefined or invalid function.

The function incorporates a local context when being called. Therefore local variables may be declared within the function.

The special local variable 'this' is a direct reference to the calling object of the method.

The special local variable 'return' is a reference to the return value that is passed back as the result of CALL.

The special local variable 'arguments' is a reference to all arguments that have been passed to local variables on switch of context.

The RETURN, BREAK and NEXT operations may be used to break-off the execution of the function, thereby implicitly returning to the original control flow of the invoking control statement.

Attributes

Name	Type	Description	Defined By
func	var	Function variable name	call
var	var	Result variable name	call
var_params	var	Variable name for associated parameter name and value pairs	call
var_this	var	Variable name for explicit rebinding of 'this'	call

Results:

Binding	Type	Predicate
var		N/A

Examples

Basic function call

<global var="name"/>

<function var="outputName">
  <output>$name</output>
</function>

<set var="name">iXML</set>
<call func="outputName"/>

<!-- iXML -->

Parameterized function call

<function var="outputName">
  <output>$name</output>
</function>

<call func="outputName">
  <param name="name">iXML</param>
</call>

<!-- iXML -->

Method call

<set var="obj.name">iXML</set>

<function var="obj.outputName">
  <output>$this.name</output>
</function>

<call func="obj.outputName"/>

<!-- iXML -->

Return from function

<function var="getName">
  <set var="return">iXML</set>
  <return/>
  <set var="return">XML</set>
</function>

<call func="getName" var="name"/>
<output>$name</output>

<!-- iXML -->

Iterating function call

<function var="outputName">
  <output>$name&n;</output>
</function>

<array var="names">
  <item>Bill Gates</item>
  <item>Steve Jobs</item>
</array>

<foreach var="names" var_value="name">
  <call func="outputName">
    <param name="name">$name</param>
  </call>
</foreach>

<!--
Bill Gates
Steve Jobs
-->

Closure function call

<set var="count">1</set>

<function var="output">
  <use var="count"/>
  
  <output>$count&n;</output>
  <math:inc var="count"/>
</function>

<for from="1" to="5">
  <call func="output"/>
</for>

<!--
1
2
3
4
5
-->

SOAP operation call

<soap:client wsdl="http://www.dneonline.com/calculator.asmx?WSDL">
  <soap:bind var="add">add</soap:bind>
</soap:client>

<array var="parameters">
  <item key="intA">2</item>
  <item key="intB">5</item>
</array>

<call func="add" var="result">
  <param var="parameters"/>
</call>

<output>$result.AddResult</output>

<!-- 7 -->

RESTful resource call

<rest:client url="https://api.predic8.de/shop">
  <rest:header>
    Content-Type: application/json
  </rest:header>
  
  <rest:bind var="createProduct" method="POST">/products/</rest:bind>
  <rest:bind var="updateProduct" method="PATCH">/products/:id</rest:bind>
  <rest:bind var="getProduct" method="GET">/products/:id</rest:bind>
</rest:client>

<decode:json var="data">
  <call func="createProduct">
    <param>{"name": "Some Fruit", "price": 4.99}</param>
  </call>
</decode:json>

<match var_matches="matches" pattern="/\d+/">$data.product_url</match>
<set var="id">$matches[0][0]</set>

<call func="updateProduct">
  <param var="id"/>
  <param>{"name": "Wildberries"}</param>
</call>

<decode:json var="data">
  <call func="getProduct">
    <param var="id"/>
  </call>
</decode:json>

<output>$data.name</output>

<!-- Wildberries -->