Event/Alien2XML definition

From PlcWiki

Device events have prefix workplace.device.<name>.event. while alien2xml node definitions have prefix node.

Example (alien2xml):

node.product = .*
node.product.item.regex = {headend}(.*?){part}
node.product.item = [[8:25]]
node.product.header.regex = "{head}(.*?){headend}"
node.product.header = <node:header=[[:]]>
node.product.part.list_member = "{part}(.*?){partend}"
node.product.part = [[:]]

node.header = .*
node.header.title = [[:]]

Example input:

{head}msg title{headend}ignored;fixed_width_item_contents;ignored{part}partnum1{partend}not used{part}partnum2{partend}

Example output:

<!DOCTYPE product>
<product>
 <header>
  <title>msg title</title>
 </header>
 <item>fixed_width_item_contents</item>
 <part>partnum1</part>
 <part>partnum2</part>
</product>

The first condition for node (or event) to be created is this:

node.<node_name> = <regex>

If the input (alien input or raw device input) doesn't match the regex, any other definition rules are ignored and an empty XML element node_name (or no event) is generated. If the regex contains a group (enclosed in a parenthesis pair), the whole input is reduced to this group substring for later processing. The node (or event) can contain any number of properties (these properties appear as subelements in alien2xml output). The definition of a property is as follows:

node.<node_name>.<property_name> = _text_

or

node.<node_name>.<property_name> = <node:_subnode_=_text_>

where _text_ is a text constant with any number of [[from:length]] input substring expressions. Input substring expression defines a substring of original input (or input reduced by any regex group definitions). Omitted from means index 0, omitted length means the rest of the input.

When <node:_subnode_=_text_> is used as a value, it tells alien2xml processor that this property is a subnode and should be expanded by using appropriate node._subnode_ definition while using _text_ as the input.

When an item

node.<node_name>.<property_name>.regex = <regex>

is present in the definition, it means the above value is assigned to property only if the input matches the regex <regex>, otherwise it is assigned an empty value. Additionally, the current input is further reduced to any regex group if present (only for the purpose of assigning to that property).

__Other special features__