Process
list
and
map
variables
are referenced in XPath expressions by name in the same way that
other types of variables are referenced. However, to access specific
data items in
list
and
map
variables,
you also need to indicate which data item in a
list
or
map
variable
you want to set or access.
list variables
To reference an entire
list
variable,
you use the name of the
list
variable. For example,
to copy all of the data from a
list
variable named
original_list
to
a
list
variable named
copy_list
,
the XPath expression that you use to reference
original_list
is
/process_data/original_list
.
To
indicate the data item in a
list
variable, you
need to specify the index position of the item. For example, a process
stores document data in a
list
variable named
listofdocs
.
You can use the execute operation of the Set Value service to retrieve
the first document in the list and save it in a
document
variable
named
firstdoc
. The XPath expression that returns
the first document in the list is
/process_data/listofdocs[1]
.
Note:
Indexes for
list
variables are
1-based so that the first item in the list has an index of 1.
Note:
When saving the results of service operations
in
list
variables, the returned data items are
appended to the list after any existing items. To replace the items
in a list, you specify the index of the first item (for example,
/process_data/listVar[1]
).
map variables
To reference an entire
map
variable,
you use the name of the
map
variable. For example,
to copy all of the data from a
map
variable named
original_map
to a
map
variable
named
copy_map
, the XPath expression that you use
to reference
original_map
is
/process_data/original_map
.
To
indicate the data item in a
map
variable, you need
to specify the key for the key-value pair. For example, a process
stores names and email addresses in a
map
variable
named
varmapofemails
. Names are used as the key,
and the email addresses are the corresponding values. You can use
the execute operation of the Set Value service to retrieve Tony’s
email address and store it in a
string
variable
named
tonyemail
. The XPath expression that returns
the value in the
map
variable that corresponds
to the key of
tony
is
/process_data/mapofemails[@id='tony']
.
Note:
Unlike
list
variables, the order
in which data items are stored in
map
variables
can be different each time you use the
map
variable.
When referencing data items in
map
variables, you
cannot make any assumptions about the order of the data items.
