The syntax of an ePath consists of three components: nodes, qualifiers, and fields, as shown below.
Node - Specifies the node type and optionally includes qualifiers to restrict the number of nodes. A node without any qualifier defaults to only the first node of the specified type. Use “node.*” to address a node rather than a field.
Qualifier - Restricts the number of nodes addressed at each level. The following qualifiers are allowed:
* (asterisk) - Denotes all nodes of the specified type.
int - Accesses the node by index.
@keystring= valuestring - Accesses the node using a key-value pair. Only one instance of the node is addressed using keys. If a composite key is defined, then multiple key-value pairs can be separated by a comma in the ePath (for example, [@key1=value1,@key2=value2]). The following ePath uses the keystring qualifier and returns the alias where the unique key field type is “Main”. It returns only one alias in a given record.
filter=value - Considers only nodes whose field matches the specified value. A subset of nodes is addressed using filters. Multiple filter-value pairs can be separated by a comma (for example, [filter1=value1, filter2=value2]). The following ePath uses the filter qualifier and returns all aliases where the last name is “Jones”.
Field - Designates the field to return and is in the form of a string.