Hi...I have written a document with some XPath examples, based on two inheritance hierarchies among the entities: one more complex (cluster->plot) and one simpler (only plot). See below:
Link to document : HERE
EXAMPLES OF CODE IN OPEN FORIS Collect
General hierarchical structures (either cluster or plot-based)
Comparison checks (i.e., start_date, start_time, end_time, tree_no, azimuth, tree distance,dbh, total_height and bole_height):
Example attribute (number type): Path: /plot/details/elevation
Severity Error
Message Elevation must be between 0
and 4000 m 0 <= elevation <= 4000
Example attribute (date type): Path: /cluster/start_date
Severity Error
Message You have written the starting date in the future!
start_date <= idm:currentDate()
Example attribute (time type): Path: /cluster/start_time
Severity Warning
Message Working hours for the survey should be from 06:00 to 19:00!
0600 < start_time <= 1900
Example attribute (time type): Path: /cluster/end_time
Severity Error
Message End time should be always after start time
start_time <= end_time
(Here we assume that start_time and end_time are under the same entity, i.e., cluster, or plot)
Example attribute (number type): Path: /cluster/plot/tree/tree_no
Severity Error
Message tree number must be >0
0 < tree_no
Example attribute (number type): Path: /cluster/plot/tree/azimuth
Severity Error
Message angle must be between 0 (inclusive) and 360 (exclusive)
0 <= azimuth < 360
Example attribute (number type, refers to tree distance): Path: /cluster/plot/tree/distance
Severity Error
Message tree distance must be positive
0 <= distance
Severity Error
Message tree outside of plot. Plot radius is 12 m.
distance <= 12
Example attribute (number type): Path: /cluster/plot/tree/dbh
Severity Warning
Message Unusually large dbh
dbh < 200
Severity Error
Message dbh must be positive
0 <= dbh
Severity Error
Message tree must be at least 20 cm if distance>2 m
20 <= dbh Apply when distance>2
Severity Error
Message tree must be at least 5 cm in any case
5 <= dbh
Example attribute (number type): Path: /cluster/plot/tree/total_height
Severity Warning
Message Unusually tall tree
total_height < 80
Severity Error
Message Impossibly tall tree
total_height < 150
Severity Error
Message height must be positive
0 <= total_height
Example attribute (number type): Path: /cluster/plot/tree/bole_height
Severity Error
Message bole height must be positive
0 <= bole_height
Severity Error
Message bole height must be less or equal than total height
bole_height <= total_height
Default values (i.e., start_date, start_time and tree_no):
Example attribute (date type): Path: /cluster/start_date
Calculated value expressions: Expression: idm:currentDate()
Example attribute (time type): Path: /cluster/start_time
Calculated value expressions: Expression: idm:currentTime()
Example attribute (number type): Path: /plot/tree/tree_id
Calculated value expressions:
Expression: math:max(parent()/tree/tree_id) + 1
(it will automatically increase the number every time a new tree is recorded in the plot)
Surveys with Plot as sampling unit or root entity and tree as sub-entity
Distance checks (i.e., plot position):
Example attribute: Path: /plot/details/position
Severity Error
Message You are more than 50 m from plot location
Destination point idm:samplingPointCoordinate(parent()/plot_id)
Max distance (m) 50
Severity Warning
Message You are more than 20 m from plot location
Destination point
idm:samplingPointCoordinate( parent()/plot_id)
Max distance (m) 20
Autocompletion (click Calculated in the General tab fot the variable) in optional variables from sample design file (i.e., province as a column after design point coordinates in the sampling_design imported file):
Example attribute (text type): Path: /plot/details/province
Calculated value expressions:
Expression: idm:samplingPointData('province', parent()/plot_id)
Requirednes of variable if expression is satisfied (i.e., tree_height only required every three third tree):
Example attribute (text type): Path: /plot/tree/tree_height
Required only when expression is verified: tree_id mod 3 = 0
Surveys with Cluster as sampling unit or root entity and plot and tree as sub-entities
Distance checks (i.e., plot position):
Example attribute: Path: /cluster/plot/details/position
Severity Error
Message You are more than 100 m from plot location
Destination point idm:samplingPointCoordinate(parent()/parent()/cluster_no, parent()/plot_no)
Max distance (m) 100
Severity Warning
Message You are more than 20 m from plot location
Destination point idm:samplingPointCoordinate(parent()/parent()/cluster_no, parent()/plot_no)
Max distance (m) 20
Autocompletion(click Calculated in the General tab fot the variable) in optional variables from sample design file (i.e., province as a column after design point coordinates in the sampling_design imported file):
Example attribute (text type): Path: /cluster/location/province
Calculated value expressions:
Expression: idm:samplingPointData('province', parent()/cluster_no)
Example attribute (text type): Path: /cluster/plot/details/province
Calculated value expressions:
Expression: idm:samplingPointData('province', parent()/plot_no)
Autocompletion (click Calculated in the General tab fot the variable) in tree-related variable (i.e., tree count):
Example attribute (number type): Path: /cluster/plot/tree_count
Calculated value expressions: Expression: math:max(parent()/plot/tree/tree_no)
Relevance of variable if expression is satisfied (i.e., tree_count, plot position, and tree entity):
Example attribute (number type): Path: /cluster/plot/tree_count
Relevant only when expression is verified: parent()/plot/details/accessibility=0
Example attribute (coordinates type): Path: /cluster/plot/details/position
Relevant only when expression is verified: accessibility=0
(here we don’t need a hierarchical path since position and accessibility belong to the same hierarchy, i.e: parent()/plot/details/position and parent()/plot/details/accessibility)
Example entity (multiple table layout): Path: /cluster/plot/tree
Relevant only when expression is verified: details/accessibility=0
