Allow expressions in LABEL PRIORITY (#6884)

* Allow expressions for LABEL PRIORITY * Add msautotest images * Add check for duplicate PRIORITY
MapServer · May 29, 2023 · db74212 · db74212
1 parent 497ba5d
commit db74212
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Showing 7 changed files with 99 additions and 2 deletions.
diff --git a/mapfile.c b/mapfile.c
@@ -1805,14 +1805,25 @@ static int loadLabel(labelObj *label)
         }
         break;
       case(PRIORITY):
-        if((symbol = getSymbol(2, MS_NUMBER,MS_BINDING)) == -1) return(-1);
+        if (label->exprBindings[MS_LABEL_BINDING_PRIORITY].string) {
+            msFreeExpression(&label->exprBindings[MS_LABEL_BINDING_PRIORITY]);
+            label->nexprbindings--;
+        }
+
+        if((symbol = getSymbol(3, MS_EXPRESSION,MS_NUMBER,MS_BINDING)) == -1) return(-1);
         if(symbol == MS_NUMBER) {
           if(msCheckNumber(msyynumber, MS_NUM_CHECK_RANGE, 1, MS_MAX_LABEL_PRIORITY) == MS_FAILURE) {
             msSetError(MS_MISCERR, "Invalid PRIORITY, must be an integer between 1 and %d (line %d)" , "loadLabel()", MS_MAX_LABEL_PRIORITY, msyylineno);
             return(-1);
           }
           label->priority = (int) msyynumber;
-        } else {
+        } else if (symbol == MS_EXPRESSION) {
+            msFree(label->exprBindings[MS_LABEL_BINDING_PRIORITY].string);
+            label->exprBindings[MS_LABEL_BINDING_PRIORITY].string = msStrdup(msyystring_buffer);
+            label->exprBindings[MS_LABEL_BINDING_PRIORITY].type = MS_EXPRESSION;
+            label->nexprbindings++;
+        }
+        else {
           if (label->bindings[MS_LABEL_BINDING_PRIORITY].item != NULL)
             msFree(label->bindings[MS_LABEL_BINDING_PRIORITY].item);
           label->bindings[MS_LABEL_BINDING_PRIORITY].item = msStrdup(msyystring_buffer);

diff --git a/maputil.c b/maputil.c
@@ -391,6 +391,12 @@ static void bindLabel(layerObj *layer, shapeObj *shape, labelObj *label, int dra
       bindColorAttribute(&label->outlinecolor, txt);
       msFree(txt);
     }
+    if (label->exprBindings[MS_LABEL_BINDING_PRIORITY].type == MS_EXPRESSION)
+    {
+        label->priority = msEvalDoubleExpression(
+            &(label->exprBindings[MS_LABEL_BINDING_PRIORITY]),
+            shape);
+    }
   }
 }
 

diff --git a/msautotest/renderers/data/label_alias_offset.dbf b/msautotest/renderers/data/label_alias_offset.dbf
diff --git a/msautotest/renderers/expected/label_priority_binding.png b/msautotest/renderers/expected/label_priority_binding.png
diff --git a/msautotest/renderers/expected/label_priority_expression.png b/msautotest/renderers/expected/label_priority_expression.png
diff --git a/msautotest/renderers/expected/label_priority_fixed.png b/msautotest/renderers/expected/label_priority_fixed.png
diff --git a/msautotest/renderers/labels-priority.map b/msautotest/renderers/labels-priority.map
@@ -0,0 +1,80 @@
+# RUN_PARMS: label_priority_binding.png [MAP2IMG] -m [MAPFILE] -l label_priority_binding -o [RESULT]
+# RUN_PARMS: label_priority_fixed.png [MAP2IMG] -m [MAPFILE] -l label_priority_fixed -o [RESULT]
+# RUN_PARMS: label_priority_expression.png [MAP2IMG] -m [MAPFILE] -l label_priority_expression -o [RESULT]
+#
+# Test label priorities
+#
+
+MAP
+    IMAGETYPE "png"
+    SIZE 400 400
+    EXTENT -.5 -.5 1.5 1.5
+    FONTSET "../misc/fonts.lst"
+    PROJECTION
+        "init=epsg:4326"
+    END
+    LAYER
+        NAME "label_priority_fixed"
+        TYPE POINT
+        STATUS OFF
+        DATA "data/label_alias_offset.shp"
+        LABELITEM "label"
+        CLASS
+            # make sure pnt7 gets labelling priority
+            EXPRESSION ([priority] = 7)
+            LABEL
+                FONT "default"
+                TYPE TRUETYPE
+                SIZE 40
+                COLOR 0 0 0
+                PRIORITY 10
+            END
+        END
+        CLASS
+            EXPRESSION ([priority] != 7)
+            LABEL
+                FONT "default"
+                TYPE TRUETYPE
+                SIZE 12
+                COLOR 0 0 0
+                PRIORITY 1
+            END
+        END
+    END
+    LAYER
+        NAME "label_priority_binding"
+        TYPE POINT
+        STATUS OFF
+        DATA "data/label_alias_offset.shp"
+        LABELITEM "label"
+        CLASS
+            LABEL
+                FONT "default"
+                TYPE TRUETYPE
+                SIZE 12
+                COLOR 0 0 0
+                PRIORITY [priority]
+            END
+        END
+    END
+    LAYER
+        NAME "label_priority_expression"
+        TYPE POINT
+        STATUS OFF
+        DATA "data/label_alias_offset.shp"
+        LABELITEM "label"
+        CLASS
+            LABEL
+                FONT "default"
+                TYPE TRUETYPE
+                SIZE 12
+                COLOR 0 0 0
+                # add a duplicate PRIORITY that will be ignored
+                # but check it is cleaned up correctly
+                PRIORITY ([priority] * 2)
+                # use an expression to invert the label priorities
+                PRIORITY (10 - [priority])
+            END
+        END
+    END
+END