Add example to doc

Author: aminya

docs/src/customConstructors.md

@@ -1,5 +1,98 @@
-# Custom Constructors - AcuteML Backend
-## Making a Type and constructor from scratch
+# Custom Constructors
+
+## Adding Custom code to the structures
+
+```julia
+using AcuteML
+# Definition
+@aml mutable struct Student "student"
+
+    # add custom code to the begining of creator function
+    # the following automatically fills IQ based on the name
+    @creator begin
+        if occursin("smart", name)
+            name = replace(name, "-smart" => "") # remove smart from name
+            IQ = "smart"
+        elseif occursin("genius", name)
+            name = replace(name, "-genius" => "") # remove smart from name
+            IQ = "genius"
+        else
+            error("Give a smart student.")
+        end
+    end
+
+    name::String, "~"
+    GPA::Float64, "~"
+    IQ::UN{String} = nothing, att"~" # default to nothing, but filled automatically by first @cretor macro
+    # add custom code to the end of extractor function
+
+    log::UN{String} = nothing, "~"
+
+    @extractor begin
+        if GPA > 4.0
+            log = "A genius with a GPA of $GPA is found" # setting fields using @extractor only changes the field and not the xml code
+        end
+    end
+end
+
+@aml mutable struct MathClass "math-class"
+    @creator begin
+        GPAsum = 0.0
+        for student in students
+            GPAsum = GPAsum + student.GPA
+        end
+        average = GPAsum / length(students) # fill average field
+    end
+
+    students::Vector{Student}, "student"
+    average::UN{Float64} = nothing, "average" # calculated automatically
+end
+
+################################################################
+# Creation
+smarts = [Student(name = "Jack-smart", GPA = 2.0), Student(name = "Sara-genius", GPA = 5.0)]
+mathclass = MathClass(students = smarts)
+
+mathclass.students[1].name # "Jack"
+mathclass.students[2].name # "Sara"
+mathclass.average # 3.5
+
+pprint(mathclass)
+# <math-class>
+#     <student IQ="smart">
+#       <name>Jack</name>
+#       <GPA>2.0</GPA>
+#     </student>
+#     <student IQ="genius">
+#       <name>Sara</name>
+#       <GPA>5.0</GPA>
+#     </student>
+#     <average>3.5</average>
+#   </math-class>
+
+################################################################
+# Extraction
+
+xml = parsexml("""
+<math-class>
+    <student>
+      <name>Jack</name>
+      <GPA>2.0</GPA>
+    </student>
+    <student>
+      <name>Sara</name>
+      <GPA>5.0</GPA>
+    </student>
+    <average>3.5</average>
+  </math-class>
+""")
+
+mathclass = MathClass(xml)
+
+mathclass.students[2].log # "A genius with a GPA of 5.0 is found"
+```
+
+## Making a Type and constructor from scratch using AcuteML Backend
 
 You can use AcuteML utilities to define custom type constructors from scratch or to override `@aml` defined constructors.
 

test/runtests.jl

@@ -9,5 +9,5 @@ include("creator.jl")
 include("extractor.jl")
 include("tables.jl")
 include("xmlutils.jl")
-# include("musicxml/musicxml.jl")
 include("customcode.jl")
+# include("musicxml/musicxml.jl")