always check if rate is an Operation

Author: isaacsas

src/graphs.jl

@@ -20,7 +20,7 @@ end
 function edgifyrates(rxs, specs)    
     es = Edge[]
     for (i,rx) in enumerate(rxs)
-        deps = get_variables(rx.rate, specs)
+        deps = rx.rate isa Operation ? get_variables(rx.rate, specs) : Operation[]        
         for dep in deps
             val = String(dep.op.name)
             attr = Attributes(:color => "#d91111", :style => "dashed")
@@ -30,6 +30,7 @@ function edgifyrates(rxs, specs)
     end
     es
 end
+
 """
     Graph(rn::ReactionSystem)
 

src/latexify_recipes.jl

@@ -57,7 +57,7 @@ function chemical_arrows(rn::ModelingToolkit.ReactionSystem;
         str *= "\\ce{ "
 
         ### Expand functions to maths expressions
-        rate = Expr(r.rate)
+        rate = r.rate isa Operation ? Expr(r.rate) : r.rate
         expand && (rate = recursive_clean!(rate))
         expand && (rate = recursive_clean!(rate))