Rave Reports Visual Designer

Lesson - CalcOp

For example, there could be two DataText components that need to be calculated together. Like , where A and B represent the two DataText component values and C represents the result. This is where the CalcOp component would be used.

To choose the DataText components in the above example, use the Src1X and Src2X properties, where X is either CalcVar (a calculation variable), DataField, or DataValue. These are the three types of value sources that can be used for calculation in a CalcOp component. Note that the Src (source) can only use ONE of the three available source types, and there can only be two sources, Src1 or Src2.

The three source types have many different values associated with them. For a CalcVar source, the drop down menu will list all the calculation variables available in that Page available for use. This calculation variable is just that, a variable for holding a value. This value can be from another CalcOp component or from some other calculation component. For the DataField source to get available values first designate what DataView the DataField will come from. In other words the DataField is a field in a table, which is the DataView. So, in order to choose a field, the DataView must first be chosen. For a Value source, typing in a numeric value is all that is needed to fill this property. Again, remember only one of these three sources can be assigned to a source.

Once the sources are chosen the operation to be used between them has to be chosen. To choose the desired operation, use the Operator property by using the drop down menu and making the appropriate choice. In the example, , the operator would be "coAdd".

There may be times when a function needs to be performed on a value before it is processed with the second value. This is where the property SrcYFunction, where Y is 1 or 2 for Src1 or Src2, will become handy. With SrcYFunction, the value can be converted (like from hours to minutes), or have a trigonometric function performed on it (like take the sin of the value), or have other functions performed on the value (like take the square root of the value, or take the absolute value).

Once the two values are chosen, it is now time to deal with the result. In the example, , C is the value of the result. The result can either be written out to a project parameter (most likely a DataText component) or just held as an intermediate value. To write out the value to a parameter, use the DestParam property to choose the desired parameter to write the result write to. If the result is going to be in intermediate result, there is nothing else to do to the component. Although, it is highly suggested to rename the component, by using the Name property, to easily recognize the component for future use. This is because, as in intermediate values, you will most likely use the components in another CalcOp component, and a good reference will help to easily create the next step in the calculation process.

After setting the values and setting the result destination, it may be necessary to format the result or to even perform one last function on the result. Using the DisplayType and DisplayFormat properties to format the result into any necessary format. The DisplayType has two options, DateTimeFormat and NumericFormat. DisplayFormat has many options that must be typed into the edit box. To find these options look at the Formatting codes in this manual. Like the two values, A and B, in the example, , the result C can also have a function performed on it before being written out to a parameter, or as a holding value. To select a function, use the ResultFunction property drop down menu.

The CalcOp components can also be chained together for more complex expressions using the Src#CalcVar properties, which can be set to other CalcOp or CalcTotal components. For example, to create the complex expression shown above in the top of box, it will be necessary to break up the expression into simple 2 value steps shown in the bottom of that box.

To break up the complex expression, four new expressions will need to be created and saved as CalcOp components. So the resulting components, Z, Y, X, and W will be four separate intermediate CalcOp's. But, as you can see from the flow of the expression, Z and Y will have to be completed before X can be created, as it is dependent upon the two previous operations. And finally, W will be completed last, after X, to get the final correct value.

Just as it is important to do the calculations in order, it is important to make sure the components are in order in the Project Tree. When a report is executed, the report executes components down the Project Tree. For CalcOp components or any calculation component, this means that they need to be in the correct order. In the example above, if Z, Y, X, and W were in the Project Tree, Z would have to be first in the tree and W would have to be last in the tree. This would mean that at execution, Z would be processed first, then Y, and so on. It is also important to note that if Z is dependent upon any other components (like other CalcOp components or DataText components), those components must come first in the Tree before the Z component is processed. Making sure the components are in correct order is known as setting the print order. To move the components up and down within the Project Tree, use the Alignment Palette to change the print order of the components.