Saving a Flow as a Custom Component¶
Denodo ITPilot enables users to create custom components which can be reused as components of a more complex process. These components are created and managed as regular wrappers in the Custom Components project. We will illustrate the process using again the Webmail example introduced in section Presentation of the Example.
A custom component can be created in several ways:
- To save the current loaded wrapper as a custom component, select the “File->Save as custom component” menu option (or use the combination of keys Ctrl+Alt+S) and assign a name to the custom component (see Selecting the output type of the custom component). A new wrapper, with the specified name, will be created in the Custom Components project. In our example, load the webmail wrapper created in section Presentation of the Example, and save it as a custom component specifying the name “WebMailCustomComponent”.
- To create a custom component from an existing wrapper, it can also be copied or moved directly to the Custom Components project.
- A new wrapper can also be created from scratch inside the Custom Components project.
When any wrapper is saved as a custom component, or copied or moved to the Custom Components project, or a wrapper contained in the Custom Components project is edited and saved, a dialog will ask which output will be used as the custom component output (see REF _Ref156721696 \r \h \* MERGEFORMAT ¡Error! No Selecting the output type of the custom component). In this case, we will check the “Use OutputComponent as output” option. Alternatively the output of one of the process’ components could also be chosen as the custom component output.
Once these steps are complete, a new component will appear under the “Custom component” entry of the Components tab in the tool’s browsing area. To test it, a small test process can be created that uses this component. Using a custom component in a new process shows this small example. It can be seen how, as a list, the customized component output is processed by an Iterator component. To create the input data we use two Expression components (see section Expression for detailed information about this component). These are needed because the initialization component returns a record as its output whereas the custom component requires two atomic values as inputs. The remaining process is similar to that shown previously in this guide.
The wrappers in the Custom Components project and the components under the “Custom component” entry of the Components tab in the tool’s browsing area are permanently linked:
- When a wrapper in the Custom Components project is deleted, its associated custom component is also deleted and vice versa.
- When a wrapper in the Custom Components project is saved and it is not complete or it has components configured incorrectly, the associated custom component will not be generated and the wrapper will be labeled with the word “Draft” in the projects menu. When the wrapper is fixed and saved, the “Draft” label disappears and the custom component appears in the Components tab.
When editing a wrapper saved in the Custom Components project, the component that was chosen as the custom component output is highlighted with a darker border and shows the label “output” over the component node. If the wrapper is modified and saved again, this output component will be selected by default in the dialog that asks for the custom component output.
The execution of a custom component can produce only one type of error, a runtime error, which is raised when any error occurs during the execution of the component. This error can be raised (wrapper execution stops), or ignored (execution continues), and the actions Trace record and Output record can be executed.
It is important to note that custom components are used by reference, so if a custom component wrapper is modified, the changes will affect all the wrappers of the Wrapper Generation Tool using that custom component. The same applies when an existing custom component is re-deployed in the Wrapper Server (see section Deploying Wrappers to the Wrapper Server): all the wrappers running in the server, and using that custom component, will use the new version.