Today, I hit a really $&#% issue regarding Oracle Digital Assistant (ODA) Chatbot. This has to do with custom component feature. I find this error message misleading and leads to hours of troubleshooting efforts. So, it is better to share here for our further reference.

Oracle Solution

The typical cause for this error is that your component folders contain non-component files. The directories that you name in the components array in the main JavaScript file should point to directories that contain only component files. This includes files in any subdirectories.

Say, for example, that the main JavaScript file sets the components array like the following code example. This statement tells the component service upload process to look in the components directory structure for the custom component definitions. The server will look at every file in the directory structure and try to process each one as a custom component. If there are files in that directory structure that aren’t custom components, the upload process fails because it can’t parse the file as a custom component.

If you get this error, create a separate folder, such as helpers, in the same folder that main.js is in. Then move the non-component files into it, and modify your code accordingly.

Source from Oracle

The Actual Error

The root cause I got from this error is JavaScript syntax error. While loading the custom component, the JavaScript with error is not identified as a component file. As such, it throws this error message in ODA.

Common Syntax Error

Reference to other JavaScript module must be within invoke function.

invoke: (context, done) => {

  const fetch=require("node-fetch")
}

Be careful of syntax like semicolon after keepTurn. This will cause the same error message while loading of custom component.

context.transition('success')
context.keepTurn(true);

Hope these ODA tips helps and ease hours of frustration. Great thanks to Oracle Kevin for these!

Freemarker array can be confusing to use in ODA (Oracle Digital Assistant). It is hard to find documentation on how to index the content for JSON array. These are the Freemarker syntax I had found to index array for ODA. Hope this helps!

Access First Level

First level JSON array are as follow:

{"results": 
    [
        {
            "index": 0,
            "field": "Number",
            "value": 1
        },
        {
            "index": 1,
            "field": "Name",
            "value": “Peter”
        }
    ]
}

The syntax to access the first level array is:

${results.value[selValue.value?number].index}

Access 2nd Level

The JSON format are:

{"results": 
   “count”: 2,
   “items”:
    [
        {
            "index": 0,
            "field": "Number",
            "value": 1
        },
        {
            "index": 1,
            "field": "Name",
            "value": “Peter”
        }
    ]
}

The syntax to access the 2nd level array is:

${results.value.items[selValue.value?number].index}

This will help you access a specific content by index in the array with Freemarker expressions in ODA.

Oracle Digital Assistant (ODA) custom component is a nice addition to extend the functionality of Chatbot. With custom component, you can utilise the functionality of NodeJs and integrate to backend services. However, it is not straightforward to be used for the typical users. You will need an intermediate level of development to understand and set it up. Of course, it is great if you have someone to guide you the overwhelming process. Here are some tips to get you started on custom components.

Getting Started

The best way to get started on custom components is to go through below steps.

1. Read and understand the purpose of custom components.
2. Do the tutorials for custom components.
3. Modify the sample template for simple use case.
4. Test your custom components and enable logs.
5. As you build more custom components, you will gain confidence for complex use cases.

Moving Forward

Custom components is a good addition. However, you will need to be familiar with JavaScript and Integration of Cloud services. It will take a while before cloud providers can come up with wizard, template or even SaaS. Meanwhile, you may need a lot of patience to setup the base library of custom components for your business needs.

One method for integration to backend services is done via custom components. It take courage to take the first step to do the tutorials. Once you setup your environment for custom components, you can create simple custom components for your use case. This will build your confidence to develop more complex scenarios.