sample-3.md

Sample 3

source code
(Use npm run sample3 to run the full sample from bellow.)

At first lets use the GeneratableImport to create a generatable import for the exported function sampleFunction in the samples/function.ts file.
The function sampleFunction expects a value of type { z: string }. So we create a GeneratableJSON with that type.
Now the function needs to be executed with the parameter.
To bring these two generatables together we use GeneratableFunctionExecution with the generatable function and parameter.

let func = new GeneratableImport(new ElementImport("sampleFunction", "samples/function"))

let value: any = { z: "World" }

let parameter = new GeneratableJSON(value)

let execution = new GenertableFunctionExecution(func, parameter)

The following code uses JS Promises (then & catch) Next we compile the generated files via typescript.
That returns a result object with a bundle.js file as a buffer. Getting the code as string and using eval(...) should execute the compiled code and print Hello World.

compileTypescript(execution.generate())
    .then(result => {
        let bundledCode = result["bundle.js"].toString()
        eval(bundledCode)
    })
    .catch(error => {
        console.log(error)
    })

But what if we now assign the number 10 to the value of value.z. value is now a invalid parameter for sampleFunction. In pure JS this would just result in Hello 10 but the typescript definition expects a string.

    .then(() => {
        value.z = 10
    })
    .then(() => compileTypescript(execution.generate()))
    .then(result => {
        let bundledCode = result["bundle.js"].toString()
        eval(bundledCode)
    })
    .catch(error => {
        console.log(error)
    })

Fortunately typescript got us covered and prevents the faulty compilation by throwing an error. TS2322: Type 'number' is not assignable to type 'string'.

Next: Sample 4 - automatic code generation on change using Generator