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Contextuals

Here is a list of predefined generators retrieving values from Fabrication Context.

Context Accessor

Returns a value from the received context. The value is reached by the given path the value is expected to be at.

The configuration is a bit more complex for this type of generator. Its declaration looks like this:

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export type ContextAccessorConfig = {
  path: string;
  sep?: PathSeparator;
  handleError?: boolean;
  useErrorValue?: any;
} & ValueGeneratorConfig;

This configuration tries to access the data provided externally by the client, while accessing object person and taking the property email. When for example you forget to provide the person, it won't struggle with accessing proeprties of undefined, it simply returns undefined without error.

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const config: ContextAccessorConfig = {
  path: "person/email";
  sep: "/";
  handleError: true;
  useErrorValue: undefined;
};

  • path represents the path in the given fabrication context (like profiles.identifiers.uuid)

  • sep represents separator to be used on path; by default it's a dot (.); supported values are ., /, # and $

  • handleError tells the accessor that if there is no value on the path or when it comes into another issue, if it should try to handle or should fail in the first place. By default, it lets the error to be thrown. Otherwise, it uses null-like value specified in useErrorValue

  • useErrorValue value to be used when an error occurs (the recommended option is using undefined)

Examples

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const config: ContextAccessorConfig = {
    path: 'input.value',
    sep: '.'
}

const generator = new ContextAccessor(config);

const context: FabricationContext = {
    input: {
        value: "Value given from outside"
    }
}

console.log(generator.generate(context));

Output

Value given from outside

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const config: ContextAccessorConfig = {
    path: 'input.value',
    sep: '.'
}

const generator = getValueGenerator('context-input', config);

const context: FabricationContext = {
    input: {
        value: "Value given from outside"
    }
}

console.log(generator.generate(context));

Output

Value given from outside

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const schema: SchemaInput = {
    fields: {
        value: {
            type: 'context-input',
            config: {
                path: 'input.value',
                sep: '.'
            }
        }
    }
}

const fabricator = new Fabricator(schema);

const context: FabricationContext = {
    input: {
        value: "Value given from outside"
    }
}

console.log(fabricator.generate(context));

Output

{ value: 'Value given from outside' }