document using AutoForm.getCurrentDataForForm() in contextAdjust function

Author: aldeed

README.md

@@ -1286,7 +1286,7 @@ Making a custom input type (form widget) is easy.
 * `valueIn`: Optional. A function that adjusts the initial value of the field, which is then available in your template as `this.value`. You could use this, for example, to change a `Date` object to a string representing the date. You could also use a helper in your template to achieve the same result.
 * `valueOut`: Required. A function that AutoForm calls when it wants to know what the current value stored in your widget is. In this function, `this` is the jQuery object representing the element that has the `data-schema-key` attribute in your custom template. So, for example, in a simple case your `valueOut` function might just do `return this.val()`.
 * `valueConverters`: Optional. An object that defines converters for one or more schema types. Generally you will use `valueOut` to return a value for the most common or logical schema type, and then define one or more converter functions here. The converters receive the `valueOut` value as an argument and should then return either the same value or a type converted/adjusted variation of it. The possible converter keys are: "string", "stringArray", "number", "numberArray", "boolean", "booleanArray", "date", and "dateArray". Refer to the built-in type definitions for examples.
-* `contextAdjust`: Optional. A function that adjusts the context object that your custom template receives. That is, this function accepts an object argument, potentially modifies it, and then returns it. That returned object then becomes `this` in your custom template.
+* `contextAdjust`: Optional. A function that adjusts the context object that your custom template receives. That is, this function accepts an object argument, potentially modifies it, and then returns it. That returned object then becomes `this` in your custom template. If you need access to attributes of the parent autoForm in this function, use `AutoForm.getCurrentDataForForm()` to get them.
 
 It's possible to use template helpers instead of `valueIn` and `contextAdjust`, but by keeping template helpers to a minimum, you make it easier for someone to override the theme template and still use your custom input type. For example, the `bootstrap3` template overrides some of the default input types to add classes and adjust markup a bit, but it does not need to redefine template helpers to make context adjustments since `valueIn` and `contextAdjust` do that.