Interface for grammar checkers

Add-ons Development
#1

Hello Addon-Developers,

We are trying to add a new interface for Grammar Checker Extensions in the Firefox Code. The existing Grammar Checker Extensions either have no good integration, like LanguageToolFx which offers no underlining, or they use their own logic to modify the DOM to produce the underlines. That is very fragile and they regularly fail after Firefox updates, or on some web pages. Thus the plan to have a proper interface in Firefox that makes it possible to write robust checkers without complex and fragile DOM manipulations.

We have come up with a Plan, which is described in the bug report url below. Please go through the Plan. As per the Plan, The Extension implements the grammar checking task. After the text has been checked, the extension calls the interface with the list of errors it has found. The interface basically accepts the list of errors from the Extension and then marks the errors in the textarea, by default using a blue underline. The interface also accepts the list of optional corrections for each error from the extension and add it to the context menu when the user right clicks on a particular error. Please read the ‘Plan for adding interfaces for Grammar Checker Extensions’ in the below url for a detailed explanation.

https://bugzilla.mozilla.org/show_bug.cgi?id=1140402

I have the following questions, which arised while preparing the Plan. I request you developers to go through the Plan and provide your answers / suggestions to the following questions, so that we could implement this interface successfully.

The questions follows:

  1. As per the Current Plan, markErrors(GrammarCheckErrorListObj) interface function in nsIEditorGrammarCheck is supposed to take in the list of errors as a parameter. We cannot pass a C++ object (containing the list of errors) or an STL vector from the Extension to the markErrors() interface. So Does it make sense to get the errors a JSON string? Thus the GrammarCheckErrorList object or the Vector should be created with in the C++ code by parsing the JSON string data. So the data will arrive from the Extension side and the C++ will add functions to operate on that data, which forms the GrammarCheckErrorList object. Please suggest.

  2. If the errors can be passed in as a JSON string, then Is there any way to convert the JSON string to say C++ vectors ? Is there any such function already exist in the Firefox code ?

  3. If the errors can be passed in as a JSON string, then Is there a JSON String Parser already exist in the Firefox code that we could use ?

  4. Regarding the Reference to the TextArea (event.target), how the Textarea object or reference can be passed to the C++ code ? What would be the type of that object ? Is it possible to do as in nsIEditorSpellCheck::InitSpellChecker ? In InitSpellChecker, the Textarea is passed in as a parameter: ‘in nsIEditor editor’. Please suggest.

  5. In nsEditorSpellCheck.cpp, I couldn’t find an underlinered() function, which underline the errors found by the Spell Checker. I wonder how this is implemented for the spell checker. Is it a feature provided by the libeditor (editor/libeditor/) ?

Thanks,
Jos Collin