Add CraftQL support for text and html fields.

[mattstein]

Hi Selvin! I'm playing with CraftQL and just Doxter to play nice. Previously, using the field handle in a GraphQL query would have resulted in an error:

Query:

{
    entries {
        ... on Blog {
            doxterFieldHandle
        }
    }
}

Result:

String cannot represent non scalar value: instance of selvinortiz\doxter\fields\data\DoxterData

This PR requires a sub-selection of either text or html. Query:

{
    entries {
        ... on Blog {
            doxterFieldHandle {
                text
                html
            }
        }
    }
}

More thrilling result:

{
    "data": {
        "entries": [
        {
            "text": "GraphQL is the bee's knees, and it's just *begging* to get Markdown from Doxter.",
            "html": "<p>GraphQL is the bee&#8217;s knees, and it&#8217;s just <em>begging</em> to get Markdown from Doxter.</p>"
        }
    ]
}

[selvinortiz]

@mattstein I'm sorry for the delay in getting back to you, Matt. Thank you for taking the time to add this in Doxter. I'll merge and cut a new release.

[selvinortiz]

@mattstein Did you test with and without CraftQL installed? Just wondering if checking whether the class exists is the safest way to register the event listener. Wondering if it would make more sense to check whether or not the plugin is installed?

[mattstein]

You're welcome, and no worries on timing @selvinortiz!

I just did a quick local test removing CraftQL via composer and restarting the development server. I can confirm that Doxter behaves normally in the control panel (entry detail w/Matrix block + Doxter plugin settings) and via front-end templates. The same is true when CraftQL is required with composer but not yet installed, as well as installed but disabled.

If there's anything else I should poke at, kindly let me know!

I'm honestly not sure if it makes more sense to see if the plugin's installed; I followed the lead of https://github.com/ethercreative/simplemap/blob/v3/src/SimpleMap.php but assume either way would be safe now that I've tested ;)

[selvinortiz]

@mattstein That sounds good to me. I'll cut a new release.

Thank you, Matt.