Add content type filter for the pages query

[mansrz]

Hi, thanks for help me with last problem Now, i don't know if it is a bug or concept error mine, but if you can help me please can be help for other

I tried to get a page specific with filter by contenttype but i got null response, so i have to query "pages" instead "page" and can't filter by contenttype this cause me get many "{}"

Example query: { page(contentType:"home.AboutPage"){ ... on AboutPage { contentType id } }

[SamuelTaylor001]

@mansrz why did you close this? Did you find a solution? I am getting the same issue with the following query

query MyQuery { wagtail { pages { ... on NewsPage { id intro title } } } }

I realise that this could be fixed on the client side however, it defeats the purpose of GraphQL if we are forced to process unnecessary data.

Can we reopen this?

[mansrz]

I would believe that it should be opened, I closed it because I "solved it" at the moment doing the query by id but isn't the correct solution

[NathHorrigan]

I can see how confusing this could be...

What do you think of the following @SamuelTaylor001:

page (contentType: "blogs.BlogPage") {
    ... on BlogPage {
         title
    }
}

will return the first result based on that contentType and will be the equivalent of the following ORM query: BlogPage.objects.first()

[isolationism]

I've added a PR for a solution that uses the pageType — I think contentType is something slightly different.

I am also filtering out the application prefix (i.e. the 'blog.' part of 'blog.BlogPage') to match the declared pageType returned in a query, but wonder if this isn't going to cause problems if two apps have the same model name.

[zerolab]

The reason the { page(contentType:"home.AboutPage"){ ... on AboutPage { contentType id } } query fails is that the content type filter only kicks in if there is a preview token - https://github.com/GrappleGQL/wagtail-grapple/blob/master/grapple/types/pages.py#L197-L209

@isolationism thank you for #144 -- I think we should stick to content type as a filter to avoid namespace clashes.

Will open a new PR to fix the filter on content type (an credit you on it as well, @isolationism )

[zerolab]

https://github.com/GrappleGQL/wagtail-grapple/pull/147

all reviews are welcome