Add support for queryParams in gatsby-source-wordpress

[u12206050]

Add support to specify a queryParams object on the options of gatsby-source-wordpress plugin.
Query params are added to each entity request to Wordpress allowing to filter on specific fields such as lang.

  {
    ...
    // Only get posts & pages that are english
    queryParams: {
      lang: 'en',
    },
  }

[u12206050]

Can solve issues with large websites that support multiple languages to build a site per language and use queryParams to filter per language.

[pieh]

Can you give context on this?

[u12206050]

Since tags and categories could be referenced across various posts even different languages filtering them could cause the gatsby-source-wordpress plugin to fail when it normalizes ids of tags&categories within posts and pages.
It could be updated to also be an option to decide exactly which routes queryParams should not be included on.

[pieh]

I could see language filtering not being only use case for queryParams. It also depends on which multilanguage plugin (or even what settings of plugin) you use.

I would need to lookup what are potential use cases that users would want to use queryParams other than language filtering. What I'm thinking right now that queryParams could accept functions:

// in gatsby-config
{
  resolve: `gatsby-source-wordpress`,
  options: {
    [...]
    queryParams: ({ url }) => url.match(/(tags|categories)/ig) ? {} : _queryParams
  }
}

[u12206050]

Agreed that is much more flexible.

[u12206050]

Updated to support function return object

[u12206050]

What is the status of this? Bound for release or?

[ghost]

#10942 adds a similar feature but per route.

[simonjoom]

hi, thks i need that,
i found a miss in the file fetch.js

_queryParams is not added in list of params

getOptions take _queryParams but _queryParams is not in params.

  const getOptions = page => {
   let qs = _queryParams
  if (typeof _queryParams === 'function') {
    qs = _queryParams({ url })
  }
  if (!qs || typeof qs !== 'object') qs = {}

[sidharthachatterjee]

@pieh Is this good to go?

[pieh]

I created detailed issue about implementing this feature ( #17943 ) and will be closing this PR for now.