Add modifiers to simplify handling migrations

Some changes need to be done to the serialized data when this tool is used for a migration (e.g. from Plone 4 to Plone 5 or 6) and/or from Archetypes to Dexterity.

To make this easier we could add a checkbox (checked by default) "Modify data for migrations".

If this is checked then some modifiers will run during export.

These could include:

Drop unused data

Some data that restapi includes is useless for migrations. E.g. @components, next_item, previous_item.

Drop all Relations

Relations are migrated seperately. haveing them in the data will mess up the site. This is probably easiest done by switching on custom serializers for IReferenceField (AT) and IRelationChoice and IRelationList (DX) that return none.

Change default-fieldnames (AT to DX):

    # Migrate AT to DX
    if item.get("expirationDate"):
        item["expires"] = item["expirationDate"]
    if item.get("effectiveDate"):
        item["effective"] = item["effectiveDate"]
    if item.get("excludeFromNav"):
        item["exclude_from_nav"] = item["excludeFromNav"]
    if item.get("subject"):
        item["subjects"] = item["subject"]

Fix datetime data

see #10

Fix issue with AT Text fields

TextField-export in Archetypes: Inspecting the AT-schema and applying a change for all Textfields if the RichtextWidget is not used (which means the field is probably Text in DX and not RichText).

    # In Archetypes Text is handled the same as RichText
    if isinstance(item.get("description", None), dict):
        item[fieldname] = item[fieldname]["data"]
    if isinstance(item.get('rights', None), dict):
        item['rights'] = item['rights']['data']

Fix collection-criteria

Some criteria have changed, e.g.

query = item.pop("query", [])
for crit in query:
    if crit["o"].endswith("relativePath") and crit["v"] == "..":
        crit["v"] = "..::1"
    if crit["i"] == "portal_type" and crit["o"].endswith("selection.is"):
        crit["o"] = "plone.app.querystring.operation.selection.any"

Fix image links and scales

Use the code in https://github.com/collective/collective.migrationhelpers/blob/master/src/collective/migrationhelpers/images.py to fix links to images and make them editable in TinyMCE.

collective / collective.exportimport