[change] Allow multiple jsonschema widgets in one page

[nemesifier]

Earlier the schema.json was bound to each view. No matter how many
different switcher were present, it was only loading one of them.

With this patch, fetching schema.json is bound to each switcher element.
This allows fetching different JSONSchemas on the same page.

[nemesifier]

@pandafy I found a minor issue while testing the widget in the credentials edit page, can you replicate it?

[coveralls]

Coverage increased (+0.0008%) to 99.174% when pulling a53c16c on improve-jsonwidget into fcfa337 on master.

[pandafy]

@pandafy I found a minor issue while testing the widget in the credentials edit page, can you replicate it?

Yes, I am able to replicate it and it is occurring on master branch as well. I have opened #334 for it.

I believe it is unrelated to this PR.

[nemesifier]

@pandafy I found a minor issue while testing the widget in the credentials edit page, can you replicate it?

Yes, I am able to replicate it and it is occurring on master branch as well. I have opened #334 for it.

I believe it is unrelated to this PR.

@pandafy you're right, so I think we can merge this one. Do you agree?

[nemesifier]

@pandafy shouldn't this line also be removed as part of this change?

openwisp-controller/openwisp_controller/config/templates/admin/config/jsonschema-widget.html

Line 5 in fcfa337

<script>django._jsonSchemaWidgetUrl = "{% url schema_view_name %}";</script>

[pandafy]

@pandafy shouldn't this line also be removed as part of this change?

openwisp-controller/openwisp_controller/config/templates/admin/config/jsonschema-widget.html

Line 5 in fcfa337

<script>django._jsonSchemaWidgetUrl = "{% url schema_view_name %}";</script>

Yes @nemesisdesign , you are right! 😄

We should than also remove this, otherwise test suite will fail.

openwisp-controller/openwisp_controller/connection/tests/test_admin.py

Lines 101 to 107 in fb6aa7e

	def test_credentials_jsonschema_widget_presence(self):
	url = reverse(f'admin:{self.app_label}_credentials_add')
	schema_url = reverse(CredentialsSchemaWidget.schema_view_name)
	expected = f'<script>django._jsonSchemaWidgetUrl = "{schema_url}";</script>'
	self._login()
	response = self.client.get(url)
	self.assertContains(response, expected)

[nemesifier]

@pandafy Thanks for your integration.

I have also noticed the advanced mode code in the JS refers to an ID, but the CSS paths should be converted to use classes.