Add initial snippets & service page model, expose API

[benweatherman]

Implements parts of #2, #3, and #6

Proof is in the pudding:

curl http://localhost:8000/api/v2/pages/\?format\=json\&type\=base.ServicePage\&fields\=content,extra_content,tags | jq

{
  "meta": {
    "total_count": 1
  },
  "items": [
    {
      "id": 4,
      "meta": {
        "type": "base.ServicePage",
        "detail_url": "http://localhost/api/v2/pages/4/",
        "html_url": "http://localhost/sweet-new-page/",
        "slug": "sweet-new-page",
        "first_published_at": "2017-11-28T19:47:05.575059Z"
      },
      "title": "This is a sweet new page",
      "content": "<p>This is some sweet content</p><p><br/></p><ol><li>do this first</li><li>then do this</li><li>now you're done<br/></li></ol>",
      "extra_content": [
        {
          "type": "content",
          "value": "<p><b>This is my extra content</b><br/></p>",
          "id": "695e363a-6ecf-457e-8e53-e351aecc2ad6"
        },
        {
          "type": "application_block",
          "value": 1,
          "id": "dbb9e30f-2aff-4669-aee3-e555192a8580"
        },
        {
          "type": "content",
          "value": "<h1>This is some other extra content<br/></h1>",
          "id": "fb4ab425-9391-496a-aa5f-70915b02bde5"
        }
      ],
      "tags": [
        "nolo",
        "rolo",
        "yolo"
      ]
    }
  ]
}

[mateoclarke]

This python stuff is v new to me. Hoping you get @briaguya to give you more feedback on this stuff if needed. But I'll give it a

[mateoclarke]

don't think this matters at all but why is this magic number different from the rest?

[benweatherman]

You have to manually specifyCharField.max_length and 255 is a pretty common default. Django chooses a sensible default for EmailField.max_length which is apparently 254 :|

[benweatherman]

These migrations are auto-generated from models, so I'll probably punt on doing that here. I'll add some constants to models.py so magic numbers aren't scattered everywhere.

[mateoclarke]

👍 Are there any other options in this list you considered or that we may want to include in the future?

Also wondering if there will be any sanitization or parsing required when passing a string of html to the frontend via the API. There must be a trick to get it to render as HTML. Maybe we'll have to use the dangerouslySetInnerHtml method in React: https://reactjs.org/docs/dom-elements.html#dangerouslysetinnerhtml

[benweatherman]

The API responses come back as HTML currently but it's fairly simple to modify if there's a better representation to use.

There are other options available listed in the docs but these seemed like most of what an author would need.

[mateoclarke]

🆒

[mateoclarke]

what does this do? what is this syntax?

[benweatherman]

It's a python decorator, which is used to modify a class/function somehow. In this case, wagtail uses it as a way to mark these classes as snippets so they can be used in the admin. Here's more on what wagtail snippets actually are http://docs.wagtail.io/en/latest/topics/snippets.html

[mateoclarke]

👍

[ifsimicoded]

I'm mostly here to provide gifs ... not even animated ones at that.

[benweatherman]

@briaguya I like the suggestion for better return structure. For now, I'll probably keep it so that it generates HTML but I filed an issue to do better #15 and we can look at that once we're past the initial prototype.