Example:
* Text: "strong and emphasized only"
* Markups:
* Strong: 0..10
* Emphasis: 7..21
First, get all the borders of the markups, including the start (0) and
end (text.size) indexes of the text in order:
```
[0, 7, 10, 21, 26]
```
Then attach markups to each range. Note that the ranges are exclusive;
they don't include the final number:
* 0...7: Strong
* 7...10: Strong, Emphasized
* 10...21: Emphasized
* 21...26: N/A
Bundle each range and it's related markups into a value object
RangeWithMarkup and return the list.
Loop through that list and recursively apply each markup to each
segment of text:
* Apply a `Strong` markup to the text "strong "
* Apply a `Strong` markup to the text "and"
* Wrap that in an `Emphasis` markup
* Apply an `Emphasis` markup to the text " emphasized"
* Leave the text " only" as is
---
This has the side effect of breaking up the nodes more than they need
to be broken up. For example right now the algorithm creates this HTML:
```
<strong>strong </strong><em><strong>and</strong></em>
```
instead of:
```
<strong>strong <em>and</em></strong>
```
But that's a task for another day.
The impetus for this change was to help make the MarkupConverter code
more robust. However, it's also possible that an Anchor can contain
styled text. For example, in markdown someone might write a link that
contains some <strong> text:
```markdown
[this link is so **good**](https://example.com)
```
This setup will now allow that. Unknown if UserAnchor can ever contain
any text that isn't just the user's name, but it's easy to deal with
and makes the typing much easier.
The API responds with a bunch of paragraphs which the client converts
into Paragraph objects.
This turns the paragraphs in a PostResponse's Paragraph objects into the
form needed to render them on a page. This includes converting flat list
elements into list elements nested by a UL. And adding a limited markups
along the way.
The array of paragraphs is passed to a recursive function. The function
takes the first paragraph and either wraps the (marked up) contents in a
container tag (like Paragraph or Heading3), and then moves onto the next
tag. If it finds a list, it starts parsing the next paragraphs as a list
instead.
Originally, this was implemented like so:
```crystal
paragraph = paragraphs.shift
if list?
convert_list([paragraph] + paragraphs)
end
```
However, passing the `paragraphs` after adding it to the already shifted
`paragraph` creates a new object. This means `paragraphs` won't be
mutated and once the list is parsed, it starts with the next element of
the list. Instead, the element is `shift`ed inside each converter.
```crystal
if paragraphs.first == list?
convert_list(paragraphs)
end
def convert_list(paragraphs)
paragraph = paragraphs.shift
# ...
end
```
When rendering, there is an Empty and Container object. These represent
a kind of "null object" for both leafs and parent objects respectively.
They should never actually render. Emptys are filtered out, and
Containers are never created explicitly but this will make the types
pass.
IFrames are a bit of a special case. Each IFrame has custom data on it
that this system would need to be aware of. For now, instead of trying
to parse the seemingly large number of iframe variations and dealing
with embedded iframe problems, this will just keep track of the source
page URL and send the user there with a link.
Edward Loveall