Overview · Rich Text View

About

iOS Text View (UIView) that Properly Displays LaTeX, HTML, Markdown, and YouTube/Vimeo Links

Installation

Using Cocoapods

Simply add the following to your Podfile:

pod 'RichTextView'

And run pod install in your repo.

Using Carthage

Simply add the following to your Cartfile:

github "tophat/RichTextView"

And run carthage update --platform iOS in your repo.

Usage

You can instantiate a RichTextView by importing the project first:

import RichTextView

To init a RichTextView:

let richTextView = RichTextView(
    input: "Test",
    latexParser: LatexParser(),
    font: UIFont.systemFont(ofSize: UIFont.systemFontSize),
    textColor: UIColor.black,
    isSelectable: true,
    isEditable: false,
    latexTextBaselineOffset: 0,
    interactiveTextColor: UIColor.blue,
    textViewDelegate: nil,
    frame: CGRect.zero,
    completion: nil
)

You can also update an existing RichTextView as follows:

richTextView.update(
    input: "Test",
    latexParser: LatexParser(),
    font: UIFont.systemFont(ofSize: UIFont.systemFontSize),
    textColor: UIColor.black,
    latexTextBaselineOffset: 0,
    interactiveTextColor: UIColor.blue,
    completion: nil
)

The parameters are defined as follows:

input - The string you want to render
latexParser - You can pass your own class that conforms to LatexParserProtocol if you want to handle LaTeX parsing in a custom way. Currently we use the iosMath Pod to handle LaTeX parsing by default
font - The font of the text to render
texColor - The color of the text to render
isSelectable - A property that determines whether or not RichTextView is selectable
isEditable - A property that determines whether or not RichTextView is editable
latexTextBaselineOffset - The baseline offset of the attributed text attachment that represents any LaTeX text that needs to be rendered
interactiveTextColor - The text color of any interactive elements/custom links (see Interactive element in Formatting the input)
textViewDelegate - A RichTextViewDelegate - conforms to UITextViewDelegate and also has handling when interactive elements/custom links are tapped
frame - A CGRect that represents the frame of the RichTextView
completion - A completion block to handle any errors that might be returned. The input will still render even if there are errors, however it might look differently than expected.

Formatting the input

In order for the RichTextView to handle the various use cases it might encounter, the input string needs to be formatted as follows:

LaTeX: Put any text you want to render as LaTeX in between two [math] and [/math] tags. Example: [math]x^n[/math]
Code: Put any text you want to render as code in between two [code] and [/code] tags. Example: [code]print('Hello World')[/code]
HTML/Markdown: No formatting necessary
YouTube Videos: Put the ID of the YouTube video in a YouTube tag as follows: youtube[dQw4w9WgXcQ]. The YouTube ID of any video can be found by looking at the URL of the video (Example: https://www.youtube.com/watch?v=dQw4w9WgXcQ) and taking the value right after the v= URL parameter. In this case the ID of the YouTube video is dQw4w9WgXcQ
Vimeo Videos: Put the ID of the Vimeo video in a Vimeo tag as follows: vimeo[100708006]. The Vimeo ID of any video can be found by looking at the URL of the video (Example: https://vimeo.com/100708006) and taking the value right after the first /. In this case the ID of the Vimeo video is 100708006
Interactive element: If you want to add text that has custom handling when you tap it, put the text in between two [interactive-element id=<id>] and [/interactive-element] tags. By doing this, when a user taps this text it will call the didTapCustomLink function of RichTextViewDelegate with the ID of the text that represents the interactive element (<id>), so be sure to hook into RichTextViewDelegate to capture this.

Screenshots

Check out the sample project in the Example root folder to see the screenshots above in action!