Text | Highlight Text Using Text Formatting Codes

Something that has popped up quite many times in classes is the need to find and highlight certain words in a text dynamically.

This technique is based on these features: #

• Text Formatting Codes
• Python String replace() method
• Python F-Strings

Tutorial #

1. Create a Text DAT and name it text_input. This will be the input text that you are going to process. For testing purposes, I asked ChatGPT to write a short story that includes the words squirrel, tree and lake. You can copy the text from here.

2. Create a Table DAT and name it table_keywords. Add all your keywords you want to search for as separate rows.

3. Create a Text DAT and name it text_output. This will be used to store the text after the code has processed the highlighting.

4. Create a Text DAT that will contain your code for searching and higlighting the text. We make this as a separate DAT so that we can run it from somewhere else. Name it text_highlight_script. Add the following code to it:

# Get references to the DATs
# Replace 'text_input' with the actual name of your input Text DAT
text_dat = op('text_input')
# Replace 'table_keywords' with the actual name of your Keywords Table DAT
keywords_dat = op('table_keywords')
# Replace 'text_output' with the actual name of your Output Text DAT
output_dat = op('text_output')  

# Get the text and keywords
text = text_dat.text
keywords = [row[0].val for row in keywords_dat.rows()]

# Define the formatting tags using the Slug Library format
start_tag = "{#color(255,0,0,255);under(true)}"
end_tag = "{#reset()}"

# Function to highlight keywords in text
def highlight_keywords(text, keywords):
    for keyword in keywords:
        text = text.replace(keyword, f"{start_tag}{keyword}{end_tag}")
    return text

# Apply the formatting
formatted_text = highlight_keywords(text, keywords)

# Output the formatted text to the Output DAT
output_dat.text = formatted_text

# Enable the following line for debugging
#print(formatted_text)

6. Add a Text COMP or GeoText COMP depending on how you want to use your text. Note that this does not work with the Text TOP. I am going to use Text COMP for this tutorial.

7. Change the properties of the Text COMP.

• Text | Change the input to expression mode (cyan box) and add the following expression: op('text_output').text
• Type | Muti Line
• Formatting Codes | On
• Word Wrap | On
• Change the Font options and Width and Height of the Layout to your liking. You can see all the setting I have changed from the image below.

6. At this point it’s a good idea to test the code. Right-click on the text_highlight_script DAT and choose Run Script. You should see the text_output DAT update with the processed text and the Text COMP update show the formatted text. If it doesn’t work, check the error messages and go back step-by-step to see where the you might have done something incorrectly.

7. Add a DAT Execute DAT, write text_input to the DATs property to monitor changes happening in the input text.

8. Edit the onTableChange() method to include a call to run our script whenever the input text changes.

def onTableChange(dat):
	op('text_highlight_script').run()
	return

9. You can also add an OP Viewer TOP if you need to process the text image further. Turn on Preserve Alpha to keep the transparent background if needed.

Downloads #

Download the example file.

Notes #

The code is now hardcoded for these specific operators. It could be made much more modular for flexible reuse.