Enhancing Instant AJAX-Based Updates for Bokeh Plots in a WordPress Dashboard
Creating dynamic, interactive dashboards is essential for delivering real-time insights. However, implementing seamless updates—especially with complex visualizations like Bokeh plots—can present challenges. If your dashboard updates KPIs instantly but your Bokeh graphs only refresh upon page reload, you’re likely facing issues related to how the plots are re-embedded after asynchronous data fetches.
Recognizing the Issue
In a typical setup, you might have:
– A Flask backend that processes filters, updates data, and returns JSON-encoded plot data and KPIs.
– Frontend JavaScript functions that apply filters, make AJAX POST requests, and re-embed Bokeh plots dynamically.
While KPIs update correctly without a page reload, the visualizations often remain static until a manual refresh. This indicates that your re-embedding process of Bokeh plots doesn’t trigger immediately or isn’t properly synchronized after the new data arrives.
Key Insights and Common Pitfalls
- Target Divs Are Correct: You’ve verified that the HTML containers exist and are correctly referenced.
- Plots Are Generated Back-End: The server-side rendering or data generation is working as expected.
- Plots Are Visible Post-Update, Just Not Re-Embedded: The plots do not auto-refresh within the browser.
Strategies for Reliable In-Place Plot Refreshes
- Clear Plots Properly Before Re-Embedding
Instead of just resetting innerHTML, ensure that all plot containers are correctly cleared and ready for new plots:
“`js
const plotDivs = [
“incident-chart”,
“injury-chart”,
“dept-donut”,
“dept-bar”,
“type-donut”,
“type-bar”
];
plotDivs.forEach((id) => {
const el = document.getElementById(id);
el.innerHTML = “”; // Remove previous plot content
el.style.display = “none”; // Hide to force reflow
void el.offsetWidth; // Trigger reflow
el.style.display = “block”; // Show container for new plot
});
“`
- Use Double RequestAnimationFrame for Smooth Embedding
Plotly and Bokeh both require the DOM to be fully ready before insertion. Wrapping embed calls with double requestAnimationFrame() can help ensure that the DOM updates are processed, preventing timing issues:
“`js
requestAnimationFrame(() => {
requestAnimation
