Hover Effect: CSS Animation or Web Animations

Problem:
SMIL's animate tag is deprecated, and CSS hover transitions need to be implemented to replace it.

Solution:
Remove the set tags and add CSS to the element_tpl:hover pseudo-class:

.element_tpl:hover {
    stroke-opacity: 0.5;
}

Scaling Effect upon Change

Problem:
Animate the element to scale a few times upon a committed change.

Solution:
Consider the following options:

1. CSS Animation: Use CSS keyframes to achieve scaling:

@keyframes scale-animation {
    0% { transform: scale(1); }
    50% { transform: scale(1.12); }
    100% { transform: scale(1); }
}

Then apply the animation to the element:

.element_tpl {
    animation: scale-animation 0.5s infinite alternate;
}

2. Web Animations: Use the Web Animations API to programmatically control the scaling:

// Create a new animation
const animation = document.timeline.addAnimation();

// Define keyframes
const keyframes = [
    { transform: 'scale(1)', offset: 0 },
    { transform: 'scale(1.12)', offset: 0.5 },
    { transform: 'scale(1)', offset: 1 }
];

// Apply keyframes to the animation
animation.effect = keyframes;

// Target the element
animation.target = document.querySelector('.element_tpl');

Scale Up and Down on Click

Problem:
Animate the element to scale up and down upon clicking.

Solution:

1. CSS Transitions: Use CSS transitions to trigger the scale changes on mousedown and mouseup events:

.element_tpl {
    transition: transform 0.2s;
}

.element_tpl:active {
    transform: scale(1.1);
}

2. Web Animations: Use the Web Animations API to handle the click event and scale the element accordingly:

// Add event listener
document.querySelector('.element_tpl').addEventListener('click', (event) => {

    // Create a new animation
    const animation = document.timeline.addAnimation();

    // Define keyframes
    const keyframes = [
        { transform: 'scale(1)', offset: 0 },
        { transform: 'scale(1.1)', offset: 0.2 },
        { transform: 'scale(1)', offset: 0.4 },
    ];

    // Apply keyframes to the animation
    animation.effect = keyframes;

    // Target the element
    animation.target = event.target;
});

Saving SMIL Animations

Problem:
Transfer SMIL animations to CSS or Web animations.

Solution:
Use the SMIL polyfill created by Eric Willigers: https://github.com/ericwilligers/svg-animation. This polyfill converts SMIL animations to Web Animations, providing an alternative way to implement them.