Computing Flows

This example shows how to compute and visualize different paths between nodes in your flow. You can use this to implement features like dependency analysis, path finding, or flow validation. The example demonstrates how to use Svelte Flow’s built-in utilities to calculate paths and highlight them in the flow.

/* xyflow theme files. Delete these to start from our base */
 
.svelte-flow {
  --xy-background-color: #f7f9fb;
  /* Custom Variables */
  --xy-theme-selected: #ff4000;
  --xy-theme-hover: #c5c5c5;
  --xy-theme-edge-hover: black;
  --xy-theme-color-focus: #e8e8e8;
 
  /* Built-in Variables see https://svelteflow.dev/learn/customization/theming */
  --xy-node-border-default: 1px solid #ededed;
 
  --xy-node-boxshadow-default: 0px 3.54px 4.55px 0px #00000005, 0px 3.54px 4.55px 0px #0000000d, 0px 0.51px 1.01px 0px #0000001a;
 
  --xy-node-border-radius-default: 8px;
 
  --xy-handle-background-color-default: #ffffff;
  --xy-handle-border-color-default: #aaaaaa;
 
  --xy-edge-label-color-default: #505050;
 
  --xy-resize-background-color-default: #9e86ed;
  --xy-node-background-color-default: #ffffff;
  --xy-theme-panel-bg: #ffffff;
  --xy-theme-panel-text: #111827;
  --xy-theme-resize-handle-bg: #ffffff;
  --xy-theme-focus-border: #d9d9d9;
  --xy-theme-muted-bg: #f3f4f6;
  --xy-theme-subtle-border: #d1d5db;
}
 
.svelte-flow.dark {
  --xy-background-color: #101012;
  --xy-node-background-color-default: #1a1b1e;
  --xy-node-border-default: 1px solid #303238;
  --xy-handle-background-color-default: #141519;
  --xy-handle-border-color-default: #5a5d66;
  --xy-edge-label-color-default: #e6e7ea;
  --xy-theme-hover: #7a7d86;
  --xy-theme-edge-hover: #f3f4f6;
  --xy-theme-panel-bg: #141519;
  --xy-theme-panel-text: #f3f4f6;
  --xy-theme-resize-handle-bg: #141519;
  --xy-theme-focus-border: #5f6470;
  --xy-theme-muted-bg: #24262c;
  --xy-theme-subtle-border: #3f434c;
  --xy-node-boxshadow-default: none;
  --xy-theme-color-focus: #4b4e57;
  --color-background: #1a1b1e;
  --color-hover-bg: #24262c;
  --color-disabled: #8b9099;
}
 
.svelte-flow {
  background-color: var(--xy-background-color);
}
 
/* Customizing Default Theming */
 
.svelte-flow__node {
  box-shadow: var(--xy-node-boxshadow-default);
  border-radius: var(--xy-node-border-radius-default);
  background-color: var(--xy-node-background-color-default);
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 10px;
  font-size: 12px;
  flex-direction: column;
  border: var(--xy-node-border-default);
  color: var(--xy-node-color, var(--xy-node-color-default));
}
 
.svelte-flow__node.selectable:focus {
  box-shadow: 0px 0px 0px 4px var(--xy-theme-color-focus);
  border-color: var(--xy-theme-focus-border);
}
 
.svelte-flow__node.selectable:focus:active {
  box-shadow: var(--xy-node-boxshadow-default);
}
 
.svelte-flow__node.selectable:hover,
.svelte-flow__node.draggable:hover {
  border-color: var(--xy-theme-hover);
}
 
.svelte-flow__node.selectable.selected {
  border-color: var(--xy-theme-selected);
  box-shadow: var(--xy-node-boxshadow-default);
}
 
.svelte-flow__node-group {
  background-color: rgba(207, 182, 255, 0.4);
  border-color: #9e86ed;
}
 
.svelte-flow.dark .svelte-flow__node-group {
  background-color: rgba(123, 107, 148, 0.22);
  border-color: #7b6b94;
}
 
.svelte-flow__edge.selectable:hover .svelte-flow__edge-path,
.svelte-flow__edge.selectable.selected .svelte-flow__edge-path {
  stroke: var(--xy-theme-edge-hover);
}
 
.svelte-flow__handle {
  background-color: var(--xy-handle-background-color-default);
}
 
.svelte-flow__handle.connectionindicator:hover {
  pointer-events: all;
  border-color: var(--xy-theme-edge-hover);
  background-color: var(--xy-handle-background-color-default);
}
 
.svelte-flow__handle.connectionindicator:focus,
.svelte-flow__handle.connectingfrom,
.svelte-flow__handle.connectingto {
  border-color: var(--xy-theme-edge-hover);
}
 
.svelte-flow__node:has(.svelte-flow__resize-control.line) {
  border-radius: 0;
}
 
.svelte-flow__resize-control.handle {
  background-color: var(--xy-theme-resize-handle-bg);
  border: none;
  border-radius: 0;
  width: 5px;
  height: 5px;
}
 
.svelte-flow__edge-label {
  background: var(--xy-background-color);
  color: var(--xy-edge-label-color-default);
}
 
/* 
  Custom Example CSS  - This CSS is to improve the example experience.
  You can remove it if you want to use the default styles.
 
  New Theme Classes:
    .xy-theme__button   - Styles for buttons.
    .xy-theme__input    - Styles for text inputs.
    .xy-theme__checkbox - Styles for checkboxes.
    .xy-theme__select   - Styles for dropdown selects.
    .xy-theme__label    - Styles for labels.
  
  Use these classes to apply consistent theming across your components.
*/
 
:root {
  --color-primary: #ff4000;
  --color-background: #fefefe;
  --color-hover-bg: #f6f6f6;
  --color-disabled: #76797e;
}
 
/* Custom Button Styling */
.xy-theme__button-group {
  display: flex;
  align-items: center;
 
  .xy-theme__button:first-child {
    border-radius: 100px 0 0 100px;
  }
 
  .xy-theme__button:last-child {
    border-radius: 0 100px 100px 0;
    margin: 0;
  }
}
 
.xy-theme__button {
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 2.5rem;
  padding: 0 1rem;
  border-radius: 100px;
  border: 1px solid var(--color-primary);
  background-color: var(--color-background);
  color: var(--color-primary);
  transition:
    background-color 0.2s ease,
    border-color 0.2s ease;
  box-shadow: var(--xy-node-boxshadow-default);
}
 
.xy-theme__button.active {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}
 
.xy-theme__button.active:hover,
.xy-theme__button.active:active {
  background-color: var(--color-primary);
  opacity: 0.9;
}
 
.xy-theme__button:hover {
  background-color: var(--xy-controls-button-background-color-hover-default);
}
 
.xy-theme__button:active {
  background-color: var(--color-hover-bg);
}
 
.xy-theme__button:disabled {
  color: var(--color-disabled);
  opacity: 0.8;
  cursor: not-allowed;
  border: 1px solid var(--color-disabled);
}
 
.xy-theme__button > span {
  margin-right: 0.2rem;
}
 
/* Add gap between adjacent buttons */
.xy-theme__button + .xy-theme__button {
  margin-left: 0.3rem;
}
 
/* Example Input Styling */
.xy-theme__input {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-primary);
  border-radius: 7px;
  background-color: var(--color-background);
  transition:
    background-color 0.2s ease,
    border-color 0.2s ease;
  font-size: 1rem;
  color: var(--xy-theme-panel-text);
}
 
.xy-theme__input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(255, 0, 115, 0.3);
}
 
/* Specific Checkbox Styling */
.xy-theme__checkbox {
  appearance: none;
  -webkit-appearance: none;
  width: 1.25rem;
  height: 1.25rem;
  border-radius: 7px;
  border: 2px solid var(--color-primary);
  background-color: var(--color-background);
  transition:
    background-color 0.2s ease,
    border-color 0.2s ease;
  cursor: pointer;
  display: inline-block;
  vertical-align: middle;
  margin-right: 0.5rem;
}
 
.xy-theme__checkbox:checked {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}
 
.xy-theme__checkbox:focus {
  outline: none;
  box-shadow: 0 0 0 2px rgba(255, 0, 115, 0.3);
}
 
/* Dropdown Styling */
.xy-theme__select {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-primary);
  border-radius: 50px;
  background-color: var(--color-background);
  transition:
    background-color 0.2s ease,
    border-color 0.2s ease;
  font-size: 1rem;
  color: var(--xy-theme-panel-text);
  margin-right: 0.5rem;
  box-shadow: var(--xy-node-boxshadow-default);
}
 
.xy-theme__select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(255, 0, 115, 0.3);
}
 
.xy-theme__label {
  margin-top: 10px;
  margin-bottom: 3px;
  display: inline-block;
  color: var(--xy-theme-panel-text);
}