budibase/packages/client/src/components/Component.svelte

491 lines
16 KiB
Svelte

<script context="module">
// Cache the definition of settings for each component type
let SettingsDefinitionCache = {}
let SettingsDefinitionMapCache = {}
// Cache the settings of each component ID.
// This speeds up remounting as well as repeaters.
let InstanceSettingsCache = {}
</script>
<script>
import { getContext, setContext, onMount, onDestroy } from "svelte"
import { writable, get } from "svelte/store"
import * as AppComponents from "components/app"
import Router from "./Router.svelte"
import {
enrichProps,
propsAreSame,
getSettingsDefinition,
} from "utils/componentProps"
import { builderStore, devToolsStore, componentStore, appStore } from "stores"
import { Helpers } from "@budibase/bbui"
import { getActiveConditions, reduceConditionActions } from "utils/conditions"
import Placeholder from "components/app/Placeholder.svelte"
import ScreenPlaceholder from "components/app/ScreenPlaceholder.svelte"
import ComponentPlaceholder from "components/app/ComponentPlaceholder.svelte"
export let instance = {}
export let isLayout = false
export let isScreen = false
export let isBlock = false
// Get parent contexts
const context = getContext("context")
const insideScreenslot = !!getContext("screenslot")
// Create component context
const store = writable({})
setContext("component", store)
// Ref to the svelte component
let ref
// Initial settings are passed in on first render of the component.
// When the first instance of cachedSettings are set, this object is set to
// reference cachedSettings, so that mutations to cachedSettings also affect
// initialSettings, but it does not get caught by svelte invalidation - which
// would happen if we spread cachedSettings directly to the component.
let initialSettings
// Dynamic settings contain bindings and need enriched
let dynamicSettings
// Static settings do not contain any bindings and can be passed on down
let staticSettings
// The enriched component settings
let enrichedSettings
// Any setting overrides that need to be applied due to conditional UI
let conditionalSettings
// Resultant cached settings which will be passed to the component instance.
// These are a combination of the enriched, nested and conditional settings.
let cachedSettings
// Latest timestamp that we started a props update.
// Due to enrichment now being async, we need to avoid overwriting newer
// settings with old ones, depending on how long enrichment takes.
let latestUpdateTime
// Keep track of stringified representations of context and instance
// to avoid enriching bindings as much as possible
let lastContextKey
let lastInstanceKey
// Visibility flag used by conditional UI
let visible = true
// Component information derived during initialisation
let constructor
let definition
let settingsDefinition
let settingsDefinitionMap
let missingRequiredSettings = false
// Set up initial state for each new component instance
$: initialise(instance)
// Extract component instance info
$: children = instance._children || []
$: id = instance._id
$: name = isScreen ? "Screen" : instance._instanceName
$: icon = definition?.icon
// Determine if the component is selected or is part of the critical path
// leading to the selected component
$: selected =
$builderStore.inBuilder && $builderStore.selectedComponentId === id
$: inSelectedPath = $componentStore.selectedComponentPath?.includes(id)
$: inDragPath = inSelectedPath && $builderStore.editMode
// Derive definition properties which can all be optional, so need to be
// coerced to booleans
$: hasChildren = !!definition?.hasChildren
$: showEmptyState = definition?.showEmptyState !== false
$: hasMissingRequiredSettings = missingRequiredSettings?.length > 0
$: editable = !!definition?.editable && !hasMissingRequiredSettings
// Interactive components can be selected, dragged and highlighted inside
// the builder preview
$: builderInteractive =
$builderStore.inBuilder && insideScreenslot && !isBlock
$: devToolsInteractive = $devToolsStore.allowSelection && !isBlock
$: interactive = builderInteractive || devToolsInteractive
$: editing = editable && selected && $builderStore.editMode
$: draggable =
!inDragPath &&
interactive &&
!isLayout &&
!isScreen &&
definition?.draggable !== false
$: droppable = interactive && !isLayout && !isScreen
$: builderHidden =
$builderStore.inBuilder && $builderStore.hiddenComponentIds?.includes(id)
// Empty components are those which accept children but do not have any.
// Empty states can be shown for these components, but can be disabled
// in the component manifest.
$: empty = interactive && !children.length && hasChildren
$: emptyState = empty && showEmptyState
// Enrich component settings
$: enrichComponentSettings($context, settingsDefinitionMap)
// Evaluate conditional UI settings and store any component setting changes
// which need to be made. This is broken into 2 lines to avoid svelte
// reactivity re-evaluating conditions more often than necessary.
$: conditions = enrichedSettings?._conditions
$: evaluateConditions(conditions)
// Determine and apply settings to the component
$: applySettings(staticSettings, enrichedSettings, conditionalSettings)
// Scroll the selected element into view
$: selected && scrollIntoView()
// Update component context
$: store.set({
id,
children: children.length,
styles: {
...instance._styles,
id,
empty: emptyState,
interactive,
draggable,
editable,
},
empty: emptyState,
selected,
name,
editing,
type: instance._component,
missingRequiredSettings,
})
const initialise = instance => {
if (instance == null) {
return
}
// Ensure we're processing a new instance
const instanceKey = Helpers.hashString(JSON.stringify(instance))
if (instanceKey === lastInstanceKey) {
return
} else {
lastInstanceKey = instanceKey
}
// Pull definition and constructor
const component = instance._component
constructor = getComponentConstructor(component)
definition = componentStore.actions.getComponentDefinition(component)
if (!definition) {
return
}
// Get the settings definition for this component, and cache it
if (SettingsDefinitionCache[definition.name]) {
settingsDefinition = SettingsDefinitionCache[definition.name]
settingsDefinitionMap = SettingsDefinitionMapCache[definition.name]
} else {
settingsDefinition = getSettingsDefinition(definition)
settingsDefinitionMap = getSettingsDefinitionMap(settingsDefinition)
SettingsDefinitionCache[definition.name] = settingsDefinition
SettingsDefinitionMapCache[definition.name] = settingsDefinitionMap
}
// Parse the instance settings, and cache them
let instanceSettings
if (InstanceSettingsCache[instanceKey]) {
instanceSettings = InstanceSettingsCache[instanceKey]
} else {
instanceSettings = getInstanceSettings(instance, settingsDefinition)
InstanceSettingsCache[instanceKey] = instanceSettings
}
// Update the settings types
staticSettings = instanceSettings.staticSettings
dynamicSettings = instanceSettings.dynamicSettings
// Check if we have any missing required settings
missingRequiredSettings = settingsDefinition.filter(setting => {
let empty = instance[setting.key] == null || instance[setting.key] === ""
let missing = setting.required && empty
// Check if this setting depends on another, as it may not be required
if (setting.dependsOn) {
const dependsOnKey = setting.dependsOn.setting || setting.dependsOn
const dependsOnValue = setting.dependsOn.value
const realDependentValue = instance[dependsOnKey]
if (dependsOnValue == null && realDependentValue == null) {
return false
}
if (dependsOnValue !== realDependentValue) {
return false
}
}
return missing
})
// Force an initial enrichment of the new settings
enrichComponentSettings(get(context), settingsDefinitionMap, {
force: true,
})
}
// Gets the component constructor for the specified component
const getComponentConstructor = component => {
const split = component?.split("/")
const name = split?.[split.length - 1]
if (name === "screenslot" && !insideScreenslot) {
return Router
}
return AppComponents[name]
}
const getSettingsDefinitionMap = settingsDefinition => {
let map = {}
settingsDefinition?.forEach(setting => {
map[setting.key] = setting
})
return map
}
const getInstanceSettings = (instance, settingsDefinition) => {
// Get raw settings
let settings = {}
Object.entries(instance)
.filter(([name]) => name === "_conditions" || !name.startsWith("_"))
.forEach(([key, value]) => {
settings[key] = value
})
// Derive static, dynamic and nested settings if the instance changed
let newStaticSettings = { ...settings }
let newDynamicSettings = { ...settings }
settingsDefinition?.forEach(setting => {
if (setting.nested) {
delete newDynamicSettings[setting.key]
} else {
const value = settings[setting.key]
if (value == null) {
delete newDynamicSettings[setting.key]
} else if (typeof value === "string" && value.includes("{{")) {
// Strings can be trivially checked
delete newStaticSettings[setting.key]
} else if (setting.type === "event") {
// Always treat button actions as dynamic
delete newStaticSettings[setting.key]
} else if (typeof value === "object") {
// Stringify and check objects
const stringified = JSON.stringify(value)
if (stringified.includes("{{")) {
delete newStaticSettings[setting.key]
} else {
delete newDynamicSettings[setting.key]
}
} else {
// For other types, we can safely assume they are static
delete newDynamicSettings[setting.key]
}
}
})
return {
staticSettings: newStaticSettings,
dynamicSettings: newDynamicSettings,
}
}
// Enriches any string component props using handlebars
const enrichComponentSettings = (
context,
settingsDefinitionMap,
options = { force: false }
) => {
const contextChanged = context.key !== lastContextKey
if (!contextChanged && !options?.force) {
return
}
lastContextKey = context.key
// Record the timestamp so we can reference it after enrichment
latestUpdateTime = Date.now()
const enrichmentTime = latestUpdateTime
// Enrich settings with context
const newEnrichedSettings = enrichProps(
dynamicSettings,
context,
settingsDefinitionMap
)
// Abandon this update if a newer update has started
if (enrichmentTime !== latestUpdateTime) {
return
}
enrichedSettings = newEnrichedSettings
}
// Evaluates the list of conditional UI conditions and determines any setting
// or visibility changes required
const evaluateConditions = conditions => {
if (!conditions?.length) {
return
}
// Default visible to false if there is a show condition
let nextVisible = !conditions.find(condition => condition.action === "show")
// Execute conditions and determine settings and visibility changes
const activeConditions = getActiveConditions(conditions)
const result = reduceConditionActions(activeConditions)
if (result.visible != null) {
nextVisible = result.visible
}
// Update state from condition results
conditionalSettings = result.settingUpdates
visible = nextVisible
}
// Combines and caches all settings which will be passed to the component
// instance. Settings are aggressively memoized to avoid triggering svelte
// reactive statements as much as possible.
const applySettings = (
staticSettings,
enrichedSettings,
conditionalSettings
) => {
const allSettings = {
...staticSettings,
...enrichedSettings,
...conditionalSettings,
}
if (!cachedSettings) {
cachedSettings = { ...allSettings }
initialSettings = cachedSettings
} else {
Object.keys(allSettings).forEach(key => {
const same = propsAreSame(allSettings[key], cachedSettings[key])
if (!same) {
// Updated cachedSettings (which is assigned by reference to
// initialSettings) so that if we remount the component then the
// initial props are up to date. By setting it this way rather than
// setting it on initialSettings directly, we avoid a double render.
cachedSettings[key] = allSettings[key]
if (ref?.$$set) {
// Programmatically set the prop to avoid svelte reactive statements
// firing inside components. This circumvents the problems caused by
// spreading a props object.
ref.$$set({ [key]: allSettings[key] })
} else {
// Sometimes enrichment can occur multiple times before the
// component has mounted and been assigned a ref.
// In these cases, for some reason we need to update the
// initial settings object, even though it is equivalent by
// reference to cached settings. This solves the problem of multiple
// initial enrichments, while also not causing wasted renders for
// any components not affected by this issue.
initialSettings[key] = allSettings[key]
}
}
})
}
}
const scrollIntoView = () => {
const node = document.getElementsByClassName(id)?.[0]?.children[0]
if (!node) {
return
}
node.style.scrollMargin = "100px"
node.scrollIntoView({
behavior: "smooth",
block: "start",
inline: "start",
})
}
onMount(() => {
if (
$appStore.isDevApp &&
!componentStore.actions.isComponentRegistered(id)
) {
componentStore.actions.registerInstance(id, {
getSettings: () => cachedSettings,
getRawSettings: () => ({ ...staticSettings, ...dynamicSettings }),
getDataContext: () => get(context),
})
}
})
onDestroy(() => {
if (
$appStore.isDevApp &&
componentStore.actions.isComponentRegistered(id)
) {
componentStore.actions.unregisterInstance(id)
}
})
</script>
{#if constructor && initialSettings && (visible || inSelectedPath) && !builderHidden}
<!-- The ID is used as a class because getElementsByClassName is O(1) -->
<!-- and the performance matters for the selection indicators -->
<div
class={`component ${id}`}
class:draggable
class:droppable
class:empty
class:interactive
class:editing
class:block={isBlock}
data-id={id}
data-name={name}
data-icon={icon}
>
<svelte:component this={constructor} bind:this={ref} {...initialSettings}>
{#if hasMissingRequiredSettings}
<ComponentPlaceholder />
{:else if children.length}
{#each children as child (child._id)}
<svelte:self instance={child} />
{/each}
{:else if emptyState}
{#if isScreen}
<ScreenPlaceholder />
{:else}
<Placeholder />
{/if}
{:else if isBlock}
<slot />
{/if}
</svelte:component>
</div>
{/if}
<style>
.component {
display: contents;
}
.interactive :global(*:hover) {
cursor: pointer;
}
.draggable :global(*:hover) {
cursor: grab;
}
.editing :global(*:hover) {
cursor: auto;
}
</style>