Component Registry: Difference between revisions
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! Name !! Type !! Description | ! Name !! Type !! Description | ||
|- | |- | ||
| style="white-space: nowrap;" | <code>:list()</code> || <code> | | style="white-space: nowrap;" | <code>:list()</code> || <code>function() -> (string, userdata), table, nil</code> || Returns an iterator function that, in each invocation returns a string representing the type of the current component along with the actual userdata instance. | ||
|- | |- | ||
| style="white-space: nowrap;" | <code>:getFirst(componentType:string)</code> || <code>userdata</code>|| Returns the first component of the given <code>componentType</code> or <code>nil</code> if no matching component exists. | | style="white-space: nowrap;" | <code>:getFirst(componentType:string)</code> || <code>userdata</code>|| Returns the first component of the given <code>componentType</code> or <code>nil</code> if no matching component exists. | ||
|} | |} | ||
While <code>:list()</code> looks very intimidating, it can simply be used in a for-loop in place of <code>ipairs(*)</code>. The built-in [[UEFI]] uses the following code to iterate over all components to find any bootable devices:<syntaxhighlight lang="lua" line="1"> | |||
{{Navbox content}} | local bootables = {} | ||
for compType, elem in components:list() do | |||
print("- " .. compType) | |||
if compType == "massStorage" then | |||
if elem:fileExists("boot.lua") then | |||
-- we found a bootable medium, use it as default if not already set | |||
defaultBoot = defaultBoot == nil and idx or defaultBoot | |||
bootables[idx] = elem | |||
end | |||
idx = idx + 1 | |||
end | |||
end | |||
</syntaxhighlight>{{Navbox content}} | |||
Revision as of 23:54, 1 August 2026
The Component Registry allows accessing all currently available Components and is the most convenient way of accessing components.
| Name | Type | Description |
|---|---|---|
:list() |
function() -> (string, userdata), table, nil |
Returns an iterator function that, in each invocation returns a string representing the type of the current component along with the actual userdata instance. |
:getFirst(componentType:string) |
userdata |
Returns the first component of the given componentType or nil if no matching component exists.
|
While :list() looks very intimidating, it can simply be used in a for-loop in place of ipairs(*). The built-in UEFI uses the following code to iterate over all components to find any bootable devices:
local bootables = {}
for compType, elem in components:list() do
print("- " .. compType)
if compType == "massStorage" then
if elem:fileExists("boot.lua") then
-- we found a bootable medium, use it as default if not already set
defaultBoot = defaultBoot == nil and idx or defaultBoot
bootables[idx] = elem
end
idx = idx + 1
end
end