This module allows Hammerspoon to preform Spotlight metadata queries.
This module will only be able to perform queries on volumes and folders which are not blocked by the Privacy settings in the System Preferences Spotlight panel.
A Spotlight query consists of two phases: an initial gathering phase where information currently in the Spotlight database is collected and returned, and a live-update phase which occurs after the gathering phase and consists of changes made to the Spotlight database, such as new entries being added, information in existing entries changing, or entities being removed.
The syntax for Spotlight Queries is beyond the scope of this module's documentation. It is a subset of the syntax supported by the Objective-C NSPredicate class. Some references for this syntax can be found at:
Depending upon the callback messages enabled with the hs.spotlight:callbackMessages method, your callback assigned with the hs.spotlight:setCallback method, you can determine the query phase by noting which messages you have received. During the initial gathering phase, the following callback messages may be observed: "didStart", "inProgress", and "didFinish". Once the initial gathering phase has completed, you will only observe "didUpdate" messages until the query is stopped with the hs.spotlight:stop method.
You can also check to see if the initial gathering phase is in progress with the hs.spotlight:isGathering method.
You can access the individual results of the query with the hs.spotlight:resultAtIndex method. For convenience, metamethods have been added to the spotlightObject which make accessing individual results easier: an individual spotlightItemObject may be accessed from a spotlightObject by treating the spotlightObject like an array; e.g. spotlightObject[n] will access the n'th spotlightItemObject in the current results.
A list of defined attribute keys as discovered in the macOS 10.12 SDK framework headers.
Notes
This list was generated by searching the Framework header files for string constants which matched one of the following regular expressions: "kMDItem.+", "NSMetadataItem.+", and "NSMetadataUbiquitousItem.+"
A table of key-value pairs describing predefined search scopes for Spotlight queries
Notes
It is uncertain at this time if the iCloud* search scopes are actually useful within Hammerspoon as Hammerspoon is not a sandboxed application that uses the iCloud API fo document storage. Further information on your experiences with these scopes, if you use them, is welcome in the Hammerspoon Google Group or at the Hammerspoon GitHub web site.
Get or specify the specific messages that should generate a callback.
Parameters
messages - an optional table or list of items specifying the specific callback messages that will generate a callback. Defaults to { "didFinish" }.
Returns
if an argument is provided, returns the spotlightObject; otherwise returns the current values
Notes
Valid messages for the table are: "didFinish", "didStart", "didUpdate", and "inProgress". See hs.spotlight:setCallback for more details about the messages.
Returns the number of results for the spotlightObject's query
Parameters
None
Returns
if the query has collected results, returns the number of results that match the query; if the query has not been started, this value will be 0.
Notes
Just because the result of this method is 0 does not mean that the query has not been started; the query itself may not match any entries in the Spotlight database.
A query which ran in the past but has been subsequently stopped will retain its queries unless the parameters have been changed. The result of this method will indicate the number of results still attached to the query, even if it has been previously stopped.
For convenience, metamethods have been added to the spotlightObject which allow you to use #spotlightObject as a shortcut for spotlightObject:count().
Returns the grouped results for a Spotlight query.
Parameters
None
Returns
an array table containing the grouped results for the Spotlight query as specified by the hs.spotlight:groupingAttributes method. Each member of the array will be a spotlightGroupObject which is detailed in the hs.spotlight.group module documentation.
Notes
The spotlightItemObjects available with the hs.spotlight.group:resultAtIndex method are the subset of the full results of the spotlightObject that match the attribute and value of the spotlightGroupObject. The same item is available through the spotlightObject and the spotlightGroupObject, though likely at different indices.
Get or set the grouping attributes for the Spotlight query.
Parameters
attributes - an optional table or list of items specifying the grouping attributes for the Spotlight query. Defaults to an empty array.
Returns
if an argument is provided, returns the spotlightObject; otherwise returns the current values
Notes
Setting this property while a query is running stops the query and discards the current results. The receiver immediately starts a new query.
Setting this property will increase CPU and memory usage while performing the Spotlight query.
This method allows you to access results grouped by the values of specific attributes. See hs.spotlight.group for more information on using and accessing grouped results.
Note that not all attributes can be used as a grouping attribute. In such cases, the grouped result will contain all results and an attribute value of nil.
Returns a boolean specifying whether or not the query is in the active gathering phase.
Parameters
None
Returns
a boolean value of true if the query is in the active gathering phase or false if it is not.
Notes
An inactive query will also return false for this method since an inactive query is neither gathering nor waiting for updates. To determine if a query is active or inactive, use the hs.spotlight:isRunning method.
Returns a boolean specifying if the query is active or inactive.
Parameters
None
Returns
a boolean value of true if the query is active or false if it is inactive.
Notes
An active query may be gathering query results (in the initial gathering phase) or listening for changes which should cause a "didUpdate" message (after the initial gathering phase). To determine which state the query may be in, use the hs.spotlight:isGathering method.
a string containing the query for the spotlightObject
Returns
the spotlightObject
Notes
Setting this property while a query is running stops the query and discards the current results. The receiver immediately starts a new query.
The query string syntax is not simple enough to fully describe here. It is a subset of the syntax supported by the Objective-C NSPredicate class. Some references for this syntax can be found at:
If the query string does not conform to an NSPredicate query string, this method will return an error. If the query string does conform to an NSPredicate query string, this method will accept the query string, but if it does not conform to the Metadata query format, which is a subset of the NSPredicate query format, the error will be generated when you attempt to start the query with hs.spotlight:start. At present, starting a query is the only way to fully guarantee that a query is in a valid format.
Some of the query strings which have been used during the testing of this module are as follows (note that [[ ]] is a Lua string specifier that allows for double quotes in the content of the string):
[[ kMDItemFSName like "AppleScript Editor.app" or kMDItemAlternateNames like "AppleScript Editor"]]
Not all attributes appear to be usable in a query; see hs.spotlight.item:attributes for a possible explanation.
As a convenience, the __call metamethod has been setup for spotlightObject so that you can use spotlightObject("query") as a shortcut for spotlightObject:queryString("query"):start. Because this shortcut includes an explicit start, this should be appended after you have set the callback function if you require a callback (e.g. spotlightObject:setCallback(fn)("query")).
Returns the spotlightItemObject at the specified index of the spotlightObject
Parameters
index - an integer specifying the index of the result to return.
Returns
the spotlightItemObject at the specified index or an error if the index is out of bounds.
Notes
For convenience, metamethods have been added to the spotlightObject which allow you to use spotlightObject[index] as a shortcut for spotlightObject:resultAtIndex(index).
Get or set the search scopes allowed for the Spotlight query.
Parameters
scope - an optional table or list of items specifying the search scope for the Spotlight query. Defaults to an empty array, specifying that the search is not limited in scope.
Returns
if an argument is provided for scope, returns the spotlightObject; otherwise returns a table containing the current search scopes.
Notes
Setting this property while a query is running stops the query and discards the current results. The receiver immediately starts a new query.
Each item listed in the scope table may be a string or a file URL table as described in documentation for the hs.sharing.URL and hs.sharing.fileURL functions.
if an item is a string and matches one of the values in the hs.spotlight.definedSearchScopes table, then the scope for that item will be added to the valid search scopes.
if an item is a string and does not match one of the predefined values, it is treated as a path on the local system and will undergo tilde prefix expansion befor being added to the search scopes (i.e. "~/" will be expanded to "/Users/username/").
if an item is a table, it will be treated as a file URL table.
Set or remove the callback function for the Spotlight search object.
Parameters
fn - the function to replace the current callback function. If this argument is an explicit nil, removes the current callback function and does not replace it. The function should expect 2 or 3 arguments and should return none.
obj, "didStart" -- occurs when the initial gathering phase of a Spotlight search begins.
obj - the spotlightObject performing the search
message - the message to the callback, in this case "didStart"
obj, "inProgress", updateTable -- occurs during the initial gathering phase at intervals set by the hs.spotlight:updateInterval method.
obj - the spotlightObject performing the search
message - the message to the callback, in this case "inProgress"
updateTable - a table containing one or more of the following keys:
kMDQueryUpdateAddedItems - an array table of spotlightItem objects that have been added to the results
kMDQueryUpdateChangedItems - an array table of spotlightItem objects that have changed since they were first added to the results
kMDQueryUpdateRemovedItems - an array table of spotlightItem objects that have been removed since they were first added to the results
obj, "didFinish" -- occurs when the initial gathering phase of a Spotlight search completes.
obj - the spotlightObject performing the search
message - the message to the callback, in this case "didFinish"
obj, "didUpdate", updateTable -- occurs after the initial gathering phase has completed. This indicates that a change has occurred after the initial query that affects the result set.
obj - the spotlightObject performing the search
message - the message to the callback, in this case "didUpdate"
updateTable - a table containing one or more of the keys described for the updateTable argument of the "inProgress" message.
All of the results are always available through the hs.spotlight:resultAtIndex method and metamethod shortcuts described in the hs.spotlight and hs.spotlight.item documentation headers; the results provided by the "didUpdate" and "inProgress" messages are just a convenience and can be used if you wish to parse partial results.
Get or set the sorting preferences for the results of a Spotlight query.
Parameters
attributes - an optional table or list of items specifying sort descriptors which affect the sorting order of results for a Spotlight query. Defaults to an empty array.
Returns
if an argument is provided, returns the spotlightObject; otherwise returns the current values
Notes
Setting this property while a query is running stops the query and discards the current results. The receiver immediately starts a new query.
A sort descriptor may be specified as a string or as a table of key-value pairs. In the case of a string, the sort descriptor will sort items in an ascending manner. When specified as a table, at least the following keys should be specified:
key - a string specifying the attribute to sort by
ascending - a boolean, default true, specifying whether the sort order should be ascending (true) or descending (false).
This method attempts to specify the sorting order of the results returned by the Spotlight query.
Note that not all attributes can be used as an attribute in a sort descriptor. In such cases, the sort descriptor will have no affect on the order of returned items.
If the query string set with hs.spotlight:queryString is invalid, an error message will be logged to the Hammerspoon console and the query will not start. You can test to see if the query is actually running with the hs.spotlight:isRunning method.
This method will prevent further gathering of items either during the initial gathering phase or from updates which may occur after the gathering phase; however it will not discard the results already discovered.
hs.spotlight:updateInterval([interval]) -> number | spotlightObject
Type
Method
Description
Get or set the time interval at which the spotlightObject will send "didUpdate" messages during the initial gathering phase.
Parameters
interval - an optional number, default 1.0, specifying how often in seconds the "didUpdate" message should be generated during the initial gathering phase of a Spotlight query.
Returns
if an argument is provided, returns the spotlightObject object; otherwise returns the current value.
Get or set the attributes for which value list summaries are produced for the Spotlight query.
Parameters
attributes - an optional table or list of items specifying the attributes for which value list summaries are produced for the Spotlight query. Defaults to an empty array.
Returns
if an argument is provided, returns the spotlightObject; otherwise returns the current values
Notes
Setting this property while a query is running stops the query and discards the current results. The receiver immediately starts a new query.
Setting this property will increase CPU and memory usage while performing the Spotlight query.
This method allows you to specify attributes for which you wish to gather summary information about. See hs.spotlight:valueLists for more information about value list summaries.
Note that not all attributes can be used as a value list attribute. In such cases, the summary for the attribute will specify all results and an attribute value of nil.
Returns the value list summaries for the Spotlight query
Parameters
None
Returns
an array table of the value list summaries for the Spotlight query as specified by the hs.spotlight:valueListAttributes method. Each member of the array will be a table with the following keys:
attribute - the attribute for the summary
value - the value of the attribute for the summary
count - the number of Spotlight items in the spotlightObject results for which this attribute has this value
Notes
Value list summaries are a quick way to gather statistics about the number of results which match certain criteria - they do not allow you easy access to the matching members, just information about their numbers.