Calibre: Allow authors/title metadata browse/searches (#10113)

c.f., https://www.mobileread.com/forums/showthread.php?t=352142

This adds dedicated "browse by" buttons for authors & tags, and adds series & tags to the search settings for the meta "Search books" button.

plugins/calibre.koplugin/main.lua

@@ -30,15 +30,9 @@ function Calibre:onCalibreSearch()
     return true
 end
 
-function Calibre:onCalibreBrowseTags()
+function Calibre:onCalibreBrowseBy(field)
     CalibreSearch.search_value = ""
-    CalibreSearch:find("tags", 1)
+    CalibreSearch:find(field)
-    return true
-end
-
-function Calibre:onCalibreBrowseSeries()
-    CalibreSearch.search_value = ""
-    CalibreSearch:find("series", 1)
     return true
 end
 
@@ -62,8 +56,10 @@ end
 
 function Calibre:onDispatcherRegisterActions()
     Dispatcher:registerAction("calibre_search", { category="none", event="CalibreSearch", title=_("Calibre metadata search"), general=true,})
-    Dispatcher:registerAction("calibre_browse_tags", { category="none", event="CalibreBrowseTags", title=_("Browse all calibre tags"), general=true,})
+    Dispatcher:registerAction("calibre_browse_tags", { category="none", event="CalibreBrowseBy", arg="tags", title=_("Browse all calibre tags"), general=true,})
-    Dispatcher:registerAction("calibre_browse_series", { category="none", event="CalibreBrowseSeries", title=_("Browse all calibre series"), general=true, separator=true,})
+    Dispatcher:registerAction("calibre_browse_series", { category="none", event="CalibreBrowseBy", arg="series", title=_("Browse all calibre series"), general=true,})
+    Dispatcher:registerAction("calibre_browse_authors", { category="none", event="CalibreBrowseBy", arg="authors", title=_("Browse all calibre authors"), general=true,})
+    Dispatcher:registerAction("calibre_browse_titles", { category="none", event="CalibreBrowseBy", arg="title", title=_("Browse all calibre titles"), general=true, separator=true,})
 end
 
 function Calibre:init()
@@ -209,13 +205,31 @@ function Calibre:getSearchMenuTable()
                 G_reader_settings:flipNilOrTrue("calibre_search_find_by_authors")
             end,
         },
+        {
+            text = _("Search by series"),
+            checked_func = function()
+                return G_reader_settings:isTrue("calibre_search_find_by_series")
+            end,
+            callback = function()
+                G_reader_settings:toggle("calibre_search_find_by_series")
+            end,
+        },
+        {
+            text = _("Search by tag"),
+            checked_func = function()
+                return G_reader_settings:isTrue("calibre_search_find_by_tag")
+            end,
+            callback = function()
+                G_reader_settings:toggle("calibre_search_find_by_tag")
+            end,
+        },
         {
             text = _("Search by path"),
             checked_func = function()
-                return G_reader_settings:nilOrTrue("calibre_search_find_by_path")
+                return G_reader_settings:isTrue("calibre_search_find_by_path")
             end,
             callback = function()
-                G_reader_settings:flipNilOrTrue("calibre_search_find_by_path")
+                G_reader_settings:toggle("calibre_search_find_by_path")
             end,
         },
     }

plugins/calibre.koplugin/metadata.lua

@@ -43,7 +43,7 @@ local function slim(book, is_search)
     for _, k in ipairs(is_search and search_used_metadata or used_metadata) do
         if k == "series" or k == "series_index" then
             slim_book[k] = book[k] or rapidjson.null
-        elseif k == "tags" then
+        elseif k == "tags" or k == "authors" then
             slim_book[k] = book[k] or {}
         else
             slim_book[k] = book[k]

plugins/calibre.koplugin/search.lua

@@ -67,25 +67,26 @@ local function match(str, query, case_insensitive)
     end
 end
 
--- get books that exactly match the search tag
+-- get books that exactly match the search in a specific flat field (series or title)
-local function getBooksByTag(t, tag)
+local function getBooksByField(t, field, query)
     local result = {}
     for _, book in ipairs(t) do
-        for __, _tag in ipairs(book.tags) do
+        local data = book[field]
-            if tag == _tag then
+        -- We can compare nil & rapidjson.null (light userdata) to a string safely
+        if data == query then
             table.insert(result, book)
         end
     end
-    end
     return result
 end
 
--- get books that exactly match the search series
+-- get books that exactly match the search in a specific array (tags or authors)
-local function getBooksBySeries(t, series)
+local function getBooksByNestedField(t, field, query)
     local result = {}
     for _, book in ipairs(t) do
-        if book.series and book.series ~= rapidjson.null then
+        local array = book[field]
-            if book.series == series then
+        for __, data in ipairs(array) do
+            if data == query then
                 table.insert(result, book)
             end
         end
@@ -93,28 +94,29 @@ local function getBooksBySeries(t, series)
     return result
 end
 
--- get tags that match the search criteria and their frequency
+-- generic search in a specific flat field (series or title), matching the search criteria and their frequency
-local function searchByTag(t, query, case_insensitive)
+local function searchByField(t, field, query, case_insensitive)
     local freq = {}
     for _, book in ipairs(t) do
-        if type(book.tags) == "table" then
+        local data = book[field]
-            for __, tag in ipairs(book.tags) do
+        -- We have to make sure we only pass strings to match
-                if match(tag, query, case_insensitive) then
+        if data and data ~= rapidjson.null then
-                    freq[tag] = (freq[tag] or 0) + 1
+            if match(data, query, case_insensitive) then
-                end
+                freq[data] = (freq[data] or 0) + 1
             end
         end
     end
     return freq
 end
 
--- get series that match the search criteria and their frequency
+-- generic search in a specific array (tags or authors), matching the search criteria and their frequency
-local function searchBySeries(t, query, case_insensitive)
+local function searchByNestedField(t, field, query, case_insensitive)
     local freq = {}
     for _, book in ipairs(t) do
-        if book.series and book.series ~= rapidjson.null then
+        local array = book[field]
-            if match(book.series, query, case_insensitive) then
+        for __, data in ipairs(array) do
-                freq[book.series] = (freq[book.series] or 0) + 1
+            if match(data, query, case_insensitive) then
+                freq[data] = (freq[data] or 0) + 1
             end
         end
     end
@@ -162,11 +164,17 @@ local CalibreSearch = WidgetContainer:extend{
     libraries = {},
     natsort_cache = {},
     last_scan = {},
-    search_options = {
+    -- These are enabled by default
+    default_search_options = {
         "cache_metadata",
         "case_insensitive",
         "find_by_title",
         "find_by_authors",
+    },
+    -- These aren't
+    extra_search_options = {
+        "find_by_series",
+        "find_by_tag",
         "find_by_path",
     },
 
@@ -205,6 +213,26 @@ function CalibreSearch:ShowSearch()
                     end,
                 },
             },
+            {
+                {
+                    text = _("Browse authors"),
+                    enabled = true,
+                    callback = function()
+                        self.search_value = self.search_dialog:getInputText()
+                        self.lastsearch = "authors"
+                        self:close()
+                    end,
+                },
+                {
+                    text = _("Browse titles"),
+                    enabled = true,
+                    callback = function()
+                        self.search_value = self.search_dialog:getInputText()
+                        self.lastsearch = "title"
+                        self:close()
+                    end,
+                },
+            },
             {
                 {
                     text = _("Cancel"),
@@ -300,11 +328,14 @@ function CalibreSearch:bookCatalog(t, option)
     return catalog
 end
 
--- find books, series or tags
+-- find books, series, tags, authors or titles
 function CalibreSearch:find(option)
-    for _, opt in ipairs(self.search_options) do
+    for _, opt in ipairs(self.default_search_options) do
         self[opt] = G_reader_settings:nilOrTrue("calibre_search_"..opt)
     end
+    for _, opt in ipairs(self.extra_search_options) do
+        self[opt] = G_reader_settings:isTrue("calibre_search_"..opt)
+    end
 
     if #self.libraries == 0 then
         local libs, err = self.cache_libs:load()
@@ -336,6 +367,8 @@ function CalibreSearch:find(option)
         "case sensitive: " .. tostring(not self.case_insensitive),
         "title: " .. tostring(self.find_by_title),
         "authors: " .. tostring(self.find_by_authors),
+        "series: " .. tostring(self.find_by_series),
+        "tag: " .. tostring(self.find_by_tag),
         "path: " .. tostring(self.find_by_path)))
 end
 
@@ -362,6 +395,16 @@ function CalibreSearch:findBooks(query)
                 end
             end
         end
+        if self.find_by_series and bookMatch(book.series, pattern) then
+            return true
+        end
+        if self.find_by_tag then
+            for _, tag in ipairs(book.tags) do
+                if bookMatch(tag, pattern) then
+                    return true
+                end
+            end
+        end
         if self.find_by_path and bookMatch(book.lpath, pattern) then
             return true
         end
@@ -393,16 +436,24 @@ function CalibreSearch:browse(option)
         local source
         if option == "tags" then
             name = _("Browse by tags")
-            source = searchByTag(self.books, search_value, self.case_insensitive)
+            source = searchByNestedField(self.books, option, search_value, self.case_insensitive)
         elseif option == "series" then
             name = _("Browse by series")
-            source = searchBySeries(self.books, search_value, self.case_insensitive)
+            source = searchByField(self.books, option, search_value, self.case_insensitive)
+        elseif option == "authors" then
+            name = _("Browse by authors")
+            source = searchByNestedField(self.books, option, search_value, self.case_insensitive)
+        elseif option == "title" then
+            name = _("Browse by titles")
+            -- This is admittedly only midly useful in the face of the generic search above,
+            -- but makes finding duplicate titles easy, at least ;).
+            source = searchByField(self.books, option, search_value, self.case_insensitive)
         end
         for k, v in pairs(source) do
             local entry = {}
             entry.text = string.format("%s (%d)", k, v)
             entry.callback = function()
-                self:expandTagOrSeries(option,k)
+                self:expandSearchResults(option, k)
             end
             table.insert(menu_entries, entry)
         end
@@ -430,13 +481,13 @@ function CalibreSearch:browse(option)
     UIManager:show(self.search_menu)
 end
 
-function CalibreSearch:expandTagOrSeries(option, chosen_item)
+function CalibreSearch:expandSearchResults(option, chosen_item)
     local results
 
-    if option == "tags" then
+    if option == "tags" or option == "authors" then
-        results = getBooksByTag(self.books, chosen_item)
+        results = getBooksByNestedField(self.books, option, chosen_item)
-    elseif option == "series" then
+    else
-        results = getBooksBySeries(self.books, chosen_item)
+        results = getBooksByField(self.books, option, chosen_item)
     end
     if results then
         local catalog = self:bookCatalog(results, option)