diff options
Diffstat (limited to 'examples/cross_todo/nim_backend')
| -rw-r--r-- | examples/cross_todo/nim_backend/backend.nim | 66 | ||||
| -rw-r--r-- | examples/cross_todo/nim_backend/testbackend.nim | 13 |
2 files changed, 23 insertions, 56 deletions
diff --git a/examples/cross_todo/nim_backend/backend.nim b/examples/cross_todo/nim_backend/backend.nim index 6869665f8..513fe304f 100644 --- a/examples/cross_todo/nim_backend/backend.nim +++ b/examples/cross_todo/nim_backend/backend.nim @@ -4,9 +4,8 @@ import db_sqlite, parseutils, strutils, times - type - TTodo* = object + Todo* = object ## A todo object holding the information serialized to the database. id: int64 ## Unique identifier of the object in the ## database, use the getId() accessor to read it. @@ -17,7 +16,7 @@ type ## outside of this module, use the ## getModificationDate accessor. - TPagedParams* = object + PagedParams* = object ## Contains parameters for a query, initialize default values with ## initDefaults(). pageSize*: int64 ## Lines per returned query page, -1 for @@ -27,11 +26,10 @@ type showUnchecked*: bool ## Get unchecked objects. showChecked*: bool ## Get checked objects. - # - General procs -# -proc initDefaults*(params: var TPagedParams) = - ## Sets sane defaults for a TPagedParams object. + +proc initDefaults*(params: var PagedParams) = + ## Sets sane defaults for a PagedParams object. ## ## Note that you should always provide a non zero pageSize, either a specific ## positive value or negative for unbounded query results. @@ -41,7 +39,6 @@ proc initDefaults*(params: var TPagedParams) = params.showUnchecked = true params.showChecked = false - proc openDatabase*(path: string): DbConn = ## Creates or opens the sqlite3 database. ## @@ -56,16 +53,14 @@ proc openDatabase*(path: string): DbConn = desc TEXT NOT NULL, modification_date INTEGER NOT NULL, CONSTRAINT Todos UNIQUE (id))""" - db_sqlite.exec(conn, query) result = conn +# - Procs related to Todo objects -# - Procs related to TTodo objects -# proc initFromDB(id: int64; text: string; priority: int, isDone: bool; - modificationDate: Time): TTodo = - ## Returns an initialized TTodo object created from database parameters. + modificationDate: Time): Todo = + ## Returns an initialized Todo object created from database parameters. ## ## The proc assumes all values are right. Note this proc is NOT exported. assert(id >= 0, "Identity identifiers should not be negative") @@ -75,29 +70,25 @@ proc initFromDB(id: int64; text: string; priority: int, isDone: bool; result.isDone = isDone result.modificationDate = modificationDate - -proc getId*(todo: TTodo): int64 = +proc getId*(todo: Todo): int64 = ## Accessor returning the value of the private id property. return todo.id - -proc getModificationDate*(todo: TTodo): Time = - ## Returns the last modification date of a TTodo entry. +proc getModificationDate*(todo: Todo): Time = + ## Returns the last modification date of a Todo entry. return todo.modificationDate - -proc update*(todo: var TTodo; conn: DbConn): bool = +proc update*(todo: var Todo; conn: DbConn): bool = ## Checks the database for the object and refreshes its variables. ## ## Use this method if you (or another entity) have modified the database and ## want to update the object you have with whatever the database has stored. ## Returns true if the update succeeded, or false if the object was not found ## in the database any more, in which case you should probably get rid of the - ## TTodo object. + ## Todo object. assert(todo.id >= 0, "The identifier of the todo entry can't be negative") let query = sql"""SELECT desc, priority, is_done, modification_date FROM Todos WHERE id = ?""" - try: let rows = conn.getAllRows(query, $todo.id) if len(rows) < 1: @@ -111,8 +102,7 @@ proc update*(todo: var TTodo; conn: DbConn): bool = except: echo("Something went wrong selecting for id " & $todo.id) - -proc save*(todo: var TTodo; conn: DbConn): bool = +proc save*(todo: var Todo; conn: DbConn): bool = ## Saves the current state of text, priority and isDone to the database. ## ## Returns true if the database object was updated (in which case the @@ -127,15 +117,13 @@ proc save*(todo: var TTodo; conn: DbConn): bool = WHERE id = ?""" rowsUpdated = conn.execAffectedRows(query, $todo.text, $todo.priority, $todo.isDone, $int(currentDate), $todo.id) - if 1 == rowsUpdated: todo.modificationDate = currentDate result = true - # - Procs dealing directly with the database -# -proc addTodo*(conn: DbConn; priority: int; text: string): TTodo = + +proc addTodo*(conn: DbConn; priority: int; text: string): Todo = ## Inserts a new todo into the database. ## ## Returns the generated todo object. If there is an error EDb will be raised. @@ -145,10 +133,8 @@ proc addTodo*(conn: DbConn; priority: int; text: string): TTodo = (priority, is_done, desc, modification_date) VALUES (?, 'false', ?, ?)""" todoId = conn.insertId(query, priority, text, $int(currentDate)) - result = initFromDB(todoId, text, priority, false, currentDate) - proc deleteTodo*(conn: DbConn; todoId: int64): int64 {.discardable.} = ## Deletes the specified todo identifier. ## @@ -156,7 +142,6 @@ proc deleteTodo*(conn: DbConn; todoId: int64): int64 {.discardable.} = let query = sql"""DELETE FROM Todos WHERE id = ?""" result = conn.execAffectedRows(query, $todoId) - proc getNumEntries*(conn: DbConn): int = ## Returns the number of entries in the Todos table. ## @@ -170,38 +155,30 @@ proc getNumEntries*(conn: DbConn): int = echo("Something went wrong retrieving number of Todos entries") result = -1 - -proc getPagedTodos*(conn: DbConn; params: TPagedParams; - page = 0'i64): seq[TTodo] = +proc getPagedTodos*(conn: DbConn; params: PagedParams; page = 0'i64): seq[Todo] = ## Returns the todo entries for a specific page. ## ## Pages are calculated based on the params.pageSize parameter, which can be ## set to a negative value to specify no limit at all. The query will be - ## affected by the TPagedParams, which should have sane values (call + ## affected by the PagedParams, which should have sane values (call ## initDefaults). assert(page >= 0, "You should request a page zero or bigger than zero") result = @[] - # Well, if you don't want to see anything, there's no point in asking the db. if not params.showUnchecked and not params.showChecked: return - let order_by = [ if params.priorityAscending: "ASC" else: "DESC", if params.dateAscending: "ASC" else: "DESC"] - query = sql("""SELECT id, desc, priority, is_done, modification_date FROM Todos WHERE is_done = ? OR is_done = ? ORDER BY priority $1, modification_date $2, id DESC LIMIT ? * ?,?""" % order_by) - args = @[$params.showChecked, $(not params.showUnchecked), $params.pageSize, $page, $params.pageSize] - #echo("Query " & string(query)) #echo("args: " & args.join(", ")) - var newId: BiggestInt for row in conn.fastRows(query, args): let numChars = row[0].parseBiggestInt(newId) @@ -209,10 +186,9 @@ proc getPagedTodos*(conn: DbConn; params: TPagedParams; result.add(initFromDB(int64(newId), row[1], row[2].parseInt, row[3].parseBool, Time(row[4].parseInt))) - -proc getTodo*(conn: DbConn; todoId: int64): ref TTodo = - ## Returns a reference to a TTodo or nil if the todo could not be found. - var tempTodo: TTodo +proc getTodo*(conn: DbConn; todoId: int64): ref Todo = + ## Returns a reference to a Todo or nil if the todo could not be found. + var tempTodo: Todo tempTodo.id = todoId if tempTodo.update(conn): new(result) diff --git a/examples/cross_todo/nim_backend/testbackend.nim b/examples/cross_todo/nim_backend/testbackend.nim index 6754f013a..4a71d5f2c 100644 --- a/examples/cross_todo/nim_backend/testbackend.nim +++ b/examples/cross_todo/nim_backend/testbackend.nim @@ -2,8 +2,7 @@ import backend, db_sqlite, strutils, times - -proc showPagedResults(conn: DbConn; params: TPagedParams) = +proc showPagedResults(conn: DbConn; params: PagedParams) = ## Shows the contents of the database in pages of specified size. ## ## Hmm... I guess this is more of a debug proc which should be moved outside, @@ -11,7 +10,6 @@ proc showPagedResults(conn: DbConn; params: TPagedParams) = var page = 0'i64 rows = conn.getPagedTodos(params) - while rows.len > 0: echo("page " & $page) for row in rows: @@ -25,7 +23,6 @@ proc showPagedResults(conn: DbConn; params: TPagedParams) = else: break - proc dumTest() = let conn = openDatabase("todo.sqlite3") try: @@ -35,10 +32,8 @@ proc dumTest() = # Fill some dummy rows if there are not many entries yet. discard conn.addTodo(3, "Filler1") discard conn.addTodo(4, "Filler2") - var todo = conn.addTodo(2, "Testing") echo("New todo added with id " & $todo.getId) - # Try changing it and updating the database. var clonedTodo = conn.getTodo(todo.getId)[] assert(clonedTodo.text == todo.text, "Should be equal") @@ -49,13 +44,11 @@ proc dumTest() = echo("Updated priority $1, done $2" % [$todo.priority, $todo.isDone]) else: assert(false, "Uh oh, I wasn't expecting that!") - # Verify our cloned copy is different but can be updated. assert(clonedTodo.text != todo.text, "Should be different") discard clonedTodo.update(conn) assert(clonedTodo.text == todo.text, "Should be equal") - - var params: TPagedParams + var params: PagedParams params.initDefaults conn.showPagedResults(params) conn.deleteTodo(todo.getId) @@ -66,7 +59,6 @@ proc dumTest() = echo("Later priority $1, done $2" % [$todo.priority, $todo.isDone]) else: echo("Can't update object $1 from db!" % $todo.getId) - # Try to list content in a different way. params.pageSize = 5 params.priorityAscending = true @@ -77,7 +69,6 @@ proc dumTest() = conn.close echo("Database closed") - # Code that will be run only on the commandline. when isMainModule: dumTest() |