Skip to content

TWebLocalTextFile

TWebLocalTextFile is a non-visual component that allows to read/write text files on the local file system. Note that this uses the web standards local file system access APIs not yet implemented on all browsers. Any browser based on the Google Chromium engine supports it.

Local file access is performed asynchronously. TWebLocalTextFile offers 3 variations of methods to open and save files. There are async methods that can use await() for sequentially written code, there are methods that perform the local file operation and trigger an event when finished and there are methods using an anonymous method parameter and calling this anonymouse method when finished.

Example:

procedure TForm1.WebButton1Click(Sender: TObject);
begin
 ATextFile.Filter.Add('All files','application/octet-stream','*.*');
 ATextFile.Filter.Add('Text files','text/plain','*.txt');
 WebMemo1.Lines.Text := await(string, ATextFile.Open());end;

Properties for TWebLocalTextFile

Property Description
Filter: TFileFilter Sets the filter for selecting the local file system
FileName: string Gets the filename of the opened local file
Text: string Gets or sets the content of the text file as string

Methods for TWebLocalTextFile

Method Description
Open: TJSPromise Async method to open a text file
Save: TJSPromise Async method to save a text file
SaveAs: TJSPromise Async method to save a text file under a new name
OpenFile Method opening a text file. Triggers the OnFileOpen event when the file is asynchronously opened
OpenFile(AOpenFile: TOpenTextFileProc) Method opening a text file with anonymous method parameter.
SaveFile Method saving a text file. Triggers the OnFileSave event when the file is asynchronously saved
SaveFile(ASaveFile: TSaveFileProc Method saving a text file with anonymous method parameter.
SaveAsFile Method saving a text file under a different name. Triggers the OnFileSave event when the file is asynchronously saved
SaveFileAs(ASaveFile: TSaveFileProc Method saving a text file under a different name with anonymous method parameter.

Events for TWebLocalTextFile

Property Description
OnFileOpen Event triggered when the browser retrieved the data from the text file to be opened
OnFileSave Event triggered when the browser performed the saving of the text file on the local file system