Fielded Text:
Xilytix: Read a Basic CSV File (Delphi)
"Fielded Text" trademark owned by Paul Klink
This tutorial demonstrates how to use the Xilytix TFieldedText component to read a CSV file and place the headings and records into a Delphi StringGrid.
The contents of the CSV file to be imported are shown here:
"Pet Name", "Age", "Color", "Date Received", "Price", "Needs Walking", "Type"
, (Years), , , (Dollars), ,
"Rover, 4.5, Brown, 12 Feb 2004, 80, True, "Dog"
"Charlie", , Gold, 5 Apr 2007, 12.3, False, "Fish"
"Molly", 2, Black, 12 Dec 2006, 25, False, "Cat"
"Gilly", , White, 10 Apr 2007, 10, False, "Guinea Pig"
This text file has 2 headings and 4 records. This tutorial will show how to read this file into a StringGrid on a Delphi Form.
Step 1: Select a folder
Create or select an empty folder for the program we are going to develop.
Step 2: Get text file
Create a text file called "BasicReadExample.txt" and place the contents of the above CSV file into it. Save this file to the folder where the compiled executable will run from (normally the project folder). Alternatively download the text file from here (Right Click | Save Link/Target As) and save to the folder where the compiled executable will run from.
Step 3: Create Fielded Text Meta file
The Meta file specifies the structure of the text file. In this step we will create a Meta file called "BasicExample.ftm" for the text file. There are 2 ways of doing this.
The easy way is to simply download the Meta file from here (Right Click | Save Link/Target As) and place in the folder where the compiled executable will run from.
Alternatively, you can create it with a Fielded Text Editor. This will provide a better understanding of what a Meta file actually is. Follow the steps here to create the "BasicExample.ftm" and then save it into the folder where the compiled executable will run from.
The contents of the Fielded Text Meta File should be similar to the text shown below:
<?xml version="1.0" encoding="utf-
<FieldedText HeadingLineCount="2" HeadingWritePrefixSpace="True">
<Field Name="PetName" ValueQuotedType="Always" HeadingWritePrefixSpace="False" Headings="Pet Name" />
<Field DataType="Float" Name="Age" ValueWritePrefixSpace="True" Headings="Age, " />
<Field Name="Color" ValueWritePrefixSpace="True" Headings="Color, (Years)" />
<Field DataType="DateTime" Name="DateReceived" ValueWritePrefixSpace="True" Headings="Date Received, " Format="d MMM yyyy" />
<Field DataType="Decimal" Name="Price" ValueWritePrefixSpace="True" Headings="Price, (Dollars)" />
<Field DataType="Boolean" Name="NeedsWalking" ValueWritePrefixSpace="True" Headings="Needs Walking, " />
<Field Name="Type" ValueQuotedType="Always" ValueWritePrefixSpace="True" Headings="Type" />
</FieldedText>
Step 4: Create a Delphi VCL Forms Application project
Create a Delphi VCL Forms Application project in the folder using a recent version of Delphi. Either a 32 or 64 bit application can be created.
Step 5: Include TFieldedText files folder in search path
Add a the folder containing either TFieldedText source files or DCU files to the project search path. Must be version 2.2.10 or later.
Step 6: Place controls on Form
Add the following items to a form in the project:
Step 6: Add FieldedText uses clauses and Button Click event
Add the following uses clause and Button Click event code:
Step 8: Compile and Run
Compile and run the program. When the button is clicked, the program will do the following:
procedure TForm1.Button1Click(Sender: TObject);
var
FieldedText: TFieldedText;
LineIdx: Integer;
FieldIdx: Integer;
PetNameField: TFieldedTextField;
AgeField: TFieldedTextField;
ColorField: TFieldedTextField;
DateReceivedField: TFieldedTextField;
PriceField: TFieldedTextField;
NeedsWalkingField: TFieldedTextField;
TypeField: TFieldedTextField;
begin
FieldedText := TFieldedText.Create;
try
// Load the Meta which describes the text file
FieldedText.LoadMeta('BasicExample.ftm');
// Specify the text file
FieldedText.FilePath := 'BasicReadExample.txt';
// Parse the file once to work out get headers and calculate number or records
FieldedText.CountRecords;
// Set up grid
StringGrid1.ColCount := FieldedText.FieldCount;
StringGrid1.RowCount := FieldedText.HeadingLineCount + FieldedText.RecordCount;
StringGrid1.FixedRows := FieldedText.HeadingLineCount;
// Write Headers to Grid
for LineIdx := 0 to FieldedText.HeadingLineCount -
begin
for FieldIdx := 0 to FieldedText.FieldCount -
begin
StringGrid1.Cells[FieldIdx, LineIdx] := FieldedText.Fields[FieldIdx].Headings[LineIdx];
end;
end;
FieldedText.BeginRead;
try
PetNameField := FieldedText.FindTableField('PetName');
AgeField := FieldedText.FindTableField('Age');
ColorField := FieldedText.FindTableField('Color');
DateReceivedField := FieldedText.FindTableField('DateReceived');
PriceField := FieldedText.FindTableField('Price');
NeedsWalkingField := FieldedText.FindTableField('NeedsWalking');
TypeField := FieldedText.FindTableField('Type');
LineIdx := FieldedText.HeadingLineCount;
// Read records and write values to grid
while FieldedText.Read do
begin
StringGrid1.Cells[0, LineIdx] := PetNameField.AsString;
if AgeField.Null then
StringGrid1.Cells[1, LineIdx] := '<Null>'
else
StringGrid1.Cells[1, LineIdx] := FloatToStr(AgeField.AsDouble);
StringGrid1.Cells[2, LineIdx] := ColorField.AsString;
StringGrid1.Cells[3, LineIdx] := DateToStr(DateReceivedField.AsDateTime);
StringGrid1.Cells[4, LineIdx] := CurrToStr(PriceField.AsCurrency);
StringGrid1.Cells[5, LineIdx] := BoolToStr(NeedsWalkingField.AsBoolean);
StringGrid1.Cells[6, LineIdx] := TypeField.AsString;
Inc(LineIdx);
end;
finally
FieldedText.EndRead;
end;
finally
FieldedText.Free;
end;
end;