# CommandTemplate

Templates of commands is description for DevTool Canvas, how it should draw finded commands with specified arguments/types.

**Namespace:** `RenownedGames.DevTool.UIElements`

## Create new template

Let's take it apart creation new command template type based on *CommandTemplateFloat*.

```csharp
[AddComponentMenu("Renowned Games/DevTool/Core Modules/Developer Tools/DevTool/Template/Command Template Float")]
[DisallowMultipleComponent]
[RequiredType(typeof(float))]
public sealed class CommandTemplateFloat : CommandTemplateSingleField<float>
{
    /// <summary>
    /// Implement this method to read parameter value from input field.
    /// </summary>
    /// <param name="field">Edited field component.</param>
    /// <param name="value">Parsed (T) value from input field.</param>
    protected override void ReadValue(InputField field, out float value)
    {
        field.text = field.text.Replace('.', ',');
        value = Convert.ToSingle(field.text);
        field.text = value.ToString("0.00", System.Globalization.CultureInfo.InvariantCulture);
    }

    /// <summary>
    /// Called after menu was repaint.
    /// </summary>
    /// <param name="parameter">Actual command parameters.</param>
    /// <param name="text">Convert to string parameter.</param>
    protected override void OnParameterUpdate(float parameter, out string text)
    {
        text = parameter.ToString("0.00", System.Globalization.CultureInfo.InvariantCulture);
    }
}
```

Class inherits from CommandTemplateSingleField which in turn inherits from CommandTemplate

CommandTemplateSingleField class allow to use commands with single argument, where `<float>` type of argument.

`[RequiredType]` attribute note DevTool engine what this template can work only with one argument type of float. If you want to create command which will work with multiple arguments add multiple`[RequiredType]` attributes.

```csharp
[RequiredType(typeof(float))]
public sealed class CommandTemplateFloat : CommandTemplateSingleField<float>
```

Next step implementation of `ReadValue` and `OnParameterUpdate` methods

`ReadValue` called before execute command. In this method you need to read value from input field and parse it to required type.

```csharp
protected override void ReadValue(InputField field, out float value)
{
    // The field contains dots we translate them into commas
    field.text = field.text.Replace('.', ',');
    
    // Parse text to float and set to output value 
    value = Convert.ToSingle(field.text);

    // Reduce the number of characters after the decimal point to two for easier reading.
    field.text = value.ToString("0.00", System.Globalization.CultureInfo.InvariantCulture);
}
```

`OnParameterUpdate` called when DevTool Canvas become repaint. In this method you need to update value in input field to actual.

```csharp
protected override void OnParameterUpdate(float parameter, out string text)
{
    // Reduce the number of characters after the decimal point to two for easier reading.
    field.text = value.ToString("0.00", System.Globalization.CultureInfo.InvariantCulture);
}
```