For instance Caption property on: 'Height=64;AssemblyQualifiedName = "System.Windows.Forms.TreeView, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089";Host.Item("Nodes.Add(`Root 1`)").Template = "Nodes{ Add(`Child 1`); Add(`Child 2`) }; Expand() }"' generates a result such as:
or in other words inserts a TreeView control with a root and two-child elements.
The Template/x-script syntax in BNF notation is defined like follows:
<x-script> := <lines>
<lines> := <line>[<eol> <lines>] | <block>
<block> := <call> [<eol>] { [<eol>] <lines> [<eol>] } [<eol>]
<eol> := ";" | "\r\n"
<line> := <dim> | <createobject> | <call> | <set> | <comment>
<dim> := "DIM" <variables>
<variables> := <variable> [, <variables>]
<variable> := "ME" | <identifier>
<createobject> := "CREATEOBJECT(`"<type>"`)"
<call> := <variable> | <property> | <variable>"."<property> | <createobject>"."<property>
<property> := [<property>"."]<identifier>["("<parameters>")"]
<set> := <call> "=" <value>
<property> := <identifier> | <identifier>"("[<parameters>]")"
<parameters> := <value> [","<parameters>]
<value> := <boolean> | <number> | <color> | <date> | <string> | <createobject> | <call>
<boolean> := "TRUE" | "FALSE"
<number> := "0X"<hexa> | ["-"]<integer>["."<integer>]
<digit10> := 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
<digit16> := <digit10> | A | B | C | D | E | F
<integer> := <digit10>[<integer>]
<hexa> := <digit16>[<hexa>]
<color> := "RGB("<integer>","<integer>","<integer>")"
<date> := "#"<integer>"/"<integer>"/"<integer>" "[<integer>":"<integer>":"<integer>"]"#"
<string> := '"'<text>'"' | "`"<text>"`"
<comment> := "'"<text>
where:
<identifier> indicates an identifier of the variable, property or
method, and should start with a letter.
<type> indicates the type the CreateObject function creates, as
the assembly-qualified name of the type to create.
<text> any string of characters
The Template / x-script is composed by lines of instructions. Instructions are separated by "\r\n" ( new line characters ) or ";" character. The TemplateThrowError property specifies whether the control fires an exception/error when the Template call fails. The TemplateError / TemplateException gets the error if the Template calls fails. The TemplateResult property returns the result of the last instruction into a Template call, as a NAVObjectTemplate object.
An x-script instruction/line can be one of the following:
- Dim variable[, variable, ...] declares the variables in the context. Multiple variables are separated by commas. The SetTemplateDef method can declare new variables to be available for the main context. ( Sample: Dim h, h1, h2 )
- variable = [object.][property/method( arguments ).]property/method( arguments ) assigns the result of the property/method call to the variable. ( Sample: h = Nodes.Add(`Node`) )
- [object.][property/method( arguments ).]property( arguments ) = value assigns the value to the property. ( Sample: Nodes.Add(`Node`).BackColor = RGB(255,0,0) )
- [object.][property/method( arguments ).]property/method( arguments ) invokes the property/method. ( Sample: Nodes.Add(`Node`) )
- {context } delimits the object's context. The properties/fields or methods called between { and } are related to the last object returned by the property/method prior to { declaration. (Sample: Nodes{Add(`Child 1`);Add(`Child 2`)} )
- . delimits the object than its property or method. (Sample: Nodes.Add(`Element`), or Nodes.Add(`Element`) and Nodes{Add(`Element`)} are equivalents )
where
- variable is the name of a variable declared with Dim command or previously defined using the SetTemplateDef method.
- property is the name of a property/field of the current object in the current context.
- method is the name of a method of the current object in the current context.
- arguments include constants and/or variables and/or property/method calls separated by comma character.
- object can be a variable of an Object type, Me or CreateObject call.
The x-script uses constant expressions as follows:
- boolean expression with possible values as True or False. The True value is equivalent with -1, while False with 0. (Sample: Visible = False )
- numeric expression may starts with 0x which indicates a hexa decimal representation, else it should starts with digit, or +/- followed by a digit, and . is the decimal separator. Sample: 13 indicates the integer 13, or 12.45 indicates the double expression 12,45. ( Sample: BackColor = 0xFF0000 )
- date expression is delimited by # character in the format #mm/dd/yyyy hh:mm:ss#. For instance, #31/12/1971# indicates the December 31, 1971 ( Sample: Chart.FirstVisibleDate = #1/1/2001# )
- string expression is delimited by " or ` characters. If using the ` character, please make sure that it is different than ' which allows adding comments inline. Sample: "text" or `text` indicates the string text, while the ' text , specifies the comment text. ( Sample: Text = "caption" )
Also , the template or x-script code supports general functions as follows:
- Me property indicates the original object, and it is defined as a predefined variable. ( Sample: Me.Nodes.Add(`Root 1`) )
- RGB(R,G,B) property retrieves an RGB value, where the R, G, B are byte values that indicates the Red Green Blue bytes for the color being specified. ( Sample: Nodes.Add(`Root 1`).BackColor = RGB(255,0,0) )
- LoadPicture(file) property loads a picture from a file and returns a Picture object required by the picture properties. (Sample: BackgroundImage = LoadPicture(`C:\exontrol\images\auction.gif`)
- CreateObject(assemblyQualifiedName) property creates an instance of the specified type using that type's default constructor. The assemblyQualifiedName indicates the assembly-qualified name of the type to get. See AssemblyQualifiedName. If the type is in the currently executing assembly or in Mscorlib.dll, it is sufficient to supply the type name qualified by its namespace. ( Sample: "CreateObject(`System.Windows.Forms.TabPage, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089`){Text = `Page`;UseVisualStyleBackColor = True}" )