`<layer>`

One or more <layer> elements can be specified within a <widget class_="text">. Each <layer> contains a 1010data query and can be used to provide data to it. (Available as of version 11.09)

Description

One or more <layer> elements, each containing a 1010data query, may appear inside the text widget. Each <layer> may bear one or more value*_ (and associated row*_/col*_) attributes) and/or a tablevalue_ attribute.

Variables set thus by layer queries have scope only in subsequent items (other <layer> tags, text, and <text>/<html>/<code> forms) within the widget itself; in other words, they do not change the global <dynamic> environment and need not be declared in the <dynamic> clause.

Syntax

<dynamic>
    <widget class_="text">
      <layer valueN_="[VAR_TO_CHANGE]" 
       rowN_="[ROW_NUMBER]" colN_="[COL_NUMBER]"
       tablevalue_="@TABLE_VAR">
        [1010data_QUERY]
      </layer>
    </widget>
</dynamic>

Attributes

valueN_

Accepts an arbitrary variable name. The value corresponding to the rowN_ and/or colN_ attributes is stored in the variable associated with the valueN_ attribute. N is a string used as an identifier (e.g., value1_).

More than one value may be stored using multiple valueN_ attributes, where N is a unique identifier for each and must correspond to the naming of the associated rowN_ and/or colN_ attributes (e.g., value1_="[VAR]" row1_="[ROW_NUMBER]" col1_="[COLUMN_NUMBER]" valuefoo_="[VAR]" rowfoo_="[ROW_NUMBER]" colfoo_="[COLUMN_NUMBER]", etc.).

If a value_ attribute is specified, but no corresponding row_ and col_ attributes, the variable associated with the value_ attribute is set to the scalar value in the first row of the first column in the result set of the query (or the empty string if there are no rows in the result set).

rowN_

Specifies a row number within the result set of the query. The value corresponding to the rowN_ and/or colN_ attributes is stored in the variable associated with the valueN_ attribute. N is a string used as an identifier (e.g., row1_).

Together, rowN_ and colN_ specify the location of a scalar value within the result set of a query.

Note: If both rowN_ and colN_ are 0, table metadata is saved as a package to the variable associated with the valueN_ attribute. (Available as of version 11.19)

If rowN_ is provided and colN_ is omitted, all the values in the row will be stored as a package in the variable associated with the valueN_ attribute. The keys of the package are the column names in the result set of the query, and the values can be referenced as @[VAR].[COLUMN_NAME].

Note: If the value of rowN_ is 0, column metadata is saved as a package to the variable associated with the valueN_ attribute. (Available as of version 11.19)

More than one row value may be specified using multiple rowN_ attributes, where N is a unique identifier for each. Note that the naming of a particular rowN_ attribute must correspond to the naming of the associated valueN_ and colN_ attributes (e.g., value1_="[VAR]" row1_="[ROW_NUMBER]" col1_="[COLUMN_NUMBER]" valuefoo_="[VAR]" rowfoo_="[ROW_NUMBER]" colfoo_="[COLUMN_NUMBER]", etc.).

If the value of rowN_ is a negative number, the row that number of rows back from the last row is used. (Available as of version 11.19)

colN_

Specifies either a column name or column number within the result set of the query. The value corresponding to the rowN_ and/or colN_ attributes is stored in the variable associated with the valueN_ attribute. N is a string used as an identifier (e.g., col1_).

Together, rowN_ and colN_ specify the location of a scalar value within the result set of a query.

Note: If both rowN_ and colN_ are 0, table metadata is saved as a package to the variable associated with the valueN_ attribute. (Available as of version 11.19)

If colN_ is provided and rowN_ is omitted, all the values of the column will be stored as a list-value in the variable associated with the valueN_ attribute.

Note: If the value of colN_ is 0, a list of the row numbers is saved as a list-value to the variable associated with the valueN_ attribute. (Available as of version 11.19)

More than one column value may be specified using multiple colN_ attributes, where N is a unique identifier for each. Note that the naming of a particular colN_ attribute must correspond to the naming of the associated valueN_ and rowN_ attributes (e.g., value1_="[VAR]" row1_="[ROW_NUMBER]" col1_="[COLUMN_NUMBER]" valuefoo_="[VAR]" rowfoo_="[ROW_NUMBER]" colfoo_="[COLUMN_NUMBER]", etc.).

If the value of colN_ is a negative number, the column that number of columns back from the last column is used. (Available as of version 11.19)

tablevalue_

Accepts the name of a variable to which the <layer> can assign the result of the [1010data_QUERY] as a table value.

The variable associated with this attribute can be indexed using the following syntax:

@foo.bar provides a list consisting of the values in the column bar
@foo.17 provides a dictionary consisting of the row 17
@foo._cols provides a list of column names
@foo._rows provides the number of rows

Example: Using `<layer>` and `<text>` within the `text` widget

<dynamic store="1">
  <layout arrange_="v">
    <widget class_="dropdown" label_="Select a store" 
     value_="@store">
      <table>1;2;3
      </table>
    </widget>
    <widget class_="text">
      <layer value_="@totalsales" row_="1" col_="1">
        <base table="pub.demo.retail.item"/>
        <tabu breaks="store">
          <tcol source="sales" name="sumsales" 
           fun="sum" label="Sales"/>
        </tabu>
        <sel value="store={@store}"/>
        <colord cols="sumsales"/>
      </layer>
      <text>The total sales for store {@store} is ${@totalsales}.
      </text>
    </widget>
  </layout>
</dynamic>

Example: Using `<layer>` with `tablevalue_`

The following example demonstrates how a <layer> is used to specify a query that provides data for the text widget. In this example, the results of the query is saved in a table-value variable named stores. That variable is then accessible to the text specified after the <layer> tag. The text references the stores variable to display the store and city associated with the selection made in the dropdown widget.

<dynamic selection="1">
  <layout arrange_="v">
    <widget class_="dropdown" label_="Select a store" value_="@selection">
      <table>1;2;3
      </table>
    </widget>
    <widget class_="text" visible_="{@selection<>''}">
      <layer tablevalue_="@stores">
        <base table="pub.demo.retail.store"/>
      </layer>
      Store {@stores.store[@selection]} is located in {@stores.city[@selection]}.
    </widget>
  </layout>
</dynamic>

<layer>