, view all tags

TWiki Forms - Foundation of TWiki Applications

Add structure to content with forms attached to twiki topics. TWiki forms (with form fields) and formatted search are the base for building database applications.


By adding form-based input to free form content, you can structure topics with unlimited, easily searchable categories. A form is enabled for a web and can be added to a topic. The form data is shown in tabular format when the topic is viewed, and can be changed in edit mode using edit fields, radio buttons, check boxes and list boxes. Many different form types can be defined in a web, though a topic can only have one form attached to it at a time.

Typical steps to build an application based on TWiki forms:

  1. Define a form template
  2. Enable the form for a web
  3. Add the form to a template topic
  4. Build an HTML form to create new topics based on that template topic
  5. Build a FormattedSearch to list topics that share the same form

TIP Tip: The blog How to Create a TWiki Application on TWiki.org is a good tutorial to get started with TWiki forms based applications.

Defining a Form

A Form Template specifies the fields in a form. A Form Template is simply a page containing a TWiki table, where each row of the table specifies one form field.

  1. Create a new topic with your form name: YourForm, ExpenseReportForm, InfoCategoryForm, RecordReviewForm, whatever you need.
  2. Create a TWiki table, with each column representing one element of an entry field: Name, Type, Size, Values, Tooltip message, and Attributes (see sample below).
  3. For each field, fill in a new line; for the type of field, select from the list.
  4. Save the topic (you can later choose to enable/disable individual forms).

| *Name* | *Type* | *Size* | *Values* | *Tooltip message* | *Attributes* |
| TopicClassification | select | 1 | NoDisclosure, PublicSupported, PublicFAQ | blah blah... |   |
| OperatingSystem | checkbox | 3 | OsHPUX, OsLinux, OsSolaris, OsWin | blah blah... |   |
| OsVersion | text | 16 | | blah blah... |   |

Name Type Size Values Tooltip message Attributes
TopicClassification select 1 NoDisclosure, PublicSupported, PublicFAQ blah blah...  
OperatingSystem checkbox 3 OsHPUX, OsLinux, OsSolaris, OsWin blah blah...  
OsVersion text 16   blah blah...  

See structure of a form for full details of what types are available and what all the columns mean.

You can also retrieve possible values for select, checkbox or radio types from other topics:


  • In the WebForm topic, define the form:
    Name Type Size Values Tooltip message Attributes
    TopicClassification select 1   blah blah...  
    OperatingSystem checkbox 3   blah blah...  
    OsVersion text 16   blah blah...  

    ALERT! Leave the Values field blank.

  • Then in the TopicClassification topic, define the possible values:
    | *Name*            |
    | NoDisclosure      |
    | Public Supported  |
    | Public FAQ        |
    Public Supported
    Public FAQ

Field values can also be set using the result of expanding other TWiki variables. For example,

%SEARCH{"Office$" scope="topic" web="%USERSWEB%" nonoise="on" type="regex" format="$web.$topic" separator=", " }%

When used in the value field of the form definition, this will find all topic names in the Main web which end in "Office" and use them as the legal field values.

Enabling Forms by Web

Forms have to be enabled for each individual web. The WEBFORMS variable in WebPreferences is optional and defines a list of possible form templates.

  • Set WEBFORMS = BugForm, FeatureForm, Books.BookLoanForm
  • With WEBFORMS enabled, an extra button is added to the edit view. If the topic doesn't have a Form, an Add Form button appears at the end of the topic. If a Form is present, a Change button appears in the top row of the Form. The buttons open a screen that enables selection of a form specified in WEBFORMS, or the No form option.
  • You have to list the available form topics explicitly. You cannot use a SEARCH to define WEBFORMS.

Adding a form to a topic

  • Edit the topic and follow the "Add form" button to add a Form. This is typically done to a template topic, either to the WebTopicEditTemplate topic in a web, or a new topic that serves as an application specific template topic. Initial Form values can be set there.

  • Additionally a new topic can be given a Form using the formtemplate parameter in the (edit or save) URL. Initial values can then be provided in the URLs or as form values:
    • other than checkboxes: name, ex: ?BugPriority=1
    • checkbox: namevalue=1, ex: ?ColorRed=1.
      Boxes with a tick must be specified.
    • Example: This will add a textfield for the new topic name and a "Create"-Button to your topic. When the button is pressed, the topic editor will open with the form "MyForm" already attached to the new topic.
          <form name="newtopic" action="%SCRIPTURLPATH{"edit"}%/%WEB%/">
             <input type="hidden" name="formtemplate" value="MyForm" />
             New topic name <input type="text" name="topic" size="40" />
             <input type="submit" class="twikiSubmit" value="Create" />
  • ALERT! Note: You can create a topic in one step, without going through the edit screen. To do that, specify the save script instead of the edit script in the form action. When you specify the save script you have to use the "post" method. Example:
        <form name="newtopic" action="%SCRIPTURLPATH{"save"}%/%WEB%/" method="post">
  • HELP The edit and save scripts understand many more parameters, see TWikiScripts#edit and TWikiScripts#save for details.

  • ALERT! Note: Initial values will not be set in the form of a new topic if you only use the formtemplate parameter.

Changing a form

  • You can change a form definition, and TWiki will try to make sure you don't lose any data from the topics that use that form.

  • If you change the form definition, the changes will not take affect in a topic that uses that form until you edit and save it.

  • If you add a new field to the form, then it will appear next time you edit a topic that uses the form.

  • If you delete a field from the form, or change a field name, then the data will not be visible when you edit the topic (the changed form definition will be used). If you save the topic, the old data will be lost (though thanks to revision control, you can always see it in older versions of the topic)

  • If two people edit the same topic containing a form at exactly the same time, and both change fields in the form, TWiki will try to merge the changes so that no data is lost.

Structure of a Form Template

A Form Template specifies the fields in a form. A Form Template is simply a page containing a TWiki table, where each row of the table specifies one form field.

Each row of the table defines one element of an input field:

Name Type Size Values Tooltip message Attributes

The Name, Type and Size columns are required. Other columns are optional. The form template must have a header row, e.g. at least | *Name* | *Type* | *Size* | is required. Columns:

  • Name column: Name is the name of the form field.

  • Type, Size, Value columns: Type, Size and Value describe the type, size and initial value of this form field. Type text, checkbox, select and more are described in the Form Field Types section below.

  • Tooltip message column: The Tooltip message will be displayed when the cursor is hovered over the field in edit view.

  • Attributes column: Attributes specifies special attributes for the field. Multiple attributes can be entered, separated by spaces.
    • An attribute H indicates that this field is hidden, e.g. not shown in view mode. However, the field is available for editing and storing information.
      TIP Tip: The TWiki form header is suppressed in view mode if all fields of the form are hidden. For better usability it is good to hide the whole form if the display and interaction of all form fields is done externally. For example, the display and modification of form field values can be done in a header topic that is included in each page.
    • An attribute M indicates that this field is mandatory. The topic cannot be saved unless a value is provided for this field. If the field is found empty during topic save, an error is raised and the user is redirected to an oops page. Mandatory fields are indicated by an asterisks next to the field name.

For example, a simple form just supporting entry of a name and a date would look as follows:

| *Name* | *Type* | *Size* |
| Name   | text   | 80     |
| Date   | date   | 30     |

Field Name Notes:

  • Field names have to be unique.
  • A very few field names are reserved. If you try to use one of these names, TWiki will automatically append an underscore to the name when the form is used.
  • You can space out the title of the field, and it will still find the topic e.g. Aeroplane Manufacturers is equivalent to AeroplaneManufacturers.
  • If a label field has no name, it will not be shown when the form is viewed, only when it is edited.
  • Field names can in theory include any text, but you should stick to alphanumeric characters. If you want to use a non-wikiname for a select, checkbox or radio field, and want to get the values from another topic, you can use [[...]] links. This notation can also be used when referencing another topic to obtain field values, but a name other than the topic name is required as the name of the field.
  • Leading and trailing spaces are not significant.

Field Value Notes:

  • The field value will be used to initialize a field when a form is created, unless specific values are given by the topic template or query parameters. The first item in the list for a select or radio type is the default item. For label, text, and textarea fields the value may also contain commas. checkbox fields cannot be initialized through the form template.
  • Leading and trailing spaces are not significant.
  • Field values can also be generated through a FormattedSearch, which must yield a suitable table as the result.
  • Variables in the initial values of a form definition get expanded when the form definition is loaded.
    • If you want to use a | character in the initial values field, you have to precede it with a backslash, thus: \|.
    • You can use <nop> to prevent TWiki variables from being expanded.
    • The FormatTokens can be used to prevent expansion of other characters.

General Notes:

  • The topic definition is not read when a topic is viewed.
  • Form definition topics can be protected in the usual manner, using TWikiAccessControl, to limit who can change the form template and/or individual value lists. Note that view access is required to be able to edit topics that use the form definition, though view access to the form definition is not required to view a topic where the form has been used.

Form Field Types

Each table row of a form template defines one element of an input field:

Name Type Size Values Tooltip message Attributes

Many types of form fields are available. Some are TWiki internal, some are provided by extensions. Find more TWiki form field extensions on TWiki.org. The Size and Value depend on the Type used. Form field types:

Type Description Size Value
text One-line text field Text box width in number of characters