A UserInputPanel can be highly dynamic, since it will be refreshed every time the user input changes and will be rendered based on conditions. For instance, it would be possible to enable or disable some options by clicking a checkbox.
The user input panel can be populated with UI elements. The specification supports text labels, input elements, explanatory text and some minor formatting options.
There is a more complex example of a userInputSpec.xml at Sample userInputSpec.xml showing 3 panels. There are some advanced features in this example, but the general flow should be looked at first.
Accessing User Input
User input is not directly inserted into your configuration files but the variables that you specify for this panel are set in the variable substitution system. After the user has completed filling in the UserInputPanel, the variables and associated values are available for substitution. This process has a number of implications of which you should be aware.
Not only can you set additional variables in this way but you can also modify variables that are defined elsewhere - even built in variables. For this reason you should be careful to avoid conflicts when choosing variable names. Although there might be cases when it seems useful to modify the value of other variables, it is generally not a good idea to do so. Because you might not exactly know when other variables are set and when and where they are used throughout the installation process, there might be unintended side effects.
The panel must be shown before the variables are used. In most cases you will use the values to substitute variables in launch and configuration files that you supply with your installation. For this to work you place this panel before the install panel, because the install panel uses the variable substitutor to replace all such variables. Although invoking this panel any later in the process will correctly set the variables internally, it will be too late to affect the files written to disk.
You can also use variables set in this way in other panels that you have written yourself.There is a section in the chapter on writing your own panel that explains how to do this. Also in this case it is important to place the input panel in the process before the variables are used.
It is possible to hide every field element based on conditions. It is also possible to hide selected elements on the panel or to hide the panel altogether if certain packs are not selected. For this to work you must place this panel after the packs panel. One side effect of using this feature is that it is not possible to step back once the user input panel is displayed. This is because the user might make changes in the packs selection that would require a complete rebuild of the UI. Unfortunately, building the UI is an irreversible process, therefore the user can not be allowed to go back to the packs panel.
XML Structure for the UserInputPanel Definition
A UserInputPanel is defined in a separate descriptor file, referred to in the src attribute in the resource "userInputSpec.xml" in the installation descriptor.
The top level XML element is <userInput>. For most requirements it does not make sense to include more than one <panel>. However, you might want to present multiple user input panels - with different content of course. Therefore the <userInput> section can contain multiple <panel> tags that each specify the details for each panel instance.
The <panel> Element
The tag name for this is <panel>. The <panel> tag uses the following attributes:
This is the id of the user input panel for which this specification should be used. This id links to the panel specification in the install.xml file.
Sets the alignment of fields used in the panelThere are three general layout rules this panel uses, they are left, center and right. While left is most commonly used, you might want to experiment with this attribute and see which you like best. The default is left.
left, center, right default: left
Normally the user input is shown with a small border. To prevent this border set this attribute to false.
true, false default: true
This can be used to set the column width of the two column layout. This value is in percent of the whole size. If it is set to 0, which is the default, the width will be set automatically. It it is set to 50 the gap between the left and right column is in the middle of the panel. This makes it possible to make a centered layout.
0-100 percent default: 0
Id of a string that represents what header name to display in the SummaryPanel of the UserInputPanel. This attribute must be defined if you would like to summarize information about the user input in this panel in the SummaryPanel.. Note that you will have to add the summaryKey attribute to the fields you would like those to show up in the SummaryPanel as well.
The readonly attribute reverses the displayHidden logic described below - readonly="true" means to display a complete panel read-only in general in case it is not disabled by a general panel condition.
The readonlyCondition attribute enhances and replaces the readonly condition and makes the related behavior dependent on another condition. Thus, all fields on the panel get displayed read-only only if it is not disabled by a general panel condition and the condition specified by readonlyCondition gets true.
Example of the readonlyCondition attributeExpand source
The displayHiddenCondition attribute enhances and is an alternative to the displayHidden condition and makes the related behavior dependent on another condition. Thus, all fields on the panel get displayed read-only only if a general condition on that panel disables it for displaying and the condition defined by displayHiddenCondition gets true.
Example of the displayHiddenCondition attributeExpand source
When set to "true", the topBuffer will represent a number of pixels rather than a percentage.
true, false default: false
Represents the percentage of leftover vertical space to place on top of the components. Setting topBuffer=0" prevents the panel from being moved up or down during dynamic layout creation. If the rigid attribute is set to true, the topBuffer value represents the number of pixels to place on top of the components rather than the percentage of left over space.
Integer default: 25
If this tag is present the appropriate user input panel gets activated just if the mentioned pack is selected by the user in the PacksPanel.
One or more user input field definitions, described on the page Fields.
Valid user input field definitions, see Fields for more information.
To provide internationalization, you create a file named userInputLang.xml_xyz where xyz is the ISO3 code of the language in lowercase. Please be aware that case is significant. This file has to be inserted in the resources section of install.xml with the id and src attributes set at the name of the file.
If you have the following userInputSpec.xml and you want to internationalize input.comment, input.proxy, input.port for English and French you have to create two files named userInputLang.xml_eng and userInputLang.xml_fra: