Navigation

The following sections provide guidelines for structuring your service's navigational model.

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Handling long choice lists

GUIDELINE: Limit numbered choices to 9 items per choice card, plus a "More" item that allows the user to navigate to other choice cards.

The UP.Phone numbers only the first nine items in choice cards; subsequent items are still selectable, but the user must scroll to them. For this reason, it is strongly recommended that you implement choice lists longer than 9 items as a series of separate, but linked, choice cards. On each choice card, create a 10th item labelled "More...", which navigates to the following choice card. Because the user can easily choose the 10th item by pressing and holding the 0 key, he or she can navigate quickly through a list that spans multiple choice cards. The user can return to a previous choice card by using the default PREV action.

For example, suppose you provide an email service and a user's inbox contains 11 email messages. To implement the inbox, you provide two separate choice cards as shown in Figure 8-5. If you determine that the cards comprise fewer than 1200 bytes, you can provide them in a single deck similar to the following.

<HDML VERSION=3.0>
    <ACTION TYPE=ACCEPT TASK=GO
        DEST="?choiceval=$ch" LABEL=Read>
    <CHOICE NAME=ccard1 KEY=ch>
        <WRAP>Messages [1-9]:
        <CE VALUE=mesg01>Re: Burphle 12:54
        <CE VALUE=mesg02>Re: Samsung 12:26
        <CE VALUE=mesg03>Motorola 11:54
        <CE VALUE=mesg04>Re: Mistubishi 10:32
        <CE VALUE=mesg05>Unwired Planet 9:26
        <CE VALUE=mesg06>Qualcomm 8:34
        <CE VALUE=mesg07>Intel 7:45
        <CE VALUE=mesg08>Microsoft 7:01
        <CE VALUE=mesg09>Burphle 6:41
        <CE TASK=GO DEST=#ccard2>More...
    </CHOICE>
    <CHOICE NAME=ccard2 KEY=ch>
        <WRAP>Messages [10-11]:
        <CE VALUE=mesg10>Re: IBM 5:54
        <CE VALUE=mesg11>Teledyne 4:26
    </CHOICE>
</HDML>

FIGURE  8-5.     Handling a long choice list with multiple choice cards

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Handling lengthy display text

GUIDELINE: Divide lengthy display text into multiple display cards.

The largest deck or digest you can send to a phone in a single response is approximately 1200 bytes (including the HDML tags). If you have display text that takes up more than 1200 bytes, divide it into separate display cards in separate HDML decks. Specify an ACCEPT action, labelled "More", which allows the user to proceed from one display card to the next.

The last display card should specify an ACCEPT action, labelled "Done", which allows the user to return to the card that originally invoked the display cards. For example, if the display cards display an email message, which the user chose from an email inbox, the ACCEPT key in the last display card should return the user to the email inbox.

For example, the following HDML divides a text message into two separate HDML decks. When the user presses the ACCEPT in the first deck, the phone requests the second deck (as shown in Figure 8-6).

<-- deck1.hdml -->
<HDML VERSION=3.0>
    <ACTION TYPE=ACCEPT LABEL=More TASK=GO DEST=deck2.hdml>
    <DISPLAY>
        <WRAP>This is a lengthy run of text, which
        we will pretend for the sake of this example,
        is considerably more than the 1200 bytes
    </DISPLAY>
</HDML>

<-- deck2.hdml -->
<HDML VERSION=3.0>
    <ACTION TYPE=ACCEPT LABEL=Done TASK=RETURN>
    <DISPLAY>
        <WRAP>allowed in a single HDML deck or digest.
    </DISPLAY>
</HDML>

FIGURE  8-6.     Handling lengthy text in multiple decks