Embedding HTML in the 5250 Data Stream


V3R1 / V3R6 Considerations

Browsers are context sensitive to the data stream that they receive. In particular, they assume that all less than signs (<) are a start of an HTML keyword and will not display any characters until it reaches the next greater than sign (>). This will cause display problems for any AS/400 data stream that contains a < that is not an HTML keyword. Because of this, Webulator/400 recognizes a subset of HTML keywords and will escape all < characters (change the < to a different set of characters) that are not part of a recognized HTML keyword. This has two sets of ramifications. First is all < characters that are not a part of a recognized HTML keyword will be displayed properly on Webulator/400 screens. The second is that it is possible to embed certain HTML keywords into the 5250 data stream and have them be interpreted by the browser. This means that you can include such things as images or links to other URLs inside your screens. Please note that the number of supported HTML keywords is very limited.

The following HTML keywords will be passed to the browser intact:

Care should be taken before embedding HTML fields in your 5250 screens. You should take into account the following constraints when designing screens that will contain embedded HTML keywords.

V3R2 and beyond

With the release of V3R2, IBM has introduced the HTML DDS keyword that will allow AS/400 applications to embed any HTML tag into the 5250 data steam. This method of embedding HTML offers the following advantages:

One limitation imposed by IBM is that HTML keywords cannot be included in subfile records.

Please refer to the following IBM publications for more information on the HTML DDS keyword.