How the screen image sections are merged

When the screen image sections created as a result of a series of BMS and non-BMS SEND commands are merged, a new screen image section is created; it contains, as far as possible, all the fields from all the screen image sections which were used to construct it. However, if fields from two or more of the constituent screen images wholly or partly overlap, this is not possible, and some of the overlapping fields may be modified or suppressed entirely: These rules are summarized in Table 1.
Table 1. Overlapping fields in a merged screen image section
Field from earlier SEND Field from later SEND Result
Input (unprotected) Input (unprotected) or Text (protected) The earlier field is entirely suppressed
Text (protected) Input (unprotected) Based upon the character position in the 3270 screen:
  • Protected characters to the left of the input field are retained.
  • Protected characters overlain by the input field are suppressed.
  • Protected characters to the right of the input field are suppressed.
Text (protected) Text (protected) Based upon the character position in the 3270 screen, characters from the later send will overwrite characters from the earlier send.
You can edit HTML templates created from BMS maps before using them in an application program. However, the algorithm by which the screen image sections are merged requires that the HTML in the sections has a particular structure. Therefore, when you edit the screen image section in a template, and the section will be merged with others, there are guidelines which you must follow: