Below is a pipe configuration showing the different
paging options. Defaults are just suggestions and are
up for discussion as much as the rest of it
var pagedPipe = AeroGear.Pipeline({
name: "pager",
settings: {
paged: {String}, // Default is
"headers", can also be "content", or undefined for no
paging
pageConfig: { // Only required if paged
is not undefined
// which page, header default is
"AG-Paging-Offset", content default is "paging.offset"
offset: {String},
offsetVal: {Number}, // Default 0
for first page
// items per page, header default
is "AG-Paging-Limit", content default is
"paging.limit"
limit: {String},
limitVal: {Number}, // Default 5
items per page
// total number of items, header
default is "AG-Paging-Total", content default is
"paging.total"
total: {String},
// link to next page, default in
both cases is undefined
next: {String},
// link to previous page, default
in both cases is undefined
prev: {String}
}
}
}).pipes.pager;
Getter/Setter methods should be provided for
getting and updating the offsetVal and limitVal
defaults
var defaultOffset = pagedPipe.getOffsetVal();
pagedPipe.setOffsetVal( defaultOffset + 1 ); //
by default the second page would be returned
var defaultLimit = pagedPipe.getLimitVal();
pagedPipe.setLimitVal( defaultLimit + 5 ); //
by default, 10 items would be returned per page
## read()
By default, a read() against a paged pipe will
return the first page based on the default offsetVal
and limitVal. We could possible add an option that
doesn't effect unpaged pipes but on a paged pipe, it
can be used to turn off paging for that read() and get
all data
// Get first page
pagedPipe.read({success callback handles
data});
// Get all data from paged pipe
pagedPipe.read({
page: false,
success: handle the data
});
To avoid code duplication, **next**, **prev**,
**first** and **last** pages can be retrieved by
passing an option to the read method of a paged pipe
since other than some paging housekeeping, the code
would be the same. We can also use that same option as
above that was used to get all data from a paged pipe.
One question, when requesting prev from first page or
next from last page, should it throw an error that
needs to be handled or just return and empty data set?
I see advantages and disadvantages of both.
// Get next page
pagedPipe.read({
page: "next",
success: handle the data
});
// Get previous page
pagedPipe.read({
page: "prev",
success: handle the data
});
// Get first page
pagedPipe.read({
page: "first",
success: handle the data
});
// Get last page
pagedPipe.read({
page: "last",
success: handle the data
});