Added to TW-Scripts On Sunday, March 31, 2019 at 7:16:22 PM UTC+4:30, Jeremy Ruston wrote: > > Hi SS > > The logic used by the set widget to determine the result assigned to the > variable is as follows: > > 1. If the "tiddler" attribute is present and not blank, then: > 1a. If the "subtiddler" attribute is also present and not blank, then get > the subtiddler from the specified tiddler, otherwise just get the tiddler > itself > 1b. If the "field" attribute is present then return return the value of > that field, or the value of the "emptyValue" attribute if the field is > blank or missing > 1c. Otherwise, if the "index" attribute is present, return the value of > the specified index, or the value of the "emptyValue" attribute if the > index is blank or missing > 1d. Otherwise, return the text field of the tiddler, or the value of the > "emptyValue" attribute if the text field is blank or missing > > 2. If the "filter" attribute is present and not blank, then evaluate the > results of the filter, and: > 2a. If the "value" attribute is present and the filter results are not > empty, return the value of the "value" attribute (even if the "value" > attribute is blank) > 2b. If the "value" attribute is present and the filter results are empty, > return the value of the "emptyValue" attribute, if present, otherwise > return a blank result > 2c. If the "value" attribute is not present, then if the "select" > attribute is a valid number it is used to retrieve a specified result from > the filter > 2d. If the "value" attribute is not present, and the "select" attribute is > not a valid number, and the filter results are not empty, then the entire > filter results are returned (using double square brackets quoting around > any results that include spaces) > 2e. If the "value" attribute is not present, the "select" attribute is not > a valid number, and the filter results are empty, then the value of the > "emptyValue" attribute is returned (or blank if it is not present) > > 3. If neither the "tiddler" or "filter" attributes are provided, return > the value of the "value" attribute, or the value of the "emptyValue" > attribute if the "value" attribute is blank or missing > > Perhaps it would be clearer expressed as a series of examples... > > Best wishes > > Jeremy > > -- > Jeremy Ruston > jer...@jermolene.com <javascript:> > https://jermolene.com > > On 30 Mar 2019, at 16:17, S. S. <sachde...@gmail.com <javascript:>> wrote: > > Within a macro, I am trying to determine if a parameter is empty, and then > set a variable based on knowing that it is empty. > > I came across the Google Group post from a last month: Check the Blank > Macro parameter > <https://groups.google.com/forum/?hl=en#!topic/tiddlywiki/82N15sAnoPs/discussion> > \define mm(newField) > <$list filter="[<__newField__>] -[[]]"> > > Do my job! > </$list> > \end > > > <<mm test>> > > So I tried using something based on that. Pasting the below into a new > tiddler on tiddlywiki.com shows the issue: > > \define test(tiddler) > <$set name="result" filter="[[$tiddler$]] -[[]]" value="Why is this > variable set when the filter ''is not missing'' and ''it's empty''?"> > > The description of the ''value'' attribute of the `$set` widget says: The > value to assign to the variable if the filter is missing or ''//not > empty//'' > > tiddler=$tiddler$ > > result=<<result>> > > <$list filter="[[$tiddler$]] -[[]]" emptyMessage="See, the filter shows > it's Empty"> > </$list> > </$set> > \end > > <<test>> > > > I don't understand where I've gone wrong. I'd appreciate some advice. > Thanks. > > > -- > You received this message because you are subscribed to the Google Groups > "TiddlyWiki" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to tiddl...@googlegroups.com <javascript:>. > To post to this group, send email to tiddl...@googlegroups.com > <javascript:>. > Visit this group at https://groups.google.com/group/tiddlywiki. > To view this discussion on the web visit > https://groups.google.com/d/msgid/tiddlywiki/1867389e-59de-4b9e-b8e6-6ecd9212d92e%40googlegroups.com > > <https://groups.google.com/d/msgid/tiddlywiki/1867389e-59de-4b9e-b8e6-6ecd9212d92e%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > >
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