Allow a Trigger Function for the dropdown API

[sourabhdesai]

Right now, the API only allows for the trigger to be a string or a RegEx. For my application, I want the trigger to fire every time the input is a prefix for a word within a dynamic list of words. As a workaround I, I created an object that matches the RegEx API that the current smart-area code uses.

To show what I mean, I have this:

var WordTrigger = function() {
    this.words = [];
    WordTrigger.prototype.exec = (text) => {

        var lastSpaceIdx = lastWhitespaceIndex(text);
        var currToken = text.substring(lastSpaceIdx >= 0 ? lastSpaceIdx+1 : 0).toLowerCase();

        if (currToken === '') {
          return null;
        }

        var results = setFilter(this.bigramDist.words, word => _.startsWith(word, currToken) && word !== currToken);
        var completions = results.map(result => result.substring(currToken.length));

        if (_.isEmpty(results)) {
          return null;
        }

        var retVal = [''];
        retVal.index = text.length;
        retVal.input = text;
        // The above 3 lines are just to appease the smart-area code
        // real results are stored in the 'results' property
        retVal.results = _.zipWith(results, completions, function (result, completion) {
            return {
                'display': result,
                'item': completion
            };
        });

        return retVal;

    };

    WordTrigger.prototype.addWord = (word) => {
        this.words.push(word);
    };
};

And in my areaConfig I just have this:

'trigger': new WordTrigger(), ...

This isn't a very clean workaround and I feel like it would be simple enough to just add support for trigger functions.

[aurbano]

Very interesting, I hadn't really thought of this use case but it definitely makes sense, I'll try to look into it this weekend.

Also, sorry for not getting back to you before, somehow missed this.

[sourabhdesai]

That'd be great! I found a hacky way to get what I wanted but I'm sure someone else would appreciate this feature!