dv.table() for custom arrays or maps

[flatlines]

I am having a hard time figuring out how dv.table() works based on the documentation (it's me, not the docs!).

The part that I struggle with is this:

.map(b => [b.file.link, b.genre, b["time-read"], b.rating])

I don't have a programming background, so I am not entirely clear what the map(b => b...) part actually does. My best guess is that in this snippet:

dv.table(["File", "Genre", "Time Read", "Rating"], dv.pages("#book")
    .sort(b => b.rating)
    .map(b => [b.file.link, b.genre, b["time-read"], b.rating]))

b represents a page with the book tag that is going to show up as a row in the results, and that the .map call retrieves the relevant value for every result in the table (so it will be called once per result, and each of the [xxx , xxx , xxxx] corresponds to a table header).

What has stumped me so far is how to adapt this code to an object that exists within the dataviewjs, e.g.

const resultObj = {name: "abc", height: "efg"}

dv.table(["name", "height"],resultObj.map(m => [m.name, m.height]))

Returns resultsObj.map is not a function.

In an ideal world, I would use a table to return a map of objects, e.g. something along the lines of:

const resultObjA = {name: "abc", height: "efg"}
const resultObjB = {name: "abc", height: "efg"}

const resultsMap = new Map([
  [0, resultObjA],
  [1, resultObjB],
]);

What am I missing?

[AB1908]

map works on arrays. resultObjA is an object, not an array. What's the overall use case? It may turn out that it could be done in DQL in case DVJS seems too painful.

[flatlines]

I would love to know how to return a table of values from a map of objects that was populated by dataviewjs. For example, I might have a map of objects that contains the following:

const resultsMap = new Map([
  [0, {name: "abc", height: "3", diameter: "2"],
  [1, {name: "efg", height: "7", diameter: "4"],
]);

Where the name might have been pulled via dv.page from a set of values in the YAML, and the height and the diameter were by the script (probably the reason for writing the script in the first place).

In a perfect world, I would then be able to display the map with something like:

| Name | Height | Diameter |
| ---- | ------ | -------- |
| abc  | 3      | 2        |
| efg  | 7      | 4        | 

I have tried using dv.el("table","") to code up something by hand in HTML - this wasn't really successful. I suppose I could try again with dv.el("div","table HTML") but I am not sure how that would deal with variables.

I had not considered DQL because I believe it only looks for the values inside the YAML of this / other pages. I would not know how to pass it a variable that was computed inside a dataviewjs script.

At the moment I am using a verbose dv.el("li",....) to output these results (essentially stringing together all the variables in a brief comment). If that is the best solution, then I am fine with it. I just wanted to make sure I had not overlooked an obvious solution due to inexperience.

[blacksmithgu]

dv.table() takes in an array of arrays, and formats it as a table. It does not support rendering maps, though you can convert a map to an array without too much trouble.

If your input is an array of maps, like this:

const results = [
  {name: "abc", height: "3", diameter: "2"},
  {name: "efg", height: "7", diameter: "4"},
];

dv.table(["name", "height", "diameter"], results.map(r => [r.name, r.height, r.diameter]));

This is the standard usage of dv.table (array of maps, which is the same as an array of pages since pages are maps). If you have a map of maps as your last example, you'll need to go through one more level of mapping:

const map = new Map([
	[0, { name: "hello" }],
	[1, { name: "goodbye" }]
]);

dv.table(["name"], dv.array(Array.from(map)).sort(([index, _]) => index)
	.map(([key, value]) => [value.name]));

[flatlines]

Enormously helpful, thank you so much @blacksmithgu!

[AB1908]

TIL about Map()s.