--- title: "The settings dialog" description: "Declare a setting by its kind and the dialog draws the right control: one page per thing you can declare, in the order you meet them." order: 22 section: "settings" --- # The settings dialog Declare a setting by its kind and the dialog draws the right control: one page per thing you can declare, in the order you meet them. ## One rule A setting is one declaration users can change without editing code. `param.(name, default, options?)` names the kind of value, and the overlay's settings dialog on the chart draws the control that kind calls for: a number field, a toggle, a menu, a color picker, a market button, a session strip. The value you read once in `onStart()` drives your logic, and changing it reruns the indicator over the loaded bars without recompiling. This is how you ship a configurable indicator: an adjustable period, a threshold, a multiplier, an on/off switch, a picked market. ```typescript param.int("length", 20, { min: 2, max: 200 }); param.bool("show_bands", true); let n: i32 = 20; let bands = true; function onStart(): void { n = i32(p_length()); bands = pb_show_bands(); } ``` Every kind keeps the contract of plain `param(name, default, { required, min, max, description })`: a top-level statement, a literal default, and a generated reader, readable from `onStart()` on. Plain `param(...)` still declares a number field, and a file that uses it runs exactly as before. ## The dialog, labelled ![The settings dialog on the first page of the tour: the rail on the left, the presets strip, then the rows with their controls](/wrun/images/wrun-dialog.svg) ![The second page of the tour's dialog: a section that carries its toggle in the header and a folded section with its row count](/wrun/images/wrun-dialog-bands.svg) The tour's dialog on its two pages. On the left, the rail: one entry per `page(...)`, then a **Chart** caption with the chart's own entries. Across the top of a page, the presets strip. Below it the rows, grouped by sections: one carries its toggle in its header, one starts folded with its row count in the header. Each row is the label, a hint glyph when the declaration has one, a dot and a reset button once the value differs from its default, and the control the kind names. ## Pages on the rail `page(title)` starts a page. Pages are entries in the dialog's left rail, in order, above a **Chart** caption that holds the chart's own entries: the plot settings, visibility and price marker pages follow the pages you declare. Settings declared before the first `page(...)` land on **General**. A file with no layout word and no `group` keeps one flat list. The layout words are on [Pages, sections, dividers, notes](layout.md). ## Rows and their controls Every `param.` you declare is a row, drawn as the control its kind names ([Setting kinds](kinds.md) has all fifteen). The row's name is its `label`; without one the row shows `description`, else the name read as words (`show_bands` reads "Show Bands"). A `hint` puts words behind a small glyph after the label, shown on hover. Rows that name the same `row` word share one line of the dialog, and a row whose `when` toggle is off is dimmed, or hidden with `hide` ([Options on a setting](options.md)). The dialog adds the rest by itself. A row that differs from its default shows a dot and a reset button that names the default, and a dialog with more than twelve settings gets a filter box over every page. ## The presets strip `presets({ Name: { setting: value, ... }, ... })` ships named sets of values with the indicator. The dialog offers them as chips after **Default**; picking one fills every setting it names in one step, and editing a row afterwards shows **Custom** ([Presets](presets.md)). ## The Style page Every output you draw gets a row on the dialog's **Style** page without a declaration: visible, width, line style and color for a line; opacity beside them for an area, and for a column with a static color; visible, width and color for a mark. A spot the file binds to a setting (`color: "@basis_color"`) is that setting's row instead, so a look never has two controls ([The Style page](style-page.md)). ## Browser or cloud Most settings are numbers the module reads, and every place that runs an indicator hands them to `onStart()` the same way: your browser, OpenMarket's servers for an indicator published as **Protected**, and the alerts engine. A setting's value on the chart is the overlay's own, read once in `onStart()`: the chart runs every setting from the dialog, or from the default when none is set, and changing one reruns the indicator over the loaded bars. An alert on a published indicator runs with the settings of the overlay you set it from ([Alerts](../functions/alerts.md)). Three kinds are applied by the chart instead: `param.source` picks the field an input reads, and `param.timeframe` and `param.symbol` pin an input. For now the chart applies them only when the indicator runs in your browser. | Where the indicator runs | A number, toggle, menu, color, time, price, range, multi, list or session | A `source`, `timeframe` or `symbol` setting | | --- | --- | --- | | your browser | read in `onStart()` from the dialog | applied by the chart | | OpenMarket's servers | read in `onStart()` from the dialog | keeps the declared default; the dialog marks the row "Browser lane only for now" | | the alerts engine | the settings of the overlay you set the alert from | the alert refuses to arm while one is off its default | An indicator that runs on OpenMarket's servers has no Style page either. The lanes in full, with the picks and the 128-setting cap: [Picks, lanes, the cap](picks-and-lanes.md). ## Where to go next - [Setting kinds](kinds.md): the fifteen kinds, the control each one draws, the reader each one generates - [Options on a setting](options.md): `label`, `hint`, `step`, `row`, `when`, `slider`, `confirm`, and which kind takes which - [Pages, sections, dividers, notes](layout.md): the words that lay the dialog out - [Presets](presets.md): named sets of values and the chip strip - [The Style page](style-page.md): the rows every drawn output gets, and `"@name"` bindings - [Sessions and units](sessions-and-units.md): a window in its zone, a number with a unit picker - [Picks, lanes, the cap](picks-and-lanes.md): time and price picks, the settings the chart applies, the 128-setting cap - [What the build checks](checks.md): every refusal, on the declaration's line