Test and measurement

Resource Picker `<smart-resource-picker>`

ResourcePicker selects an instrument or a channel: it lists the resources the application has found, grouped by interface and named by alias, filters them as text is typed, and reads a typed resource string before it is accepted.

JavaScript TypeScript Angular React Vue Blazor

<smart-resource-picker> · 10 properties, 5 methods, 4 events · source/modules/smart.resourcepicker.js

Usage in JavaScript

The component is a custom element: its properties are set on the element, its events are DOM CustomEvents with the data in event.detail, and its methods are called on the element. The properties can also be written as attributes in kebab case (precision-digits="1").

const resourcePicker = document.querySelector('smart-resource-picker');

resourcePicker.value = 'GPIB0::16::INSTR';
resourcePicker.addEventListener('refreshRequest', (event) => console.log(event.detail));
resourcePicker.open();

Properties

Property	Type, default	Description
`resources`	array	Sets or retrieves the resources found. Each is an object with name (the resource string), alias, description, kind (gpib, tcpip, usb, serial, pxi, daq or other; worked out from the name when absent), available and an optional id. A plain string is taken as a resource name; null and anything else that is not an object is skipped, with one console warning per list.
`value`	string	Sets or retrieves the resource string in force.
`kinds`	array	Sets or retrieves the kinds listed. Empty lists every kind.
`allowCustom`	boolean false	Accepts a typed resource the list does not have, once it parses as a resource name.
`availableOnly`	boolean false	Lists only the resources that are available.
`refreshable`	boolean true	Shows the refresh button, which raises refreshRequest.
`busy`	boolean false	Shows discovery in progress: the refresh button waits and the empty list says so. The application sets it while it searches.
`label`	string	Sets or retrieves the label above the field, which also names the combobox.
`placeholder`	string	Sets or retrieves the text shown when nothing is selected. Empty uses the localized default.
`readonly`	boolean false	Shows the value without allowing a change.

Methods

Method	Description
`open()`	Opens the list.
`close()`	Closes the list and shows the value again.
`select(name)`	Selects a resource by name and raises change. A name the list does not have is taken only when custom entries are allowed and it parses; otherwise the hint says so. `name` string The resource string or id.
`static parse(name)` returns object static: `customElements.get('smart-resource-picker').parse(…)`	Also available as a static method of the class. Reads a resource string into its parts by the VISA resource syntax (IVI VPP-4.3): { kind, interface, ... } with the fields of its kind - board, address (0 to 30) and secondary (0 to 30, or 96 to 126 as the bus code some tools write; reported as written) for GPIB; board, host, addressType (ipv4, ipv6 or hostname), device, port, socket and protocol (vxi-11, hislip or socket) for LAN, where the host is an IPv4 address of four octets 0 to 255, an RFC 1123 host name or an IPv6 address - in brackets as VISA writes it (TCPIP0::[fe80::1]::inst0::INSTR), or bare where that is unambiguous, and the port is 0 to 65535; vendor, product (0 to 0xFFFF), serial and interfaceNumber for USB; board and port for serial (ASRL3, ASRLCOM3, and device paths such as ASRL/dev/ttyUSB0, whose board is null); board, bus (0 to 255), device (0 to 31), function (0 to 7), chassis and slot for PXI, from any of its three forms - PXI[bus]::device[::function], PXI[interface]::[bus-]device[.function] and PXI[interface]::CHASSISn::SLOTn[::FUNCn] - where only the last names a slot and the others give slot null, since a PCI device number is not a slot; device, channelType, channel and channelEnd for DAQ. The trailing ::INSTR may be left out, as the syntax allows. Text that is not a resource, including one that breaks these ranges (GPIB0::31::INSTR, TCPIP0::999.1.1.1::INSTR, PXI0::2::11::INSTR), is { kind: "other", name, reason } with reason the rule it broke in English, or null; empty text is null. `name` string The resource string.
`static isValid(name)` returns boolean static: `customElements.get('smart-resource-picker').isValid(…)`	Also available as a static method of the class. True for a name the picker recognises as a resource: one that parse() reads as a kind other than "other", within the VISA ranges. `name` string The resource string.

Events

The data of an event is in event.detail. change reports a resource the resource picker has already set as value, and open and close report its list opening and closing; while readonly is true the list stays closed. refreshRequest is a request: the picker raises it only while busy is false and shows the new list when the application sets resources.

Event	Description and detail
`change`	This event is triggered when a resource is selected from the list or typed and accepted. `value` string The resource string. `previousValue` string The one before. `resource` object The entry of the list, or null for a typed resource. `parsed` object The parts of the name, as parse() reads them.
`refreshRequest`	This event is triggered when the refresh button is pressed. The application performs the discovery, sets busy while it runs and assigns the resources it found.
`open`	This event is triggered when the list opens.
`close`	This event is triggered when the list closes.

CSS variables

The component declares 4 CSS variables; the CSS page shows how to set them.

--smart-resource-height --smart-resource-background --smart-resource-border --smart-resource-list-background