Auto-complete could provide some help for Sys, Sim and Loc DataSource

[utzeln]

The DataSource sys, sim and loc could be supported and “://” would be added automatically.

Typing “sys” in a PV Name entry field and the auto-complete would propose “sys://time”, … “sys://user”. For system property, it would stop at “sys://system.”.
As in Excel, a tooltip could be added for the highlighted choice:

Typing “sim” would list the simulation PVs. When at least 1 parameter is required, the parenthesis will be automatically added. For example, selecting “sim://const” will result in “sim://const(“.

When parameters are required, some help could be provided like in Excel:

So having entered “sim://noise(“, the tooltip would be:
“sim://noise(minValue, maxValue, timeStep)” with the first parameter highlighted.

If there are many parameter options, a list of tooltips will be displayed. Let’s say that I have entered “sim://ramp“, then 3 tooltips will appear:
“sim://ramp“ equivalent to sim://ramp(-5, 5, 1, 1)
“sim://ramp(minValue, maxValue, timeStep)“
“sim://ramp(minValue, maxValue, step, timeStep)“

After specifying the first parameter, the tooltip would highlight the second one:

The tooltip would remain until “)” is entered.

For Local DataSource, having typing “loc:” some help about the syntax would be provided as tooltips:
“loc://pvname”
“loc://pvname”
“loc://pvname(initialValue)”
“loc://pvname(initialValue)”
After having entered some PV Name such as “loc://myLocalPV<”, the different VType would be listed: VString, VStringArray, VDouble…

If everyone is OK with that I propose that we provide this feature.

[gcarcassi]

For epics, there is also the {"longString":true} part. You can detect that with a space in the name.

For future changes in syntax: how should it work? Will it be something easy enough for me to do directly, by just changing some dictionary? Or is will it be something where it's best done by someone who understands the whole thing?

Also: the formula function completion should actually be much easier to implement, since you can get the whole dictionary from pvmanager!

[utzeln]

Dictionary is definitively the good way to go.And as you mentioned we have also to extend the auto completion to formula.Have you already an API to access the dictionary? Will it be possible to retrieve the explanatory tooltip from the dictionary?

[gcarcassi]

For the pv syntax, there is nothing of the kind. The problem is that each datasource have a different syntax, and that most datasources can't be "enumerated". So, that part is better handled like you guys are doing.

For the formula:
http://pvmanager.sourceforge.net/apidocs/org/epics/pvmanager/formula/FormulaRegistry.html
The FormulaRegistry allows to search for functions. You may want a findFunctions(String name) without the number of arguments. I can add that. Then for each function, you have:
http://pvmanager.sourceforge.net/apidocs/org/epics/pvmanager/formula/FormulaFunction.html
With name, argument name and types, you can construct the signature. The description would be the tooltip. You can also look at:
http://pvmanager.sourceforge.net/apidocs/org/epics/pvmanager/formula/FormulaFunctions.html
You'll find a formatSignature which gives you the exact spec to display the format of the function (it's the one used in the formula explorer, that allows you to browse the functions available)