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LuCI

Executing a LuCI command from the Linux shell


Note:
    -l     Used to load the module
    -e    Executes some lua script

root@OpenWrt:~# lua -lluci.sys -e 'print(luci.sys.sysinfo())'

Config file for init-scripts and dependences

/etc/config/unitrack

Disable Authentication on a web page

setting sysauth=false for the node does the job, therefore no change is required.

CBI: How to filter based in the value of an option


For example: to be able to display interfaces based on the "proto" option

m = map ("network", "title", "description")
s = m:section(TypedSection, "interface", "")
function s.filter(self, section)
    return self.map:get(section, "proto") ~= "gre"    <---- here is the magic
end


CBI: Validating all options on a page

In you have a requirement to validate that all parameters are unique, or have other relationships that cannot be defined in the schema you will need to be able to validate ALL parameters on a page level rather than use the existing CBI option or section  level validation

To Validate a field/option

If you require a validation of field or option, you can define a validate function for for the option,
the value passed is the uncommitted value from the submitted form.

NOTE: boolean options don't call a validate function

m = Map(...)

s = m:section(...)

o = option(...)

function o.validate(self, value)
    if value < min then return nil end
    if value > max then return nil end
    return value
end


To Validate a section

If you require a validation of a section you can define a validate function for a whole section, this allows you  to validate all fields within it. It gets self and the section id as  parameters.  The fields are stored in a key->value table within self.fields, you can access their :formvalue() member function to obtain the values you want.

Try something like that:

m = Map(...)

s = m:section(...)

function s.validate(self, sectionid)
    local field, obj
    local values = { }

    for field, obj in pairs(self.fields) do
        local fieldval = obj:formvalue(sectionid)
        if not values[fieldval] then
            values[fieldval] = true
        else
            return nil -- raise error
        end
    end

    return sectionid -- signal success
end

To Validate a whole page

When a CBI map is rendered after a form submit, the associated controller calls m:parse() which triggers form value fetching and
validation across all sections within the map, each section in turn does validation on each fields within it.

If one of the field validation functions fail, the whole map is flagged invalid by setting .save = false on the map object.

When a validation error occurs on a per-field or per-section level, the associated error handling sets the property .error to a table value to flag the error condition in a specific field (or section) - this is used by the templates later on to highlight failed options (for example make them red and print an error text next to it).

The error structure looks like this:

.error = {
    [section_id_1] = "Error message string",
    [section_id_2] = "Another error message"
}

The format is the same for per-section and per-option errors. The variables section_id_1 and section_id_2 are the uci identifiers of the
underlying section e.g. "lan" for "config interface lan" and "cfg12ab23f" for "config foo" (anonymous section).

To complicate it further, sections of the type TypedSection are not 1:1 mapped to the CBI model, one TypeSection declaration may result in multiple actual section blocks rendered in the form so you need to treat it correctly when traversing the map->sections->options tree.


With that in mind, you can hijack the Map's .parse function to implement some kind of global validation:

local utl = require "luci.util"

m = Map("config", ...)

function m.parse(self, ...) -- NB: "..." actually means ellipsis here

    -- call the original parse implementation
    Map.parse(self, ...)

    -- do custom processing
    local sobj

    for _, sobj in ipairs(self.children) do

        local sids

        -- check section type
        if utl.instanceof(sobj, NamedSection) then

            -- this is a named section,
            -- the uci id of this section is
            -- stored in sobj.section
            sids = { sobj.section }

        elseif utl.instanceof(sobj, TypedSection) then

            -- this is a typed section,
            -- it may map to multiple uci ids
            sids = sobj:cfgsections()

        end

        -- now validate the fields within this section
        -- for each associated config section
        local sid, fld

        for _, sid in ipairs(sids) do

            for _, fld in ipairs(sobj.children) do

                -- get the value for a specific field in
                -- a specific section
                local val = fld:formvalue(sid)

                -- do some custom checks on val,
                -- e.g. compare against :cfgvalue(),
                -- some global structure etc.
                if not is_valid(val, other_stuff) then

                    -- failed, flag map (self == m)
                    self.save = false

                    -- create field error for
                    -- template highlight
                    fld.error = {
                        [sid] = "Error foobar"
                    }
                end
            end
        end
    end
end


Regenerate translation POT files

You need to checkout the LuCI tree and use the "i18n-scan.pl" script in build/. Use that to scan the subdir containing the code and it will
output the *.pot code to stdout:

$ ./build/i18n-scan.pl applications/luci-polipo/
msgid "enable"
msgstr ""

#. Polipo
msgid "polipo"
msgstr "Polipo"

msgid "enable"
msgstr ""

#. Polipo
msgid "polipo"
msgstr "Polipo"


Save & Apply Hooks

LuCI Trunk and the 0.9 branch offer hooks for that:

on_initBefore rendering the model
 on_parseBefore writing the config
 on_before_commitBefore writing the config 
 on_after_commitAfter writing the config 
 on_before_applyBefore restarting services 
 on_after_applyAfter restarting services 
 on_cancelWhen the form was cancelled 

Use them like this:

m = Map("foo", ...)
m.on_after_commit = function(self)
    -- all written config names are in self.parsechain
    local file
    for _, file in ipairs(self.parsechain) do
        -- copy "file" ...
    done
end


Schema

option type

one of { "enum", "lazylist", "list", "reference", "variable" }

option datatype

one of {"Integer", "Boolean", "String"}


Getting Anonymous UCI Config Data

When accessing "anonymous" sections via LUA do the following:

local hostname
luci.model.uci.cursor():foreach("system", "system", function(s) hostname = s.hostname end)
print(hostname)

Since this is often needed, we added a shortcut doing exactly that:

local hostname = luci.model.uci.cursor():get_first("system", "system", "hostname")
print(hostname)

See also http://luci.subsignal.org/api/luci/modules/luci.model.uci.html#Cursor.get_first

Enabling / Disabling Authentication

To enable authentication you need to set the sysauth properties on your root-level node:

x = entry({"myApp"}, template("myApp/overview"), "myApp", 1)
x.dependant = false
x.sysauth = "root"
x.sysauth_authenticator = "htmlauth"

(see controller/admin/index.lua)

To make your site the index, use:

local root = node()
root.target = alias("myApp")
root.index = true

This should work as long as the name of your app > "admin" due to alphabetical sorting.

Using a template to create custom fields

Create a new view e.g. luasrc/view/cbi_timeval.htm like this
<%+cbi/valueheader%> <input type="text" class="cbi-input-text" onchange="cbi_d_update(this.id)"<%= attr("name", cbid .. ".hour") .. attr("id", cbid ..".hour") .. attr("value", (self:cfgvalue(section) or ""):match("(%d%d):%d%d")) %> /> : <input type="text" class="cbi-input-text" onchange="cbi_d_update(this.id)"<%= attr("name", cbid .. ".min") .. attr("id", cbid ..".min") .. attr("value", (self:cfgvalue(section) or ""):match("%d%d:(%d%d)")) %> /> <%+cbi/valuefooter%>
Important are the includes at the beggining and the end, and that the id, name and value attributes are correct. The rest can be adapted.

(self:cfgvalue(section) or ""):match(".*:?(.*)") will only match the part of the configvalue behind the : whereas (self:cfgvalue(section) or ""):match("(.*):?.*") will only match the first part of the real config value. 

In your Model do something like this.

somename = s:option(Value, "option", "name") -- or whatever creating a Value
somename.template = "cbi_timeval"            -- Template name from above
somename.formvalue = function(self, section) -- This will assemble the parts
            local hour = self.map:formvalue(self:cbid(section) .. ".hour")
            local min = self.map:formvalue(self:cbid(section) .. ".min")
            if hour and min and #hour > 0 and #min > 0 then
		return hour .. ":" .. min
            else
		return nil
            end
         end

Save vs Save & Apply

[Save] pushes the change to /etc/config /* and [Save & Apply] does the same plus it calls corresponding init scripts defined in /etc/config/ucitrack .
If my custom page only needs to write to /etc/config/myapp.lua but not reboot the router, how do I get ONLY a [Save] button?

Change the cbi() invocation in your controller to something like this:

cbi("my/form", {autoapply=true})


Run  a Script from a Button

This bit of code needs "s" to be a section from either a SimpleForm or a Map

btn = s:option(Button, "_btn", translate("Click this to run a script"))

function btn.write()
luci.sys.call("/usr/bin/script.sh")
end