// widget_jsontable.ysl2

widget_desc("JsonTable") {

longdesc

||

Send given variables as POST to http URL argument, spread returned JSON in

SVG sub-elements of "data" labeled element.

Documentation to be written. see svghmi example.

||

shortdesc > Http POST variables, spread JSON back

arg name="url" accepts="string" >

path name="edit" accepts="HMI_INT, HMI_REAL, HMI_STRING" > single variable to edit

}

widget_class("JsonTable")

||

// arbitrary defaults to avoid missing entries in query

cache = [0,0,0];

init_common() {

this.spread_json_data_bound = this.spread_json_data.bind(this);

this.handle_http_response_bound = this.handle_http_response.bind(this);

this.fetch_error_bound = this.fetch_error.bind(this);

this.promised = false;

}

handle_http_response(response) {

if (!response.ok) {

console.log("HTTP error, status = " + response.status);

}

return response.json();

}

fetch_error(e){

console.log("HTTP fetch error, message = " + e.message + "Widget:" + this.element_id);

}

do_http_request(...opt) {

this.abort_controller = new AbortController();

return Promise.resolve().then(() => {

const query = {

args: this.args,

range: this.cache[1],

position: this.cache[2],

visible: this.visible,

extra: this.cache.slice(4),

options: opt

};

const options = {

method: 'POST',

body: JSON.stringify(query),

headers: {'Content-Type': 'application/json'},

signal: this.abort_controller.signal

};

return fetch(this.args[0], options)

.then(this.handle_http_response_bound)

.then(this.spread_json_data_bound)

.catch(this.fetch_error_bound);

});

}

unsub(){

this.abort_controller.abort();

super.unsub();

}

sub(...args){

this.cache[0] = undefined;

super.sub(...args);

}

dispatch(value, oldval, index) {

if(this.cache[index] != value)

this.cache[index] = value;

else

return;

if(!this.promised){

this.promised = true;

this.do_http_request().finally(() => {

this.promised = false;

});

}

}

make_on_click(...options){

let that = this;

return function(evt){

that.do_http_request(...options);

}

}

// on_click(evt, ...options) {

// this.do_http_request(...options);

// }

||

gen_index_xhtml {

template "svg:*", mode="json_table_elt_render" {

error > JsonTable Widget can't contain element of type «local-name()».

}

def "func:json_expressions" {

param "expressions";

param "label";

// compute javascript expressions to access JSON data

// described in given svg element's "label"

// knowing that parent element already has given "expressions".

choose {

when "$label" {

const "suffixes", "str:split($label)";

const "res" foreach "$suffixes" expression {

const "suffix",".";

const "pos","position()";

// take last available expression (i.e can have more suffixes than expressions)

const "expr","$expressions[position() <= $pos][last()]/expression";

choose {

when "contains($suffix,'=')" {

const "name", "substring-before($suffix,'=')";

if "$expr/@name[. != $name]"

error > JsonTable : misplaced '=' or inconsistent names in Json data expressions.

attrib "name" value "$name";

attrib "content" > «$expr/@content»«substring-after($suffix,'=')»

}

otherwise {

copy "$expr/@name";

attrib "content" > «$expr/@content»«$suffix»

}

}

}

result "exsl:node-set($res)";

}

// Empty labels are ignored, expressions are then passed as-is.

otherwise result "$expressions";

}

}

const "initexpr" expression attrib "content" > jdata

const "initexpr_ns", "exsl:node-set($initexpr)";

template "svg:use", mode="json_table_elt_render" {

param "expressions";

// cloned element must be part of a HMI:List or a HMI:List

const "targetid", "substring-after(@xlink:href,'#')";

const "from_list", "$hmi_lists[(@id | */@id) = $targetid]";

choose {

when "count($from_list) > 0" {

| id("«@id»").href.baseVal =

// obtain new target id from HMI:List widget

| "#"+hmi_widgets["«$from_list/@id»"].items[«$expressions/expression[1]/@content»];

}

otherwise

warning > Clones (svg:use) in JsonTable Widget must point to a valid HMI:List widget or item. Reference "«@xlink:href»" is not valid and will not be updated.

}

}

template "svg:text", mode="json_table_elt_render" {

param "expressions";

const "value_expr", "$expressions/expression[1]/@content";

const "original", "@original";

const "from_textstylelist", "$textstylelist_related_ns/list[elt/@eltid = $original]";

choose {

when "count($from_textstylelist) > 0" {

const "content_expr", "$expressions/expression[2]/@content";

if "string-length($content_expr) = 0 or $expressions/expression[2]/@name != 'textContent'"

error > Clones (svg:use) in JsonTable Widget pointing to a HMI:TextStyleList widget or item must have a "textContent=.someVal" assignment following value expression in label.

| {

| let elt = id("«@id»");

| elt.textContent = String(«$content_expr»);

| elt.style = hmi_widgets["«$from_textstylelist/@listid»"].styles[«$value_expr»];

| }

}

otherwise {

| id("«@id»").textContent = String(«$value_expr»);

}

}

}

template "svg:image", mode="json_table_elt_render" {

param "expressions";

const "value_expr", "$expressions/expression[1]/@content";

| id("«@id»").setAttribute('href', String(«$value_expr»));

}

// only labels coming from Json widget are counted in

def "func:filter_non_widget_label" {

param "elt";

param "widget_elts";

const "eltid" choose {

when "$elt/@original" value "$elt/@original";

otherwise value "$elt/@id";

}

result "$widget_elts[@id=$eltid]/@inkscape:label";

}

template "svg:*", mode="json_table_render_except_comments"{

param "expressions";

param "widget_elts";

const "label", "func:filter_non_widget_label(., $widget_elts)";

// filter out "# commented" elements

if "not(starts-with($label,'#'))"

apply ".", mode="json_table_render"{

with "expressions", "$expressions";

with "widget_elts", "$widget_elts";

with "label", "$label";

}

}

template "svg:*", mode="json_table_render" {

param "expressions";

param "widget_elts";

param "label";

const "new_expressions", "func:json_expressions($expressions, $label)";

const "elt",".";

foreach "$new_expressions/expression[position() > 1][starts-with(@name,'onClick')]"

| id("«$elt/@id»").onclick = this.make_on_click('«@name»', «@content»);

apply ".", mode="json_table_elt_render"

with "expressions", "$new_expressions";

}

template "svg:g", mode="json_table_render" {

param "expressions";

param "widget_elts";

param "label";

// use intermediate variables for optimization

const "varprefix" > obj_«@id»_

| try {

foreach "$expressions/expression"{

| let «$varprefix»«position()» = «@content»;

| if(«$varprefix»«position()» == undefined) {

| throw null;

| }

}

// because we put values in a variables, we can replace corresponding expression with variable name

const "new_expressions" foreach "$expressions/expression" xsl:copy {

copy "@name";

attrib "content" > «$varprefix»«position()»

}

// revert hiding in case it did happen before

| id("«@id»").style = "«@style»";

apply "*", mode="json_table_render_except_comments" {

with "expressions", "func:json_expressions(exsl:node-set($new_expressions), $label)";

with "widget_elts", "$widget_elts";

}

| } catch(err) {

| id("«@id»").style = "display:none";

| }

}

}

widget_defs("JsonTable") {

labels("data");

const "data_elt", "$result_svg_ns//*[@id = $hmi_element/@id]/*[@inkscape:label = 'data']";

| visible: «count($data_elt/*[@inkscape:label])»,

| spread_json_data: function(janswer) {

| let [range,position,jdata] = janswer;

| [[1, range], [2, position], [3, this.visible]].map(([i,v]) => {

| this.apply_hmi_value(i,v);

| this.cache[i] = v;

| });

apply "$data_elt", mode="json_table_render_except_comments" {

with "expressions","$initexpr_ns";

with "widget_elts","$hmi_element/*[@inkscape:label = 'data']/descendant::svg:*";

}

| },

| init() {

| this.init_common();

foreach "$hmi_element/*[starts-with(@inkscape:label,'action_')]" {

| id("«@id»").onclick = this.make_on_click("«func:escape_quotes(@inkscape:label)»");

}

| }

}