SVGHMI: JsonTable now use intermediate variables again to address JSON data without duplicating code or referencing. Using intermediate variables also alows to check for availability of data and stop evaluating early if data is missing. Finally added complete roundtrip example to illustrate use of JSonTable to display "alarms" collected in python from changes on PLC boolean variables.
// widget_jsontable.ysl2
template "widget[@type='JsonTable']", mode="widget_class"
||
class JsonTableWidget extends Widget{
cache = [];
do_http_request() {
const query = {
args: this.args,
vars: this.cache,
visible: this.visible
};
const options = {
method: 'POST',
body: JSON.stringify(query),
headers: {'Content-Type': 'application/json'}
};
fetch(this.args[0], options)
.then(res => res.json())
.then(this.spread_json_data);
}
dispatch(value, oldval, index) {
this.cache[index] = value;
this.do_http_request();
}
on_click(evt) {
this.do_http_request();
}
init() {
this.element.setAttribute("onclick", "hmi_widgets['"+this.element_id+"'].on_click(evt)");
}
}
||
template "svg:*", mode="json_table_elt_render" {
error > JsonTable Widget can't contain element of type «local-name()».
}
const "hmi_textstylelists_descs", "$parsed_widgets/widget[@type = 'TextStyleList']";
const "hmi_textstylelists", "$hmi_elements[@id = $hmi_textstylelists_descs/@id]";
const "textstylelist_related" foreach "$hmi_textstylelists" list {
attrib "listid" value "@id";
foreach "func:refered_elements(.)" elt {
attrib "eltid" value "@id";
}
}
const "textstylelist_related_ns", "exsl:node-set($textstylelist_related)";
def "func:json_expressions" {
param "expressions";
param "label";
// compute javascript expressions to access JSON data
// desscribed in given svg element's "label"
// knowing that parent element already has given "expressions".
choose {
when "$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[. != $name]"
error > JsonTable : missplaced '=' or inconsistent names in Json data expressions.
attrib "name" value "$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
const "targetid", "substring-after(@xlink:href,'#')";
const "from_list", "$hmi_lists[(@id | */@id) = $targetid]";
choose {
when "count($from_list) > 0" {
| id("«@id»").setAttribute("xlink:href",
// 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 $expressions/expression[2]/@name != 'textContent'"
error > Clones (svg:use) in JsonTable Widget pointing to a HMI:TextStyleList widget or item must have a "textContent=.someVal" assignement following value expression in label.
| {
| let elt = id("«@id»");
| elt.textContent = String(«$content_expr»);
| elt.style = hmi_widgets["«$from_textstylelist/@listid»"].styles[«$value_expr»];
| }
}
otherwise {
| id("«@id»").textContent = String(«$value_expr»);
}
}
}
// only labels comming from Json widget are counted in
def "func:filter_non_widget_label" {
param "elt";
param "widget_elts";
const "eltid" choose {
when "$elt/@original" value "$elt/@original";
otherwise value "$elt/@id";
}
result "$widget_elts[@id=$eltid]/@inkscape:label";
}
template "svg:*", mode="json_table_render" {
param "expressions";
param "widget_elts";
const "label", "func:filter_non_widget_label(., $widget_elts)";
apply ".", mode="json_table_elt_render" {
with "expressions", "func:json_expressions($expressions, $label)";
}
}
template "svg:g", mode="json_table_render" {
param "expressions";
param "widget_elts";
const "gid", "@id";
// use intermediate variables for optimization
const "varprefix" > obj_«$gid»_
| try {
foreach "$expressions/expression"{
| let «$varprefix»«position()» = «@content»;
| if(«$varprefix»«position()» == undefined) {
| console.log("«$varprefix»«position()» = «@content»");
| 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»").setAttribute("style", "«@style»");
const "label", "func:filter_non_widget_label(., $widget_elts)";
apply "*", mode="json_table_render" {
with "expressions", "func:json_expressions(exsl:node-set($new_expressions), $label)";
with "widget_elts", "$widget_elts";
}
| } catch(err) {
| id("«$gid»").setAttribute("style", "display:none");
| }
}
template "widget[@type='JsonTable']", mode="widget_defs" {
param "hmi_element";
labels("data");
optional_labels("forward backward cursor");
const "data_elt", "$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;
| console.log(range,position,jdata);
apply "$data_elt/*", mode="json_table_render" {
with "expressions","$initexpr_ns";
with "widget_elts","$hmi_element/*[@inkscape:label = 'data']/descendant::svg:*";
}
| }
}