How to hand an object from backend to frontend - html

Question

I try to create a Web App. Therefor I have to pass an Object from the backend to the HTML-Script. I tried a lot of possibilites but nothing worked.
Backend
function searchMain (allSeaVal) {
var headCon = DbSheet.getRange(1, 1, 1, DbSheet.getLastColumn()).getValues();
var bodyCon = DbSheet.getRange(valRow, typesCol, 1, DbSheet.getLastColumn()).getValues();
var Con = {
headline: headCon,
values: bodyCon
};
var tmp = HtmlService.createTemplateFromFile('page_js');
tmp.Con = Con.map(function(r){ return r; });
return tmp.evaluate();
}
HTML
<script>
function searchValues() {
var allSeaVal = {};
allSeaVal.seaType = document.getElementById('valSearchTyp').value;
allSeaVal.seaVal = document.getElementById('HSearchVal').value;
google.script.run.searchMain(allSeaVal);
Logger.log(Con);
}
<script/>
I want to use the information in "Con" in the Website. The script-code is stored in the file "page_js.
I don´t know why but I can´t pass the information into the frontend.

Answer 1

In your html interface you have to use the success and failure handler in your google.script.run.
Code will looks like
google.script.run
.withSuccessHandler(
function(msg) {
// Respond to success conditions here.
console.log('Execution successful.');
})
.withFailureHandler(
function(msg) {
// Respond to failure conditions here.
console.log('Execution failed: ' + msg, 'error');
})
.searchMain(allSeaVal);
Do not hesitate to check the documentation : https://developers.google.com/apps-script/guides/html/communication
Stéphane

Answer 2

I solved my problem with your help. Thank you so much. I struggled with this many days.
My solution is the code below.
Backend
function searchMain (allSeaVal) {
var typesCol = searchTypesCol(allSeaVal.seaType);
var valRow = searchRow(allSeaVal.seaVal, typesCol);
var headCon = DbSheet.getRange(1, 1, 1, DbSheet.getLastColumn()).getValues();
var bodyCon = DbSheet.getRange(valRow, typesCol, 1, DbSheet.getLastColumn()).getValues();
var Con = {
headline: headCon,
values: bodyCon
};
return Con;
}
HTML
function searchValues() {
var allSeaVal = {};
allSeaVal.seaType = document.getElementById('valSearchTyp').value;
allSeaVal.seaVal = document.getElementById('HSearchVal').value;
google.script.run
.withSuccessHandler(
function(Con) {
console.log(Con + 'success');
})
.withFailureHandler(
function(Con) {
console.log(Con + 'failure');
})
.searchMain(allSeaVal);
}