ERROR TypeError: Cannot read property 'isConnected' of null while using Blockly.Xml.domToWorkspace()

[Khushbu Yeole]

Hi,

I have my Xml is:

<?xml version="1.0" encoding="UTF-8"?>

<xml xmlns="http://www.w3.org/1999/xhtml">

   <block type="khushi123:Event:ultrasonic_D6_changed" id="iPme*c;v@l7G5UAsD[=?" x="243" y="57">

      <next>

         <block type="controls_if" id="AItA7cnY)LQP%nD$dTgI">

            <value name="IF0">

               <block type="logic_compare" id="sp2d4S%z6!MwbqTt`wKC">

                  <field name="OP">LT</field>

                  <value name="A">

                     <block type="khushi123:Get_Data:ultrasonic_D6" id="X1S9{s)~EM@IksF8.#om" />

                  </value>

                  <value name="B">

                     <block type="math_number" id="oxdM4:Sricpt#MDVDI89">

                        <field name="NUM">11</field>

                     </block>

                  </value>

               </block>

            </value>

            <statement name="DO0">

               <block type="khushi123:Set_Data:buzzer_D2" id="^{_r9[#;UJ0oT5Af}%q5">

                  <value name="buzzer_D2">

                     <block type="logic_boolean" id="iZ5uBfuoK@=DB~!]8Za|">

                        <field name="BOOL">TRUE</field>

                     </block>

                  </value>

                  <next>

                     <block type="khushi321:Set_Data:relay_D2" id="SI(L!r]8wz^hG;}Uj?hq">

                        <value name="relay_D2">

                           <block type="logic_boolean" id="V(5_];B|U#pbWHZ]%wye">

                              <field name="BOOL">FALSE</field>

                           </block>

                        </value>

                        <next>

                           <block type="khushi123:Set_Data:led_D4" id="_D6e~(a)Q7)LSnHwl;4L">

                              <value name="led_D4">

                                 <block type="logic_boolean" id=";^SC6UDln*S#08BqXn3u">

                                    <field name="BOOL">TRUE</field>

                                 </block>

                              </value>

                              <next>

                                 <block type="khushi321:Set_Data:led_D3" id="Nb7jy)JogG(2`]o+Fp@2">

                                    <value name="led_D3">

                                       <block type="logic_boolean" id="q9H`o!rs.jWS2Mk/Uv?~">

                                          <field name="BOOL">FALSE</field>

                                       </block>

                                    </value>

                                 </block>

                              </next>

                           </block>

                        </next>

                     </block>

                  </next>

               </block>

            </statement>

         </block>

      </next>

   </block>

</xml>

And am using 

let xml = Blockly.Xml.textToDom(workspaceXml);
Blockly.Xml.domToWorkspace(xml, Blockly.mainWorkspace);

also tried with excahnging parameters of Blockly.Xml.domToWorkspace

but still getting error ERROR TypeError: Cannot read property 'isConnected' of null

Please help me i am missing something.

[Erik Pasternak]

Hi Khushbu,

That probably means one of the connections in your xml doesn't actually exist on the block, so when Blockly tries to get the connection it fails. It could be a missing next, previous, or output connection on a block or one of the value/statement inputs has a typo in the name. You might try loading just a few blocks at a time to figure out which block has the issue and then double check the block's connections match the ones in the xml.

Did you generate this xml from blocks or did you write some of it by hand?

Cheers,

Erik

[Khushbu Yeole]

It works for me 

Thanks.