how to find lines and update values in an XML file and then export the updated XML file?

I have an XML file(attached here as text file , but I'll be using an XML file in MATLAB) and in this file I want to find the following lines:

<Ptr Name="DG.GSA[0]" Value="5"/>

<Ptr Name="DG.RIT[0]" Value="9"/>

<Ptr Name="P.M[4]" Value="X=62,Y=24"/>

and update it as (bold are the updated values)

<Ptr Name="DG.GSA[0]" Value="7"/>

<Ptr Name="DG.RIT[0]" Value="6"/>

<Ptr Name="P.M[4]" Value="X=45,Y=20"/>

after the updating is done I want to export the new XML file as Ptr.valout

Answer 1

[Benjamin Thompson]

The easiest thing (other than just your own text editor), is xml2struct and struct2xml from Wouter Falkena from the File Exchange:

https://www.mathworks.com/matlabcentral/fileexchange/28518-xml2struct?s_tid=srchtitle

https://www.mathworks.com/matlabcentral/fileexchange/28639-struct2xml?s_tid=prof_contriblnk

Your example is missing a square bracket on line 7 but that should not interfere with XML parsing. For more complicated XML problems use the MATLAB XML Parser MAXP. See the article "Import an XML File into a Document Object Model" in the help documentation.

>> S = xml2struct('Ptr.val.txt')

S =

struct with fields:

PtrVal: [1×1 struct]

>> S

S =

struct with fields:

PtrVal: [1×1 struct]

>> S.PtrVal

ans =

struct with fields:

Ptr: [1×1 struct]

Attributes: [1×1 struct]

>> S.PtrVal.Ptr

ans =

struct with fields:

Ptr: {1×19 cell}

>> S.PtrVal.Ptr{1}

Brace indexing is not supported for variables of this type.

>> S.PtrVal.Ptr.Ptr{1}

ans =

struct with fields:

Text: [1×0 char]

Attributes: [1×1 struct]

>> S.PtrVal.Ptr.Ptr{1}.Attributes

ans =

struct with fields:

Name: 'DG.RO[0]'

Value: 'Default'