Thanks, Regina, for such detailed information. This helped me to approach the import/export for the Histogram Chart.
I have added changes to the ODF Export for the Histogram Chart. Have to add support for the Import and addition in the RNG file. https://gerrit.libreoffice.org/c/core/+/177364 Would anyone from the community be able to help me by reviewing the PR? On Sun, 1 Dec 2024 at 02:03, Regina Henschel <rb.hensc...@t-online.de> wrote: > Hi Devansh, > > I have put the dev list in CC, because such questions should go to the > dev list. There are other people too that can answer your questions. I'm > not an expert for charts and I have not always time to answers in a > reasonable time frame. > > Devansh Varshney schrieb am 29.11.2024 um 14:38: > > Hi Regina, > > > > I have been working on adding the Histogram Chart to the LO > > codebase(part of GSoC-24), and it is working well. > > I think, it is still a lot to do: > > Missing "bin"-properties > > Filesave, bug 164108. > > The use and meaning of "Y-Values" in the wizard is unclear, bug 164109. > Problem with empty "Categories" in the wizard, no bug report yet. The > role "values-y-original" is undocumented. > > > > > Now I am tasked to add the import and export support for the same but > > what I am unable to get is where to begin exactly I have added the > > entries in the token files - > https://gerrit.libreoffice.org/c/core/+/177364 > > > > These two are the import files for the import and export - > > > > xmloff/source/chart/SchXMLExport.cxx > > > > xmloff/source/chart/SchXMLImport.cxx > > I have looked for ODF-related PRs and even on OOo but could not find > > anything related to adding new chart support for ODF. > > The type of a chart is determined by the chart:class attribute of the > <chart:chart> element. The value of the chart:class attribute is a > namespaced token. The twelve predefined chart types use the namespace > 'chart'. Since a histogram chart does not belong to the predefined chart > types, it needs a namespace other than 'chart'. So you should write it > out as chart:class="loext:histogram". > > Because your new chart type needs some properties, which will be in > loext namespace as well, you can write the new chart type only in an > extended ODF version. > > The chart:class attribute is specified in section 19.15.1 in ODF 1.3, [1]. > > Properties of the new chart type do not become attributes of the > <chart:chart> element, but become attributes of the > <style:chart-properties> child element of the <style:style> element > which is referenced by the chart:style-name attribute of an affected > element. That is a <chart:plot-area>, <chart:series> or <chart:axis> > element, for example. > > That is currently wrong for ofPie charts, see bug 163921. So you cannot > use ofPie charts as template. > > Such properties belong to the property map aXMLChartPropMap[]. > > In your case the labels of the x-axis are generated strings which are > not contained in the sheet. So you cannot use the > chart:cell-range-address attribute of the <chart:categories> element > with a reference into the sheet. > In your case the values in y-direction are generated values which are > not contained in the sheet. So you cannot use the > chart:value-cell-range-address of the <chart:series> element with a > reference into the sheet. > > I have no ready to use solution to solve the problems. The same problems > are visible in the chart wizard as mentioned above. > There can currently only be one local table. So using an additional > local table would require changes in that area. > Changing the <chart:categories> and <chart:series> elements so that they > can carry fixed values might be a solution too. > OOXML does not save the values themselves but only writes the layout > properties. So that idea might be a way to go as well. In that case we > would need to decide whether new attributes of <chart:categories> and > <chart:series> are used or new entries in <style:chart-properties> > I think these problems need some discussion. > > [1] > > https://docs.oasis-open.org/office/OpenDocument/v1.3/os/part3-schema/OpenDocument-v1.3-os-part3-schema.html > The change to version 1.4 is ongoing. In your case you can still use the > v1.3 specification. The access to the ODF 1.3 specification is easier. > > Kind regards, > Regina > > > > > > > -- *Regards,* *Devansh*
