get_translatable_string.py

#! usr/bin/env python
# Author: Roberta Fagandini roberta.fagandini@gter.it 
# GTER copyleft 2020 - https://creativecommons.org/licenses/by/4.0/
#############################################################################################
# This python script retrieves all possible translatable strings (layers name, groups name,
# layouts name, fields or aliases name, etc.) from the project and the .cfg file and saves a
# json file, for eache specified language, in which the key is the retrived string and the
# value should contain the translation of the string. ATTENTION: this script uses the
# attributeAliases() method to retrieve fields names/aliases. This method does not read
# aliases of layers added during the active sessionof QGIS. If you add layers in the project,
# you have to save and close the project, open the project again and then launch this script.
# The translation has to be provided manually by editing the json file.
# This script has to be run from the qgis python console of the project.
# It requires the .cfg file created with the lizmap plugin.
#############################################################################################

import json
import os

sel_gr = 'ConcertEaux' #the name of the group containing the layers from which fields name/aliases are retrieved, to be commented if not necessary 
languages = ['fr', 'en'] #the list of the desired language ID Code. This code must be the same provided in the translation.js for the langId variable.
lyrs = []
lyrs_tmp = []
title_dict = {}
abstract_dict = {}
layout_dict = {}
info_dict = {}
translation = {}
fields_dict = {}
diff_dict = {}
projectInstance = QgsProject.instance()
root = projectInstance.layerTreeRoot()

#retrieves layers and groups titles and abstracts from the .cfg file
prjName = projectInstance.fileName() #the project .qgs file
prjPath = projectInstance.homePath() #the project .qgs folder

json_file = '{}.cfg'.format(prjName) #the .cfg file
if os.path.exists(json_file): #check if the file esists
    print('Found!')
    #reads the .cfg file
    cfg_file = open(json_file, 'r')
    json_file_reader = cfg_file.read()
    sjson = json.loads(json_file_reader)
    #gets title and abstract values from the layers key and put them in the related dictionary
    json_layers = sjson['layers']
    for key, value in json_layers.items():
        title_dict[value['title']] = ""
        if value['abstract'] != "":
            abstract_dict[value['abstract']] = ""
else:
    print('Not found!')

#retrives the names of the defined print layouts and put them in the related dictionary
projectLayoutManager = projectInstance.layoutManager()
for l in projectLayoutManager.layouts():
    layout_dict[l.name()] = ""

#retrieves the title of the project defined in the Qgis server tab of the project properties
#and put it in the related dictionary
#The sub title i.e. the name of the repository cannot be retrieved from the project or the .cfg file
#hence it has to be translated directly in the translation.js file
info_dict['\n          {}\n        '.format(projectInstance.readEntry('WMSServiceTitle', '')[0])] = ""

#retrieves the aliases or the fields names of all vector layer in a specified group
#and put them in the related dictionary.
#It works over the whole layer tree too. Comment the lines related to the specified group
#to retrieve the alias/fields name of all vector layers in the project

for child in root.children():
    if isinstance(child, QgsLayerTreeGroup):
        if child.name() == sel_gr: #to be commented if not necessary 
            for gr in child.children():
                if isinstance(gr, QgsLayerTreeGroup):
                    lyrs_tmp = gr.findLayers()
                    for lt in lyrs_tmp:
                        if isinstance(lt.layer(), QgsVectorLayer):
                            lyrs.append(lt)
                elif isinstance(gr.layer(), QgsVectorLayer):
                    lyrs.append(gr)

#ATTENTION: the attributeAliases() method does not read aliases of layers added during the active session of QGIS.
#If you add layers in the project, you have to save and close the project, open the project again and then launch this script
for l in lyrs:
    alias = l.layer().attributeAliases()
    #put the alias or the field name, if the alias is not defined, in the related dictionary
    for key, value in alias.items():
        if value != '':
            fields_dict[value] = ""
        else:
            fields_dict[key] = ""

##merge all dictionaries in a new one
translation = {**title_dict, **abstract_dict, **layout_dict, **info_dict, **fields_dict}

#creates a .json file in the media folder with the dictionary containing all strings to be translated
#if the .json file already exists, only possible new string found will be added to the .json file
for lang in languages:
    jsonFilePath = '{}/media/translation_{}.json'.format(prjPath, lang) #the output .json file
    if os.path.exists(jsonFilePath):
        with open(jsonFilePath, 'r') as jf:
            exist_dict = json.load(jf)
        for key_t, value_t in translation.items():
            if not key_t in exist_dict:
                diff_dict[key_t] = ""
        if diff_dict != {}:
            exist_dict.update(diff_dict)
            try:
                with open(jsonFilePath, 'w', encoding='utf-8') as fp:
                    json.dump(exist_dict, fp, ensure_ascii=False, indent=4)
                print('The translation_{}.json file has been updated'.format(lang))
            except:
                print('Unable to update the translation_{}.json file'.format(lang))
        else:
            print('The translation_{}.json file already contains all translatable strings. It will not be updated.'.format(lang))
    else:
        try:
            with open(jsonFilePath, 'w', encoding='utf-8') as fp:
                json.dump(translation, fp, ensure_ascii=False, indent=4)
            print('The translation_{}.json file has been saved'.format(lang))
        except:
            print('Unable to save the translation_{}.json file to "{}"'.format(lang, jsonFilePath))
            print('Check that the folder exists.')