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<p>Hi Jacky,</p>
<p>I recommend to use PostgreSQL service names instead of hostname/port/db settings. The projects would connect the layers to a central pg_service.conf file that you can put on a network drive. On the day the db hostname changes, you can centrally switch the hostname/port/db in just a single text-file.</p>
<p>This also helps to switch between test/integration/production environments by simply pointing to a different pg_service.conf file (see Options --> System --> Environment and user defined variables. You can use either PGSERVICEFILE or PGSYSCONFDIR).</p>
<p>Seems to me easier and more flexible than what you have in mind with scripting and signals.</p>
<p>Greetings,</p>
<p>Andreas</p>
<p id="reply-intro">On 2020-11-26 16:06, VOLPES-EXT, Jacky wrote:</p>
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<p class="v1MsoNormal">Hello QGIS dev team <span style="font-family: Wingdings;">J</span></p>
<p class="v1MsoNormal"> </p>
<p class="v1MsoNormal"><span>I need to modify QGIS project file at reading (loading) time.</span></p>
<p class="v1MsoNormal"><span>The database hostname used in the company is changing soon, and I need this to be transparent for the users.</span></p>
<p class="v1MsoNormal"><span> </span></p>
<p class="v1MsoNormal"><span>The problem is that all their layers with the old database connections (uri) will trigger a connection error, having the old hostname.</span></p>
<p class="v1MsoNormal"><span>The idea is to update the .qgs file that is being opened with the new hostname with a text-replacement plugin, save the file, and eventually load it in QGIS.</span></p>
<p class="v1MsoNormal"><span>So that the user will not see any difference or error message.</span></p>
<p class="v1MsoNormal"><span> </span></p>
<p class="v1MsoNormal"><span>Sadly, the QgsProject.readLayer signal is sent after the project has been loaded, hence after the connection error messages…</span></p>
<p class="v1MsoNormal"><span> </span></p>
<p class="v1MsoNormal"><span>Any suggestion/idea welcome!</span></p>
<p class="v1MsoNormal"><span>Thanks,</span></p>
<p class="v1MsoNormal"><span> </span></p>
<p class="v1MsoNormal" style="margin-top: 5.0pt; page-break-after: avoid;"><strong><span style="font-size: 9.0pt; font-family: 'Segoe UI',sans-serif; color: #0054a5; mso-fareast-language: FR;">Jacky Volpes</span></strong><strong><span style="font-size: 10.5pt; font-family: 'Segoe UI',sans-serif; color: #0054a5; mso-fareast-language: FR;"> <br /></span></strong><span style="font-size: 8.0pt; font-family: 'Segoe UI Semilight',sans-serif; color: #595959; mso-fareast-language: FR;">Développeur python </span></p>
<p class="v1MsoNormal" style="margin-bottom: 5.0pt; page-break-after: avoid;"><span style="font-size: 8.0pt; font-family: 'Segoe UI Semilight',sans-serif; color: #595959; mso-fareast-language: FR;">HR-Team pour la Société du Canal de Provence<br />Direction des Systèmes d’Information<br /><br /></span><span style="font-size: 9.0pt; font-family: 'Segoe UI Semilight',sans-serif; color: #595959; mso-fareast-language: FR;">Tél.</span><span style="font-size: 9.0pt; font-family: 'Segoe UI',sans-serif; color: #595959; mso-fareast-language: FR;"> </span><strong><span style="font-size: 9.0pt; font-family: 'Segoe UI',sans-serif; color: #0054a5; mso-fareast-language: FR;">04 42 66 70 34</span></strong><span style="font-size: 9.0pt; font-family: 'Segoe UI Semilight',sans-serif; color: #595959; mso-fareast-language: FR;"><br />Le Tholonet - CS 70064 - 13182 Aix-en-Provence CEDEX 5</span><span style="font-size: 10.5pt; font-family: 'Segoe UI',sans-serif; color: #7f7f7f; mso-fareast-language: FR;"><br /></span><span style="mso-fareast-language: FR;"><img id="v1Image_x0020_1" src="cid:16064040205fbfc7b47d11d821625778@carto.net" alt="cid:image001.png@01D34C22.F8A861A0" width="314" height="96" /></span><span style="font-size: 8.0pt; font-family: 'Segoe UI Semilight',sans-serif; color: #595959; mso-fareast-language: FR;"></span></p>
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