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<p>Hi Enrico,</p>
<p>I can't tell why this expression fails, but there is a more elegant way to distinguish between even and odd numbers. The modulus operator (%).</p>
<p>CASE WHEN <span>@atlas_featurenumber % 2 = 0 THEN --these are the even pages<br /> 210 - @value<br /> ELSE --these are the odd pages<br /> @value<br />END</span></p>
<p><span>The modulus operator returns the remainder after the divison - e.g. 5 % 2 returns 1, 6 % 2 returns 0, 7 % 2 returns 1, 8 % 2 returns 0 and so on.</span></p>
<p><span>Als note, that @atlas_featureid is not a good variable to use, because it isn't always guaranteed that the is no hole in your primary key sequence (e.g. if you delete features) - you would also run into troubles if you start filtering features in the atlas. I would rather suggest to use the variable @atlas_featurenumber. This should always start at 1 and increment by one for each subsequent atlas record, regardless of any filter or holes in the primary key sequence.</span></p>
<p>Hope this helps,</p>
<p>Andreas</p>
<p>On 2016-04-06 10:29, Enrico Ferreguti wrote:</p>
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<div>Is there a way to get the current item value that is being modified by expressions.</div>
I would like to reformat my print composer atlas for two sided printing referencing to @value variable without success:<br /><br />CASE <br />WHEN floor( @atlas_featureid/2 )*2 = @atlas_featureid THEN 210 - @value<br />ELSE @value<br />END<br /><br /></div>
but I get always @value....<br />
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